effects of global warming in the past 10 years essay

Essay on Effects of Global Warming for Students and Children

500+ words essay on effects of global warming.

Global warming refers to climate change that causes an increase in the average of Earth’s temperature. Natural events and human influences are believed to be top contributions towards the increase in average temperatures. Global warming is a rise in the surface and atmospheric temperature of the earth that has changed various life forms on the earth. The issues that ascertain global warming are divided into two broad categories – “natural” and “human influences” of global warming.

Natural Causes of Global Warming

The climate has been continuously changing for centuries. One natural cause of global warming is greenhouse gases. Greenhouse gases are carbon monoxide and sulphur dioxide . It traps the solar rays and prevents them from escaping the surface of the earth.

This causes an increase in the temperature of the earth. Volcanic eruptions are another reason for global warming. A single volcanic eruption can release a great amount of carbon dioxide and ash to the atmosphere. Increased carbon dioxide leads to a rise in the temperature of the earth.

Also, methane gas is another contributor to global warming. Methane is also a greenhouse gas. Methane is twenty times more effective in trapping heat in the atmosphere than carbon dioxide. Usually, methane gas is released from many areas like animal waste, landfill, natural gas, and others.

Get the huge list of more than 500 Essay Topics and Ideas

Human Influences on Global Warming

Human influence has been a very serious issue now as it is contributing more than natural causes of global warming. Since human evolution, the earth has been changing for many years until now and it is still changing because of our modern lifestyle. Human activities include industrial production, burning fossil fuel, mining of minerals, cattle rearing and deforestation.

Industries, transportation such as cars, buses, trucks burn fuel to power machines, which eventually releases carbon dioxide and monoxide from the exhaust, leading to an increase in a temperature rise of Earth’s atmosphere.

Another contributor is mining. During the process of mining, the methane gas trapped below the earth escapes. Rearing cattle also causes the release of methane from manure. Another cause is the most common but most dangerous – deforestation.

Deforestation is a human influence because human have been cutting down trees to produce paper, wood, build houses and more. Trees can absorb carbon dioxide from the atmosphere and their absence can lead to the concentration of such gases.

The Effect of Global Warming

The impact that global warming is causing on earth is extremely serious. There are many hazardous effects that will happen in the future if global warming continues. It includes melting of polar ice caps, leading to an increase in sea level drowning coastlines and slowly submerging continents.

Recent studies by National Snow and Ice Datacenter “if the ice melted today the seas would rise about 230 feet”. Another effect is climate change leading to the extinction of various species. More hurricanes, cyclonic storms, heat waves, drought, and extreme rainfalls will occur causing disaster to humankind.

The solution to Stop Global Warming

We humans need to work together towards the prevention of global warming. To reduce global warming we can contribute by reducing the production and concentration of greenhouse gases in the atmosphere. We need to curb usage of gasoline, electricity and other activities including mining and industrialization that cause global warming.

Another way to reduce global warming is through recycling. Recycling can help reduce open burning of garbage by reusing plastic bags, bottles, papers or glass. We need to stop open burning dry leaves or burning garbage. It contributes to releasing carbon dioxide and toxins. Besides, we should reduce deforestation and start planting more trees. Trees will help improve the temperature on earth and prevent drastic climatic change.

From today’s scenario, we can derive that our earth is “sick” and we humans need to “heal” it. Global Warming has already caused many problems for human and we need to prevent disasters of the future. Our generation needs to take care of the earth with immediate effect to safeguard future generations or they will suffer the consequences of global warming.

Customize your course in 30 seconds

Which class are you in.

• Travelling Essay
• Picnic Essay
• Our Country Essay
• My Parents Essay
• Essay on Favourite Personality
• Essay on Memorable Day of My Life
• Essay on Knowledge is Power
• Essay on Gurpurab
• Essay on My Favourite Season
• Essay on Types of Sports

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Download the App

• The Society
• Science News
• Science News Explores
• Student Science
• Science News on Twitter
• Science News on Facebook
• Science News on Google+

Changing climate: 10 years after An Inconvenient Truth

By thomas sumner april 8, 2016.

• CHANGING CLIMATE
• Ocean Circulation
• Drought Climate and Conflict

Antarctic Ice Sheet

Sea level rise, extreme temperatures, climate action.

By Thomas Sumner

M ore than 25 years before the star-studded Los Angeles premiere of An Inconvenient Truth , glaciologist Lonnie Thompson was about as far away from the red carpet as possible. It was 1978, and high in the rugged Andes, Thompson and fellow scientists were witnessing the first glimpses of a pending worldwide disaster. Rising temperatures were melting ancient titans of ice and snow. Mammoth glaciers were disappearing at unprecedented rates and withering to the smallest sizes in millennia. The delicate balance of Earth’s climate was upset.

As research mounted, scientists around the world from fields as diverse as chemistry and astronomy were coming to grips with a newfound truth: Carbon dioxide spewed by fossil fuel burning and other greenhouse gases were warming the world at an alarming rate, potentially threatening the health and livelihoods of millions of people. Despite the gravity and urgency of their findings, the scientists’ warnings fell mostly on deaf ears for years.

Until 2006. Six years after his unsuccessful presidential campaign, Al Gore reentered the national spotlight to release An Inconvenient Truth , which heavily featured Thompson’s mountaintop research. Thompson missed the premiere of the documentary because he was gearing up to return to South America’s vanishing ice. But the film did what he and other researchers had been unable to do: “It got climate change on the radar,” Thompson says. Last December, Gore was on hand in Paris as 195 nations committed to the most ambitious pledge yet to fight back against climate change and curb carbon emissions ( SN: 1/9/16, p. 6 ).

In the 10 years since the movie sparked increased public discussion, climate scientists have made major advances. More observations, faster climate-simulating computers and an improved understanding of the planet’s inner workings now provide a clearer window on how Earth’s climate will change.

Some of the bold forecasts of the 2006 movie are holding, and others are on an accelerated track. A few of the most dire warnings need revising, says Thompson, at Ohio State University in Columbus. And plenty of questions remain. In a controversial paper in March in Atmospheric Chemistry and Physics , researchers argued that the effects of climate change could be even more severe and sudden than current predictions.

While a lot has changed, the fundamental understanding of climate change, dating back to the 19th century recognition that carbon dioxide warms the planet, has held strong, he says.

“The physics and chemistry that we’ve known about for over 200 years is bearing out,” Thompson says. “We’ve learned so much in the last 10 years, but the fact that the unprecedented climate change of the last 40 years is being driven by increased CO 2 hasn’t changed.”

The far-reaching effects of climate change — from ocean acidification to disrupted ecosystems — are too numerous to examine all at once. But below are a few of the areas where climate scientists have made significant progress since 2006.

Above, video: Warming is altering Earth’s landscape, such as via accelerated ice loss on this Norwegian glacier. Alternate photo: Scientists with NASA’s ICESCAPE mission investigate the effects of climate change on Arctic ecosystems.

Video: Incredible Arctic/Shutterstock; photo: Kathryn Hansen/NASA

Hurricane Katrina devastated New Orleans in 2005. The storm’s destruction, compounded by failed levees, sparked concerns that climate change could have been at least partially responsible. Jocelyn Augustino/FEMA

2006: The warming ocean could fuel more frequent and more intense Atlantic hurricanes.

2016: Hurricane frequency has dropped somewhat; hurricane intensities haven’t changed much — yet.

In August 2005, Hurricane Katrina slammed into the Gulf Coast. Floodwaters covered roughly 80 percent of New Orleans, 1,836 people died, hundreds of thousands became homeless and the most active Atlantic hurricane season on record was far from over. As the last storm fizzled, damages had reached $160 billion, meteorologists had run through the alphabet of preselected storm names and many people, including Gore, were indicting global warming as a probable culprit.

“Hurricanes were the poster child of global warming,” says Christopher Landsea, a meteorologist at the National Oceanic and Atmospheric Administration’s National Hurricane Center in Miami. “In reality, it’s a lot more subtle than that.”

Tropical cyclones, such as Atlantic hurricanes, are stirred up where seawater is warmer than the overlying air. Because climate change raises ocean temperatures, it made sense that such storms could strike more often and with more ferocity. A closer look at hurricanes past and future suggests, however, that the relationship between warming and hurricanes is less clear-cut.

STEADY STORMS The record-smashing 2005 hurricane season raised concerns that storms were becoming stronger and more frequent. Yet, a closer look at the long-term trends revealed that Atlantic hurricane frequency has not significantly changed since 1878. Source: C. Landsea/NHC/NOAA

Several studies in the mid-2000s examining the history of Atlantic hurricanes pointed to an overall rise in the number of 20th century storms in step with warming sea surface temperatures. Scrutinizing those numbers, Landsea uncovered a problem: Hurricane-spotting satellites date back only to 1961’s Hurricane Esther. Before then, storm watchers probably missed many weaker, shorter-lived storms. Taking this into account, Landsea and colleagues reported in 2010 that the number of annual storms has actually decreased somewhat over the last century.

That decrease could be explained by climate factors other than rising sea surface temperatures. Changes in atmospheric heating can increase the variation in wind speed at different elevations, known as wind shear. The shearing winds rip apart burgeoning storms and decrease the number of fully formed hurricanes, researchers reported in 2007 in Geophysical Research Letters .

The overall frequency of storms, however, is less important than the number of Katrina-scale events, says Gabriel Vecchi, an oceanographer at NOAA’s Geophysical Fluid Dynamics Laboratory in Princeton, N.J. Category 4 and 5 storms, the most violent, make up only 6 percent of U.S. hurricane landfalls, but they cause nearly half of all damage. Vecchi and colleagues used the latest understanding of how hurricanes form and intensify to forecast how the storms will behave under future climate conditions.

LANDFALL Hurricane Katrina slammed into Louisiana in August 2004. The storm devastated the state and flooded much of New Orleans. Radar data from NWS New Orleans and processed by the National Climatic Data Center

The work, published in 2010 in Science , predicted that the frequency of Category 4 and 5 storms could nearly double by 2100 due to ocean warming, even if the overall number of hurricanes doesn’t rise. At present, however, climate change’s influence on hurricanes is probably too small to detect, Vecchi says, adding that Katrina’s wrath can’t be blamed on global warming.

Future hurricanes will cause more damage, Landsea predicts, whether or not there’s any change in storm intensity. Rising sea levels mean floodwaters will climb higher and reach farther inland. Hurricane Sandy, which stormed over New Jersey and New York in October 2012, had weakened by the time it reached the coast. But it drove a catastrophic storm surge into the coastline that caused about $50 billion in damages. If sea levels were higher, Sandy’s surge would have reached even farther inland and damage could have been much worse.

Many vulnerable areas such as St. Petersburg, Fla., are woefully underprepared for threats posed by storms at current sea levels, Landsea warns. Higher sea levels won’t help. “We don’t need to invoke climate change decades down the line — we’ve got a big problem now,” he says.

“Hurricanes were the poster child of global warming. In reality it’s a lot more subtle than that.” Christopher Landsea

Researchers have directly monitored Atlantic circulation, which includes the Gulf Stream, since the 2004 deployment of the RAPID array (shown). Direct measurements suggest that the circulation may be slowing down. National Oceanography Centre (UK)

Ocean circulation

2006: Freshwater flowing into the North Atlantic could shut down the ocean conveyor belt that shuttles warm water toward Western Europe.

2016: The ocean conveyor belt may already be slowing, but it’s not much of a conveyor belt at that.

Last year may have been Earth’s hottest on record ( SN: 2/20/16, p. 13 ). But for one small corner of the globe, 2015 was one of the coldest . Surface temperatures in the subpolar North Atlantic have chilled in recent years and, oddly enough, some research suggests global warming is partly responsible.

An influx of freshwater from melting glaciers and increasing rainfall can slow — and possibly even shut down — the ocean currents that ferry warm water from the tropics to the North Atlantic. About 10 years ago, scientists warned of a possible abrupt shutdown of this “ocean conveyor belt.” After years of closely monitoring Earth’s flowing oceans, researchers say a sudden slowdown isn’t in the cards. Some researchers report that they may now be seeing a more gradual slowing of the ocean currents. Others, meanwhile, have discovered that Earth’s ocean conveyor belt may be less of a sea superhighway and more of a twisted network of side roads.

The consequences of a sea current slowdown won’t be anywhere near as catastrophic as the over-the-top weather disasters envisioned in the 2004 film The Day After Tomorrow , says Stephen Griffies, a physical oceanographer at NOAA’s Geophysical Fluid Dynamics Laboratory. “The doomsday scenario is overblown, but the possibility of a slowing down of the circulation is real and will have important impacts on Atlantic climates,” Griffies says.

EVERY WHICH WAY Tracking the motion of floating markers dropped into the northwest Atlantic (white-rimmed circles), researchers found that the idea of an ocean conveyor belt is overly simplistic. The markers quickly split up, ending up in many different destinations (solid circles). Amy S. Bower et al / Nature 2009

The Atlantic mixing that feeds the currents is powered by differences in the density of seawater. In the simple ocean conveyor-belt model, warm, less-dense surface water flows northward into the North Atlantic. Off Greenland, cold, denser water sinks into the deep ocean and flows southward. This heat exchange, known as the Atlantic overturning circulation, helps keep European cities warmer than their counterparts elsewhere in the world.

Ten years ago, scientists knew from past changes in Earth’s climate that temperature shifts can disrupt this density balance. Freshwater from the shrinking Greenland ice sheet and increased rainfall make the North Atlantic waters less dense and therefore less likely to sink. Investigations into Earth’s ancient climates show that the overturning circulation weakened around 12,800 years ago, probably causing cooling in Europe and sea level rise along North America’s East Coast, as piled-up water in the north sloshed southward.

Tracking sea surface temperatures, researchers reported last year that the Atlantic overturning circulation significantly slowed during the 20th century, particularly after 1970. Comparing the recent slowdown with past events, the researchers reported in March in Nature Climate Change that the rapid weakening of the circulation is unprecedented in the last 1,000 years .

That result isn’t the final word, though, says Duke University physical oceanographer Susan Lozier. Scientists have directly measured the speed of the ocean circulation only since the deployment of a network of ocean sensors in 2004. Earlier Atlantic circulation speed changes have to be gleaned from less reliable indirect sources such as sea surface temperature changes. “If you look at the most recent results, there’s a decline, yes,” she says. “But we can’t say that’s part of a long-term trend right now.” And effects on Europe’s climate could be masked by other factors.

Another challenge is that over the last 10 years, “the ocean conveyor-belt model broke,” Lozier said in February at the American Geophysical Union’s Ocean Sciences Meeting in New Orleans. From 2003 through 2005, she and colleagues tracked the movements of 76 floating markers dropped into the North Atlantic and pulled around by ocean waters. If the model was right, these markers should have traveled along the southward-flowing part of the conveyor belt. Instead, the markers moved every which way , the researchers reported in 2009 in Nature .

“We went from this simple ribbon of a conveyor belt to a complex flow field with multiple pathways,” Lozier says. Determining past and possible future effects of climate change on ocean currents will require more measurements and a better understanding of how the ocean truly flows, she says.

Even if the overturning circulation cuts out completely, the resulting cooling effect will probably be short-lived, Griffies says. “At some point, even if the circulation collapses, it would only be 10 or 20 years before the global warming signal would overwhelm that cooling” in Europe, he says. “This is not going to save us from a warmer planet.”

Drought conditions worsened by climate change helped fuel the civil unrest that led to 2011’s Syrian civil war. Global security experts worry that continuing climate change will help spark more conflicts. Christiaan Triebert/Flickr (CC BY 2.0)

Drought, Climate and Conflict

2006: Climate change exacerbated droughts that contributed to regional conflicts, such as the war in Darfur.

2016: Drought conditions worsened by climate change helped spark the Syrian civil war.

Following escalating unrest and a wave of demonstrations across the Arab world, a bloody civil war broke out in Syria in 2011. The ongoing conflict sparked an international crisis and has left hundreds of thousands of people dead and millions more displaced. While the root cause of the conflict centered on clashes between the Syrian government and its people, multiple studies argue that climate change helped stoke the flames of rebellion.

Mounting evidence from around the world has indicted climate change in several recent severe droughts from Syria to California. Computer simulations and direct measurements of weather patterns show that climate change can redirect the paths of rainstorms and cause higher temperatures that dry out soil.

The recent Eastern Mediterranean drought was the most extreme in 900 years, new research suggests. Continuing drought conditions (red) may have contributed to the unrest that preceded the Syrian Civil War. Conditions shown here are for late 2015. NASA

In March 2015 in the Proceedings of the National Academy of Sciences , researchers estimated that decades-long shifts in Syria’s rainfall and temperatures doubled or even tripled the severity of the three-year drought that preceded the Syrian civil war. Using tree rings, a separate group reported this March in the Journal of Geophysical Research: Atmospheres that 1998 through 2012 was the driest period in the Eastern Mediterranean since at least 1100.

The recent drought upset regional food security, prompted a mass migration into urban areas and emboldened anti-government forces , 11 retired U.S. admirals and generals wrote in a 2014 report published by CNA, a nonprofit research and analysis organization in Arlington, Va. The clash joins another conflict partly pinned on climate change: the war in Darfur, which broke out in 2003 following a decades-long drop in regional rainfall.

Since the 1970s, droughts have become longer and more severe across the globe, and scientists expect that trend to continue. Dwindling agricultural production in certain high-population areas such as parts of Africa could lead to food shortages that spark refugee crises, the report warned.

“We see more clearly now that while projected climate change should serve as a catalyst for change and cooperation, it can also be a catalyst for conflict,” the retired admirals and generals wrote.

Since the 1970s, droughts have become longer and more severe across the globe and scientists expect that trend to continue.

The minimum extent of Arctic sea ice has shrunk substantially since 1979. Shrinking sea ice can have both regional and global impacts for climate and ecosystems. NASA Scientific Visualization Studio

2006: The Arctic could see its first sea ice–free summers in the next 50 to 70 years.

2016: Arctic summer sea ice may disappear as early as 2052.

The top of the world could see its first iceless summer roughly a decade sooner than thought in 2006, according to a 2015 report ( SN Online: 8/3/15 ). Simulating how sea ice interacts with the ocean using the latest understanding of how sea ice and climate interact, scientists estimated that the North Pole will be ice-free around 2052 , nine years earlier than previous simulations suggested. Last year saw the fourth smallest footprint of summer sea ice in the Arctic on record. Ice-free Arctic summers would open the region to shipping and could affect climates elsewhere by redirecting the winds that circle the North Pole, the researchers wrote. The loss of reflective sea ice could also hasten warming as the dark ocean absorbs more sunlight. Newly open passages may also allow mingling of animals from formerly separated habitats ( SN: 1/23/16, p. 14 ).

OPEN WATER Rising temperatures in the Arctic have dwindled the extent of summer sea ice, like that seen at left, taken from the deck of a research ship in July 2011. Since 1979, the minimum summer sea ice extent has decreased more than 7.5 percent per decade. Source: NSDIC; Image: Kathryn Hansen/NASA

The top of the world could see its first iceless summer almost a decade sooner than thought a decade ago

Antarctica’s Larsen B Ice Shelf collapsed into hundreds of icebergs in 2002, speeding the melt of its tributary glaciers. Ted Scambos/National Snow and Ice Data Center

2006: Rising temperatures are warming the Antarctic and melting the West Antarctic Ice Sheet.

2016: The West Antarctic Ice Sheet could cross a point of no return.

In 2002, an ice behemoth crumbled. Antarctica’s Larsen B Ice Shelf, after 12,000 years of frozen stability, collapsed. The breakdown rapidly shattered 3,250 square kilometers of ice — an area about the size of Rhode Island ( SN: 10/18/14, p. 9 ).

“Larsen B was a real wake-up call,” says Maureen Raymo, a marine geologist at Columbia University’s Lamont-Doherty Earth Observatory in Palisades, N.Y. “It was like, ‘whoa, this ice shelf didn’t just slowly retreat on its edge — the whole thing just collapsed catastrophically over the course of two weeks.’ ”

FAREWELL, ICE As Antarctica’s ice melts, warm seawater will flow through low-lying channels currently filled with ice and accelerate further melting. An ice-free Antarctica (beige area) would leave less land above sea level (blue shows footprint of current continent). Mark Helper/Univ. of Texas at Austin

Now with 10 years of on-the-ice research, scientists warn that the rest of the West Antarctic ice could share a shockingly swift fate unimaginable a decade ago. The ice sheet’s collapse would raise global sea levels by about 3 meters ( SN: 6/14/14, p. 11 ).

Ice shelves line about 45 percent of the Antarctic coast and help slow the flow of the continent’s ice into the sea. For healthy ice shelves, the flow of ice from inland balances losses from melting and icebergs snapping off the shelf’s seaward edge. Rising temperatures below and above the ice can fracture and thin the ice, upsetting this balance.

The loss of just a few ice shelves in the West Antarctic Ice Sheet could destabilize the whole region, according to new research by climate scientists Anders Levermann and Johannes Feldmann of the University of Potsdam in Germany. In a computer simulation, the researchers found that the loss of a few key ice shelves around Antarctica’s Amundsen Sea would trigger a domino effect. Seawater would flow into the flanks of other ice and expedite melting. Such a collapse would annihilate the entire West Antarctic Ice Sheet within hundreds to thousands of years, they predict.

Once started, this chain reaction would be unstoppable , the researchers reported last November in the Proceedings of the National Academy of Sciences . Even if global temperatures return to normal, the ice sheet would still be doomed, according to the simulation. In 2014, researchers reported that one of those keystone ice shelves, the Thwaites Glacier, is on track to recede past an underwater ridge currently stalling its retreat and undergo catastrophic collapse in as few as two centuries.

Thousands of square kilometers of ice disintegrated from Antarctica’s Larsen B Ice Shelf in the Southern Hemisphere in summer 2002. In January, blue melt ponds crisscrossed the ice shelf’s surface. MODIS, NASA's Earth Observatory

By February 17, the leading edge of the shelf had retreated 10 kilometers and the ice began to splinter. MODIS, NASA's Earth Observatory

Several more massive icebergs fractured from the ice shelf by February 23. MODIS, NASA's Earth Observatory

A satellite image captured March 7 revealed a mixture of slush and icebergs. MODIS, NASA's Earth Observatory

Churned up ice from the shelf’s underside gave this debris a bright blue tinge. MODIS, NASA's Earth Observatory

As cold autumn temperatures arrived, white snow fell on the remnants of the ice shelf and, by April 13, fresh sea ice packed into the bay. MODIS, NASA's Earth Observatory

Exactly what magnitude of warming will push the West Antarctic Ice Sheet past the point of no return remains uncertain, says Richard Alley, a glaciologist at Penn State. “It’s hard to predict how the ice will fracture,” he says. “That’s why you don’t want to tiptoe up on the disaster point. The edge between ‘it’s still there’ and ‘it’s had a catastrophic failure’ is something to be completely avoided.”

The other half of the Antarctic continent has shown more resistance to climate change, and hasn’t kept up with the global warming trend of the last few decades. That’s good news, since the East Antarctic Ice Sheet holds more water than its sibling — enough to raise sea levels by about 60 meters if it fails.

Last year, however, researchers using radar to penetrate the Antarctic ice announced that East Antarctica’s largest glacier, Totten Glacier, is still vulnerable. It may be at risk from encroaching ice-melting seawater . Radar maps revealed two seafloor troughs that could allow warm ocean water to melt the glacier’s underside, the researchers reported in Nature Geoscience . The glacier alone holds enough water to raise global sea levels by at least 3.3 meters, though its collapse could take centuries, the researchers noted.

The West Antarctic Ice Sheet collapse would raise global sea levels by as much as 3 meters

Expanding seawater and melting ice threaten the very existence of many island nations, including the Maldives. As climate change continues, rising sea levels could reshape Earth’s coastlines. KlemenR/iStockphoto

2006: Melting ice and expanding seawater are raising global sea levels.

2016: Historical evidence suggests sea levels can rise more than 10 times as fast as they are now.

In the Indian Ocean, a city seems to rise out of the waves. The island of Malé, the capital of the Maldives and home to more than 150,000 people, sits just two or three meters above sea level ( SN: 2/28/09, p. 24 ). The residents of Malé are a small portion of the approximately 200 million people worldwide living along coastlines within five meters of sea level. By the end of the century, as sea levels reach inland and coastal communities grow, the population at risk of rising waters may balloon to as high as 500 million.

The global average sea level currently rises about three millimeters per year, with a meter of total sea level rise expected by 2100 if carbon emissions aren’t curtailed. Some areas, such as the U.S. East Coast, are experiencing even faster sea level rise. In February, researchers reported in the Proceedings of the National Academy of Sciences that 20th century sea level rise was faster than any other century since Rome was founded ( SN: 4/2/16, p. 20 ).

RAISING THE STAKES Projections of future sea level rise vary, but scientists warn that even a small increase in sea level can worsen flooding and change coastlines. Sea level rise primarily stems from two sources: the thermal expansion of seawater and meltwater from land-based ice. Source: NOAA, Global Sea Level Rise Scenarios for the United States National Climate Assessment 2012

While sea levels are rising fast, they have the ability to climb even faster. Scientists are looking further into the future and investigating just how fast sea level rise could get, especially with a hypothetical collapse of the Antarctic ice sheets. Results gleaned from past warm periods suggest that sea levels can rise much faster than suggested just a few years ago — more than 10 times the present rate.

“Sea level is probably the biggest irreversible risk of global warming,” Columbia’s Raymo says. “I expect a hell of a lot more people are going to be personally impacted by a one-meter rise in sea level than by the extinction of the grand ladybug of something or other.”

Most records of ancient climates provide only a snapshot of how high sea levels have reached at a given time, not how quickly they moved up or down. But on a 2005 expedition to Tahiti, a research team caught a break. Because coral reefs require plenty of light to thrive, they typically take root in waters shallower than 10 meters deep. As sea levels rose in the past, corals moved higher up the newly submerged coastline. Off the coast of Tahiti, the researchers sampled fossils of ancient corals from the last 150,000 years buried in layers of ocean sediment. Dating the corals using the known decay rate of radioactive uranium into other elements, the researchers created an accurate, long-term sea level record.

Move slider at center to compare images

RISING TIDE A one-meter rise in sea levels would reshape many U.S. coastlines, including this section of North Carolina’s coast. Blue regions show areas submerged by water. Many scientists expect that sea levels will rise by a meter by 2100. Sea Level Rise and Coastal Flooding Impacts /NOAA

Around the end of Earth’s last glacial period, about 14,650 years ago, sea levels rose about 14 to 18 meters, the researchers reported in 2012 in Nature . What surprised those researchers is how quickly this rise happened: Sea levels rose at least 46 millimeters per year during that period. The scientists concluded that at least half of the 14 meters of sea level rise during this bout of warming originated from melting Antarctic ice.

“The scary thing, and this is why it’s kind of apocalyptic, is that once you start these things, they don’t stop,” Raymo says. “Everything we see shows that, if you look in the past, each increment of warmth seems to correlate with increasingly higher sea level.”

Approximate number of people worldwide living along coastlines within five meters of sea level.

Scorching temperatures killed hundreds of people last year in Pakistan. Continued global warming will increase the risk of heat-related deaths, researchers warn. Shakil Adil/AP Photo

2006: Warming temperatures will cause more frequent and more deadly heat waves.

2016: Humidity may make future heat waves deadlier; cold snaps are on the decline.

Last summer, sweltering heat waves scorched India and Pakistan. The extreme temperatures killed thousands of people and were two of the deadliest heat waves since 1900. Such lethal heat will become more common as the planet continues warming, climate scientist Ethan Coffel of Columbia University said last December at the American Geophysical Union’s fall meeting.

LESS EXTREME COLD Since the early 1900s in the United States, climate change has increased the frequency of abnormally hot summer days. But an expected rise in cold snaps has not played out. Areas hit by unusually cold temperatures in winter are declining. Source: NOAA 2015

The problem, Coffel said, is that climate change will raise humidity in many places alongside temperature as hot air wicks up more moisture. The evaporation of sweat keeps people cool when it’s hot, but high humidity can slow or even shut off this skin-cooling evaporation. Rising humidity will make rising temperatures more deadly than previously feared , he said. By the 2060s, Coffel predicts, 250 million people worldwide could face deadly levels of heat and humidity at least once a year.

While heat waves worsen, researchers say that another killer weather phenomenon will become less common . The frequency of abnormally cold periods in North America will decrease by roughly 20 percent by the 2030s , researchers reported last year ( SN Online: 4/2/15 ). The work overturned previous projections of a rise in cold snaps over the coming decades as climate change redirects frigid Arctic winds. From 2006 through 2010, about twice as many people in the United States died from cold-related causes, such as hypothermia, than from excessive heat.

By the 2060s, Coffel predicts that 250 million people worldwide could face deadly levels of heat and humidity at least once a year.

China’s cities (Beijing’s Tiananmen Square shown) have suffered worsening air quality. Health risks posed by that pollution have motivated the country’s government to invest in low-emission alternatives to fossil fuels such as wind, solar and nuclear power. Spondylolithesis/iStockphoto

2006: The long-term effects of climate change deserve immediate action.

2016: Taking action comes with other, more immediate perks.

After decades of troubled negotiations and false starts, 195 nations from around the world gathered last December in Paris and agreed to take action on climate change ( SN: 1/9/16, p. 6 ). The new commitment, to reverse the rise in greenhouse gas emissions and limit global warming to 2 degrees Celsius above the preindustrial level, would have seemed impossible 10 years ago. Delegates will meet in a few years to decide whether to target a more ambitious limit of 1.5 degrees.

What’s changed is motivation, says Andrew Jones, a system dynamics modeler at Climate Interactive, a nonprofit organization in Washington, D.C., that works in partnership with MIT’s Sloan School of Management. Rather than focus on global climate benefits of curtailing fossil fuel emissions, which will take years to pan out, climate action is now increasingly driven by more immediate benefits, he says, such as improving public health. In February, researchers estimated that ambitious climate action in the United States would improve air quality enough to prevent 295,000 premature deaths by 2030 and save the economy hundreds of billions of dollars in medical costs.

Nearly 10 years after An Inconvenient Truth , 195 nations agreed to try to curb climate change. While Al Gore argued in the film that swift action was needed to prevent long-term problems, politicians are now increasingly motivated by immediate benefits. Patrick Kovarik/AFP/Getty Images

“Waiting for climate results is delayed gratification — it’s difficult to motivate continued action,” Jones says. “But if you reduce burning coal, air quality improves almost immediately.”

China, the world’s largest greenhouse gas emitter, backed the new climate deal after years of dragging its feet. The change of heart was chiefly driven by a desire to cut air pollution, not combat climate change, says MIT atmospheric scientist Kerry Emanuel. Earlier in December, smog-filled Beijing issued the country’s first pollution red alert and shut down the city until conditions improved.

Scouring recent climate change pledges, Jones and colleagues found that 60 percent of commitments, including those made by the United States, Mexico and South Korea, were explicitly motivated by short-term public health and economic benefits. Jones helps maintain C-ROADS, a climate simulator that forecasts the long-term outcome of climate action plans. Understanding and embracing the benefits of climate action will be essential to paving a path forward, Jones says, because C-ROADS has demonstrated that there are “hundreds” of ways to meet the 2-degree warming goal.

“We’ve moved from whether we’re going to do this to how we’re going to do this,” he says. “And that is very encouraging.”

Meeting the challenges posed by climate change will be hard, but Lonnie Thompson remains optimistic. “Three-and-a-half years ago I had a heart transplant,” he says. “At any other time in human history, this would have been thought of as impossible — my father died at age 41 of a heart attack. As human beings we’ve made tremendous progress on so many fronts. There will always be this resistance to change, but as a species, we’re capable of dealing with those changes.”

“Waiting for climate results is delayed gratification.... But if you reduce burning coal, air quality improves almost immediately.” Andrew Jones

What are the effects of global warming?

The effects of global warming will be far-reaching and often devastating, scientists have warned.

• Temperature extremes
• Extreme weather

Sea levels and ocean acidification

Plants and animals, social effects.

• Further reading

Additional resources

Bibliography.

The effects of global warming can be seen and felt across the planet. Global warming , the gradual heating of Earth's surface, oceans and atmosphere, is caused by human activity, primarily the burning of fossil fuels that pump carbon dioxide (CO2), methane and other greenhouse gases into the atmosphere.

Already, the consequences of global warming are measurable and visible.

"We can observe this happening in real time in many places," Josef Werne, a professor of geology and environmental science at the University of Pittsburgh, told Live Science. "Ice is melting in both polar ice caps and mountain glaciers. Lakes around the world, including Lake Superior, are warming rapidly — in some cases faster than the surrounding environment. Animals are changing migration patterns and plants are changing the dates of activity," such as trees budding their leaves earlier in the spring and dropping them later in the fall.

Here is an in-depth look at the ongoing effects of global warming.

Global warming increases average temperatures and temperature extremes

One of the most immediate and obvious consequences of global warming is the increase in temperatures around the world. The average global temperature has increased by about 1.4 degrees Fahrenheit (0.8 degrees Celsius) over the past 100 years, according to the National Oceanic and Atmospheric Administration (NOAA).

Since record keeping began in 1895, the hottest year on record worldwide was 2016, according to NOAA and NASA data . That year Earth's surface temperature was 1.78 degrees F (0.99 degrees C) warmer than the average across the entire 20th century. Before 2016, 2015 was the warmest year on record, globally. And before 2015? Yep, 2014. In fact, all 10 of the warmest years on record have occurred since 2005, which tied with 2013 as the 10th-warmest year on record, according to NOAA’s Global Climate Report 2021 . Rounding out the top 6 hottest years on record across the globe are (in order of hottest to not as hot): 2020, 2019, 2015, 2017 and 2021.

For the contiguous United States and Alaska, 2016 was the second-warmest year on record and the 20th consecutive year that the annual average surface temperature exceeded the 122-year average since record keeping began, according to NOAA . Shattered heat records in the U.S. are increasingly becoming the norm: June 2021, for example, saw the warmest temperatures on record for that month for 15.2%of the contiguous U.S. That's the largest extent of record warm temperatures ever recorded in the country, according to the National Centers for Environmental Information .

Global warming increases extreme weather events

As global average temperatures warm, weather patterns are changing. An immediate consequence of global warming is extreme weather. 

These extremes come in a lot of different flavors. Paradoxically, one effect of climate change can be colder-than-normal winters in some areas.

Changes in climate can cause the polar jet stream — the boundary between the cold North Pole air and the warm equatorial air — to migrate south, bringing with it cold, Arctic air. This is why some states can have a sudden cold snap or colder-than-normal winter, even during the long-term trend of global warming, Werne explained.

Werne received his doctorate in Geological Sciences at Northwestern University in 2000 with an emphasis in Biogeochemistry. He was a postdoctoral research scientist at the Royal Netherlands Institute for Sea Research from 2000 to 2002 and on the faculty of the Large Lakes Observatory and Department of Chemistry and Biochemistry (assistant/associate professor) at the University of Minnesota Duluth, before joining the department in 2012. Werne spent a year in Perth, Australia, as a visiting senior fellow at the Institute for Advanced Studies of the University of Western Australia, as well as a visiting scientist in the Western Australia Organic and Isotope Geochemistry Centre at Curtin University.

"Climate is, by definition, the long-term average of weather, over many years. One cold (or warm) year or season has little to do with overall climate. It is when those cold (or warm) years become more and more regular that we start to recognize it as a change in climate rather than simply an anomalous year of weather," he said. Global warming is also changing other extreme weather. According to the Geophysical Fluid Dynamics Laboratory of NOAA , hurricanes are likely to become more intense, on average, in a warming world. Most computer models suggest that hurricane frequency will stay about the same (or even decrease), but those storms that do form will have the capacity to drop more rain due to the fact that warmer air holds more moisture.

"And even if they become less frequent globally, hurricanes could still become more frequent in some particular areas," said atmospheric scientist Adam Sobel, author of " Storm Surge: Hurricane Sandy, Our Changing Climate, and Extreme Weather of the Past and Future " (HarperWave, 2014). "Additionally, scientists are confident that hurricanes will become more intense due to climate change." This is because hurricanes get their energy from the temperature difference between the warm tropical ocean and the cold upper atmosphere. Global warming increases that temperature difference. "Since the most damage by far comes from the most intense hurricanes — such as typhoon Haiyan in the Philippines in 2013 — this means that hurricanes could become overall more destructive," said Sobel, a Columbia University professor in the departments of Earth and Environmental Sciences, and Applied Physics and Applied Mathematics. (Hurricanes are called typhoons in the western North Pacific, and they're called cyclones in the South Pacific and Indian oceans.) What's more, hurricanes of the future will be hitting shorelines that are already prone to flooding due to the sea-level rise caused by climate change. This means that any given storm will likely cause more damage than it would have in a world without global warming.

Lightning is another weather feature that is being affected by global warming. According to a 2014 study , a 50% increase in the number of lightning strikes within the United States is expected by 2100 if global temperatures continue to rise. The researchers of the study found a 12% increase in lightning activity for every 1.8 degree F (1 degree C) of warming in the atmosphere. NOAA established the U.S. Climate Extremes Index (CEI) in 1996 to track extreme weather events. The number of extreme weather events that are among the most unusual in the historical record, according to the CEI, has been rising over the last four decades. Scientists project that extreme weather events, such as heat waves, droughts , blizzards and rainstorms will continue to occur more often and with greater intensity due to global warming, according to Climate Central . Climate models forecast that global warming will cause climate patterns worldwide to experience significant changes. These changes will likely include major shifts in wind patterns, annual precipitation and seasonal temperatures variations. These impacts vary by location and geography. For example, according to the U.S. Environmental Protection Agency (EPA) , the eastern United States has been trending wetter over time, while the West – and particularly the Southwest – have become increasingly dry. Because high levels of greenhouse gases are likely to remain in the atmosphere for many years, these changes are expected to last for several decades or longer, according to the EPA.

Global warming melts ice

One of the primary manifestations of climate change so far is melt. North America, Europe and Asia have all seen a trend toward less snow cover between 1960 and 2015, according to 2016 research published in the journal Current Climate Change Reports. According to the National Snow and Ice Data Center, there is now 10% less permafrost , or permanently frozen ground, in the Northern Hemisphere than there was in the early 1900s. The thawing of permafrost can cause landslides and other sudden land collapses . It can also release long-buried microbes, as in a 2016 case when a cache of buried reindeer carcasses thawed and caused an outbreak of anthrax . One of the most dramatic effects of global warming is the reduction in Arctic sea ice. Sea ice hit record-low extents in both the fall and winter of 2015 and 2016, meaning that at the time when the ice is supposed to be at its peak, it was lagging. The melt means there is less thick sea ice that persists for multiple years. That means less heat is reflected back into the atmosphere by the shiny surface of the ice and more is absorbed by the comparatively darker ocean, creating a feedback loop that causes even more melt, according to NASA's Operation IceBridge . Glacial retreat, too, is an obvious effect of global warming. Only 25 glaciers bigger than 25 acres are now found in Montana's Glacier National Park, where about 150 glaciers were once found, according to the U.S. Geological Survey. A similar trend is seen in glacial areas worldwide. According to a 2016 study in the journal Nature Geoscience, there is a 99% likelihood that this rapid retreat is due to human-caused climate change. Some glaciers retreated up to 15 times as much as they would have without global warming, those researchers found.

In general, as ice melts, sea levels rise. According to a 2021 report by the World Meteorological Organization , the pace of sea level rise doubled from 0.08 inches (2.1 millimeters) per year between 1993 and 2002 to 0.17 inches (4.4 mm) per year between 2013 and 2021. 

Melting polar ice in the Arctic and Antarctic regions, coupled with melting ice sheets and glaciers across Greenland, North America, South America, Europe and Asia, are expected to raise sea levels significantly. Global sea levels have risen about 8 inches since 1870, according to the EPA, and the rate of increase is expected to accelerate in the coming years. If current trends continue, many coastal areas, where roughly half of the Earth's human population lives, will be inundated.

Researchers project that by 2100, average sea levels will be 2.3 feet (.7 meters) higher in New York City, 2.9 feet (0.88 m) higher at Hampton Roads, Virginia, and 3.5 feet (1.06 m) higher at Galveston, Texas, the EPA reports. According to an IPCC report , if greenhouse gas emissions remain unchecked, global sea levels could rise by as much as 3 feet (0.9 meters) by 2100. That estimate is an increase from the estimated 0.9 to 2.7 feet (0.3 to 0.8 meters) that was predicted in the 2007 IPCC report for future sea-level rise.

Sea level isn't the only thing changing for the oceans due to global warming. As levels of CO2 increase, the oceans absorb some of that gas, which increases the acidity of seawater. Werne explains it this way: "When you dissolved CO2 in water, you get carbonic acid. This is the same exact thing that happens in cans of soda. When you pop the top on a can of Dr Pepper, the pH is 2 — quite acidic."  

Since the Industrial Revolution began in the early 1700s, the acidity of the oceans has increased about 25 percent, according to the EPA. "This is a problem in the oceans, in large part, because many marine organisms make shells out of calcium carbonate (think corals, oysters), and their shells dissolve in acid solution," said Werne. "So as we add more and more CO2 to the ocean, it gets more and more acidic, dissolving more and more shells of sea creatures. It goes without saying that this is not good for their health."

If current ocean acidification trends continue, coral reefs are expected to become increasingly rare in areas where they are now common, including most U.S. waters, the EPA reports. In 2016 and 2017, portions of the Great Barrier Reef in Australia were hit with bleaching , a phenomenon in which coral eject their symbiotic algae. Bleaching is a sign of stress from too-warm waters, unbalanced pH or pollution; coral can recover from bleaching, but back-to-back episodes make recovery less likely.

The effects of global warming on Earth's ecosystems are expected to be significant and widespread. Many species of plants and animals are already moving their range northward or to higher altitudes as a result of warming temperatures, according to a report from the National Academy of Sciences.

"They are not just moving north, they are moving from the equator toward the poles. They are quite simply following the range of comfortable temperatures, which is migrating to the poles as the global average temperature warms," Werne said. Ultimately, he said, this becomes a problem when the rate of climate change velocity (how fast a region changes put into a spatial term) is faster than the rate that many organisms can migrate. Because of this, many animals may not be able to compete in the new climate regime and may go extinct.

Additionally, migratory birds and insects are now arriving in their summer feeding and nesting grounds several days or weeks earlier than they did in the 20th century, according to the EPA.

Warmer temperatures will also expand the range of many disease-causing pathogens that were once confined to tropical and subtropical areas, killing off plant and animal species that formerly were protected from disease.

In addition, animals that live in the polar regions are facing an existential threat. In the Arctic, the decline in sea ice and changes in ice melt threaten particularly ice-dependent species, such as narwhals ( Monodon monoceros ), polar bears ( Ursus maritimus ) and walruses ( Odobenus rosmarus ), the World Wildlife Fund (WWF) noted. Animals in the Antarctic also face serious challenges — in Oct. 2022 the U.S. Fish and Wildlife Service declared emperor penguins (Aptenodytes forsteri) as endangered due to the threat of climate change. 

A 2020 study published in the journal Proceedings of the National Academy of Sciences suggested that 1 in every 3 species of plant and animal are at risk of extinction by 2070 due to climate change.

As dramatic as the effects of climate change are expected to be on the natural world, the projected changes to human society may be even more devastating.

Agricultural systems will likely be dealt a crippling blow. Though growing seasons in some areas will expand, the combined impacts of drought, severe weather, lack of accumulated snowmelt, greater number and diversity of pests, lower groundwater tables and a loss of arable land could cause severe crop failures and livestock shortages worldwide.

North Carolina State University also notes that carbon dioxide is affecting plant growth. Though CO2 can increase the growth of plants, the plants may become less nutritious.

This loss of food security may, in turn, create havoc in international food markets and could spark famines, food riots, political instability and civil unrest worldwide, according to a number of analyses from sources as diverse as the U.S Department of Defense, the Center for American Progress and the Woodrow Wilson International Center for Scholars.

In addition to less nutritious food, the effect of global warming on human health is also expected to be serious. The American Medical Association has reported an increase in mosquito-borne diseases like malaria and dengue fever, as well as a rise in cases of chronic conditions like asthma, most likely as a direct result of global warming. The 2016 outbreak of Zika virus , a mosquito-borne illness, highlighted the dangers of climate change. The disease causes devastating birth defects in fetuses when pregnant women are infected, and climate change could make higher-latitude areas habitable for the mosquitoes that spread the disease, experts said. Longer, hotter summers could also lead to the spread of tick-borne illnesses .

Further reading on the impacts of global warming

Many governments and agencies keep up-to-date information on climate change research and statistics online. The most comprehensive and in-depth global reports are produced by the Intergovernmental Panel on Climate Change (IPCC), which released its Sixth Assessment Report on the science of climate change in 2021.

— 8 ominous climate milestones reached in 2021

— Ignoring climate change will lead to 'untold suffering,' scientist panel warns

— Earth's lower atmosphere is expanding due to climate change

For a historical look at the effects of climate change on Earth (and how modern warming compares), read Peter Brannen's " The Ends of the Earth: Volcanic Apocalypses, Lethal Oceans, and Our Quest to Understand Earth’s Past Mass Extinctions " (Ecco, 2017).

For more on the potential impacts of climate change in urban environments, the freely available book chapter Climate Change and its Impacts in the book " Climate Change Resilience in the Urban Environment " (IOP Publishing, 2017) covers the challenges that lay ahead for human populations.

Finally, for a psychological deep-dive on why all of this bad news is hard to take in, try " Don't Even Think About It: Why Our Brains Are Wired to Ignore Climate Change " (Bloomsbury USA, 2015) by climate activist and communicator George Marshall.

• This NASA page includes a series of visualizations that illustrate how some of Earth's key climate indicators —  sea ice, sea level, global temperature and carbon dioxide — are changing over time.
• This NOAA sea-level rise learning module includes educational videos, background for teachers, learning objectives and more.
• ClimateBrief has gathered 10 of the best climate change videos on YouTube. 
• EPA: Climate Change: Basic Information  
• NASA: Global Climate Change
• NOAA: Climate News and Data

Sign up for the Live Science daily newsletter now

Get the world’s most fascinating discoveries delivered straight to your inbox.

Stephanie Pappas is a contributing writer for Live Science, covering topics ranging from geoscience to archaeology to the human brain and behavior. She was previously a senior writer for Live Science but is now a freelancer based in Denver, Colorado, and regularly contributes to Scientific American and The Monitor, the monthly magazine of the American Psychological Association. Stephanie received a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz. 

Yellowstone Lake's weird resistance to climate change could be about to crack

AI-powered 'digital twin' of Earth could make weather predictions at super speeds

Enormous 'San Andreas fault' on Saturn's moon could help reveal signs of alien life

Most Popular

• 2 James Webb telescope confirms there is something seriously wrong with our understanding of the universe
• 3 6G speeds hit 100 Gbps in new test — 500 times faster than average 5G cellphones
• 4 DARPA's autonomous 'Manta Ray' drone can glide through ocean depths undetected
• 5 2 plants randomly mated up to 1 million years ago to give rise to one of the world's most popular drinks
• 2 2 plants randomly mated up to 1 million years ago to give rise to one of the world's most popular drinks
• 3 Deepest blue hole in the world discovered, with hidden caves and tunnels believed to be inside
• 4 Hundreds of black 'spiders' spotted in mysterious 'Inca City' on Mars in new satellite photos
• 5 Stunning image shows atoms transforming into quantum waves — just as Schrödinger predicted

 view all topics  > Climate change

Humans are causing global warming

Search the United Nations

• What Is Climate Change
• Myth Busters
• Renewable Energy
• Finance & Justice
• Initiatives
• Sustainable Development Goals
• Paris Agreement
• Climate Ambition Summit 2023
• Climate Conferences
• Press Material
• Communications Tips

Causes and Effects of Climate Change

Fossil fuels – coal, oil and gas – are by far the largest contributor to global climate change, accounting for over 75 per cent of global greenhouse gas emissions and nearly 90 per cent of all carbon dioxide emissions. As greenhouse gas emissions blanket the Earth, they trap the sun’s heat. This leads to global warming and climate change. The world is now warming faster than at any point in recorded history. Warmer temperatures over time are changing weather patterns and disrupting the usual balance of nature. This poses many risks to human beings and all other forms of life on Earth. 

Sacred plant helps forge a climate-friendly future in Paraguay

El Niño and climate crisis raise drought fears in Madagascar

The El Niño climate pattern, a naturally occurring phenomenon, can significantly disrupt global weather systems, but the human-made climate emergency is exacerbating the destructive effects.

“Verified for Climate” champions: Communicating science and solutions

Gustavo Figueirôa, biologist and communications director at SOS Pantanal, and Habiba Abdulrahman, eco-fashion educator, introduce themselves as champions for “Verified for Climate,” a joint initiative of the United Nations and Purpose to stand up to climate disinformation and put an end to the narratives of denialism, doomism, and delay.

Facts and figures

• What is climate change?
• Causes and effects
• Myth busters

Cutting emissions

• Explaining net zero
• High-level expert group on net zero
• Checklists for credibility of net-zero pledges
• Greenwashing
• What you can do

Clean energy

• Renewable energy – key to a safer future
• What is renewable energy
• Five ways to speed up the energy transition
• Why invest in renewable energy
• Clean energy stories
• A just transition

Adapting to climate change

• Climate adaptation
• Early warnings for all
• Youth voices

Financing climate action

• Finance and justice
• Loss and damage
• $100 billion commitment
• Why finance climate action
• Biodiversity
• Human Security

International cooperation

• What are Nationally Determined Contributions
• Acceleration Agenda
• Climate Ambition Summit
• Climate conferences (COPs)
• Youth Advisory Group
• Action initiatives
• Secretary-General’s speeches
• Press material
• Fact sheets
• Communications tips

Unbalanced: How Climate Change Is Shifting Earth’s Ecosystems

We can already see how climate change is impacting humans and wildlife. But what about the abiotic, or nonliving, parts of the environment?

Earth Science, Climatology

Melting Iceberg

Glaciers are disappearing, melting faster than they can be replenished, like this glacier located in Greenland. Melting is happening faster in Greenland and the rest of the Arctic, which is warming faster than anywhere else on Earth.

Photograph by Steve Allen

Glaciers are melting, sea levels are rising, and storms are more intense. These are some of the visible impacts of global warming , caused by rising levels of carbon dioxide and other greenhouse gases that are due to warming in the atmosphere and ocean. In a 2018 report, the Intergovernmental Panel on Climate Change (IPCC) stated that the average global temperature has risen about 1ºC (1.8ºF) since pre-industrial times. If the current rate of warming continues, this number is expected to nearly double in a relatively short time, reaching 1.5ºC (2.7ºF) between 2030 and 2052. This could have devastating effects on ecosystems around the world, from tropical coral reefs to the icy Arctic Ocean. Why is such a small increase in global temperature causing such big problems for Earth’s ecosystems ? The Ocean Is Feeling the Heat More than 80 percent of global warming is absorbed by the ocean, which has a massive capacity to store and release heat. Elevated sea-surface temperatures are causing long-term damage to coral reefs. Corals are bleaching and dying. The IPCC report projects that up to 90 percent of coral reefs could disappear if the global warming reaches 1.5ºC (2.7ºF). Another reason corals are in trouble is because of ocean acidification. Higher carbon dioxide levels have shifted the chemistry of the ocean, making it more acidic, and corals and shelled sea creatures have trouble growing in acidic conditions. Sea Levels Are Rising When ocean water warms, it expands in volume. This is a major cause of the rise in sea levels, along with the water added to the ocean by the melting of land-based glaciers. The sea level has risen an average of 20 centimeters (8 inches) since the late 19th century, and research by scientists studying the last 25 years of satellite data found that the ocean water is rising faster and faster. If it continues at its current rate of acceleration, the rise in sea level by 2100 will be more than double current estimates. Sea level rise leads to the destruction of coastal wetlands, salt marshes, and mangrove swamps, as well as flooding and damage to aquatic ecosystems. Drought to Deluge: The Impacts of Shifting Temperature and Precipitation Temperature and precipitation are key ingredients of climate. A warmer climate means that more water evaporates from both the land and ocean, and a warmer atmosphere holds more of that water. Scientists have noticed that heavy rainfall events are increasing. Additionally, higher water temperature in streams, lakes, and reservoirs lead to lower levels of dissolved oxygen in the water, which impacts the survival and populations of fish and other aquatic life. Especially troubling are the extreme weather events that are happening more often around the world. Hurricanes are ramping up in intensity, particularly in the North Atlantic. The year 2017 was a busy one for Atlantic hurricanes. Hurricanes Harvey, Irma, and Maria unleashed their destructive power on Texas, Florida, and Puerto Rico. A group of scientists using high-resolution computer modeling determined that the main reason the 2017 hurricane season was so violent was due to warm sea-surface conditions in the North Atlantic. This led to a new way of predicting what to expect each year. The intensity of the Atlantic hurricane season depends on how much the tropical Atlantic warms in comparison to the rest of the global ocean. Meanwhile, in the western United States, the state of California has had record-setting drought conditions, which began in 2012. Researchers analyzing the history of California’s droughts found that the state is more likely to experience drought when low precipitation combines with warm weather conditions. Extended drought periods can lead to a higher fire risk. Today, large fires are five times more common and fire season is three months longer than it was 40 years ago. Besides the obvious loss of habitat for wildlife, new research has found that ecosystems burned out by a wildfire no longer regenerate and bounce back to life the way they used to. Melting Away: What Is Happening to the World’s Ice? Snow pack, sea ice, and glaciers are melting around the world. One of the most visible effects of climate change is the rapid disappearance of glaciers . Scientists from Glacier National Park in Montana, U.S., have documented the steady decline of the park’s iconic glaciers with photographs. Glaciers around the world are melting faster than snow and ice can replenish them. In fact, the Arctic is warming faster than any other place on Earth, at a rate of two to three times the global average. This has led to a 40 percent decrease in the minimum summer sea-ice cover since 1978. When ice melts in the ocean, fresher and less dense water is added to the North Atlantic, which could potentially disrupt a pattern of ocean circulation that is driven by the sinking of cold, salty water in the North Atlantic, known as thermohaline circulation . The Arctic ecosystem is especially vulnerable to global warming . Polar bears, narwhals, and walruses are all iconic species native to the Arctic , but as the ice melts, they may have to adapt to a new way of life, or risk dying out. In an interview published in the British newspaper, The Guardian , marine ecologist Tom Brown said, “The Arctic food chain relies on a stable sea ice platform and that is now disappearing, putting the region’s wildlife at risk.”

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Production Managers

Program specialists, last updated.

October 19, 2023

User Permissions

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text on this page is printable and can be used according to our Terms of Service .

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources

Donate to Defend Our Planet

Drilling on public lands, mass wildlife extinctions, worsening climate change—our planet is in crisis. Help us fight back and your gift will be matched $1 for $1.

Global Warming 101

Everything you wanted to know about our changing climate but were too afraid to ask.

Temperatures in Beijing rose above 104 degrees Fahrenheit on July 6, 2023.

Jia Tianyong/China News Service/VCG via Getty Images

• Share this page block

What is global warming?

What causes global warming, how is global warming linked to extreme weather, what are the other effects of global warming, where does the united states stand in terms of global-warming contributors, is the united states doing anything to prevent global warming, is global warming too big a problem for me to help tackle.

A: Since the Industrial Revolution, the global annual temperature has increased in total by a little more than 1 degree Celsius, or about 2 degrees Fahrenheit. Between 1880—the year that accurate recordkeeping began—and 1980, it rose on average by 0.07 degrees Celsius (0.13 degrees Fahrenheit) every 10 years. Since 1981, however, the rate of increase has more than doubled: For the last 40 years, we’ve seen the global annual temperature rise by 0.18 degrees Celsius, or 0.32 degrees Fahrenheit, per decade.

The result? A planet that has never been hotter . Nine of the 10 warmest years since 1880 have occurred since 2005—and the 5 warmest years on record have all occurred since 2015. Climate change deniers have argued that there has been a “pause” or a “slowdown” in rising global temperatures, but numerous studies, including a 2018 paper published in the journal Environmental Research Letters , have disproved this claim. The impacts of global warming are already harming people around the world.

Now climate scientists have concluded that we must limit global warming to 1.5 degrees Celsius by 2040 if we are to avoid a future in which everyday life around the world is marked by its worst, most devastating effects: the extreme droughts, wildfires, floods, tropical storms, and other disasters that we refer to collectively as climate change . These effects are felt by all people in one way or another but are experienced most acutely by the underprivileged, the economically marginalized, and people of color, for whom climate change is often a key driver of poverty, displacement, hunger, and social unrest.

A: Global warming occurs when carbon dioxide (CO 2 ) and other air pollutants collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface. Normally this radiation would escape into space, but these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter. These heat-trapping pollutants—specifically carbon dioxide, methane, nitrous oxide, water vapor, and synthetic fluorinated gases—are known as greenhouse gases, and their impact is called the greenhouse effect.

Though natural cycles and fluctuations have caused the earth’s climate to change several times over the last 800,000 years, our current era of global warming is directly attributable to human activity—specifically to our burning of fossil fuels such as coal, oil, gasoline, and natural gas, which results in the greenhouse effect. In the United States, the largest source of greenhouse gases is transportation (29 percent), followed closely by electricity production (28 percent) and industrial activity (22 percent). Learn about the natural and human causes of climate change .

Curbing dangerous climate change requires very deep cuts in emissions, as well as the use of alternatives to fossil fuels worldwide. The good news is that countries around the globe have formally committed—as part of the 2015 Paris Climate Agreement —to lower their emissions by setting new standards and crafting new policies to meet or even exceed those standards. The not-so-good news is that we’re not working fast enough. To avoid the worst impacts of climate change, scientists tell us that we need to reduce global carbon emissions by as much as 40 percent by 2030. For that to happen, the global community must take immediate, concrete steps: to decarbonize electricity generation by equitably transitioning from fossil fuel–based production to renewable energy sources like wind and solar; to electrify our cars and trucks; and to maximize energy efficiency in our buildings, appliances, and industries.

A: Scientists agree that the earth’s rising temperatures are fueling longer and hotter heat waves , more frequent droughts , heavier rainfall , and more powerful hurricanes .

In 2015, for example, scientists concluded that a lengthy drought in California—the state’s worst water shortage in 1,200 years —had been intensified by 15 to 20 percent by global warming. They also said the odds of similar droughts happening in the future had roughly doubled over the past century. And in 2016, the National Academies of Science, Engineering, and Medicine announced that we can now confidently attribute some extreme weather events, like heat waves, droughts, and heavy precipitation, directly to climate change.

The earth’s ocean temperatures are getting warmer, too—which means that tropical storms can pick up more energy. In other words, global warming has the ability to turn a category 3 storm into a more dangerous category 4 storm. In fact, scientists have found that the frequency of North Atlantic hurricanes has increased since the early 1980s, as has the number of storms that reach categories 4 and 5. The 2020 Atlantic hurricane season included a record-breaking 30 tropical storms, 6 major hurricanes, and 13 hurricanes altogether. With increased intensity come increased damage and death. The United States saw an unprecedented 22 weather and climate disasters that caused at least a billion dollars’ worth of damage in 2020, but, according to NOAA, 2017 was the costliest on record and among the deadliest as well: Taken together, that year's tropical storms (including Hurricanes Harvey, Irma, and Maria) caused nearly $300 billion in damage and led to more than 3,300 fatalities.

The impacts of global warming are being felt everywhere. Extreme heat waves have caused tens of thousands of deaths around the world in recent years. And in an alarming sign of events to come, Antarctica has lost nearly four trillion metric tons of ice since the 1990s. The rate of loss could speed up if we keep burning fossil fuels at our current pace, some experts say, causing sea levels to rise several meters in the next 50 to 150 years and wreaking havoc on coastal communities worldwide.

A: Each year scientists learn more about the consequences of global warming , and each year we also gain new evidence of its devastating impact on people and the planet. As the heat waves, droughts, and floods associated with climate change become more frequent and more intense, communities suffer and death tolls rise. If we’re unable to reduce our emissions, scientists believe that climate change could lead to the deaths of more than 250,000 people around the globe every year and force 100 million people into poverty by 2030.

Global warming is already taking a toll on the United States. And if we aren’t able to get a handle on our emissions, here’s just a smattering of what we can look forward to:

• Disappearing glaciers, early snowmelt, and severe droughts will cause more dramatic water shortages and continue to increase the risk of wildfires in the American West.
• Rising sea levels will lead to even more coastal flooding on the Eastern Seaboard, especially in Florida, and in other areas such as the Gulf of Mexico.
• Forests, farms, and cities will face troublesome new pests , heat waves, heavy downpours, and increased flooding . All of these can damage or destroy agriculture and fisheries.
• Disruption of habitats such as coral reefs and alpine meadows could drive many plant and animal species to extinction.
• Allergies, asthma, and infectious disease outbreaks will become more common due to increased growth of pollen-producing ragweed , higher levels of air pollution , and the spread of conditions favorable to pathogens and mosquitoes.

Though everyone is affected by climate change, not everyone is affected equally. Indigenous people, people of color, and the economically marginalized are typically hit the hardest. Inequities built into our housing , health care , and labor systems make these communities more vulnerable to the worst impacts of climate change—even though these same communities have done the least to contribute to it.

A: In recent years, China has taken the lead in global-warming pollution , producing about 26 percent of all CO2 emissions. The United States comes in second. Despite making up just 4 percent of the world’s population, our nation produces a sobering 13 percent of all global CO2 emissions—nearly as much as the European Union and India (third and fourth place) combined. And America is still number one, by far, in cumulative emissions over the past 150 years. As a top contributor to global warming, the United States has an obligation to help propel the world to a cleaner, safer, and more equitable future. Our responsibility matters to other countries, and it should matter to us, too.

A: We’ve started. But in order to avoid the worsening effects of climate change, we need to do a lot more—together with other countries—to reduce our dependence on fossil fuels and transition to clean energy sources.

Under the administration of President Donald Trump (a man who falsely referred to global warming as a “hoax”), the United States withdrew from the Paris Climate Agreement, rolled back or eliminated dozens of clean air protections, and opened up federally managed lands, including culturally sacred national monuments, to fossil fuel development. Although President Biden has pledged to get the country back on track, years of inaction during and before the Trump administration—and our increased understanding of global warming’s serious impacts—mean we must accelerate our efforts to reduce greenhouse gas emissions.

Despite the lack of cooperation from the Trump administration, local and state governments made great strides during this period through efforts like the American Cities Climate Challenge and ongoing collaborations like the Regional Greenhouse Gas Initiative . Meanwhile, industry and business leaders have been working with the public sector, creating and adopting new clean-energy technologies and increasing energy efficiency in buildings, appliances, and industrial processes. 

Today the American automotive industry is finding new ways to produce cars and trucks that are more fuel efficient and is committing itself to putting more and more zero-emission electric vehicles on the road. Developers, cities, and community advocates are coming together to make sure that new affordable housing is built with efficiency in mind , reducing energy consumption and lowering electric and heating bills for residents. And renewable energy continues to surge as the costs associated with its production and distribution keep falling. In 2020 renewable energy sources such as wind and solar provided more electricity than coal for the very first time in U.S. history.

President Biden has made action on global warming a high priority. On his first day in office, he recommitted the United States to the Paris Climate Agreement, sending the world community a strong signal that we were determined to join other nations in cutting our carbon pollution to support the shared goal of preventing the average global temperature from rising more than 1.5 degrees Celsius above preindustrial levels. (Scientists say we must stay below a 2-degree increase to avoid catastrophic climate impacts.) And significantly, the president has assembled a climate team of experts and advocates who have been tasked with pursuing action both abroad and at home while furthering the cause of environmental justice and investing in nature-based solutions.

A: No! While we can’t win the fight without large-scale government action at the national level , we also can’t do it without the help of individuals who are willing to use their voices, hold government and industry leaders to account, and make changes in their daily habits.

Wondering how you can be a part of the fight against global warming? Reduce your own carbon footprint by taking a few easy steps: Make conserving energy a part of your daily routine and your decisions as a consumer. When you shop for new appliances like refrigerators, washers, and dryers, look for products with the government’s ENERGY STAR ® label; they meet a higher standard for energy efficiency than the minimum federal requirements. When you buy a car, look for one with the highest gas mileage and lowest emissions. You can also reduce your emissions by taking public transportation or carpooling when possible.

And while new federal and state standards are a step in the right direction, much more needs to be done. Voice your support of climate-friendly and climate change preparedness policies, and tell your representatives that equitably transitioning from dirty fossil fuels to clean power should be a top priority—because it’s vital to building healthy, more secure communities.

You don’t have to go it alone, either. Movements across the country are showing how climate action can build community , be led by those on the front lines of its impacts, and create a future that’s equitable and just for all .

This story was originally published on March 11, 2016 and has been updated with new information and links.

This NRDC.org story is available for online republication by news media outlets or nonprofits under these conditions: The writer(s) must be credited with a byline; you must note prominently that the story was originally published by NRDC.org and link to the original; the story cannot be edited (beyond simple things such as grammar); you can’t resell the story in any form or grant republishing rights to other outlets; you can’t republish our material wholesale or automatically—you need to select stories individually; you can’t republish the photos or graphics on our site without specific permission; you should drop us a note to let us know when you’ve used one of our stories.

Related Stories

Liquefied Natural Gas 101

What’s the Most Energy-Efficient Water Heater?

What Do “Better” Batteries Look Like?

When you sign up, you’ll become a member of NRDC’s Activist Network. We will keep you informed with the latest alerts and progress reports.

Capital Weather Gang

Climate change in the 2010s: Decade of fires, floods and scorching heat waves

By Andrew Freedman , Jason Samenow , Rick Noack and Karly Domb Sadof | Jan. 1, 2020

The 2010s were the decade of climate change consequences — when the clear signal of human-driven extreme events fully emerged and affected the lives of millions worldwide. As the decade closes, there is a growing recognition that climate change is having more calamitous impacts on ecosystems and human society than expected, and scientific concern over tipping points that no longer seem as distant.

Mason Trinca/For The Washington Post

This browser does not support the video element.

A progression of changing global surface temperature anomalies from 1880 through 2018.

These include the melting of Arctic permafrost, which could release billions of tons of carbon dioxide and the potentially abrupt transition of the lush Amazon rainforest into a dry savanna. So far, though, the biggest disruptive impact of climate change in most peoples’ lives has come through extreme events, from heat waves to floods and wildfires.

A large iceberg near Kulusuk, Greenland.

Felipe Dana/AP

2010: Heat wave in Russia and Pakistan floods

An early sign that the 2010s would bring damaging climate extremes came in July 2010, when a record heat wave struck western Russia. Temperatures soared above 100 degrees for the first time on record in Moscow, as wildfires broke out that turned skies a sickening yellowish-orange in the capital city.

Mikhail Metzel/ASSOCIATED PRESS

Tourists wear masks protecting them smog as they walk along Red Square in Moscow in August 2010.

The heat is estimated to have killed thousands and devastated the country’s wheat crop. A study published in 2011 tied the heat wave in part to global warming, noting that gradually increasing temperatures in western Russia made the extreme heat more likely.

Women carry belongings as they wade through floodwaters in Nowshera, Pakistan, in August 2010.

Daniel Berehulak/Getty Images

The same weather pattern that produced the heat wave, featuring a sluggish and wavy jet stream, had more disastrous consequences downstream. In Pakistan, the jet stream buckled in such a way that it directed the full fury of the Asian Monsoon into that mountainous country. The results were devastating floods that affected 18 million and killed at least 1,800.

Pakistani women hold up ration cards at a camp for people displaced by floods in southern Pakistan in September 2010.

2011-2012: East Africa drought

Drought in East Africa threw the region into a famine crisis in 2011 and 2012. In Somalia alone, famine killed more than a quarter of a million people between 2010 and 2012, according to a study by the U.N. Food and Agriculture Organization and the Famine Early Warning Systems Network. A report by Save the Children and Oxfam later suggested that a lack of international preparedness was to blame for the high death toll.

Habibo Bashir, 1, rests on a bed in 2011 at a Doctors Without Borders hospital where he is being treated for severe malnutrition outside Kenya.

Another key factor in the drought, according to the U.K. Met Office, was climate change. This poor, highly vulnerable region is facing the prospect of more intense precipitation extremes as the climate warms worldwide: more intense rainfall and disastrous drought.

2015: Heat wave in India and Pakistan

Among the worst heat waves in the region on record, the 2015 heat wave in India and Pakistan reached temperatures up to 120 degrees and resulted in at least 4,000 deaths. It came amid warnings of more frequent and extreme heat waves in the region.

A Pakistani volunteer puts an identification paper onto the body of a heat wave victim in Karachi in June 2015.

A number of factors — including urbanization, drained soil moisture, delayed onset of the summer monsoon season, and the increased odds of hotter and longer-lasting heat events — have contributed to the region’s recent heat waves.

2019: Carbon Dioxide passes 410 ppm

In 2019, global amounts of carbon dioxide in our atmosphere briefly reached 415 parts per million for the first time in human history. For the year, it’s likely that carbon dioxide, the most important long-lived greenhouse gas, reached or exceeded a global average of 410 ppm.

Kevin Frayer/Getty Images

Smoke billows from a coal-fired power plant as a Chinese woman wears a mask while walking in Shanxi in November 2015.

This would be the highest level seen in about 3 million years. The last time carbon dioxide levels were this high, the world was significantly warmer than it is today, and sea levels were 50 to 80 feet higher.

2015-2019: Globe’s hottest years on record

The 2010s will go down as the warmest decade in recorded history, with 2016 ranking as the hottest. Remarkably, the past six years have been the warmest six on record, with 2019 very likely ranking as the second-warmest year. Nineteen of the 20 warmest years on record have now occurred since 2000.

NurPhoto/NurPhoto via Getty Images

Indian Hindu devotees protect themselves from a dust storm during a hot day in Allahabad in April 2016.

2015-2017: Global coral bleaching event

It was a bleak decade for coral reefs around the world. The longest-ever global coral bleaching event occurred between 2015 and 2017, with 3 in 4 tropical reefs affected by heat stress. Among them was the Great Barrier Reef in Australia, which suffered consecutive mass bleaching events and a dramatic uptick in coral mortality.

Kyodo News/Kyodo News Stills via Getty Imag

Coral bleaching at the Great Barrier Reef in Australia, a World Heritage Site in 2016.

Coral shows the distinct markings left by stony coral tissue loss disease in St. Thomas in the U.S. Virgin Islands in 2019.

Lucas Jackson/REUTERS

2015: Paris climate agreement

Countries came together in 2015 to craft a new climate agreement that for the first time secured emissions reduction commitments from industrialized and developing nations alike. The United States, under President Barack Obama, and China played major roles in shaping the agreement, while leaders from small island countries, such as the Marshall Islands, emerged as the moral voice for those hardest-hit by global warming.

Anadolu Agency/Getty Images

The Arc de Triomphe is illuminated in green to celebrate the ratification of the Paris climate accords in 2016.

Under the pact, countries pledged to hold global warming to “well below” 3.6 degrees (2 Celsius) of warming, and to aspire to keep it to 2.7 degrees (1.5 Celsius) compared to preindustrial levels.

2019: Tipping points near

As 2019 came to a close, new warnings arrived about tipping points that could significantly accelerate climate change. One of these involves melting permafrost, a band of frozen soil that circles the top of the world. As it thaws, these soils are releasing long-buried stores of planet warming gases such as carbon dioxide and methane.

Bonnie Jo Mount/The Washington Post

Water surrounds displaced graves at a cemetery in Nuiqsut, Alaska, in May. Shorter winters and a thawing landscape contribute to shifts in the site.

One study found that the Arctic may already be a net source of greenhouse gases, on the scale of a major industrialized nation such as Japan. In addition, scientists sounded alarms about the possibility of an abrupt transition of the Amazon rainforest into a fragmented, drier savanna. If it occurs, this would also release greenhouse gases that had been locked away.

2017: South Asia floods

Torrents of rain caused floods in South Asia in 2017 that killed more than 1,000 and affected over 40 million, according to United Nations estimates. Among the most affected countries were Bangladesh, Nepal, India and Pakistan.

AFP Contributor/AFP via Getty Images

People wade through a flooded street during heavy rain showers in Mumbai in August 2017.

Even though floods during the monsoon season are not uncommon in this part of the world, climate change can exacerbate them. As the globe warms, the atmosphere is able to carry more water vapor, and warmer ocean temperatures also help fuel more intense storm systems. Both of these factors lead to more extreme precipitation events.

2018: California wildfires

A spate of devastating fires struck California in recent years. The most destructive and deadly of these blazes was the Camp Fire, which in a matter of hours on Nov. 8, 2018, destroyed the community of Paradise, killing 86.

Kevin Ciotta looks over the burned out community center at the Butte Creek Mobile Home Park in Chico, Calif., on Nov. 26, 2018.

Denise Chester, an evacuee of the Camp Fire, hugs her son Antonio Batres as she volunteers to sort clothes at a makeshift shelter in Chico in November 2018.

Noah Berger/AP

Research has linked climate change to an increased frequency of large fires in the American West as well as changes in fire behavior.

2014-2018: Arctic heat waves

Intrusions of abnormally warm air swept over the North Pole in several recent winters, causing the temperature to rise above freezing — some 50 degrees above normal. Such exceptional warm events were previously rare, happening only four times between 1980 and 2010, but occurred in four of five winters from 2014 to 2018.

David Goldman/AP

Melting sea ice is seen along the Northwest Passage in the Canadian Arctic Archipelago in July 2017.

Climate scientists have linked these warm episodes to a reduction in Arctic sea ice. Thinner and spottier ice is easily pushed around by storms, exposing open ocean water, which releases heat into the atmosphere. Arctic sea ice has been shrinking at all times of the year. It set a record for its lowest winter maximum extent in 2017 and established a record low summer extent in 2012.

2018-2019: Massive Northern Hemisphere summer heat waves

The Northern Hemisphere endured exceptionally hot summers the past two years, which brought some of the most extreme high temperatures ever observed. In 2019, record highs were shattered in several European countries during July, including Germany, Belgium and the Netherlands. Paris set an record temperature of 108.7 degrees, crushing the previous record of 104.7 degrees set in June 1947.

A personal care assistant gives a glass of water to an elderly woman to help her avoid heatstroke and dehydration during the 2019 heat wave in France.

While 2019 turned out to be the hottest summer on record in the Northern Hemisphere, the summer of 2018 was also brutally hot. According to a study on the 2018 heat events, we’ve entered “a new climate regime,” featuring “extraordinary” heat waves on a scale and ferocity not seen before.

2012, 2019: Greenland’s extreme melt seasons

Exceptional summer warmth in Greenland led to the top two melt events over the ice sheet in recorded history. On July 31, 2019, melting occurred over 60 percent of the ice sheet, the greatest area since July 2012, when an extraordinary 97 percent of the ice sheet experienced melting. The 2019 melt event, however, produced the greatest volume loss from the ice sheet, at 12.5 billion tons.

Steffen Olsen/Centre For Ocean And Ice At The

Sled dogs wade through standing water on the sea ice during an expedition in northwestern Greenland in June 2019.

The Greenland ice sheet is already the biggest contributor to modern sea level rise. A study published this year found Greenland’s glaciers increased their melt sixfold since the period of 1980 to 1990, to 286 billion tons between 2010 and 2018.

The crew of patrol vessel KV Svalbard and scientists from the Norwegian Institute of Marine Research play football on ice offshore in the sea around Greenland in March 2018.

MARIUS VAGENES VILLANGER/AFP via Getty Images

Record-shattering hurricanes

This was the decade that hurricanes intensified more rapidly than we’ve seen before, dumped heavier rainfall and reached unprecedented levels of ferocity. This year, Hurricane Dorian, a 185-mph monster, pummeled the northwestern Bahamas as the strongest storm on record to hit there.

Ramon Espinosa/AP

Volunteers wade through a flooded road against wind and rain brought on by Hurricane Dorian to rescue families near the Causarina bridge in Freeport, Grand Bahama, Bahamas, in September 2019.

In 2013, Super Typhoon Haiyan set intensity records and destroyed the city of Tacloban in the Philippines with sustained winds of 195 mph. In the eastern Pacific, Hurricane Patricia set a record for the strongest storm on record in the Western Hemisphere, with sustained winds of 215 mph.

The hurricane seasons of 2017 and 2018 were rough on the United States. Hurricane Michael struck Florida in 2018 as a Category 5 storm, flattening a major air force base along with coastal towns. Hurricane Maria devastated Puerto Rico, cutting power across the island and contributing to thousands of excess deaths. And Hurricane Harvey turned highways into raging rapids in Houston, setting an all-time U.S. rainfall record.

Gladys Rivera Rodriguez is overcome with emotion standing in her bedroom, which had the roof ripped off by Hurricane Maria, in Caonillas, Puerto Rico.

Michael Robinson Chavez/The Washington Post

2019: Global wildfires

Severe wildfires have expanded their reach in recent years, including throughout the Amazon rainforest and the carbon-rich boreal forests of Siberia and Alaska. As 2019 closed out, bush fires raged amid record heat and drought in parts of Australia — whose Prime Minister Scott Morrison came to the defense of the country’s coal industry, cautioning against “reckless” climate action.

David Gray/Getty Images

Two bush fires approach a home located on the outskirts of the town of Bargo on Dec. 21 in Sydney.

Antonio Enzsio Tenharin, one of the nearly 3,000 indigenous Tenharin people who live an area of the Brazilian rainforest where fire “springs from nowhere.”

In Brazil, the pro-development policies of President Jair Bolsonaro have been blamed for a sharp uptick in Amazon fires during the past year. Scientists fear the blazes could permanently transform the fragile rainforest.

2019: Scientists’ warnings give rise to a movement

As scientific warnings have grown more urgent and damaging climate impacts have become more obvious, a new generation is demanding climate action. Youth activists have staged school strikes and protests, and pressured lawmakers and the courts to act. Swedish student Greta Thunberg has given voice to the anger felt by many who are inheriting a hotter, more inhospitable planet.

Paul White/AP

Youth climate activist Greta Thunberg listens to scientists speak during a meeting with leading climate scientists at the 2019 U.N. Climate Change Conference in Madrid.

2019: U.N. climate talks in Madrid

The scientific warnings and activists in the streets were not enough to compel leaders to act at the annual U.N. climate negotiations, held in Madrid in December. The talks laid bare bitter divisions between rich and poor nations on how to grapple with global warming and its damaging effects. President Trump is set to pull the United States out of the Paris climate agreement in 2020.

Demonstrators walk past the city hall in Madrid during a march to demand urgent action on the climate crisis from world leaders attending the annual climate summit.

As the decade closes, scientists are increasingly tying extreme weather events to long-term climate change. It’s clear that humans have altered the background conditions in which all weather takes place, tilting the odds in favor of more severe, damaging and deadly weather.

With greenhouse gas emissions continuing to climb, the weather of the 2020s will be even more extreme.

Knowledge is power

Stay in the know about climate impacts and solutions. Subscribe to our weekly newsletter.

By clicking submit, you agree to share your email address with the site owner and Mailchimp to receive emails from the site owner. Use the unsubscribe link in those emails to opt out at any time.

Yale Climate Connections

Scientists agree: Climate change is real and caused by people

Share this:

• Click to share on Facebook (Opens in new window)
• Click to share on X (Opens in new window)

[Leer en español aquí]

The scientific consensus that climate change is happening and that it is human-caused is strong. Scientific investigation of global warming began in the 19th century , and by the early 2000s, this research began to coalesce into confidence about the reality, causes, and general range of adverse effects of global warming. This conclusion was drawn from studying air and ocean temperatures, the atmosphere’s composition, satellite records, ice cores, modeling, and more.

In 1988 the United Nations and World Meteorological Organization founded the Intergovernmental Panel on Climate Change, IPCC, to provide regular updates on the scientific evidence on global warming. In a 2013 report , the IPCC concluded that scientific evidence of warming is “unequivocal” and that the largest cause is an increase of carbon dioxide in the atmosphere as a result of humans burning fossil fuels. The IPCC continues to assess this science, periodically issuing new reports.

Climate change is real and caused by humans

The IPCC is not the only scientific group that has reached a clear consensus on the scientific evidence of human-caused global warming. As this NASA page points out, 200 global scientific organizations, 11 international science academies, and 18 American science associations have released statements in alignment with this consensus.

Amanda Staudt is the senior director for climate, atmospheric and polar sciences at the National Academies of Science, Engineering and Medicine, where she has worked since 2001. The Academies, she said, first began studying climate change in 1979, researching how much warming would likely happen if the amount of carbon dioxide concentrations in the atmosphere were doubled.

Four decades later, those findings have held up and have been strengthened based on scores of continued studies and analysis. “The remarkable thing about that study,” she said, “is that they basically got the right answer” from the start. This 1979 study by the National Research Council, Staudt said, led to investment in climate science in the U.S. 

Though this consensus has been thoroughly established, scientific research and new findings continue. Staudt said countless attempted rebuttals of climate science findings have been researched and disproved.

“We did a lot of studies in that time period, looking at those questions,” she said, ”and one by one, putting them to bed and convincing ourselves over and over again, that humans were affecting climate, and that we could document that effect.”

At the National Academies, reaching consensus requires open sessions and dialogue with scientists and agreement from committees, which typically consist of 12-15 experts. Their draft reports go through peer review, and reviewers’ concerns are resolved before publication is approved. The goal is for the complex science of climate change to become as thoroughly researched and substantiated as possible.

“One of the things I think about scientists is that we’re all inherently skeptics at some level,” Staudt said. “That’s what drives us to science, that we have questions about the world around us. And we want to prove that for ourselves.”

Scientists consistently reaffirm evidence that climate change is happening

Climate scientists worldwide go through similar processes before their findings are published. And their research papers, too, show a strong consensus about global warming. As NASA states on its website , “Multiple studies published in peer-reviewed scientific journals show that 97 percent or more of actively publishing climate scientists agree: Climate-warming trends over the past century are extremely likely due to human activities.” (By sound practice, scientists resist saying science is for all times “certain” or that its findings are “final,” and the “extremely likely” language respects that practice.)

One of the studies about the consensus was led by John Cook, a fellow at the Climate Change Communication Research Hub at Monash University in Melbourne, Australia. Cook and colleagues reviewed nearly 12,000 scientific papers to examine how aligned published research is on major findings on climate change. That study found that 97 percent of scholarly papers that take a position on climate change do endorse the consensus. The papers that rejected the consensus position contained errors, according to subsequent research .

In reviewing the papers, Cook has said he and his colleagues found the consensus to have been so widely accepted by 2013 that many researchers by then no longer felt a need to mention or reaffirm it in their research papers.

Also see: Causes of global warming: How scientists know that humans are responsible

Samantha Harrington

Samantha Harrington, director of audience experience for Yale Climate Connections, is a journalist and graphic designer with a background in digital media and entrepreneurship. Sam is especially interested... More by Samantha Harrington

Past decade was the hottest on record

The last 10 years have shown that climate change is happening now, shows a new report from NOAA. It's likely to get much worse.

A report published today by NOAA and NASA confirmed that 2010 to 2019 was the hottest decade since record keeping began 140 years ago. The analysis also revealed that 2019 was the second hottest year ever recorded and that ocean temperatures were the highest they’ve ever been. The scientists behind the report point to carbon dioxide and other greenhouse gas emissions as the sources of continued global warming.

These hotter temperatures helped fuel a slew of natural disasters as the world finally confronted the realities of climate change. The research is the latest to confirm that conditions could worsen unless action to reduce emissions are taken.

This decade, many people around the world woke up to a grim reality: Climate change is here, it’s happening now, and it could very easily get much, much worse.

These 10 years were punctuated by a series of deadly, dramatic, devastating events. Hurricanes like Sandy, Maria, and Harvey fundamentally changed the communities they barreled into, leaving behind scars that have yet to heal. Stronger and stronger heat waves forced communities across the country and world into dangerous swelter. Wildfires tore up hundreds of thousands of acres in a flash.

Climate records fell left and right. Hottest-ever year for the planet’s atmosphere? Check. Hottest-ever year for its oceans? Also check. Puny, unprecedentedly tiny stretches of Arctic sea ice? Check, check, check.

The underlying force beneath the changes is indisputable. Steadily increasing greenhouse gas concentrations in the atmosphere , caused primarily by humans burning fossil fuels, are trapping extra heat near Earth’s surface. That warms Earth as a whole. The outcome is both straightforward—a hotter planet—and incredibly complex, as changes cascade through the oceans, atmosphere, soil, rocks, trees, and every living thing on the planet.

For Hungry Minds

“God, this was a terrible decade,” says Leah Stokes, a climate policy expert at the University of California, Santa Barbara. “Let’s make the next one less bad.”

We wrecked records large and small

The last decade was the hottest ever recorded , flashing a warning sign to anyone who was paying attention. On average, the annual temperatures over the years hover a little less than 1.8 degrees Fahrenheit (1 degree Celsius) higher now than they did from 1950 to 1980; the last five years alone was the hottest stretch ever recorded . So far, 2019 is shaping up to be the second hottest year ever, about 1.7 degrees F (0.94 degree C) above that long-term average.

That number might not sound like much, but its effects are large. Each little shift in the average increases the likelihood of extreme hot events. And just little shifts in the overall amount of heat stored in the oceans, air, and water can have huge effects on the planet.

For example, scientists think the planet was only about 10.8 degrees F colder (6 degrees C), on average, during the last ice age 20,000 or so years ago. But at that time a huge ice sheet covered North America, extending as far south as Long Island. The world looked very different, and there was only a small change in average temperature.

The hottest hot temperatures are also creeping higher—exactly what scientists would expect. As the average shifts upward, the likelihood of the extremely hot moments grows. Sure enough, “ extreme” heat events have come with more frequency in the past decade, and that pattern is only expected to intensify.

There’s another important dimension to the overall warming, which is that it’s not happening evenly over the year or over distances . Winters are warming up faster than summers. The change in minimum temperatures between 2009 and 2018 (the last ten years that we have records for; 2019 records do not exist yet) was 1.34 degrees F. With milder winters come a whole host of unsettling, ecosystem-reshaping changes : Earlier springs cause a mismatch between pollinators and plant flowering times. More rain and less snow, and earlier-melting snow, affect water availability through the summer and fall. Unfrozen lakes , thawing permafrost , and open water appear where there should be ice.

Equally alarming and even more notable change is apparent in the oceans . While air temperatures tend to wobble around from year to year, responding to big patterns like El Niño—the periodic Pacific water-warming weather event—the ocean smooths out the signal, integrating all the warming that’s happened over past years . It responds more slowly and more steadily to changes happening above its surface, and what it’s telling us is clear.

The ocean has sucked up over 90 percent of all the extra heat trapped by human-caused climate change, and that signal is already apparent in its surface temperatures. Marine heat waves, like the heat waves we feel on land , and bigger changes—ones that could affect weather patterns around the entire planet— may be coming sooner than we think.

An icy tale tells us we’re in trouble

Earth’s ice served as the most obvious signpost of change over the past decade. The Arctic experienced about 1.8 F degrees (1 degree C) of warming in the past decade alone —compared to just under 1 degree C for the planet at large over the past 50 years. And its ice and frozen landscapes are responding just as sensitively as scientists predicted they would.

In 2012, nearly the entire Greenland ice sheet turned to slush, gushing cascades of melt into its coastal waters . Then the softening happened again, and again. Arctic sea ice bottomed out at its lowest ever recorded extent in 2012 as well, and has hovered at historic lows ever since , distorting “normal” weather patterns that depend on Arctic cold.

You May Also Like

The world is still falling short of meeting its climate goals

Weather disaster-related deaths are down—warming could undo that trend

5 possible climate futures—from the optimistic to the strange

West Antarctica’s towering glaciers, home to enough ice to raise sea levels by 10 feet or more if they melted, have begun an inexorable retreat . Almost every single glacier in Earth’s high mountains is shrinking now, reshaping life in those high elevation zones. It’s also hitting life far downstream, where billions of people depend on the water that has long been sourced from snow and ice in the high peaks above.

Both ocean-trapped heat and melting ice contributed to record-breaking sea levels across much of the planet . A warmer ocean expands, driving those levels higher, and simultaneously, melt from Greenland and Antarctica has added about 36 millimeters of extra fresh water to the world’s oceans in the past 10 years, and the rate is jacking up every year . The injection of fresh water is changing the composition of the ocean in the Far North, which is in turn slowing down the conveyor belt of current from north to south that controls the world’s weather, with uncertain—but not positive—effects.

Behind all of the change is one clear driver: atmospheric carbon dioxide. In 2009, atmospheric CO 2 concentrations hovered around 390 parts per million. By 2014, the number blew past 400 parts per million. Today, we hover around 410 ppm. The planet hasn’t seen concentrations that high since at least 2.6 million years ago. And at that time, no ice sheet existed in the northern polar regions and forests grew on Antarctica , sea levels were likely more than 40 feet higher than today, and the planet as a whole operated under very different conditions.

“This last decade mattered a lot and it looked pretty bad,” says Kate Marvel , a climate scientist at Columbia University and NASA GISS. “We’ve just got to make it so the next one is different.”

How did people change attitudes around climate change?

The physical patterns of climate change are becoming clearer and clearer. Alongside those physical changes, attitudes are also shifting.

Throughout the 2000s, explains Anthony Leiserowitz , the director of the Yale Program on Climate Change Communication, Americans were engaged with the question of climate change. A 2007 IPCC report stoked conversation about how to deal with the issue, as did political communities. Scientists were speaking out.

But even the belief that climate was changing—let alone whether solutions should be pursued—dropped precipitously in the U.S. between 2008 and 2010, for a suite of political and social reasons. The first part of the decade, Leiserowitz says, was spent rebuilding attention to and interest in climate change as a major issue.

At the same time, scientists have developed new techniques to determine exactly how much more likely an event—from a hurricane to a heat wave to a wildfire—was because of climate change. They can link the wider patterns of change directly to a weather event. That kind of explicit linkage is changing the way people think about the broader issue, he says.

Climate change supercharged Hurricane Harvey, for example, adding an extra 20 percent of rain to what might have been expected. Clear messaging that links the science with the impact influences the way people understand the causes of such events.

In the past few years, public interest in and concern about climate change has increased dramatically . In 2010, 59 percent of the U.S. adults the Yale program surveyed thought global warming was happening; by this year, that number was up to 67 percent. In 2009, 31 percent of respondents thought global warming would harm them personally; by this year, that number was up to 42 percent.

And in the past year, activity has exploded amongst young people . Youth climate activists are gathering, millions deep, to bring attention to their stolen futures. Scientific teams are issuing stronger and stronger warnings. Global attention to the problem and the potential solutions is growing. But at the same time, the action that’s been taken so far is far from enough.

“A lot of people are starting to connect the dots,” says Leiserowitz. “Saying, oh my god, this event, is it climate change? And for a larger swath of the population, they’re starting to see it too, asking, ‘Huh, what’s going on with this record-setting event after record-setting event? Are these things connected?’”

“It was a very bad decade,” says Stokes. “I’d say we lost nine years of the decade, but we really started getting somewhere in the last 12 months. There’s a whole new energy and dynamism,” and that, she says, could signal that the next decade in climate might, hopefully, be different than the last.

Related Topics

• CLIMATE CHANGE

Rising Seas

Extreme weather is coming for our homes. Experts weigh in on how to prepare.

For Antarctica’s emperor penguins, ‘there is no time left’

Wildfires are making their way east—where they could be much deadlier

Chile’s glaciers are dying. You can actually hear it.

• Environment

History & Culture

• History & Culture
• History Magazine
• Mind, Body, Wonder
• Coronavirus Coverage
• Paid Content
• Terms of Use
• Privacy Policy
• Your US State Privacy Rights
• Children's Online Privacy Policy
• Interest-Based Ads
• About Nielsen Measurement
• Do Not Sell or Share My Personal Information
• Nat Geo Home
• Attend a Live Event
• Book a Trip
• Inspire Your Kids
• Shop Nat Geo
• Visit the D.C. Museum
• Learn About Our Impact
• Support Our Mission
• Advertise With Us
• Customer Service
• Renew Subscription
• Manage Your Subscription
• Work at Nat Geo
• Sign Up for Our Newsletters
• Contribute to Protect the Planet

Copyright © 1996-2015 National Geographic Society Copyright © 2015-2024 National Geographic Partners, LLC. All rights reserved

• Share full article

The Science of Climate Change Explained: Facts, Evidence and Proof

Definitive answers to the big questions.

Credit... Photo Illustration by Andrea D'Aquino

Supported by

By Julia Rosen

Ms. Rosen is a journalist with a Ph.D. in geology. Her research involved studying ice cores from Greenland and Antarctica to understand past climate changes.

• Published April 19, 2021 Updated Nov. 6, 2021

The science of climate change is more solid and widely agreed upon than you might think. But the scope of the topic, as well as rampant disinformation, can make it hard to separate fact from fiction. Here, we’ve done our best to present you with not only the most accurate scientific information, but also an explanation of how we know it.

How do we know climate change is really happening?

How much agreement is there among scientists about climate change, do we really only have 150 years of climate data how is that enough to tell us about centuries of change, how do we know climate change is caused by humans, since greenhouse gases occur naturally, how do we know they’re causing earth’s temperature to rise, why should we be worried that the planet has warmed 2°f since the 1800s, is climate change a part of the planet’s natural warming and cooling cycles, how do we know global warming is not because of the sun or volcanoes, how can winters and certain places be getting colder if the planet is warming, wildfires and bad weather have always happened. how do we know there’s a connection to climate change, how bad are the effects of climate change going to be, what will it cost to do something about climate change, versus doing nothing.

Climate change is often cast as a prediction made by complicated computer models. But the scientific basis for climate change is much broader, and models are actually only one part of it (and, for what it’s worth, they’re surprisingly accurate ).

For more than a century , scientists have understood the basic physics behind why greenhouse gases like carbon dioxide cause warming. These gases make up just a small fraction of the atmosphere but exert outsized control on Earth’s climate by trapping some of the planet’s heat before it escapes into space. This greenhouse effect is important: It’s why a planet so far from the sun has liquid water and life!

However, during the Industrial Revolution, people started burning coal and other fossil fuels to power factories, smelters and steam engines, which added more greenhouse gases to the atmosphere. Ever since, human activities have been heating the planet.

We know this is true thanks to an overwhelming body of evidence that begins with temperature measurements taken at weather stations and on ships starting in the mid-1800s. Later, scientists began tracking surface temperatures with satellites and looking for clues about climate change in geologic records. Together, these data all tell the same story: Earth is getting hotter.

Average global temperatures have increased by 2.2 degrees Fahrenheit, or 1.2 degrees Celsius, since 1880, with the greatest changes happening in the late 20th century. Land areas have warmed more than the sea surface and the Arctic has warmed the most — by more than 4 degrees Fahrenheit just since the 1960s. Temperature extremes have also shifted. In the United States, daily record highs now outnumber record lows two-to-one.

Where it was cooler or warmer in 2020 compared with the middle of the 20th century

This warming is unprecedented in recent geologic history. A famous illustration, first published in 1998 and often called the hockey-stick graph, shows how temperatures remained fairly flat for centuries (the shaft of the stick) before turning sharply upward (the blade). It’s based on data from tree rings, ice cores and other natural indicators. And the basic picture , which has withstood decades of scrutiny from climate scientists and contrarians alike, shows that Earth is hotter today than it’s been in at least 1,000 years, and probably much longer.

In fact, surface temperatures actually mask the true scale of climate change, because the ocean has absorbed 90 percent of the heat trapped by greenhouse gases . Measurements collected over the last six decades by oceanographic expeditions and networks of floating instruments show that every layer of the ocean is warming up. According to one study , the ocean has absorbed as much heat between 1997 and 2015 as it did in the previous 130 years.

We also know that climate change is happening because we see the effects everywhere. Ice sheets and glaciers are shrinking while sea levels are rising. Arctic sea ice is disappearing. In the spring, snow melts sooner and plants flower earlier. Animals are moving to higher elevations and latitudes to find cooler conditions. And droughts, floods and wildfires have all gotten more extreme. Models predicted many of these changes, but observations show they are now coming to pass.

Back to top .

There’s no denying that scientists love a good, old-fashioned argument. But when it comes to climate change, there is virtually no debate: Numerous studies have found that more than 90 percent of scientists who study Earth’s climate agree that the planet is warming and that humans are the primary cause. Most major scientific bodies, from NASA to the World Meteorological Organization , endorse this view. That’s an astounding level of consensus given the contrarian, competitive nature of the scientific enterprise, where questions like what killed the dinosaurs remain bitterly contested .

Scientific agreement about climate change started to emerge in the late 1980s, when the influence of human-caused warming began to rise above natural climate variability. By 1991, two-thirds of earth and atmospheric scientists surveyed for an early consensus study said that they accepted the idea of anthropogenic global warming. And by 1995, the Intergovernmental Panel on Climate Change, a famously conservative body that periodically takes stock of the state of scientific knowledge, concluded that “the balance of evidence suggests that there is a discernible human influence on global climate.” Currently, more than 97 percent of publishing climate scientists agree on the existence and cause of climate change (as does nearly 60 percent of the general population of the United States).

So where did we get the idea that there’s still debate about climate change? A lot of it came from coordinated messaging campaigns by companies and politicians that opposed climate action. Many pushed the narrative that scientists still hadn’t made up their minds about climate change, even though that was misleading. Frank Luntz, a Republican consultant, explained the rationale in an infamous 2002 memo to conservative lawmakers: “Should the public come to believe that the scientific issues are settled, their views about global warming will change accordingly,” he wrote. Questioning consensus remains a common talking point today, and the 97 percent figure has become something of a lightning rod .

To bolster the falsehood of lingering scientific doubt, some people have pointed to things like the Global Warming Petition Project, which urged the United States government to reject the Kyoto Protocol of 1997, an early international climate agreement. The petition proclaimed that climate change wasn’t happening, and even if it were, it wouldn’t be bad for humanity. Since 1998, more than 30,000 people with science degrees have signed it. However, nearly 90 percent of them studied something other than Earth, atmospheric or environmental science, and the signatories included just 39 climatologists. Most were engineers, doctors, and others whose training had little to do with the physics of the climate system.

A few well-known researchers remain opposed to the scientific consensus. Some, like Willie Soon, a researcher affiliated with the Harvard-Smithsonian Center for Astrophysics, have ties to the fossil fuel industry . Others do not, but their assertions have not held up under the weight of evidence. At least one prominent skeptic, the physicist Richard Muller, changed his mind after reassessing historical temperature data as part of the Berkeley Earth project. His team’s findings essentially confirmed the results he had set out to investigate, and he came away firmly convinced that human activities were warming the planet. “Call me a converted skeptic,” he wrote in an Op-Ed for the Times in 2012.

Mr. Luntz, the Republican pollster, has also reversed his position on climate change and now advises politicians on how to motivate climate action.

A final note on uncertainty: Denialists often use it as evidence that climate science isn’t settled. However, in science, uncertainty doesn’t imply a lack of knowledge. Rather, it’s a measure of how well something is known. In the case of climate change, scientists have found a range of possible future changes in temperature, precipitation and other important variables — which will depend largely on how quickly we reduce emissions. But uncertainty does not undermine their confidence that climate change is real and that people are causing it.

Earth’s climate is inherently variable. Some years are hot and others are cold, some decades bring more hurricanes than others, some ancient droughts spanned the better part of centuries. Glacial cycles operate over many millenniums. So how can scientists look at data collected over a relatively short period of time and conclude that humans are warming the planet? The answer is that the instrumental temperature data that we have tells us a lot, but it’s not all we have to go on.

Historical records stretch back to the 1880s (and often before), when people began to regularly measure temperatures at weather stations and on ships as they traversed the world’s oceans. These data show a clear warming trend during the 20th century.

Global average temperature compared with the middle of the 20th century

+0.75°C

–0.25°

Some have questioned whether these records could be skewed, for instance, by the fact that a disproportionate number of weather stations are near cities, which tend to be hotter than surrounding areas as a result of the so-called urban heat island effect. However, researchers regularly correct for these potential biases when reconstructing global temperatures. In addition, warming is corroborated by independent data like satellite observations, which cover the whole planet, and other ways of measuring temperature changes.

Much has also been made of the small dips and pauses that punctuate the rising temperature trend of the last 150 years. But these are just the result of natural climate variability or other human activities that temporarily counteract greenhouse warming. For instance, in the mid-1900s, internal climate dynamics and light-blocking pollution from coal-fired power plants halted global warming for a few decades. (Eventually, rising greenhouse gases and pollution-control laws caused the planet to start heating up again.) Likewise, the so-called warming hiatus of the 2000s was partly a result of natural climate variability that allowed more heat to enter the ocean rather than warm the atmosphere. The years since have been the hottest on record .

Still, could the entire 20th century just be one big natural climate wiggle? To address that question, we can look at other kinds of data that give a longer perspective. Researchers have used geologic records like tree rings, ice cores, corals and sediments that preserve information about prehistoric climates to extend the climate record. The resulting picture of global temperature change is basically flat for centuries, then turns sharply upward over the last 150 years. It has been a target of climate denialists for decades. However, study after study has confirmed the results , which show that the planet hasn’t been this hot in at least 1,000 years, and probably longer.

Scientists have studied past climate changes to understand the factors that can cause the planet to warm or cool. The big ones are changes in solar energy, ocean circulation, volcanic activity and the amount of greenhouse gases in the atmosphere. And they have each played a role at times.

For example, 300 years ago, a combination of reduced solar output and increased volcanic activity cooled parts of the planet enough that Londoners regularly ice skated on the Thames . About 12,000 years ago, major changes in Atlantic circulation plunged the Northern Hemisphere into a frigid state. And 56 million years ago, a giant burst of greenhouse gases, from volcanic activity or vast deposits of methane (or both), abruptly warmed the planet by at least 9 degrees Fahrenheit, scrambling the climate, choking the oceans and triggering mass extinctions.

In trying to determine the cause of current climate changes, scientists have looked at all of these factors . The first three have varied a bit over the last few centuries and they have quite likely had modest effects on climate , particularly before 1950. But they cannot account for the planet’s rapidly rising temperature, especially in the second half of the 20th century, when solar output actually declined and volcanic eruptions exerted a cooling effect.

That warming is best explained by rising greenhouse gas concentrations . Greenhouse gases have a powerful effect on climate (see the next question for why). And since the Industrial Revolution, humans have been adding more of them to the atmosphere, primarily by extracting and burning fossil fuels like coal, oil and gas, which releases carbon dioxide.

Bubbles of ancient air trapped in ice show that, before about 1750, the concentration of carbon dioxide in the atmosphere was roughly 280 parts per million. It began to rise slowly and crossed the 300 p.p.m. threshold around 1900. CO2 levels then accelerated as cars and electricity became big parts of modern life, recently topping 420 p.p.m . The concentration of methane, the second most important greenhouse gas, has more than doubled. We’re now emitting carbon much faster than it was released 56 million years ago .

30 billion metric tons

Carbon dioxide emitted worldwide 1850-2017

Rest of world

Other developed

European Union

Developed economies

Other countries

United States

E.U. and U.K.

These rapid increases in greenhouse gases have caused the climate to warm abruptly. In fact, climate models suggest that greenhouse warming can explain virtually all of the temperature change since 1950. According to the most recent report by the Intergovernmental Panel on Climate Change, which assesses published scientific literature, natural drivers and internal climate variability can only explain a small fraction of late-20th century warming.

Another study put it this way: The odds of current warming occurring without anthropogenic greenhouse gas emissions are less than 1 in 100,000 .

But greenhouse gases aren’t the only climate-altering compounds people put into the air. Burning fossil fuels also produces particulate pollution that reflects sunlight and cools the planet. Scientists estimate that this pollution has masked up to half of the greenhouse warming we would have otherwise experienced.

Greenhouse gases like water vapor and carbon dioxide serve an important role in the climate. Without them, Earth would be far too cold to maintain liquid water and humans would not exist!

Here’s how it works: the planet’s temperature is basically a function of the energy the Earth absorbs from the sun (which heats it up) and the energy Earth emits to space as infrared radiation (which cools it down). Because of their molecular structure, greenhouse gases temporarily absorb some of that outgoing infrared radiation and then re-emit it in all directions, sending some of that energy back toward the surface and heating the planet . Scientists have understood this process since the 1850s .

Greenhouse gas concentrations have varied naturally in the past. Over millions of years, atmospheric CO2 levels have changed depending on how much of the gas volcanoes belched into the air and how much got removed through geologic processes. On time scales of hundreds to thousands of years, concentrations have changed as carbon has cycled between the ocean, soil and air.

Today, however, we are the ones causing CO2 levels to increase at an unprecedented pace by taking ancient carbon from geologic deposits of fossil fuels and putting it into the atmosphere when we burn them. Since 1750, carbon dioxide concentrations have increased by almost 50 percent. Methane and nitrous oxide, other important anthropogenic greenhouse gases that are released mainly by agricultural activities, have also spiked over the last 250 years.

We know based on the physics described above that this should cause the climate to warm. We also see certain telltale “fingerprints” of greenhouse warming. For example, nights are warming even faster than days because greenhouse gases don’t go away when the sun sets. And upper layers of the atmosphere have actually cooled, because more energy is being trapped by greenhouse gases in the lower atmosphere.

We also know that we are the cause of rising greenhouse gas concentrations — and not just because we can measure the CO2 coming out of tailpipes and smokestacks. We can see it in the chemical signature of the carbon in CO2.

Carbon comes in three different masses: 12, 13 and 14. Things made of organic matter (including fossil fuels) tend to have relatively less carbon-13. Volcanoes tend to produce CO2 with relatively more carbon-13. And over the last century, the carbon in atmospheric CO2 has gotten lighter, pointing to an organic source.

We can tell it’s old organic matter by looking for carbon-14, which is radioactive and decays over time. Fossil fuels are too ancient to have any carbon-14 left in them, so if they were behind rising CO2 levels, you would expect the amount of carbon-14 in the atmosphere to drop, which is exactly what the data show .

It’s important to note that water vapor is the most abundant greenhouse gas in the atmosphere. However, it does not cause warming; instead it responds to it . That’s because warmer air holds more moisture, which creates a snowball effect in which human-caused warming allows the atmosphere to hold more water vapor and further amplifies climate change. This so-called feedback cycle has doubled the warming caused by anthropogenic greenhouse gas emissions.

A common source of confusion when it comes to climate change is the difference between weather and climate. Weather is the constantly changing set of meteorological conditions that we experience when we step outside, whereas climate is the long-term average of those conditions, usually calculated over a 30-year period. Or, as some say: Weather is your mood and climate is your personality.

So while 2 degrees Fahrenheit doesn’t represent a big change in the weather, it’s a huge change in climate. As we’ve already seen, it’s enough to melt ice and raise sea levels, to shift rainfall patterns around the world and to reorganize ecosystems, sending animals scurrying toward cooler habitats and killing trees by the millions.

It’s also important to remember that two degrees represents the global average, and many parts of the world have already warmed by more than that. For example, land areas have warmed about twice as much as the sea surface. And the Arctic has warmed by about 5 degrees. That’s because the loss of snow and ice at high latitudes allows the ground to absorb more energy, causing additional heating on top of greenhouse warming.

Relatively small long-term changes in climate averages also shift extremes in significant ways. For instance, heat waves have always happened, but they have shattered records in recent years. In June of 2020, a town in Siberia registered temperatures of 100 degrees . And in Australia, meteorologists have added a new color to their weather maps to show areas where temperatures exceed 125 degrees. Rising sea levels have also increased the risk of flooding because of storm surges and high tides. These are the foreshocks of climate change.

And we are in for more changes in the future — up to 9 degrees Fahrenheit of average global warming by the end of the century, in the worst-case scenario . For reference, the difference in global average temperatures between now and the peak of the last ice age, when ice sheets covered large parts of North America and Europe, is about 11 degrees Fahrenheit.

Under the Paris Climate Agreement, which President Biden recently rejoined, countries have agreed to try to limit total warming to between 1.5 and 2 degrees Celsius, or 2.7 and 3.6 degrees Fahrenheit, since preindustrial times. And even this narrow range has huge implications . According to scientific studies, the difference between 2.7 and 3.6 degrees Fahrenheit will very likely mean the difference between coral reefs hanging on or going extinct, and between summer sea ice persisting in the Arctic or disappearing completely. It will also determine how many millions of people suffer from water scarcity and crop failures, and how many are driven from their homes by rising seas. In other words, one degree Fahrenheit makes a world of difference.

Earth’s climate has always changed. Hundreds of millions of years ago, the entire planet froze . Fifty million years ago, alligators lived in what we now call the Arctic . And for the last 2.6 million years, the planet has cycled between ice ages when the planet was up to 11 degrees cooler and ice sheets covered much of North America and Europe, and milder interglacial periods like the one we’re in now.

Climate denialists often point to these natural climate changes as a way to cast doubt on the idea that humans are causing climate to change today. However, that argument rests on a logical fallacy. It’s like “seeing a murdered body and concluding that people have died of natural causes in the past, so the murder victim must also have died of natural causes,” a team of social scientists wrote in The Debunking Handbook , which explains the misinformation strategies behind many climate myths.

Indeed, we know that different mechanisms caused the climate to change in the past. Glacial cycles, for example, were triggered by periodic variations in Earth’s orbit , which take place over tens of thousands of years and change how solar energy gets distributed around the globe and across the seasons.

These orbital variations don’t affect the planet’s temperature much on their own. But they set off a cascade of other changes in the climate system; for instance, growing or melting vast Northern Hemisphere ice sheets and altering ocean circulation. These changes, in turn, affect climate by altering the amount of snow and ice, which reflect sunlight, and by changing greenhouse gas concentrations. This is actually part of how we know that greenhouse gases have the ability to significantly affect Earth’s temperature.

For at least the last 800,000 years , atmospheric CO2 concentrations oscillated between about 180 parts per million during ice ages and about 280 p.p.m. during warmer periods, as carbon moved between oceans, forests, soils and the atmosphere. These changes occurred in lock step with global temperatures, and are a major reason the entire planet warmed and cooled during glacial cycles, not just the frozen poles.

Today, however, CO2 levels have soared to 420 p.p.m. — the highest they’ve been in at least three million years . The concentration of CO2 is also increasing about 100 times faster than it did at the end of the last ice age. This suggests something else is going on, and we know what it is: Since the Industrial Revolution, humans have been burning fossil fuels and releasing greenhouse gases that are heating the planet now (see Question 5 for more details on how we know this, and Questions 4 and 8 for how we know that other natural forces aren’t to blame).

Over the next century or two, societies and ecosystems will experience the consequences of this climate change. But our emissions will have even more lasting geologic impacts: According to some studies, greenhouse gas levels may have already warmed the planet enough to delay the onset of the next glacial cycle for at least an additional 50,000 years.

The sun is the ultimate source of energy in Earth’s climate system, so it’s a natural candidate for causing climate change. And solar activity has certainly changed over time. We know from satellite measurements and other astronomical observations that the sun’s output changes on 11-year cycles. Geologic records and sunspot numbers, which astronomers have tracked for centuries, also show long-term variations in the sun’s activity, including some exceptionally quiet periods in the late 1600s and early 1800s.

We know that, from 1900 until the 1950s, solar irradiance increased. And studies suggest that this had a modest effect on early 20th century climate, explaining up to 10 percent of the warming that’s occurred since the late 1800s. However, in the second half of the century, when the most warming occurred, solar activity actually declined . This disparity is one of the main reasons we know that the sun is not the driving force behind climate change.

Another reason we know that solar activity hasn’t caused recent warming is that, if it had, all the layers of the atmosphere should be heating up. Instead, data show that the upper atmosphere has actually cooled in recent decades — a hallmark of greenhouse warming .

So how about volcanoes? Eruptions cool the planet by injecting ash and aerosol particles into the atmosphere that reflect sunlight. We’ve observed this effect in the years following large eruptions. There are also some notable historical examples, like when Iceland’s Laki volcano erupted in 1783, causing widespread crop failures in Europe and beyond, and the “ year without a summer ,” which followed the 1815 eruption of Mount Tambora in Indonesia.

Since volcanoes mainly act as climate coolers, they can’t really explain recent warming. However, scientists say that they may also have contributed slightly to rising temperatures in the early 20th century. That’s because there were several large eruptions in the late 1800s that cooled the planet, followed by a few decades with no major volcanic events when warming caught up. During the second half of the 20th century, though, several big eruptions occurred as the planet was heating up fast. If anything, they temporarily masked some amount of human-caused warming.

The second way volcanoes can impact climate is by emitting carbon dioxide. This is important on time scales of millions of years — it’s what keeps the planet habitable (see Question 5 for more on the greenhouse effect). But by comparison to modern anthropogenic emissions, even big eruptions like Krakatoa and Mount St. Helens are just a drop in the bucket. After all, they last only a few hours or days, while we burn fossil fuels 24-7. Studies suggest that, today, volcanoes account for 1 to 2 percent of total CO2 emissions.

When a big snowstorm hits the United States, climate denialists can try to cite it as proof that climate change isn’t happening. In 2015, Senator James Inhofe, an Oklahoma Republican, famously lobbed a snowball in the Senate as he denounced climate science. But these events don’t actually disprove climate change.

While there have been some memorable storms in recent years, winters are actually warming across the world. In the United States, average temperatures in December, January and February have increased by about 2.5 degrees this century.

On the flip side, record cold days are becoming less common than record warm days. In the United States, record highs now outnumber record lows two-to-one . And ever-smaller areas of the country experience extremely cold winter temperatures . (The same trends are happening globally.)

So what’s with the blizzards? Weather always varies, so it’s no surprise that we still have severe winter storms even as average temperatures rise. However, some studies suggest that climate change may be to blame. One possibility is that rapid Arctic warming has affected atmospheric circulation, including the fast-flowing, high-altitude air that usually swirls over the North Pole (a.k.a. the Polar Vortex ). Some studies suggest that these changes are bringing more frigid temperatures to lower latitudes and causing weather systems to stall , allowing storms to produce more snowfall. This may explain what we’ve experienced in the U.S. over the past few decades, as well as a wintertime cooling trend in Siberia , although exactly how the Arctic affects global weather remains a topic of ongoing scientific debate .

Climate change may also explain the apparent paradox behind some of the other places on Earth that haven’t warmed much. For instance, a splotch of water in the North Atlantic has cooled in recent years, and scientists say they suspect that may be because ocean circulation is slowing as a result of freshwater streaming off a melting Greenland . If this circulation grinds almost to a halt, as it’s done in the geologic past, it would alter weather patterns around the world.

Not all cold weather stems from some counterintuitive consequence of climate change. But it’s a good reminder that Earth’s climate system is complex and chaotic, so the effects of human-caused changes will play out differently in different places. That’s why “global warming” is a bit of an oversimplification. Instead, some scientists have suggested that the phenomenon of human-caused climate change would more aptly be called “ global weirding .”

Extreme weather and natural disasters are part of life on Earth — just ask the dinosaurs. But there is good evidence that climate change has increased the frequency and severity of certain phenomena like heat waves, droughts and floods. Recent research has also allowed scientists to identify the influence of climate change on specific events.

Let’s start with heat waves . Studies show that stretches of abnormally high temperatures now happen about five times more often than they would without climate change, and they last longer, too. Climate models project that, by the 2040s, heat waves will be about 12 times more frequent. And that’s concerning since extreme heat often causes increased hospitalizations and deaths, particularly among older people and those with underlying health conditions. In the summer of 2003, for example, a heat wave caused an estimated 70,000 excess deaths across Europe. (Human-caused warming amplified the death toll .)

Climate change has also exacerbated droughts , primarily by increasing evaporation. Droughts occur naturally because of random climate variability and factors like whether El Niño or La Niña conditions prevail in the tropical Pacific. But some researchers have found evidence that greenhouse warming has been affecting droughts since even before the Dust Bowl . And it continues to do so today. According to one analysis , the drought that afflicted the American Southwest from 2000 to 2018 was almost 50 percent more severe because of climate change. It was the worst drought the region had experienced in more than 1,000 years.

Rising temperatures have also increased the intensity of heavy precipitation events and the flooding that often follows. For example, studies have found that, because warmer air holds more moisture, Hurricane Harvey, which struck Houston in 2017, dropped between 15 and 40 percent more rainfall than it would have without climate change.

It’s still unclear whether climate change is changing the overall frequency of hurricanes, but it is making them stronger . And warming appears to favor certain kinds of weather patterns, like the “ Midwest Water Hose ” events that caused devastating flooding across the Midwest in 2019 .

It’s important to remember that in most natural disasters, there are multiple factors at play. For instance, the 2019 Midwest floods occurred after a recent cold snap had frozen the ground solid, preventing the soil from absorbing rainwater and increasing runoff into the Missouri and Mississippi Rivers. These waterways have also been reshaped by levees and other forms of river engineering, some of which failed in the floods.

Wildfires are another phenomenon with multiple causes. In many places, fire risk has increased because humans have aggressively fought natural fires and prevented Indigenous peoples from carrying out traditional burning practices. This has allowed fuel to accumulate that makes current fires worse .

However, climate change still plays a major role by heating and drying forests, turning them into tinderboxes. Studies show that warming is the driving factor behind the recent increases in wildfires; one analysis found that climate change is responsible for doubling the area burned across the American West between 1984 and 2015. And researchers say that warming will only make fires bigger and more dangerous in the future.

It depends on how aggressively we act to address climate change. If we continue with business as usual, by the end of the century, it will be too hot to go outside during heat waves in the Middle East and South Asia . Droughts will grip Central America, the Mediterranean and southern Africa. And many island nations and low-lying areas, from Texas to Bangladesh, will be overtaken by rising seas. Conversely, climate change could bring welcome warming and extended growing seasons to the upper Midwest , Canada, the Nordic countries and Russia . Farther north, however, the loss of snow, ice and permafrost will upend the traditions of Indigenous peoples and threaten infrastructure.

It’s complicated, but the underlying message is simple: unchecked climate change will likely exacerbate existing inequalities . At a national level, poorer countries will be hit hardest, even though they have historically emitted only a fraction of the greenhouse gases that cause warming. That’s because many less developed countries tend to be in tropical regions where additional warming will make the climate increasingly intolerable for humans and crops. These nations also often have greater vulnerabilities, like large coastal populations and people living in improvised housing that is easily damaged in storms. And they have fewer resources to adapt, which will require expensive measures like redesigning cities, engineering coastlines and changing how people grow food.

Already, between 1961 and 2000, climate change appears to have harmed the economies of the poorest countries while boosting the fortunes of the wealthiest nations that have done the most to cause the problem, making the global wealth gap 25 percent bigger than it would otherwise have been. Similarly, the Global Climate Risk Index found that lower income countries — like Myanmar, Haiti and Nepal — rank high on the list of nations most affected by extreme weather between 1999 and 2018. Climate change has also contributed to increased human migration, which is expected to increase significantly .

Even within wealthy countries, the poor and marginalized will suffer the most. People with more resources have greater buffers, like air-conditioners to keep their houses cool during dangerous heat waves, and the means to pay the resulting energy bills. They also have an easier time evacuating their homes before disasters, and recovering afterward. Lower income people have fewer of these advantages, and they are also more likely to live in hotter neighborhoods and work outdoors, where they face the brunt of climate change.

These inequalities will play out on an individual, community, and regional level. A 2017 analysis of the U.S. found that, under business as usual, the poorest one-third of counties, which are concentrated in the South, will experience damages totaling as much as 20 percent of gross domestic product, while others, mostly in the northern part of the country, will see modest economic gains. Solomon Hsiang, an economist at University of California, Berkeley, and the lead author of the study, has said that climate change “may result in the largest transfer of wealth from the poor to the rich in the country’s history.”

Even the climate “winners” will not be immune from all climate impacts, though. Desirable locations will face an influx of migrants. And as the coronavirus pandemic has demonstrated, disasters in one place quickly ripple across our globalized economy. For instance, scientists expect climate change to increase the odds of multiple crop failures occurring at the same time in different places, throwing the world into a food crisis .

On top of that, warmer weather is aiding the spread of infectious diseases and the vectors that transmit them, like ticks and mosquitoes . Research has also identified troubling correlations between rising temperatures and increased interpersonal violence , and climate change is widely recognized as a “threat multiplier” that increases the odds of larger conflicts within and between countries. In other words, climate change will bring many changes that no amount of money can stop. What could help is taking action to limit warming.

One of the most common arguments against taking aggressive action to combat climate change is that doing so will kill jobs and cripple the economy. But this implies that there’s an alternative in which we pay nothing for climate change. And unfortunately, there isn’t. In reality, not tackling climate change will cost a lot , and cause enormous human suffering and ecological damage, while transitioning to a greener economy would benefit many people and ecosystems around the world.

Let’s start with how much it will cost to address climate change. To keep warming well below 2 degrees Celsius, the goal of the Paris Climate Agreement, society will have to reach net zero greenhouse gas emissions by the middle of this century. That will require significant investments in things like renewable energy, electric cars and charging infrastructure, not to mention efforts to adapt to hotter temperatures, rising sea-levels and other unavoidable effects of current climate changes. And we’ll have to make changes fast.

Estimates of the cost vary widely. One recent study found that keeping warming to 2 degrees Celsius would require a total investment of between $4 trillion and $60 trillion, with a median estimate of $16 trillion, while keeping warming to 1.5 degrees Celsius could cost between $10 trillion and $100 trillion, with a median estimate of $30 trillion. (For reference, the entire world economy was about $88 trillion in 2019.) Other studies have found that reaching net zero will require annual investments ranging from less than 1.5 percent of global gross domestic product to as much as 4 percent . That’s a lot, but within the range of historical energy investments in countries like the U.S.

Now, let’s consider the costs of unchecked climate change, which will fall hardest on the most vulnerable. These include damage to property and infrastructure from sea-level rise and extreme weather, death and sickness linked to natural disasters, pollution and infectious disease, reduced agricultural yields and lost labor productivity because of rising temperatures, decreased water availability and increased energy costs, and species extinction and habitat destruction. Dr. Hsiang, the U.C. Berkeley economist, describes it as “death by a thousand cuts.”

As a result, climate damages are hard to quantify. Moody’s Analytics estimates that even 2 degrees Celsius of warming will cost the world $69 trillion by 2100, and economists expect the toll to keep rising with the temperature. In a recent survey , economists estimated the cost would equal 5 percent of global G.D.P. at 3 degrees Celsius of warming (our trajectory under current policies) and 10 percent for 5 degrees Celsius. Other research indicates that, if current warming trends continue, global G.D.P. per capita will decrease between 7 percent and 23 percent by the end of the century — an economic blow equivalent to multiple coronavirus pandemics every year. And some fear these are vast underestimates .

Already, studies suggest that climate change has slashed incomes in the poorest countries by as much as 30 percent and reduced global agricultural productivity by 21 percent since 1961. Extreme weather events have also racked up a large bill. In 2020, in the United States alone, climate-related disasters like hurricanes, droughts, and wildfires caused nearly $100 billion in damages to businesses, property and infrastructure, compared to an average of $18 billion per year in the 1980s.

Given the steep price of inaction, many economists say that addressing climate change is a better deal . It’s like that old saying: an ounce of prevention is worth a pound of cure. In this case, limiting warming will greatly reduce future damage and inequality caused by climate change. It will also produce so-called co-benefits, like saving one million lives every year by reducing air pollution, and millions more from eating healthier, climate-friendly diets. Some studies even find that meeting the Paris Agreement goals could create jobs and increase global G.D.P . And, of course, reining in climate change will spare many species and ecosystems upon which humans depend — and which many people believe to have their own innate value.

The challenge is that we need to reduce emissions now to avoid damages later, which requires big investments over the next few decades. And the longer we delay, the more we will pay to meet the Paris goals. One recent analysis found that reaching net-zero by 2050 would cost the U.S. almost twice as much if we waited until 2030 instead of acting now. But even if we miss the Paris target, the economics still make a strong case for climate action, because every additional degree of warming will cost us more — in dollars, and in lives.

Veronica Penney contributed reporting.

Illustration photographs by Esther Horvath, Max Whittaker, David Maurice Smith and Talia Herman for The New York Times; Esther Horvath/Alfred-Wegener-Institut

An earlier version of this article misidentified the authors of The Debunking Handbook. It was written by social scientists who study climate communication, not a team of climate scientists.

How we handle corrections

What’s Up in Space and Astronomy

Keep track of things going on in our solar system and all around the universe..

Never miss an eclipse, a meteor shower, a rocket launch or any other 2024 event  that’s out of this world with  our space and astronomy calendar .

A celestial image, an Impressionistic swirl of color in the center of the Milky Way, represents a first step toward understanding the role of magnetic fields  in the cycle of stellar death and rebirth.

Scientists may have discovered a major flaw in their understanding of dark energy, a mysterious cosmic force . That could be good news for the fate of the universe.

A new set of computer simulations, which take into account the effects of stars moving past our solar system, has effectively made it harder to predict Earth’s future and reconstruct its past.

Dante Lauretta, the planetary scientist who led the OSIRIS-REx mission to retrieve a handful of space dust , discusses his next final frontier.

Is Pluto a planet? And what is a planet, anyway? Test your knowledge here .

Advertisement

Quick links

• Climate change
• COVID-19 research
• Staff profiles

How has climate changed in the past?

There is a great deal of evidence that the Earth's climate has warmed over the past century, with recent years the warmest on record.

Earth's climate has warmed

Both natural and human influences have affected climate over the past century, but it is extremely likely that human activities have been the dominant cause of the observed warming since the mid-20th century.

The evidence that climate has changed over the past century includes temperature observations from around the world at the surface and from satellites, over land and sea. In addition, measurements of rainfall, sea levels, and ocean acidity and salinity show identify large scale changes.

Over time, these measurements give us a picture of how climate has changed, both in Australia and globally.

Global changes

Globally averaged air temperature at the Earth’s surface has warmed by 1.1 °C since reliable records began in 1850.

There is no record of temperature having increased as rapidly as it has over the past century.

Most of the hottest years on record have occurred in the 21st century. Worldwide, every year from 2013 onwards has been among the 10 warmest on record: 2016 and 2019 were the warmest years on record, followed by 2020, 2015, 2017 and 2018.

The heat content of the world's oceans has increased during recent decades and accounts for more than 90 per cent of the total heat accumulated by the land, air and ocean since the 1970s.

On a global scale, the ocean warming is largest near the surface, and the upper 75 m warmed by between 0.09°C and 0.13°C per decade over the period 1971–2010.

As well as temperatures increasing, global average sea levels have risen by around 25 cm since 1880, and there have been large-scale changes to climate, seasonal patterns such as the monsoon, and to the intensity and frequency of extreme weather events.

Changes in Australia

In Australia, land surface temperatures have been recorded at many sites since the mid to late 19th century.

By 1910, Australia had a reliable and standardised network of thermometers. The data they produced have been extensively analysed by the Bureau of Meteorology and scientists at CSIRO, Australian universities and international research institutions.

These high-quality temperature observations reveal that since 1910, Australia's climate has warmed by 1.44 °C (plus or minus 0.24 °C).

This long-term warming trend means that most years are now warmer than almost any year during the 20th century. Since the 1950s, each decade has been warmer than the one before.

We've also experienced an increase in record hot days and a decrease in record cold days across the country. For example, 2019 experienced 43 extremely warm days, more than triple the number in any of the years prior to 2000.

Some years have been relatively cool due to natural effects such as La Niña that partially offset the background warming trend, but overall the trend is clear and distinct: Australia has become warmer.

Rainfall has decreased by around 16 per cent in April to October in the southwest of Australia since 1970. In the southeast of Australia, there has been a decline of around 12 per cent in April to October rainfall since the late 1990s.

Rainfall has increased across most of northern Australia since the 1970s, with a general trend towards increased spring and summer monsoonal rainfall. There has been an increase in the intensity of heavy rainfall events in Australia.

Sea-surface temperatures around Australia have increased faster than the global average, warming by more than 1 °C since 1900, with 8 of the 10 warmest years on record occurring since 2010.

Useful links

• State of the Climate
• Climate Change in Australia
• Bureau of Meteorology Annual Climate Statement 2020

Find out how we can help you and your business. Get in touch using the form below and our experts will get in contact soon!

CSIRO will handle your personal information in accordance with the Privacy Act 1988 (Cth) and our Privacy Policy .

Enter a valid email address, for example [email protected]

A Country value must be provided

First name must be filled in

Surname must be filled in

Please choose an option

Organisation must be filled in

Please provide a subject for the enquriy

We'll need to know what you want to contact us about so we can give you an answer

We have received your enquiry and will reply soon.

We're Sorry

The contact form is currently unavailable. Please try again later. If this problem persists, please call us with your enquiry on 1300 363 400 or +61 3 9545 2176. We are available from 9.00 am to 4.00 pm AEST Monday - Friday.

25,000+ students realised their study abroad dream with us. Take the first step today

Here’s your new year gift, one app for all your, study abroad needs, start your journey, track your progress, grow with the community and so much more.

Verification Code

An OTP has been sent to your registered mobile no. Please verify

Thanks for your comment !

Our team will review it before it's shown to our readers.

Essay on Global Warming

• Updated on  
• Apr 27, 2024

Being able to write an essay is an integral part of mastering any language. Essays form an integral part of many academic and scholastic exams like the SAT , and UPSC amongst many others. It is a crucial evaluative part of English proficiency tests as well like IELTS , TOEFL , etc. Major essays are meant to emphasize public issues of concern that can have significant consequences on the world. To understand the concept of Global Warming and its causes and effects, we must first examine the many factors that influence the planet’s temperature and what this implies for the world’s future. Here’s an unbiased look at the essay on Global Warming and other essential related topics.

Short Essay on Global Warming and Climate Change?

Since the industrial and scientific revolutions, Earth’s resources have been gradually depleted. Furthermore, the start of the world’s population’s exponential expansion is particularly hard on the environment. Simply put, as the population’s need for consumption grows, so does the use of natural resources , as well as the waste generated by that consumption.

Climate change has been one of the most significant long-term consequences of this. Climate change is more than just the rise or fall of global temperatures; it also affects rain cycles, wind patterns, cyclone frequencies, sea levels, and other factors. It has an impact on all major life groupings on the planet.

Also Read: World Population Day

What is Global Warming?

Global warming is the unusually rapid increase in Earth’s average surface temperature over the past century, primarily due to the greenhouse gases released by people burning fossil fuels . The greenhouse gases consist of methane, nitrous oxide, ozone, carbon dioxide, water vapour, and chlorofluorocarbons. The weather prediction has been becoming more complex with every passing year, with seasons more indistinguishable, and the general temperatures hotter.

The number of hurricanes, cyclones, droughts, floods, etc., has risen steadily since the onset of the 21st century. The supervillain behind all these changes is Global Warming. The name is quite self-explanatory; it means the rise in the temperature of the Earth.

Also Read: What is a Natural Disaster?

What are the Causes of Global Warming?

According to recent studies, many scientists believe the following are the primary four causes of global warming:

• Deforestation 
• Greenhouse emissions
• Carbon emissions per capita

Extreme global warming is causing natural disasters , which can be seen all around us. One of the causes of global warming is the extreme release of greenhouse gases that become trapped on the earth’s surface, causing the temperature to rise. Similarly, volcanoes contribute to global warming by spewing excessive CO2 into the atmosphere.

The increase in population is one of the major causes of Global Warming. This increase in population also leads to increased air pollution . Automobiles emit a lot of CO2, which remains in the atmosphere. This increase in population is also causing deforestation, which contributes to global warming.

The earth’s surface emits energy into the atmosphere in the form of heat, keeping the balance with the incoming energy. Global warming depletes the ozone layer, bringing about the end of the world. There is a clear indication that increased global warming will result in the extinction of all life on Earth’s surface.

Also Read: Land, Soil, Water, Natural Vegetation, and Wildlife Resources

Solutions for Global Warming

Of course, industries and multinational conglomerates emit more carbon than the average citizen. Nonetheless, activism and community effort are the only viable ways to slow the worsening effects of global warming. Furthermore, at the state or government level, world leaders must develop concrete plans and step-by-step programmes to ensure that no further harm is done to the environment in general.

Although we are almost too late to slow the rate of global warming, finding the right solution is critical. Everyone, from individuals to governments, must work together to find a solution to Global Warming. Some of the factors to consider are pollution control, population growth, and the use of natural resources.

One very important contribution you can make is to reduce your use of plastic. Plastic is the primary cause of global warming, and recycling it takes years. Another factor to consider is deforestation, which will aid in the control of global warming. More tree planting should be encouraged to green the environment. Certain rules should also govern industrialization. Building industries in green zones that affect plants and species should be prohibited.

Also Read: Essay on Pollution

Effects of Global Warming

Global warming is a real problem that many people want to disprove to gain political advantage. However, as global citizens, we must ensure that only the truth is presented in the media.

This decade has seen a significant impact from global warming. The two most common phenomena observed are glacier retreat and arctic shrinkage. Glaciers are rapidly melting. These are clear manifestations of climate change.

Another significant effect of global warming is the rise in sea level. Flooding is occurring in low-lying areas as a result of sea-level rise. Many countries have experienced extreme weather conditions. Every year, we have unusually heavy rain, extreme heat and cold, wildfires, and other natural disasters.

Similarly, as global warming continues, marine life is being severely impacted. This is causing the extinction of marine species as well as other problems. Furthermore, changes are expected in coral reefs, which will face extinction in the coming years. These effects will intensify in the coming years, effectively halting species expansion. Furthermore, humans will eventually feel the negative effects of Global Warming.

Also Read: Concept of Sustainable Development

Sample Essays on Global Warming

Here are some sample essays on Global Warming:

Essay on Global Warming Paragraph in 100 – 150 words

Global Warming is caused by the increase of carbon dioxide levels in the earth’s atmosphere and is a result of human activities that have been causing harm to our environment for the past few centuries now. Global Warming is something that can’t be ignored and steps have to be taken to tackle the situation globally. The average temperature is constantly rising by 1.5 degrees Celsius over the last few years.

The best method to prevent future damage to the earth, cutting down more forests should be banned and Afforestation should be encouraged. Start by planting trees near your homes and offices, participate in events, and teach the importance of planting trees. It is impossible to undo the damage but it is possible to stop further harm.

Also Read: Social Forestry

Essay on Global Warming in 250 Words

Over a long period, it is observed that the temperature of the earth is increasing. This affected wildlife, animals, humans, and every living organism on earth. Glaciers have been melting, and many countries have started water shortages, flooding, and erosion and all this is because of global warming. 

No one can be blamed for global warming except for humans. Human activities such as gases released from power plants, transportation, and deforestation have increased gases such as carbon dioxide, CFCs, and other pollutants in the earth’s atmosphere.                                              The main question is how can we control the current situation and build a better world for future generations. It starts with little steps by every individual. 

Start using cloth bags made from sustainable materials for all shopping purposes, instead of using high-watt lights use energy-efficient bulbs, switch off the electricity, don’t waste water, abolish deforestation and encourage planting more trees. Shift the use of energy from petroleum or other fossil fuels to wind and solar energy. Instead of throwing out the old clothes donate them to someone so that it is recycled. 

Donate old books, don’t waste paper.  Above all, spread awareness about global warming. Every little thing a person does towards saving the earth will contribute in big or small amounts. We must learn that 1% effort is better than no effort. Pledge to take care of Mother Nature and speak up about global warming.

Also Read: Types of Water Pollution

Essay on Global Warming in 500 Words

Global warming isn’t a prediction, it is happening! A person denying it or unaware of it is in the most simple terms complicit. Do we have another planet to live on? Unfortunately, we have been bestowed with this one planet only that can sustain life yet over the years we have turned a blind eye to the plight it is in. Global warming is not an abstract concept but a global phenomenon occurring ever so slowly even at this moment. Global Warming is a phenomenon that is occurring every minute resulting in a gradual increase in the Earth’s overall climate. Brought about by greenhouse gases that trap the solar radiation in the atmosphere, global warming can change the entire map of the earth, displacing areas, flooding many countries, and destroying multiple lifeforms. Extreme weather is a direct consequence of global warming but it is not an exhaustive consequence. There are virtually limitless effects of global warming which are all harmful to life on earth. The sea level is increasing by 0.12 inches per year worldwide. This is happening because of the melting of polar ice caps because of global warming. This has increased the frequency of floods in many lowland areas and has caused damage to coral reefs. The Arctic is one of the worst-hit areas affected by global warming. Air quality has been adversely affected and the acidity of the seawater has also increased causing severe damage to marine life forms. Severe natural disasters are brought about by global warming which has had dire effects on life and property. As long as mankind produces greenhouse gases, global warming will continue to accelerate. The consequences are felt at a much smaller scale which will increase to become drastic shortly. The power to save the day lies in the hands of humans, the need is to seize the day. Energy consumption should be reduced on an individual basis. Fuel-efficient cars and other electronics should be encouraged to reduce the wastage of energy sources. This will also improve air quality and reduce the concentration of greenhouse gases in the atmosphere. Global warming is an evil that can only be defeated when fought together. It is better late than never. If we all take steps today, we will have a much brighter future tomorrow. Global warming is the bane of our existence and various policies have come up worldwide to fight it but that is not enough. The actual difference is made when we work at an individual level to fight it. Understanding its import now is crucial before it becomes an irrevocable mistake. Exterminating global warming is of utmost importance and each one of us is as responsible for it as the next.  

Also Read: Essay on Library: 100, 200 and 250 Words

Essay on Global Warming UPSC

Always hear about global warming everywhere, but do we know what it is? The evil of the worst form, global warming is a phenomenon that can affect life more fatally. Global warming refers to the increase in the earth’s temperature as a result of various human activities. The planet is gradually getting hotter and threatening the existence of lifeforms on it. Despite being relentlessly studied and researched, global warming for the majority of the population remains an abstract concept of science. It is this concept that over the years has culminated in making global warming a stark reality and not a concept covered in books. Global warming is not caused by one sole reason that can be curbed. Multifarious factors cause global warming most of which are a part of an individual’s daily existence. Burning of fuels for cooking, in vehicles, and for other conventional uses, a large amount of greenhouse gases like carbon dioxide, and methane amongst many others is produced which accelerates global warming. Rampant deforestation also results in global warming as lesser green cover results in an increased presence of carbon dioxide in the atmosphere which is a greenhouse gas.  Finding a solution to global warming is of immediate importance. Global warming is a phenomenon that has to be fought unitedly. Planting more trees can be the first step that can be taken toward warding off the severe consequences of global warming. Increasing the green cover will result in regulating the carbon cycle. There should be a shift from using nonrenewable energy to renewable energy such as wind or solar energy which causes less pollution and thereby hinder the acceleration of global warming. Reducing energy needs at an individual level and not wasting energy in any form is the most important step to be taken against global warming. The warning bells are tolling to awaken us from the deep slumber of complacency we have slipped into. Humans can fight against nature and it is high time we acknowledged that. With all our scientific progress and technological inventions, fighting off the negative effects of global warming is implausible. We have to remember that we do not inherit the earth from our ancestors but borrow it from our future generations and the responsibility lies on our shoulders to bequeath them a healthy planet for life to exist. 

Also Read: Essay on Disaster Management

Climate Change and Global Warming Essay

Global Warming and Climate Change are two sides of the same coin. Both are interrelated with each other and are two issues of major concern worldwide. Greenhouse gases released such as carbon dioxide, CFCs, and other pollutants in the earth’s atmosphere cause Global Warming which leads to climate change. Black holes have started to form in the ozone layer that protects the earth from harmful ultraviolet rays. 

Human activities have created climate change and global warming. Industrial waste and fumes are the major contributors to global warming. 

Another factor affecting is the burning of fossil fuels, deforestation and also one of the reasons for climate change.  Global warming has resulted in shrinking mountain glaciers in Antarctica, Greenland, and the Arctic and causing climate change. Switching from the use of fossil fuels to energy sources like wind and solar. 

When buying any electronic appliance buy the best quality with energy savings stars. Don’t waste water and encourage rainwater harvesting in your community. 

Also Read: Essay on Air Pollution

Tips to Write an Essay

Writing an effective essay needs skills that few people possess and even fewer know how to implement. While writing an essay can be an assiduous task that can be unnerving at times, some key pointers can be inculcated to draft a successful essay. These involve focusing on the structure of the essay, planning it out well, and emphasizing crucial details.

Mentioned below are some pointers that can help you write better structure and more thoughtful essays that will get across to your readers:

• Prepare an outline for the essay to ensure continuity and relevance and no break in the structure of the essay
• Decide on a thesis statement that will form the basis of your essay. It will be the point of your essay and help readers understand your contention
• Follow the structure of an introduction, a detailed body followed by a conclusion so that the readers can comprehend the essay in a particular manner without any dissonance.
• Make your beginning catchy and include solutions in your conclusion to make the essay insightful and lucrative to read
• Reread before putting it out and add your flair to the essay to make it more personal and thereby unique and intriguing for readers  

Also Read: I Love My India Essay: 100 and 500+ Words in English for School Students

Ans. Both natural and man-made factors contribute to global warming. The natural one also contains methane gas, volcanic eruptions, and greenhouse gases. Deforestation, mining, livestock raising, burning fossil fuels, and other man-made causes are next.

Ans. The government and the general public can work together to stop global warming. Trees must be planted more often, and deforestation must be prohibited. Auto usage needs to be curbed, and recycling needs to be promoted.

Ans. Switching to renewable energy sources , adopting sustainable farming, transportation, and energy methods, and conserving water and other natural resources.

Relevant Blogs

For more information on such interesting topics, visit our essay writing page and follow Leverage Edu.

Digvijay Singh

Having 2+ years of experience in educational content writing, withholding a Bachelor's in Physical Education and Sports Science and a strong interest in writing educational content for students enrolled in domestic and foreign study abroad programmes. I believe in offering a distinct viewpoint to the table, to help students deal with the complexities of both domestic and foreign educational systems. Through engaging storytelling and insightful analysis, I aim to inspire my readers to embark on their educational journeys, whether abroad or at home, and to make the most of every learning opportunity that comes their way.

Leave a Reply Cancel reply

Save my name, email, and website in this browser for the next time I comment.

Contact no. *

This was really a good essay on global warming… There has been used many unic words..and I really liked it!!!Seriously I had been looking for a essay about Global warming just like this…

Thank you for the comment!

I want to learn how to write essay writing so I joined this page.This page is very useful for everyone.

Hi, we are glad that we could help you to write essays. We have a beginner’s guide to write essays ( https://leverageedu.com/blog/essay-writing/ ) and we think this might help you.

It is not good , to have global warming in our earth .So we all have to afforestation program on all the world.

thank you so much

Very educative , helpful and it is really going to strength my English knowledge to structure my essay in future

Thank you for the comment, please follow our newsletter to get more insights on studying abroad and exams!

Global warming is the increase in 𝓽𝓱𝓮 ᴀᴠᴇʀᴀɢᴇ ᴛᴇᴍᴘᴇʀᴀᴛᴜʀᴇs ᴏғ ᴇᴀʀᴛʜ🌎 ᴀᴛᴍᴏsᴘʜᴇʀᴇ

Leaving already?

8 Universities with higher ROI than IITs and IIMs

Grab this one-time opportunity to download this ebook

Connect With Us

25,000+ students realised their study abroad dream with us. take the first step today..

Resend OTP in

Need help with?

Study abroad.

UK, Canada, US & More

IELTS, GRE, GMAT & More

Scholarship, Loans & Forex

Country Preference

New Zealand

Which English test are you planning to take?

Which academic test are you planning to take.

Not Sure yet

When are you planning to take the exam?

Already booked my exam slot

Within 2 Months

Want to learn about the test

Which Degree do you wish to pursue?

When do you want to start studying abroad.

September 2024

January 2025

What is your budget to study abroad?

How would you describe this article ?

Please rate this article

We would like to hear more.

What evidence exists that Earth is warming and that humans are the main cause?

We know the world is warming because people have been recording daily high and low temperatures at thousands of weather stations worldwide, over land and ocean, for many decades and, in some locations, for more than a century. When different teams of climate scientists in different agencies (e.g., NOAA and NASA) and in other countries (e.g., the U.K.’s Hadley Centre) average these data together, they all find essentially the same result: Earth’s average surface temperature has risen by about 1.8°F (1.0°C) since 1880. 

Yearly temperature compared to the twentieth-century average (red bars mean warmer than average, blue bars mean colder than average) from 1850–2022 and atmospheric carbon dioxide amounts (gray line): 1850-1958 from IAC , 1959-2019 from NOAA ESRL . Original graph by Dr. Howard Diamond (NOAA ARL), and adapted by NOAA Climate.gov.

In addition to our surface station data, we have many different lines of evidence that Earth is warming ( learn more ). Birds are migrating earlier, and their migration patterns are changing.  Lobsters  and  other marine species  are moving north. Plants are blooming earlier in the spring. Mountain glaciers are melting worldwide, and snow cover is declining in the Northern Hemisphere (Learn more  here  and  here ). Greenland’s ice sheet—which holds about 8 percent of Earth’s fresh water—is melting at an accelerating rate ( learn more ). Mean global sea level is rising ( learn more ). Arctic sea ice is declining rapidly in both thickness and extent ( learn more ).

The Greenland Ice Sheet lost mass again in 2020, but not as much as it did 2019. Adapted from the 2020 Arctic Report Card, this graph tracks Greenland mass loss measured by NASA's GRACE satellite missions since 2002. The background photo shows a glacier calving front in western Greenland, captured from an airplane during a NASA Operation IceBridge field campaign. Full story.

We know this warming is largely caused by human activities because the key role that carbon dioxide plays in maintaining Earth’s natural greenhouse effect has been understood since the mid-1800s. Unless it is offset by some equally large cooling influence, more atmospheric carbon dioxide will lead to warmer surface temperatures. Since 1800, the amount of carbon dioxide in the atmosphere  has increased  from about 280 parts per million to 410 ppm in 2019. We know from both its rapid increase and its isotopic “fingerprint” that the source of this new carbon dioxide is fossil fuels, and not natural sources like forest fires, volcanoes, or outgassing from the ocean.

Philip James de Loutherbourg's 1801 painting, Coalbrookdale by Night , came to symbolize the start of the Industrial Revolution, when humans began to harness the power of fossil fuels—and to contribute significantly to Earth's atmospheric greenhouse gas composition. Image from Wikipedia .

Finally, no other known climate influences have changed enough to account for the observed warming trend. Taken together, these and other lines of evidence point squarely to human activities as the cause of recent global warming.

USGCRP (2017). Climate Science Special Report: Fourth National Climate Assessment, Volume 1 [Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, 470 pp, doi:  10.7930/J0J964J6 .

National Fish, Wildlife, and Plants Climate Adaptation Partnership (2012):  National Fish, Wildlife, and Plants Climate Adaptation Strategy . Association of Fish and Wildlife Agencies, Council on Environmental Quality, Great Lakes Indian Fish and Wildlife Commission, National Oceanic and Atmospheric Administration, and U.S. Fish and Wildlife Service. Washington, D.C. DOI: 10.3996/082012-FWSReport-1

IPCC (2019). Summary for Policymakers. In: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate. [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. In press.

NASA JPL: "Consensus: 97% of climate scientists agree."  Global Climate Change . A website at NASA's Jet Propulsion Laboratory (climate.nasa.gov/scientific-consensus). (Accessed July 2013.)

We value your feedback

Help us improve our content

Related Content

News & features, 2017 state of the climate: mountain glaciers, warming waters shift fish communities northward in the arctic, climate & fish sticks, maps & data, past climate, land - terrestrial climate variables, future climate, teaching climate, toolbox for teaching climate & energy, student climate & conservation congress (sc3), climate youth engagement, climate resilience toolkit, arctic oceans, sea ice, and coasts, alaska and the arctic, agriculture and ecosystems.

• Climate modelling
• Extreme weather
• Health and Security
• Temperature
• China energy
• Oil and gas
• Other technologies
• China Policy
• International policy
• Other national policy
• Rest of world policy
• UN climate talks
• Country profiles
• Guest posts
• Infographics
• Media analysis
• State of the climate
• Translations
• Daily Brief
• China Briefing
• Comments Policy
• Cookies Policy
• Global emissions
• Rest of world emissions
• UK emissions
• EU emissions
• Global South Climate Database
• Newsletters
• COP21 Paris
• COP22 Marrakech
• COP24 Katowice
• COP25 Madrid
• COP26 Glasgow
• COP27 Sharm el-Sheikh
• COP28 Dubai
• Privacy Policy
• Attribution
• Geoengineering
• Food and farming
• Plants and forests
• Marine life
• Ocean acidification
• Ocean warming
• Sea level rise
• Human security
• Public health
• Public opinion
• Risk and adaptation
• Science communication
• Carbon budgets
• Climate sensitivity
• GHGs and aerosols
• Global temperature
• Negative emissions
• Rest of world temperature
• Tipping points
• UK temperature
• Thank you for subscribing

Social Channels

Search archive.

Receive a Daily or Weekly summary of the most important articles direct to your inbox, just enter your email below. By entering your email address you agree for your data to be handled in accordance with our Privacy Policy .

• Factcheck: Why the recent ‘acceleration’ in global warming is what scientists expect

Zeke Hausfather

Over the past year, there has been a vigorous debate among scientists – and more broadly – about whether global warming is “accelerating”.

This, in turn, has led to questions about whether the world is warming “ faster than scientists expected ”.

Here, Carbon Brief takes a detailed look at the issue and finds that there is increasing evidence of an acceleration in the rate of warming over the past 15 years. 

However, this acceleration is broadly in line with projections from the latest generation of climate models and the recent sixth assessment report (AR6) from the Intergovernmental Panel on Climate Change (IPCC). They all expect the world to warm notably faster in both current and future decades than the rate the world has experienced since 1970.

Carbon Brief’s analysis also reveals that the speed up in warming projected in the latest climate models (known as CMIP6 ) is similar to the acceleration estimated by prominent climate scientist Dr James Hansen and colleagues in their much-discussed 2023 paper in Oxford Open Climate Change . 

The IPCC’s AR6 also produced a set of “ assessed warming projections ” that incorporate multiple lines of evidence . While these project future warming levels a bit below the average of CMIP6 models, they still expect the rate of warming up to 2050 to be around 26% faster than the world has experienced to date since 1970.

Even with an apparent acceleration in recent warming, there remain major questions regarding drivers of 2023’s record-breaking heat relative to 2022, though annual temperatures still remain well within the range of climate-model projections.

An accelerating debate

Between 1970 and 2008, the world warmed at an approximately linear rate – by 0.18C per decade. 

However, in recent years, the rise in global surface temperatures has climbed above this long-term trend, with eight of the past nine years showing warming levels above what would be expected given the historical warming rate. 

In December 2022, former NASA scientist Dr James Hansen and colleagues published a preprint (later published as a peer-reviewed paper in 2023 ) projecting an acceleration in the rate of warming over the next few decades. Hansen and colleagues argued that the rate of warming would increase to between 0.27C and 0.36C per decade – or a 50-to-100% increase in the warming rate since 1970 – over the next 30 years.

These projections – coupled with the exceptional and unusual temperatures in 2023 – has fuelled a debate within the scientific community and among the broader public about a potential acceleration in warming in recent years.

This potential acceleration is illustrated in the figure below, which shows a composite of global surface temperatures from five different groups –  NASA GISTEMP , NOAA’s GlobalTemp , the UK Met Office/University of East Anglia’s HadCRUT5 , Berkeley Earth and Copernicus’ ERA5 – following an approach used by the World Meteorological Organization .

The circles indicate individual years and the dashed lines show the trend over 1970-2008 (blue) and 2009-23 (red). (The past 15 years are highlighted here as that is the time period that has previously been used to assess potential changes in the underlying trend in the scientific literature.)

The chart shows how the warming rate of 0.18C per decade seen since 1970 has almost doubled to roughly 0.3C per decade over the past 15 years. 

Researchers have proposed a number of potential contributors to the increased rate of warming seen in recent years.

One is the significant decline in global air pollution over the past few decades, as well as a 2020 phase-out of sulphur in marine fuels, which have reduced the levels of cooling aerosols in the atmosphere.

Other suggested factors include an approaching peak in the 11-year solar cycle, the 2022 eruption of the Hunga Tonga volcano and the continued increases in atmospheric greenhouse gas concentrations. 

The fact that the past 15 years ended on a particularly high point due to the current El Niño event might also result in higher warming rates – although the contribution of El Niño to overall 2023 temperatures remains an area of vigorous scientific debate .

It is possible to remove the estimated influence of some of the natural factors – such as El Niño and La Niña events, volcanic eruptions and variations in solar output – from the global temperature record. 

The figure below shows a version of the temperature record above where these natural factors are removed. The recent warming (red dashed line) is even more evident in this chart compared to the prior trend (blue).

However, despite this spate of very warm years, it is challenging to draw firm conclusions on the overall rate of global warming based on a time period as short as 15 years. 

Even though recent trends appear to show significant acceleration, the long-term trend remains – just barely – within the full range of uncertainty in climate model projections. 

There is a risk of conflating shorter-term climate variability with longer-term changes – a pitfall that the climate science community has encountered before. 

Parallels with the warming ‘hiatus’

The debate around a potential acceleration in warming shares similarities with another scientific contretemps – the so-called “ hiatus ” in warming of the early 21st century.

During the 15-year period from 1998 to 2012, the rate of warming at the surface appeared to nearly “pause” – or at least slow down dramatically compared to climate-model projections. 

The debate so consumed the scientific community – and some sections of the media – that there was a running joke among scientists that the journal Nature Climate Change should be renamed “Nature Hiatus” for the number of studies it published trying to explain the apparent slowdown.

In retrospect, the apparent hiatus and associated disagreement between climate models and observations was caused by a number of different factors. Key among them were natural variability (in the form of more heat uptake by the oceans), disparities in surface temperature records associated with a transition from ship engine room to automated buoy-based measurements of sea surface temperatures, and incomplete comparisons between climate models and observations that excluded areas such as the Arctic that had sparser observational coverage.

With the development of the 2015-16 “super” El Niño, any sign of a “pause” in warming quickly vanished and the argument faded away – though it made a brief return in climate-sceptic circles in more recent years. However, it left behind a lasting appreciation among many scientists for the danger of overinterpreting short-term climate variability and is one of the reasons why there has been reticence in some circles about current claims of an acceleration.

Nonetheless, there are a number of reasons to expect that what the world is currently experiencing is not just the influence of natural variability on top of human-caused warming . An acceleration of warming in recent decades also shows up in ocean heat content and in satellite measurements of the Earth’s energy imbalance .   

And, perhaps most importantly, an acceleration in the rate of warming in recent years – and over the coming decades – is exactly what is seen in climate models under a scenario in keeping with current global policies (known as SSP2-4.5 ). Under this scenario, greenhouse gas emissions remain around current levels until the middle of the century, alongside a decline in emissions of planet-cooling aerosols such as sulphur dioxide .

An expected acceleration

The most notable thing about the current apparent acceleration in warming is that it was expected.

Climate models have long shown a faster rate of warming in current and future decades than has been observed to date, though there is some disagreement among modelling estimates. 

The table below shows a compilation of both observed rates of warming to date and different model projections out to 2050. 

Global surface temperatures have warmed at a rate of 0.19C per decade between 1970 and 2023. They have warmed at a faster rate (~0.3C per decade) over the past 15 years – though with large uncertainties of 0.17C to 0.43C given the shorter time period.

The estimated human contribution to global warming of 0.23C for the past decade (2013 to 2022), as published in Earth System Science Data by Prof Piers Forster and colleagues, is based on a climate model emulator that is driven by an updated estimate of factors including the influence of greenhouse gases and aerosols on the Earth’s climate in recent years.

The IPCC’s AR6 provided “assessed warming projections” based on CMIP6 models – weighted based on their ability to accurately reproduce historical temperatures – and the recent synthesis of climate sensitivity estimates. These assessed warming projections show 0.24C warming per decade between 2015 and 2050 with an uncertainty range of 0.17C to 0.34C in the current-policy-type SSP2-4.5 scenario. This represents approximately 26% faster warming than the world has experienced since 1970.

The full CMIP6 ensemble of models has notably more warming than the IPCC-assessed warming projections. CMIP6 models, on average, warm by 0.29C per decade with a range of 0.2C to 0.4C, or 53% faster than historical warming since 1970.

The recent projections by Dr James Hansen and colleagues has a very similar projection of future warming rates to the CMIP6 ensemble, estimating warming of around 0.32C per decade with an uncertainty of 0.27C to 0.36C.

These estimates are summarised in the charts below, which show the historical warming rate (top left), the AR6 assessed range under SSP2-4.5 (top right), the CMIP6 models under SSP2-4.5 (bottom left) and Hansen et al’s future warming projection (bottom right). The blue dots and red dashed lines show observed data and the long-term trend, while the black lines and yellow shading show the average of model projections and their ranges.

In all three cases, there is an expectation of acceleration of warming both at present and in coming decades compared to the warming the world has experienced since 1970. 

However, this does not mean that the world will pass climate limits such as 1.5C sooner than expected. The current best estimates of when these thresholds will be passed are based on climate models that include the near-term warming acceleration.

The apparent acceleration of warming in recent years is well in line with climate model projections, which lends confidence that what the world is experiencing is a result of human activity rather than a result of natural variability.

However, this does not mean that the world will not experience cool years in the future; the next La Niña year – likely in 2025 – will probably end up well below some of the prior record-setting years. 

But, as long as global emissions of CO2 and other greenhouse gases fail to decline and the world continues to tackle aerosol pollution, the world will likely warm faster than experienced in the past.

Factcheck: 18 misleading myths about heat pumps

Factcheck: 21 misleading myths about electric vehicles

Factcheck: Scientists pour cold water on claims of ‘journal bias’ by author of wildfires study

Factcheck: Why fracking is not the answer to the UK’s energy crisis

Expert analysis direct to your inbox.

Get a round-up of all the important articles and papers selected by Carbon Brief by email. Find out more about our newsletters here .

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

• View all journals
• My Account Login
• Explore content
• About the journal
• Publish with us
• Sign up for alerts
• Open access
• Published: 17 April 2024

The economic commitment of climate change

• Maximilian Kotz   ORCID: orcid.org/0000-0003-2564-5043 1 , 2 ,
• Anders Levermann   ORCID: orcid.org/0000-0003-4432-4704 1 , 2 &
• Leonie Wenz   ORCID: orcid.org/0000-0002-8500-1568 1 , 3  

Nature volume  628 ,  pages 551–557 ( 2024 ) Cite this article

89k Accesses

3471 Altmetric

Metrics details

• Environmental economics
• Environmental health
• Interdisciplinary studies
• Projection and prediction

Global projections of macroeconomic climate-change damages typically consider impacts from average annual and national temperatures over long time horizons 1 , 2 , 3 , 4 , 5 , 6 . Here we use recent empirical findings from more than 1,600 regions worldwide over the past 40 years to project sub-national damages from temperature and precipitation, including daily variability and extremes 7 , 8 . Using an empirical approach that provides a robust lower bound on the persistence of impacts on economic growth, we find that the world economy is committed to an income reduction of 19% within the next 26 years independent of future emission choices (relative to a baseline without climate impacts, likely range of 11–29% accounting for physical climate and empirical uncertainty). These damages already outweigh the mitigation costs required to limit global warming to 2 °C by sixfold over this near-term time frame and thereafter diverge strongly dependent on emission choices. Committed damages arise predominantly through changes in average temperature, but accounting for further climatic components raises estimates by approximately 50% and leads to stronger regional heterogeneity. Committed losses are projected for all regions except those at very high latitudes, at which reductions in temperature variability bring benefits. The largest losses are committed at lower latitudes in regions with lower cumulative historical emissions and lower present-day income.

Similar content being viewed by others

Climate damage projections beyond annual temperature

Investment incentive reduced by climate damages can be restored by optimal policy

Climate economics support for the UN climate targets

Projections of the macroeconomic damage caused by future climate change are crucial to informing public and policy debates about adaptation, mitigation and climate justice. On the one hand, adaptation against climate impacts must be justified and planned on the basis of an understanding of their future magnitude and spatial distribution 9 . This is also of importance in the context of climate justice 10 , as well as to key societal actors, including governments, central banks and private businesses, which increasingly require the inclusion of climate risks in their macroeconomic forecasts to aid adaptive decision-making 11 , 12 . On the other hand, climate mitigation policy such as the Paris Climate Agreement is often evaluated by balancing the costs of its implementation against the benefits of avoiding projected physical damages. This evaluation occurs both formally through cost–benefit analyses 1 , 4 , 5 , 6 , as well as informally through public perception of mitigation and damage costs 13 .

Projections of future damages meet challenges when informing these debates, in particular the human biases relating to uncertainty and remoteness that are raised by long-term perspectives 14 . Here we aim to overcome such challenges by assessing the extent of economic damages from climate change to which the world is already committed by historical emissions and socio-economic inertia (the range of future emission scenarios that are considered socio-economically plausible 15 ). Such a focus on the near term limits the large uncertainties about diverging future emission trajectories, the resulting long-term climate response and the validity of applying historically observed climate–economic relations over long timescales during which socio-technical conditions may change considerably. As such, this focus aims to simplify the communication and maximize the credibility of projected economic damages from future climate change.

In projecting the future economic damages from climate change, we make use of recent advances in climate econometrics that provide evidence for impacts on sub-national economic growth from numerous components of the distribution of daily temperature and precipitation 3 , 7 , 8 . Using fixed-effects panel regression models to control for potential confounders, these studies exploit within-region variation in local temperature and precipitation in a panel of more than 1,600 regions worldwide, comprising climate and income data over the past 40 years, to identify the plausibly causal effects of changes in several climate variables on economic productivity 16 , 17 . Specifically, macroeconomic impacts have been identified from changing daily temperature variability, total annual precipitation, the annual number of wet days and extreme daily rainfall that occur in addition to those already identified from changing average temperature 2 , 3 , 18 . Moreover, regional heterogeneity in these effects based on the prevailing local climatic conditions has been found using interactions terms. The selection of these climate variables follows micro-level evidence for mechanisms related to the impacts of average temperatures on labour and agricultural productivity 2 , of temperature variability on agricultural productivity and health 7 , as well as of precipitation on agricultural productivity, labour outcomes and flood damages 8 (see Extended Data Table 1 for an overview, including more detailed references). References  7 , 8 contain a more detailed motivation for the use of these particular climate variables and provide extensive empirical tests about the robustness and nature of their effects on economic output, which are summarized in Methods . By accounting for these extra climatic variables at the sub-national level, we aim for a more comprehensive description of climate impacts with greater detail across both time and space.

Constraining the persistence of impacts

A key determinant and source of discrepancy in estimates of the magnitude of future climate damages is the extent to which the impact of a climate variable on economic growth rates persists. The two extreme cases in which these impacts persist indefinitely or only instantaneously are commonly referred to as growth or level effects 19 , 20 (see Methods section ‘Empirical model specification: fixed-effects distributed lag models’ for mathematical definitions). Recent work shows that future damages from climate change depend strongly on whether growth or level effects are assumed 20 . Following refs.  2 , 18 , we provide constraints on this persistence by using distributed lag models to test the significance of delayed effects separately for each climate variable. Notably, and in contrast to refs.  2 , 18 , we use climate variables in their first-differenced form following ref.  3 , implying a dependence of the growth rate on a change in climate variables. This choice means that a baseline specification without any lags constitutes a model prior of purely level effects, in which a permanent change in the climate has only an instantaneous effect on the growth rate 3 , 19 , 21 . By including lags, one can then test whether any effects may persist further. This is in contrast to the specification used by refs.  2 , 18 , in which climate variables are used without taking the first difference, implying a dependence of the growth rate on the level of climate variables. In this alternative case, the baseline specification without any lags constitutes a model prior of pure growth effects, in which a change in climate has an infinitely persistent effect on the growth rate. Consequently, including further lags in this alternative case tests whether the initial growth impact is recovered 18 , 19 , 21 . Both of these specifications suffer from the limiting possibility that, if too few lags are included, one might falsely accept the model prior. The limitations of including a very large number of lags, including loss of data and increasing statistical uncertainty with an increasing number of parameters, mean that such a possibility is likely. By choosing a specification in which the model prior is one of level effects, our approach is therefore conservative by design, avoiding assumptions of infinite persistence of climate impacts on growth and instead providing a lower bound on this persistence based on what is observable empirically (see Methods section ‘Empirical model specification: fixed-effects distributed lag models’ for further exposition of this framework). The conservative nature of such a choice is probably the reason that ref.  19 finds much greater consistency between the impacts projected by models that use the first difference of climate variables, as opposed to their levels.

We begin our empirical analysis of the persistence of climate impacts on growth using ten lags of the first-differenced climate variables in fixed-effects distributed lag models. We detect substantial effects on economic growth at time lags of up to approximately 8–10 years for the temperature terms and up to approximately 4 years for the precipitation terms (Extended Data Fig. 1 and Extended Data Table 2 ). Furthermore, evaluation by means of information criteria indicates that the inclusion of all five climate variables and the use of these numbers of lags provide a preferable trade-off between best-fitting the data and including further terms that could cause overfitting, in comparison with model specifications excluding climate variables or including more or fewer lags (Extended Data Fig. 3 , Supplementary Methods Section  1 and Supplementary Table 1 ). We therefore remove statistically insignificant terms at later lags (Supplementary Figs. 1 – 3 and Supplementary Tables 2 – 4 ). Further tests using Monte Carlo simulations demonstrate that the empirical models are robust to autocorrelation in the lagged climate variables (Supplementary Methods Section  2 and Supplementary Figs. 4 and 5 ), that information criteria provide an effective indicator for lag selection (Supplementary Methods Section  2 and Supplementary Fig. 6 ), that the results are robust to concerns of imperfect multicollinearity between climate variables and that including several climate variables is actually necessary to isolate their separate effects (Supplementary Methods Section  3 and Supplementary Fig. 7 ). We provide a further robustness check using a restricted distributed lag model to limit oscillations in the lagged parameter estimates that may result from autocorrelation, finding that it provides similar estimates of cumulative marginal effects to the unrestricted model (Supplementary Methods Section 4 and Supplementary Figs. 8 and 9 ). Finally, to explicitly account for any outstanding uncertainty arising from the precise choice of the number of lags, we include empirical models with marginally different numbers of lags in the error-sampling procedure of our projection of future damages. On the basis of the lag-selection procedure (the significance of lagged terms in Extended Data Fig. 1 and Extended Data Table 2 , as well as information criteria in Extended Data Fig. 3 ), we sample from models with eight to ten lags for temperature and four for precipitation (models shown in Supplementary Figs. 1 – 3 and Supplementary Tables 2 – 4 ). In summary, this empirical approach to constrain the persistence of climate impacts on economic growth rates is conservative by design in avoiding assumptions of infinite persistence, but nevertheless provides a lower bound on the extent of impact persistence that is robust to the numerous tests outlined above.

Committed damages until mid-century

We combine these empirical economic response functions (Supplementary Figs. 1 – 3 and Supplementary Tables 2 – 4 ) with an ensemble of 21 climate models (see Supplementary Table 5 ) from the Coupled Model Intercomparison Project Phase 6 (CMIP-6) 22 to project the macroeconomic damages from these components of physical climate change (see Methods for further details). Bias-adjusted climate models that provide a highly accurate reproduction of observed climatological patterns with limited uncertainty (Supplementary Table 6 ) are used to avoid introducing biases in the projections. Following a well-developed literature 2 , 3 , 19 , these projections do not aim to provide a prediction of future economic growth. Instead, they are a projection of the exogenous impact of future climate conditions on the economy relative to the baselines specified by socio-economic projections, based on the plausibly causal relationships inferred by the empirical models and assuming ceteris paribus. Other exogenous factors relevant for the prediction of economic output are purposefully assumed constant.

A Monte Carlo procedure that samples from climate model projections, empirical models with different numbers of lags and model parameter estimates (obtained by 1,000 block-bootstrap resamples of each of the regressions in Supplementary Figs. 1 – 3 and Supplementary Tables 2 – 4 ) is used to estimate the combined uncertainty from these sources. Given these uncertainty distributions, we find that projected global damages are statistically indistinguishable across the two most extreme emission scenarios until 2049 (at the 5% significance level; Fig. 1 ). As such, the climate damages occurring before this time constitute those to which the world is already committed owing to the combination of past emissions and the range of future emission scenarios that are considered socio-economically plausible 15 . These committed damages comprise a permanent income reduction of 19% on average globally (population-weighted average) in comparison with a baseline without climate-change impacts (with a likely range of 11–29%, following the likelihood classification adopted by the Intergovernmental Panel on Climate Change (IPCC); see caption of Fig. 1 ). Even though levels of income per capita generally still increase relative to those of today, this constitutes a permanent income reduction for most regions, including North America and Europe (each with median income reductions of approximately 11%) and with South Asia and Africa being the most strongly affected (each with median income reductions of approximately 22%; Fig. 1 ). Under a middle-of-the road scenario of future income development (SSP2, in which SSP stands for Shared Socio-economic Pathway), this corresponds to global annual damages in 2049 of 38 trillion in 2005 international dollars (likely range of 19–59 trillion 2005 international dollars). Compared with empirical specifications that assume pure growth or pure level effects, our preferred specification that provides a robust lower bound on the extent of climate impact persistence produces damages between these two extreme assumptions (Extended Data Fig. 3 ).

Estimates of the projected reduction in income per capita from changes in all climate variables based on empirical models of climate impacts on economic output with a robust lower bound on their persistence (Extended Data Fig. 1 ) under a low-emission scenario compatible with the 2 °C warming target and a high-emission scenario (SSP2-RCP2.6 and SSP5-RCP8.5, respectively) are shown in purple and orange, respectively. Shading represents the 34% and 10% confidence intervals reflecting the likely and very likely ranges, respectively (following the likelihood classification adopted by the IPCC), having estimated uncertainty from a Monte Carlo procedure, which samples the uncertainty from the choice of physical climate models, empirical models with different numbers of lags and bootstrapped estimates of the regression parameters shown in Supplementary Figs. 1 – 3 . Vertical dashed lines show the time at which the climate damages of the two emission scenarios diverge at the 5% and 1% significance levels based on the distribution of differences between emission scenarios arising from the uncertainty sampling discussed above. Note that uncertainty in the difference of the two scenarios is smaller than the combined uncertainty of the two respective scenarios because samples of the uncertainty (climate model and empirical model choice, as well as model parameter bootstrap) are consistent across the two emission scenarios, hence the divergence of damages occurs while the uncertainty bounds of the two separate damage scenarios still overlap. Estimates of global mitigation costs from the three IAMs that provide results for the SSP2 baseline and SSP2-RCP2.6 scenario are shown in light green in the top panel, with the median of these estimates shown in bold.

Damages already outweigh mitigation costs

We compare the damages to which the world is committed over the next 25 years to estimates of the mitigation costs required to achieve the Paris Climate Agreement. Taking estimates of mitigation costs from the three integrated assessment models (IAMs) in the IPCC AR6 database 23 that provide results under comparable scenarios (SSP2 baseline and SSP2-RCP2.6, in which RCP stands for Representative Concentration Pathway), we find that the median committed climate damages are larger than the median mitigation costs in 2050 (six trillion in 2005 international dollars) by a factor of approximately six (note that estimates of mitigation costs are only provided every 10 years by the IAMs and so a comparison in 2049 is not possible). This comparison simply aims to compare the magnitude of future damages against mitigation costs, rather than to conduct a formal cost–benefit analysis of transitioning from one emission path to another. Formal cost–benefit analyses typically find that the net benefits of mitigation only emerge after 2050 (ref.  5 ), which may lead some to conclude that physical damages from climate change are simply not large enough to outweigh mitigation costs until the second half of the century. Our simple comparison of their magnitudes makes clear that damages are actually already considerably larger than mitigation costs and the delayed emergence of net mitigation benefits results primarily from the fact that damages across different emission paths are indistinguishable until mid-century (Fig. 1 ).

Although these near-term damages constitute those to which the world is already committed, we note that damage estimates diverge strongly across emission scenarios after 2049, conveying the clear benefits of mitigation from a purely economic point of view that have been emphasized in previous studies 4 , 24 . As well as the uncertainties assessed in Fig. 1 , these conclusions are robust to structural choices, such as the timescale with which changes in the moderating variables of the empirical models are estimated (Supplementary Figs. 10 and 11 ), as well as the order in which one accounts for the intertemporal and international components of currency comparison (Supplementary Fig. 12 ; see Methods for further details).

Damages from variability and extremes

Committed damages primarily arise through changes in average temperature (Fig. 2 ). This reflects the fact that projected changes in average temperature are larger than those in other climate variables when expressed as a function of their historical interannual variability (Extended Data Fig. 4 ). Because the historical variability is that on which the empirical models are estimated, larger projected changes in comparison with this variability probably lead to larger future impacts in a purely statistical sense. From a mechanistic perspective, one may plausibly interpret this result as implying that future changes in average temperature are the most unprecedented from the perspective of the historical fluctuations to which the economy is accustomed and therefore will cause the most damage. This insight may prove useful in terms of guiding adaptation measures to the sources of greatest damage.

Estimates of the median projected reduction in sub-national income per capita across emission scenarios (SSP2-RCP2.6 and SSP2-RCP8.5) as well as climate model, empirical model and model parameter uncertainty in the year in which climate damages diverge at the 5% level (2049, as identified in Fig. 1 ). a , Impacts arising from all climate variables. b – f , Impacts arising separately from changes in annual mean temperature ( b ), daily temperature variability ( c ), total annual precipitation ( d ), the annual number of wet days (>1 mm) ( e ) and extreme daily rainfall ( f ) (see Methods for further definitions). Data on national administrative boundaries are obtained from the GADM database version 3.6 and are freely available for academic use ( https://gadm.org/ ).

Nevertheless, future damages based on empirical models that consider changes in annual average temperature only and exclude the other climate variables constitute income reductions of only 13% in 2049 (Extended Data Fig. 5a , likely range 5–21%). This suggests that accounting for the other components of the distribution of temperature and precipitation raises net damages by nearly 50%. This increase arises through the further damages that these climatic components cause, but also because their inclusion reveals a stronger negative economic response to average temperatures (Extended Data Fig. 5b ). The latter finding is consistent with our Monte Carlo simulations, which suggest that the magnitude of the effect of average temperature on economic growth is underestimated unless accounting for the impacts of other correlated climate variables (Supplementary Fig. 7 ).

In terms of the relative contributions of the different climatic components to overall damages, we find that accounting for daily temperature variability causes the largest increase in overall damages relative to empirical frameworks that only consider changes in annual average temperature (4.9 percentage points, likely range 2.4–8.7 percentage points, equivalent to approximately 10 trillion international dollars). Accounting for precipitation causes smaller increases in overall damages, which are—nevertheless—equivalent to approximately 1.2 trillion international dollars: 0.01 percentage points (−0.37–0.33 percentage points), 0.34 percentage points (0.07–0.90 percentage points) and 0.36 percentage points (0.13–0.65 percentage points) from total annual precipitation, the number of wet days and extreme daily precipitation, respectively. Moreover, climate models seem to underestimate future changes in temperature variability 25 and extreme precipitation 26 , 27 in response to anthropogenic forcing as compared with that observed historically, suggesting that the true impacts from these variables may be larger.

The distribution of committed damages

The spatial distribution of committed damages (Fig. 2a ) reflects a complex interplay between the patterns of future change in several climatic components and those of historical economic vulnerability to changes in those variables. Damages resulting from increasing annual mean temperature (Fig. 2b ) are negative almost everywhere globally, and larger at lower latitudes in regions in which temperatures are already higher and economic vulnerability to temperature increases is greatest (see the response heterogeneity to mean temperature embodied in Extended Data Fig. 1a ). This occurs despite the amplified warming projected at higher latitudes 28 , suggesting that regional heterogeneity in economic vulnerability to temperature changes outweighs heterogeneity in the magnitude of future warming (Supplementary Fig. 13a ). Economic damages owing to daily temperature variability (Fig. 2c ) exhibit a strong latitudinal polarisation, primarily reflecting the physical response of daily variability to greenhouse forcing in which increases in variability across lower latitudes (and Europe) contrast decreases at high latitudes 25 (Supplementary Fig. 13b ). These two temperature terms are the dominant determinants of the pattern of overall damages (Fig. 2a ), which exhibits a strong polarity with damages across most of the globe except at the highest northern latitudes. Future changes in total annual precipitation mainly bring economic benefits except in regions of drying, such as the Mediterranean and central South America (Fig. 2d and Supplementary Fig. 13c ), but these benefits are opposed by changes in the number of wet days, which produce damages with a similar pattern of opposite sign (Fig. 2e and Supplementary Fig. 13d ). By contrast, changes in extreme daily rainfall produce damages in all regions, reflecting the intensification of daily rainfall extremes over global land areas 29 , 30 (Fig. 2f and Supplementary Fig. 13e ).

The spatial distribution of committed damages implies considerable injustice along two dimensions: culpability for the historical emissions that have caused climate change and pre-existing levels of socio-economic welfare. Spearman’s rank correlations indicate that committed damages are significantly larger in countries with smaller historical cumulative emissions, as well as in regions with lower current income per capita (Fig. 3 ). This implies that those countries that will suffer the most from the damages already committed are those that are least responsible for climate change and which also have the least resources to adapt to it.

Estimates of the median projected change in national income per capita across emission scenarios (RCP2.6 and RCP8.5) as well as climate model, empirical model and model parameter uncertainty in the year in which climate damages diverge at the 5% level (2049, as identified in Fig. 1 ) are plotted against cumulative national emissions per capita in 2020 (from the Global Carbon Project) and coloured by national income per capita in 2020 (from the World Bank) in a and vice versa in b . In each panel, the size of each scatter point is weighted by the national population in 2020 (from the World Bank). Inset numbers indicate the Spearman’s rank correlation ρ and P -values for a hypothesis test whose null hypothesis is of no correlation, as well as the Spearman’s rank correlation weighted by national population.

To further quantify this heterogeneity, we assess the difference in committed damages between the upper and lower quartiles of regions when ranked by present income levels and historical cumulative emissions (using a population weighting to both define the quartiles and estimate the group averages). On average, the quartile of countries with lower income are committed to an income loss that is 8.9 percentage points (or 61%) greater than the upper quartile (Extended Data Fig. 6 ), with a likely range of 3.8–14.7 percentage points across the uncertainty sampling of our damage projections (following the likelihood classification adopted by the IPCC). Similarly, the quartile of countries with lower historical cumulative emissions are committed to an income loss that is 6.9 percentage points (or 40%) greater than the upper quartile, with a likely range of 0.27–12 percentage points. These patterns reemphasize the prevalence of injustice in climate impacts 31 , 32 , 33 in the context of the damages to which the world is already committed by historical emissions and socio-economic inertia.

Contextualizing the magnitude of damages

The magnitude of projected economic damages exceeds previous literature estimates 2 , 3 , arising from several developments made on previous approaches. Our estimates are larger than those of ref.  2 (see first row of Extended Data Table 3 ), primarily because of the facts that sub-national estimates typically show a steeper temperature response (see also refs.  3 , 34 ) and that accounting for other climatic components raises damage estimates (Extended Data Fig. 5 ). However, we note that our empirical approach using first-differenced climate variables is conservative compared with that of ref.  2 in regard to the persistence of climate impacts on growth (see introduction and Methods section ‘Empirical model specification: fixed-effects distributed lag models’), an important determinant of the magnitude of long-term damages 19 , 21 . Using a similar empirical specification to ref.  2 , which assumes infinite persistence while maintaining the rest of our approach (sub-national data and further climate variables), produces considerably larger damages (purple curve of Extended Data Fig. 3 ). Compared with studies that do take the first difference of climate variables 3 , 35 , our estimates are also larger (see second and third rows of Extended Data Table 3 ). The inclusion of further climate variables (Extended Data Fig. 5 ) and a sufficient number of lags to more adequately capture the extent of impact persistence (Extended Data Figs. 1 and 2 ) are the main sources of this difference, as is the use of specifications that capture nonlinearities in the temperature response when compared with ref.  35 . In summary, our estimates develop on previous studies by incorporating the latest data and empirical insights 7 , 8 , as well as in providing a robust empirical lower bound on the persistence of impacts on economic growth, which constitutes a middle ground between the extremes of the growth-versus-levels debate 19 , 21 (Extended Data Fig. 3 ).

Compared with the fraction of variance explained by the empirical models historically (<5%), the projection of reductions in income of 19% may seem large. This arises owing to the fact that projected changes in climatic conditions are much larger than those that were experienced historically, particularly for changes in average temperature (Extended Data Fig. 4 ). As such, any assessment of future climate-change impacts necessarily requires an extrapolation outside the range of the historical data on which the empirical impact models were evaluated. Nevertheless, these models constitute the most state-of-the-art methods for inference of plausibly causal climate impacts based on observed data. Moreover, we take explicit steps to limit out-of-sample extrapolation by capping the moderating variables of the interaction terms at the 95th percentile of the historical distribution (see Methods ). This avoids extrapolating the marginal effects outside what was observed historically. Given the nonlinear response of economic output to annual mean temperature (Extended Data Fig. 1 and Extended Data Table 2 ), this is a conservative choice that limits the magnitude of damages that we project. Furthermore, back-of-the-envelope calculations indicate that the projected damages are consistent with the magnitude and patterns of historical economic development (see Supplementary Discussion Section  5 ).

Missing impacts and spatial spillovers

Despite assessing several climatic components from which economic impacts have recently been identified 3 , 7 , 8 , this assessment of aggregate climate damages should not be considered comprehensive. Important channels such as impacts from heatwaves 31 , sea-level rise 36 , tropical cyclones 37 and tipping points 38 , 39 , as well as non-market damages such as those to ecosystems 40 and human health 41 , are not considered in these estimates. Sea-level rise is unlikely to be feasibly incorporated into empirical assessments such as this because historical sea-level variability is mostly small. Non-market damages are inherently intractable within our estimates of impacts on aggregate monetary output and estimates of these impacts could arguably be considered as extra to those identified here. Recent empirical work suggests that accounting for these channels would probably raise estimates of these committed damages, with larger damages continuing to arise in the global south 31 , 36 , 37 , 38 , 39 , 40 , 41 , 42 .

Moreover, our main empirical analysis does not explicitly evaluate the potential for impacts in local regions to produce effects that ‘spill over’ into other regions. Such effects may further mitigate or amplify the impacts we estimate, for example, if companies relocate production from one affected region to another or if impacts propagate along supply chains. The current literature indicates that trade plays a substantial role in propagating spillover effects 43 , 44 , making their assessment at the sub-national level challenging without available data on sub-national trade dependencies. Studies accounting for only spatially adjacent neighbours indicate that negative impacts in one region induce further negative impacts in neighbouring regions 45 , 46 , 47 , 48 , suggesting that our projected damages are probably conservative by excluding these effects. In Supplementary Fig. 14 , we assess spillovers from neighbouring regions using a spatial-lag model. For simplicity, this analysis excludes temporal lags, focusing only on contemporaneous effects. The results show that accounting for spatial spillovers can amplify the overall magnitude, and also the heterogeneity, of impacts. Consistent with previous literature, this indicates that the overall magnitude (Fig. 1 ) and heterogeneity (Fig. 3 ) of damages that we project in our main specification may be conservative without explicitly accounting for spillovers. We note that further analysis that addresses both spatially and trade-connected spillovers, while also accounting for delayed impacts using temporal lags, would be necessary to adequately address this question fully. These approaches offer fruitful avenues for further research but are beyond the scope of this manuscript, which primarily aims to explore the impacts of different climate conditions and their persistence.

Policy implications

We find that the economic damages resulting from climate change until 2049 are those to which the world economy is already committed and that these greatly outweigh the costs required to mitigate emissions in line with the 2 °C target of the Paris Climate Agreement (Fig. 1 ). This assessment is complementary to formal analyses of the net costs and benefits associated with moving from one emission path to another, which typically find that net benefits of mitigation only emerge in the second half of the century 5 . Our simple comparison of the magnitude of damages and mitigation costs makes clear that this is primarily because damages are indistinguishable across emissions scenarios—that is, committed—until mid-century (Fig. 1 ) and that they are actually already much larger than mitigation costs. For simplicity, and owing to the availability of data, we compare damages to mitigation costs at the global level. Regional estimates of mitigation costs may shed further light on the national incentives for mitigation to which our results already hint, of relevance for international climate policy. Although these damages are committed from a mitigation perspective, adaptation may provide an opportunity to reduce them. Moreover, the strong divergence of damages after mid-century reemphasizes the clear benefits of mitigation from a purely economic perspective, as highlighted in previous studies 1 , 4 , 6 , 24 .

Historical climate data

Historical daily 2-m temperature and precipitation totals (in mm) are obtained for the period 1979–2019 from the W5E5 database. The W5E5 dataset comes from ERA-5, a state-of-the-art reanalysis of historical observations, but has been bias-adjusted by applying version 2.0 of the WATCH Forcing Data to ERA-5 reanalysis data and precipitation data from version 2.3 of the Global Precipitation Climatology Project to better reflect ground-based measurements 49 , 50 , 51 . We obtain these data on a 0.5° × 0.5° grid from the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) database. Notably, these historical data have been used to bias-adjust future climate projections from CMIP-6 (see the following section), ensuring consistency between the distribution of historical daily weather on which our empirical models were estimated and the climate projections used to estimate future damages. These data are publicly available from the ISIMIP database. See refs.  7 , 8 for robustness tests of the empirical models to the choice of climate data reanalysis products.

Future climate data

Daily 2-m temperature and precipitation totals (in mm) are taken from 21 climate models participating in CMIP-6 under a high (RCP8.5) and a low (RCP2.6) greenhouse gas emission scenario from 2015 to 2100. The data have been bias-adjusted and statistically downscaled to a common half-degree grid to reflect the historical distribution of daily temperature and precipitation of the W5E5 dataset using the trend-preserving method developed by the ISIMIP 50 , 52 . As such, the climate model data reproduce observed climatological patterns exceptionally well (Supplementary Table 5 ). Gridded data are publicly available from the ISIMIP database.

Historical economic data

Historical economic data come from the DOSE database of sub-national economic output 53 . We use a recent revision to the DOSE dataset that provides data across 83 countries, 1,660 sub-national regions with varying temporal coverage from 1960 to 2019. Sub-national units constitute the first administrative division below national, for example, states for the USA and provinces for China. Data come from measures of gross regional product per capita (GRPpc) or income per capita in local currencies, reflecting the values reported in national statistical agencies, yearbooks and, in some cases, academic literature. We follow previous literature 3 , 7 , 8 , 54 and assess real sub-national output per capita by first converting values from local currencies to US dollars to account for diverging national inflationary tendencies and then account for US inflation using a US deflator. Alternatively, one might first account for national inflation and then convert between currencies. Supplementary Fig. 12 demonstrates that our conclusions are consistent when accounting for price changes in the reversed order, although the magnitude of estimated damages varies. See the documentation of the DOSE dataset for further discussion of these choices. Conversions between currencies are conducted using exchange rates from the FRED database of the Federal Reserve Bank of St. Louis 55 and the national deflators from the World Bank 56 .

Future socio-economic data

Baseline gridded gross domestic product (GDP) and population data for the period 2015–2100 are taken from the middle-of-the-road scenario SSP2 (ref.  15 ). Population data have been downscaled to a half-degree grid by the ISIMIP following the methodologies of refs.  57 , 58 , which we then aggregate to the sub-national level of our economic data using the spatial aggregation procedure described below. Because current methodologies for downscaling the GDP of the SSPs use downscaled population to do so, per-capita estimates of GDP with a realistic distribution at the sub-national level are not readily available for the SSPs. We therefore use national-level GDP per capita (GDPpc) projections for all sub-national regions of a given country, assuming homogeneity within countries in terms of baseline GDPpc. Here we use projections that have been updated to account for the impact of the COVID-19 pandemic on the trajectory of future income, while remaining consistent with the long-term development of the SSPs 59 . The choice of baseline SSP alters the magnitude of projected climate damages in monetary terms, but when assessed in terms of percentage change from the baseline, the choice of socio-economic scenario is inconsequential. Gridded SSP population data and national-level GDPpc data are publicly available from the ISIMIP database. Sub-national estimates as used in this study are available in the code and data replication files.

Climate variables

Following recent literature 3 , 7 , 8 , we calculate an array of climate variables for which substantial impacts on macroeconomic output have been identified empirically, supported by further evidence at the micro level for plausible underlying mechanisms. See refs.  7 , 8 for an extensive motivation for the use of these particular climate variables and for detailed empirical tests on the nature and robustness of their effects on economic output. To summarize, these studies have found evidence for independent impacts on economic growth rates from annual average temperature, daily temperature variability, total annual precipitation, the annual number of wet days and extreme daily rainfall. Assessments of daily temperature variability were motivated by evidence of impacts on agricultural output and human health, as well as macroeconomic literature on the impacts of volatility on growth when manifest in different dimensions, such as government spending, exchange rates and even output itself 7 . Assessments of precipitation impacts were motivated by evidence of impacts on agricultural productivity, metropolitan labour outcomes and conflict, as well as damages caused by flash flooding 8 . See Extended Data Table 1 for detailed references to empirical studies of these physical mechanisms. Marked impacts of daily temperature variability, total annual precipitation, the number of wet days and extreme daily rainfall on macroeconomic output were identified robustly across different climate datasets, spatial aggregation schemes, specifications of regional time trends and error-clustering approaches. They were also found to be robust to the consideration of temperature extremes 7 , 8 . Furthermore, these climate variables were identified as having independent effects on economic output 7 , 8 , which we further explain here using Monte Carlo simulations to demonstrate the robustness of the results to concerns of imperfect multicollinearity between climate variables (Supplementary Methods Section  2 ), as well as by using information criteria (Supplementary Table 1 ) to demonstrate that including several lagged climate variables provides a preferable trade-off between optimally describing the data and limiting the possibility of overfitting.

We calculate these variables from the distribution of daily, d , temperature, T x , d , and precipitation, P x , d , at the grid-cell, x , level for both the historical and future climate data. As well as annual mean temperature, \({\bar{T}}_{x,y}\) , and annual total precipitation, P x , y , we calculate annual, y , measures of daily temperature variability, \({\widetilde{T}}_{x,y}\) :

the number of wet days, Pwd x , y :

and extreme daily rainfall:

in which T x , d , m , y is the grid-cell-specific daily temperature in month m and year y , \({\bar{T}}_{x,m,{y}}\) is the year and grid-cell-specific monthly, m , mean temperature, D m and D y the number of days in a given month m or year y , respectively, H the Heaviside step function, 1 mm the threshold used to define wet days and P 99.9 x is the 99.9th percentile of historical (1979–2019) daily precipitation at the grid-cell level. Units of the climate measures are degrees Celsius for annual mean temperature and daily temperature variability, millimetres for total annual precipitation and extreme daily precipitation, and simply the number of days for the annual number of wet days.

We also calculated weighted standard deviations of monthly rainfall totals as also used in ref.  8 but do not include them in our projections as we find that, when accounting for delayed effects, their effect becomes statistically indistinct and is better captured by changes in total annual rainfall.

Spatial aggregation

We aggregate grid-cell-level historical and future climate measures, as well as grid-cell-level future GDPpc and population, to the level of the first administrative unit below national level of the GADM database, using an area-weighting algorithm that estimates the portion of each grid cell falling within an administrative boundary. We use this as our baseline specification following previous findings that the effect of area or population weighting at the sub-national level is negligible 7 , 8 .

Empirical model specification: fixed-effects distributed lag models

Following a wide range of climate econometric literature 16 , 60 , we use panel regression models with a selection of fixed effects and time trends to isolate plausibly exogenous variation with which to maximize confidence in a causal interpretation of the effects of climate on economic growth rates. The use of region fixed effects, μ r , accounts for unobserved time-invariant differences between regions, such as prevailing climatic norms and growth rates owing to historical and geopolitical factors. The use of yearly fixed effects, η y , accounts for regionally invariant annual shocks to the global climate or economy such as the El Niño–Southern Oscillation or global recessions. In our baseline specification, we also include region-specific linear time trends, k r y , to exclude the possibility of spurious correlations resulting from common slow-moving trends in climate and growth.

The persistence of climate impacts on economic growth rates is a key determinant of the long-term magnitude of damages. Methods for inferring the extent of persistence in impacts on growth rates have typically used lagged climate variables to evaluate the presence of delayed effects or catch-up dynamics 2 , 18 . For example, consider starting from a model in which a climate condition, C r , y , (for example, annual mean temperature) affects the growth rate, Δlgrp r , y (the first difference of the logarithm of gross regional product) of region r in year y :

which we refer to as a ‘pure growth effects’ model in the main text. Typically, further lags are included,

and the cumulative effect of all lagged terms is evaluated to assess the extent to which climate impacts on growth rates persist. Following ref.  18 , in the case that,

the implication is that impacts on the growth rate persist up to NL years after the initial shock (possibly to a weaker or a stronger extent), whereas if

then the initial impact on the growth rate is recovered after NL years and the effect is only one on the level of output. However, we note that such approaches are limited by the fact that, when including an insufficient number of lags to detect a recovery of the growth rates, one may find equation ( 6 ) to be satisfied and incorrectly assume that a change in climatic conditions affects the growth rate indefinitely. In practice, given a limited record of historical data, including too few lags to confidently conclude in an infinitely persistent impact on the growth rate is likely, particularly over the long timescales over which future climate damages are often projected 2 , 24 . To avoid this issue, we instead begin our analysis with a model for which the level of output, lgrp r , y , depends on the level of a climate variable, C r , y :

Given the non-stationarity of the level of output, we follow the literature 19 and estimate such an equation in first-differenced form as,

which we refer to as a model of ‘pure level effects’ in the main text. This model constitutes a baseline specification in which a permanent change in the climate variable produces an instantaneous impact on the growth rate and a permanent effect only on the level of output. By including lagged variables in this specification,

we are able to test whether the impacts on the growth rate persist any further than instantaneously by evaluating whether α L  > 0 are statistically significantly different from zero. Even though this framework is also limited by the possibility of including too few lags, the choice of a baseline model specification in which impacts on the growth rate do not persist means that, in the case of including too few lags, the framework reverts to the baseline specification of level effects. As such, this framework is conservative with respect to the persistence of impacts and the magnitude of future damages. It naturally avoids assumptions of infinite persistence and we are able to interpret any persistence that we identify with equation ( 9 ) as a lower bound on the extent of climate impact persistence on growth rates. See the main text for further discussion of this specification choice, in particular about its conservative nature compared with previous literature estimates, such as refs.  2 , 18 .

We allow the response to climatic changes to vary across regions, using interactions of the climate variables with historical average (1979–2019) climatic conditions reflecting heterogenous effects identified in previous work 7 , 8 . Following this previous work, the moderating variables of these interaction terms constitute the historical average of either the variable itself or of the seasonal temperature difference, \({\hat{T}}_{r}\) , or annual mean temperature, \({\bar{T}}_{r}\) , in the case of daily temperature variability 7 and extreme daily rainfall, respectively 8 .

The resulting regression equation with N and M lagged variables, respectively, reads:

in which Δlgrp r , y is the annual, regional GRPpc growth rate, measured as the first difference of the logarithm of real GRPpc, following previous work 2 , 3 , 7 , 8 , 18 , 19 . Fixed-effects regressions were run using the fixest package in R (ref.  61 ).

Estimates of the coefficients of interest α i , L are shown in Extended Data Fig. 1 for N  =  M  = 10 lags and for our preferred choice of the number of lags in Supplementary Figs. 1 – 3 . In Extended Data Fig. 1 , errors are shown clustered at the regional level, but for the construction of damage projections, we block-bootstrap the regressions by region 1,000 times to provide a range of parameter estimates with which to sample the projection uncertainty (following refs.  2 , 31 ).

Spatial-lag model

In Supplementary Fig. 14 , we present the results from a spatial-lag model that explores the potential for climate impacts to ‘spill over’ into spatially neighbouring regions. We measure the distance between centroids of each pair of sub-national regions and construct spatial lags that take the average of the first-differenced climate variables and their interaction terms over neighbouring regions that are at distances of 0–500, 500–1,000, 1,000–1,500 and 1,500–2000 km (spatial lags, ‘SL’, 1 to 4). For simplicity, we then assess a spatial-lag model without temporal lags to assess spatial spillovers of contemporaneous climate impacts. This model takes the form:

in which SL indicates the spatial lag of each climate variable and interaction term. In Supplementary Fig. 14 , we plot the cumulative marginal effect of each climate variable at different baseline climate conditions by summing the coefficients for each climate variable and interaction term, for example, for average temperature impacts as:

These cumulative marginal effects can be regarded as the overall spatially dependent impact to an individual region given a one-unit shock to a climate variable in that region and all neighbouring regions at a given value of the moderating variable of the interaction term.

Constructing projections of economic damage from future climate change

We construct projections of future climate damages by applying the coefficients estimated in equation ( 10 ) and shown in Supplementary Tables 2 – 4 (when including only lags with statistically significant effects in specifications that limit overfitting; see Supplementary Methods Section  1 ) to projections of future climate change from the CMIP-6 models. Year-on-year changes in each primary climate variable of interest are calculated to reflect the year-to-year variations used in the empirical models. 30-year moving averages of the moderating variables of the interaction terms are calculated to reflect the long-term average of climatic conditions that were used for the moderating variables in the empirical models. By using moving averages in the projections, we account for the changing vulnerability to climate shocks based on the evolving long-term conditions (Supplementary Figs. 10 and 11 show that the results are robust to the precise choice of the window of this moving average). Although these climate variables are not differenced, the fact that the bias-adjusted climate models reproduce observed climatological patterns across regions for these moderating variables very accurately (Supplementary Table 6 ) with limited spread across models (<3%) precludes the possibility that any considerable bias or uncertainty is introduced by this methodological choice. However, we impose caps on these moderating variables at the 95th percentile at which they were observed in the historical data to prevent extrapolation of the marginal effects outside the range in which the regressions were estimated. This is a conservative choice that limits the magnitude of our damage projections.

Time series of primary climate variables and moderating climate variables are then combined with estimates of the empirical model parameters to evaluate the regression coefficients in equation ( 10 ), producing a time series of annual GRPpc growth-rate reductions for a given emission scenario, climate model and set of empirical model parameters. The resulting time series of growth-rate impacts reflects those occurring owing to future climate change. By contrast, a future scenario with no climate change would be one in which climate variables do not change (other than with random year-to-year fluctuations) and hence the time-averaged evaluation of equation ( 10 ) would be zero. Our approach therefore implicitly compares the future climate-change scenario to this no-climate-change baseline scenario.

The time series of growth-rate impacts owing to future climate change in region r and year y , δ r , y , are then added to the future baseline growth rates, π r , y (in log-diff form), obtained from the SSP2 scenario to yield trajectories of damaged GRPpc growth rates, ρ r , y . These trajectories are aggregated over time to estimate the future trajectory of GRPpc with future climate impacts:

in which GRPpc r , y =2020 is the initial log level of GRPpc. We begin damage estimates in 2020 to reflect the damages occurring since the end of the period for which we estimate the empirical models (1979–2019) and to match the timing of mitigation-cost estimates from most IAMs (see below).

For each emission scenario, this procedure is repeated 1,000 times while randomly sampling from the selection of climate models, the selection of empirical models with different numbers of lags (shown in Supplementary Figs. 1 – 3 and Supplementary Tables 2 – 4 ) and bootstrapped estimates of the regression parameters. The result is an ensemble of future GRPpc trajectories that reflect uncertainty from both physical climate change and the structural and sampling uncertainty of the empirical models.

Estimates of mitigation costs

We obtain IPCC estimates of the aggregate costs of emission mitigation from the AR6 Scenario Explorer and Database hosted by IIASA 23 . Specifically, we search the AR6 Scenarios Database World v1.1 for IAMs that provided estimates of global GDP and population under both a SSP2 baseline and a SSP2-RCP2.6 scenario to maintain consistency with the socio-economic and emission scenarios of the climate damage projections. We find five IAMs that provide data for these scenarios, namely, MESSAGE-GLOBIOM 1.0, REMIND-MAgPIE 1.5, AIM/GCE 2.0, GCAM 4.2 and WITCH-GLOBIOM 3.1. Of these five IAMs, we use the results only from the first three that passed the IPCC vetting procedure for reproducing historical emission and climate trajectories. We then estimate global mitigation costs as the percentage difference in global per capita GDP between the SSP2 baseline and the SSP2-RCP2.6 emission scenario. In the case of one of these IAMs, estimates of mitigation costs begin in 2020, whereas in the case of two others, mitigation costs begin in 2010. The mitigation cost estimates before 2020 in these two IAMs are mostly negligible, and our choice to begin comparison with damage estimates in 2020 is conservative with respect to the relative weight of climate damages compared with mitigation costs for these two IAMs.

Data availability

Data on economic production and ERA-5 climate data are publicly available at https://doi.org/10.5281/zenodo.4681306 (ref. 62 ) and https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5 , respectively. Data on mitigation costs are publicly available at https://data.ene.iiasa.ac.at/ar6/#/downloads . Processed climate and economic data, as well as all other necessary data for reproduction of the results, are available at the public repository https://doi.org/10.5281/zenodo.10562951  (ref. 63 ).

Code availability

All code necessary for reproduction of the results is available at the public repository https://doi.org/10.5281/zenodo.10562951  (ref. 63 ).

Glanemann, N., Willner, S. N. & Levermann, A. Paris Climate Agreement passes the cost-benefit test. Nat. Commun. 11 , 110 (2020).

Article   ADS   CAS   PubMed   PubMed Central   Google Scholar  

Burke, M., Hsiang, S. M. & Miguel, E. Global non-linear effect of temperature on economic production. Nature 527 , 235–239 (2015).

Article   ADS   CAS   PubMed   Google Scholar  

Kalkuhl, M. & Wenz, L. The impact of climate conditions on economic production. Evidence from a global panel of regions. J. Environ. Econ. Manag. 103 , 102360 (2020).

Article   Google Scholar  

Moore, F. C. & Diaz, D. B. Temperature impacts on economic growth warrant stringent mitigation policy. Nat. Clim. Change 5 , 127–131 (2015).

Article   ADS   Google Scholar  

Drouet, L., Bosetti, V. & Tavoni, M. Net economic benefits of well-below 2°C scenarios and associated uncertainties. Oxf. Open Clim. Change 2 , kgac003 (2022).

Ueckerdt, F. et al. The economically optimal warming limit of the planet. Earth Syst. Dyn. 10 , 741–763 (2019).

Kotz, M., Wenz, L., Stechemesser, A., Kalkuhl, M. & Levermann, A. Day-to-day temperature variability reduces economic growth. Nat. Clim. Change 11 , 319–325 (2021).

Kotz, M., Levermann, A. & Wenz, L. The effect of rainfall changes on economic production. Nature 601 , 223–227 (2022).

Kousky, C. Informing climate adaptation: a review of the economic costs of natural disasters. Energy Econ. 46 , 576–592 (2014).

Harlan, S. L. et al. in Climate Change and Society: Sociological Perspectives (eds Dunlap, R. E. & Brulle, R. J.) 127–163 (Oxford Univ. Press, 2015).

Bolton, P. et al. The Green Swan (BIS Books, 2020).

Alogoskoufis, S. et al. ECB Economy-wide Climate Stress Test: Methodology and Results European Central Bank, 2021).

Weber, E. U. What shapes perceptions of climate change? Wiley Interdiscip. Rev. Clim. Change 1 , 332–342 (2010).

Markowitz, E. M. & Shariff, A. F. Climate change and moral judgement. Nat. Clim. Change 2 , 243–247 (2012).

Riahi, K. et al. The shared socioeconomic pathways and their energy, land use, and greenhouse gas emissions implications: an overview. Glob. Environ. Change 42 , 153–168 (2017).

Auffhammer, M., Hsiang, S. M., Schlenker, W. & Sobel, A. Using weather data and climate model output in economic analyses of climate change. Rev. Environ. Econ. Policy 7 , 181–198 (2013).

Kolstad, C. D. & Moore, F. C. Estimating the economic impacts of climate change using weather observations. Rev. Environ. Econ. Policy 14 , 1–24 (2020).

Dell, M., Jones, B. F. & Olken, B. A. Temperature shocks and economic growth: evidence from the last half century. Am. Econ. J. Macroecon. 4 , 66–95 (2012).

Newell, R. G., Prest, B. C. & Sexton, S. E. The GDP-temperature relationship: implications for climate change damages. J. Environ. Econ. Manag. 108 , 102445 (2021).

Kikstra, J. S. et al. The social cost of carbon dioxide under climate-economy feedbacks and temperature variability. Environ. Res. Lett. 16 , 094037 (2021).

Article   ADS   CAS   Google Scholar  

Bastien-Olvera, B. & Moore, F. Persistent effect of temperature on GDP identified from lower frequency temperature variability. Environ. Res. Lett. 17 , 084038 (2022).

Eyring, V. et al. Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) experimental design and organization. Geosci. Model Dev. 9 , 1937–1958 (2016).

Byers, E. et al. AR6 scenarios database. Zenodo https://zenodo.org/records/7197970 (2022).

Burke, M., Davis, W. M. & Diffenbaugh, N. S. Large potential reduction in economic damages under UN mitigation targets. Nature 557 , 549–553 (2018).

Kotz, M., Wenz, L. & Levermann, A. Footprint of greenhouse forcing in daily temperature variability. Proc. Natl Acad. Sci. 118 , e2103294118 (2021).

Article   CAS   PubMed   PubMed Central   Google Scholar  

Myhre, G. et al. Frequency of extreme precipitation increases extensively with event rareness under global warming. Sci. Rep. 9 , 16063 (2019).

Min, S.-K., Zhang, X., Zwiers, F. W. & Hegerl, G. C. Human contribution to more-intense precipitation extremes. Nature 470 , 378–381 (2011).

England, M. R., Eisenman, I., Lutsko, N. J. & Wagner, T. J. The recent emergence of Arctic Amplification. Geophys. Res. Lett. 48 , e2021GL094086 (2021).

Fischer, E. M. & Knutti, R. Anthropogenic contribution to global occurrence of heavy-precipitation and high-temperature extremes. Nat. Clim. Change 5 , 560–564 (2015).

Pfahl, S., O’Gorman, P. A. & Fischer, E. M. Understanding the regional pattern of projected future changes in extreme precipitation. Nat. Clim. Change 7 , 423–427 (2017).

Callahan, C. W. & Mankin, J. S. Globally unequal effect of extreme heat on economic growth. Sci. Adv. 8 , eadd3726 (2022).

Diffenbaugh, N. S. & Burke, M. Global warming has increased global economic inequality. Proc. Natl Acad. Sci. 116 , 9808–9813 (2019).

Callahan, C. W. & Mankin, J. S. National attribution of historical climate damages. Clim. Change 172 , 40 (2022).

Burke, M. & Tanutama, V. Climatic constraints on aggregate economic output. National Bureau of Economic Research, Working Paper 25779. https://doi.org/10.3386/w25779 (2019).

Kahn, M. E. et al. Long-term macroeconomic effects of climate change: a cross-country analysis. Energy Econ. 104 , 105624 (2021).

Desmet, K. et al. Evaluating the economic cost of coastal flooding. National Bureau of Economic Research, Working Paper 24918. https://doi.org/10.3386/w24918 (2018).

Hsiang, S. M. & Jina, A. S. The causal effect of environmental catastrophe on long-run economic growth: evidence from 6,700 cyclones. National Bureau of Economic Research, Working Paper 20352. https://doi.org/10.3386/w2035 (2014).

Ritchie, P. D. et al. Shifts in national land use and food production in Great Britain after a climate tipping point. Nat. Food 1 , 76–83 (2020).

Dietz, S., Rising, J., Stoerk, T. & Wagner, G. Economic impacts of tipping points in the climate system. Proc. Natl Acad. Sci. 118 , e2103081118 (2021).

Bastien-Olvera, B. A. & Moore, F. C. Use and non-use value of nature and the social cost of carbon. Nat. Sustain. 4 , 101–108 (2021).

Carleton, T. et al. Valuing the global mortality consequences of climate change accounting for adaptation costs and benefits. Q. J. Econ. 137 , 2037–2105 (2022).

Bastien-Olvera, B. A. et al. Unequal climate impacts on global values of natural capital. Nature 625 , 722–727 (2024).

Malik, A. et al. Impacts of climate change and extreme weather on food supply chains cascade across sectors and regions in Australia. Nat. Food 3 , 631–643 (2022).

Article   ADS   PubMed   Google Scholar  

Kuhla, K., Willner, S. N., Otto, C., Geiger, T. & Levermann, A. Ripple resonance amplifies economic welfare loss from weather extremes. Environ. Res. Lett. 16 , 114010 (2021).

Schleypen, J. R., Mistry, M. N., Saeed, F. & Dasgupta, S. Sharing the burden: quantifying climate change spillovers in the European Union under the Paris Agreement. Spat. Econ. Anal. 17 , 67–82 (2022).

Dasgupta, S., Bosello, F., De Cian, E. & Mistry, M. Global temperature effects on economic activity and equity: a spatial analysis. European Institute on Economics and the Environment, Working Paper 22-1 (2022).

Neal, T. The importance of external weather effects in projecting the macroeconomic impacts of climate change. UNSW Economics Working Paper 2023-09 (2023).

Deryugina, T. & Hsiang, S. M. Does the environment still matter? Daily temperature and income in the United States. National Bureau of Economic Research, Working Paper 20750. https://doi.org/10.3386/w20750 (2014).

Hersbach, H. et al. The ERA5 global reanalysis. Q. J. R. Meteorol. Soc. 146 , 1999–2049 (2020).

Cucchi, M. et al. WFDE5: bias-adjusted ERA5 reanalysis data for impact studies. Earth Syst. Sci. Data 12 , 2097–2120 (2020).

Adler, R. et al. The New Version 2.3 of the Global Precipitation Climatology Project (GPCP) Monthly Analysis Product 1072–1084 (University of Maryland, 2016).

Lange, S. Trend-preserving bias adjustment and statistical downscaling with ISIMIP3BASD (v1.0). Geosci. Model Dev. 12 , 3055–3070 (2019).

Wenz, L., Carr, R. D., Kögel, N., Kotz, M. & Kalkuhl, M. DOSE – global data set of reported sub-national economic output. Sci. Data 10 , 425 (2023).

Article   PubMed   PubMed Central   Google Scholar  

Gennaioli, N., La Porta, R., Lopez De Silanes, F. & Shleifer, A. Growth in regions. J. Econ. Growth 19 , 259–309 (2014).

Board of Governors of the Federal Reserve System (US). U.S. dollars to euro spot exchange rate. https://fred.stlouisfed.org/series/AEXUSEU (2022).

World Bank. GDP deflator. https://data.worldbank.org/indicator/NY.GDP.DEFL.ZS (2022).

Jones, B. & O’Neill, B. C. Spatially explicit global population scenarios consistent with the Shared Socioeconomic Pathways. Environ. Res. Lett. 11 , 084003 (2016).

Murakami, D. & Yamagata, Y. Estimation of gridded population and GDP scenarios with spatially explicit statistical downscaling. Sustainability 11 , 2106 (2019).

Koch, J. & Leimbach, M. Update of SSP GDP projections: capturing recent changes in national accounting, PPP conversion and Covid 19 impacts. Ecol. Econ. 206 (2023).

Carleton, T. A. & Hsiang, S. M. Social and economic impacts of climate. Science 353 , aad9837 (2016).

Article   PubMed   Google Scholar  

Bergé, L. Efficient estimation of maximum likelihood models with multiple fixed-effects: the R package FENmlm. DEM Discussion Paper Series 18-13 (2018).

Kalkuhl, M., Kotz, M. & Wenz, L. DOSE - The MCC-PIK Database Of Subnational Economic output. Zenodo https://zenodo.org/doi/10.5281/zenodo.4681305 (2021).

Kotz, M., Wenz, L. & Levermann, A. Data and code for “The economic commitment of climate change”. Zenodo https://zenodo.org/doi/10.5281/zenodo.10562951 (2024).

Dasgupta, S. et al. Effects of climate change on combined labour productivity and supply: an empirical, multi-model study. Lancet Planet. Health 5 , e455–e465 (2021).

Lobell, D. B. et al. The critical role of extreme heat for maize production in the United States. Nat. Clim. Change 3 , 497–501 (2013).

Zhao, C. et al. Temperature increase reduces global yields of major crops in four independent estimates. Proc. Natl Acad. Sci. 114 , 9326–9331 (2017).

Wheeler, T. R., Craufurd, P. Q., Ellis, R. H., Porter, J. R. & Prasad, P. V. Temperature variability and the yield of annual crops. Agric. Ecosyst. Environ. 82 , 159–167 (2000).

Rowhani, P., Lobell, D. B., Linderman, M. & Ramankutty, N. Climate variability and crop production in Tanzania. Agric. For. Meteorol. 151 , 449–460 (2011).

Ceglar, A., Toreti, A., Lecerf, R., Van der Velde, M. & Dentener, F. Impact of meteorological drivers on regional inter-annual crop yield variability in France. Agric. For. Meteorol. 216 , 58–67 (2016).

Shi, L., Kloog, I., Zanobetti, A., Liu, P. & Schwartz, J. D. Impacts of temperature and its variability on mortality in New England. Nat. Clim. Change 5 , 988–991 (2015).

Xue, T., Zhu, T., Zheng, Y. & Zhang, Q. Declines in mental health associated with air pollution and temperature variability in China. Nat. Commun. 10 , 2165 (2019).

Article   ADS   PubMed   PubMed Central   Google Scholar  

Liang, X.-Z. et al. Determining climate effects on US total agricultural productivity. Proc. Natl Acad. Sci. 114 , E2285–E2292 (2017).

Desbureaux, S. & Rodella, A.-S. Drought in the city: the economic impact of water scarcity in Latin American metropolitan areas. World Dev. 114 , 13–27 (2019).

Damania, R. The economics of water scarcity and variability. Oxf. Rev. Econ. Policy 36 , 24–44 (2020).

Davenport, F. V., Burke, M. & Diffenbaugh, N. S. Contribution of historical precipitation change to US flood damages. Proc. Natl Acad. Sci. 118 , e2017524118 (2021).

Dave, R., Subramanian, S. S. & Bhatia, U. Extreme precipitation induced concurrent events trigger prolonged disruptions in regional road networks. Environ. Res. Lett. 16 , 104050 (2021).

Download references

Acknowledgements

We gratefully acknowledge financing from the Volkswagen Foundation and the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH on behalf of the Government of the Federal Republic of Germany and Federal Ministry for Economic Cooperation and Development (BMZ).

Open access funding provided by Potsdam-Institut für Klimafolgenforschung (PIK) e.V.

Author information

Authors and affiliations.

Research Domain IV, Research Domain IV, Potsdam Institute for Climate Impact Research, Potsdam, Germany

Maximilian Kotz, Anders Levermann & Leonie Wenz

Institute of Physics, Potsdam University, Potsdam, Germany

Maximilian Kotz & Anders Levermann

Mercator Research Institute on Global Commons and Climate Change, Berlin, Germany

Leonie Wenz

You can also search for this author in PubMed   Google Scholar

Contributions

All authors contributed to the design of the analysis. M.K. conducted the analysis and produced the figures. All authors contributed to the interpretation and presentation of the results. M.K. and L.W. wrote the manuscript.

Corresponding author

Correspondence to Leonie Wenz .

Ethics declarations

Competing interests.

The authors declare no competing interests.

Peer review

Peer review information.

Nature thanks Xin-Zhong Liang, Chad Thackeray and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data figures and tables

Extended data fig. 1 constraining the persistence of historical climate impacts on economic growth rates..

The results of a panel-based fixed-effects distributed lag model for the effects of annual mean temperature ( a ), daily temperature variability ( b ), total annual precipitation ( c ), the number of wet days ( d ) and extreme daily precipitation ( e ) on sub-national economic growth rates. Point estimates show the effects of a 1 °C or one standard deviation increase (for temperature and precipitation variables, respectively) at the lower quartile, median and upper quartile of the relevant moderating variable (green, orange and purple, respectively) at different lagged periods after the initial shock (note that these are not cumulative effects). Climate variables are used in their first-differenced form (see main text for discussion) and the moderating climate variables are the annual mean temperature, seasonal temperature difference, total annual precipitation, number of wet days and annual mean temperature, respectively, in panels a – e (see Methods for further discussion). Error bars show the 95% confidence intervals having clustered standard errors by region. The within-region R 2 , Bayesian and Akaike information criteria for the model are shown at the top of the figure. This figure shows results with ten lags for each variable to demonstrate the observed levels of persistence, but our preferred specifications remove later lags based on the statistical significance of terms shown above and the information criteria shown in Extended Data Fig. 2 . The resulting models without later lags are shown in Supplementary Figs. 1 – 3 .

Extended Data Fig. 2 Incremental lag-selection procedure using information criteria and within-region R 2 .

Starting from a panel-based fixed-effects distributed lag model estimating the effects of climate on economic growth using the real historical data (as in equation ( 4 )) with ten lags for all climate variables (as shown in Extended Data Fig. 1 ), lags are incrementally removed for one climate variable at a time. The resulting Bayesian and Akaike information criteria are shown in a – e and f – j , respectively, and the within-region R 2 and number of observations in k – o and p – t , respectively. Different rows show the results when removing lags from different climate variables, ordered from top to bottom as annual mean temperature, daily temperature variability, total annual precipitation, the number of wet days and extreme annual precipitation. Information criteria show minima at approximately four lags for precipitation variables and ten to eight for temperature variables, indicating that including these numbers of lags does not lead to overfitting. See Supplementary Table 1 for an assessment using information criteria to determine whether including further climate variables causes overfitting.

Extended Data Fig. 3 Damages in our preferred specification that provides a robust lower bound on the persistence of climate impacts on economic growth versus damages in specifications of pure growth or pure level effects.

Estimates of future damages as shown in Fig. 1 but under the emission scenario RCP8.5 for three separate empirical specifications: in orange our preferred specification, which provides an empirical lower bound on the persistence of climate impacts on economic growth rates while avoiding assumptions of infinite persistence (see main text for further discussion); in purple a specification of ‘pure growth effects’ in which the first difference of climate variables is not taken and no lagged climate variables are included (the baseline specification of ref.  2 ); and in pink a specification of ‘pure level effects’ in which the first difference of climate variables is taken but no lagged terms are included.

Extended Data Fig. 4 Climate changes in different variables as a function of historical interannual variability.

Changes in each climate variable of interest from 1979–2019 to 2035–2065 under the high-emission scenario SSP5-RCP8.5, expressed as a percentage of the historical variability of each measure. Historical variability is estimated as the standard deviation of each detrended climate variable over the period 1979–2019 during which the empirical models were identified (detrending is appropriate because of the inclusion of region-specific linear time trends in the empirical models). See Supplementary Fig. 13 for changes expressed in standard units. Data on national administrative boundaries are obtained from the GADM database version 3.6 and are freely available for academic use ( https://gadm.org/ ).

Extended Data Fig. 5 Contribution of different climate variables to overall committed damages.

a , Climate damages in 2049 when using empirical models that account for all climate variables, changes in annual mean temperature only or changes in both annual mean temperature and one other climate variable (daily temperature variability, total annual precipitation, the number of wet days and extreme daily precipitation, respectively). b , The cumulative marginal effects of an increase in annual mean temperature of 1 °C, at different baseline temperatures, estimated from empirical models including all climate variables or annual mean temperature only. Estimates and uncertainty bars represent the median and 95% confidence intervals obtained from 1,000 block-bootstrap resamples from each of three different empirical models using eight, nine or ten lags of temperature terms.

Extended Data Fig. 6 The difference in committed damages between the upper and lower quartiles of countries when ranked by GDP and cumulative historical emissions.

Quartiles are defined using a population weighting, as are the average committed damages across each quartile group. The violin plots indicate the distribution of differences between quartiles across the two extreme emission scenarios (RCP2.6 and RCP8.5) and the uncertainty sampling procedure outlined in Methods , which accounts for uncertainty arising from the choice of lags in the empirical models, uncertainty in the empirical model parameter estimates, as well as the climate model projections. Bars indicate the median, as well as the 10th and 90th percentiles and upper and lower sixths of the distribution reflecting the very likely and likely ranges following the likelihood classification adopted by the IPCC.

Supplementary information

Supplementary information, peer review file, rights and permissions.

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ .

Reprints and permissions

About this article

Cite this article.

Kotz, M., Levermann, A. & Wenz, L. The economic commitment of climate change. Nature 628 , 551–557 (2024). https://doi.org/10.1038/s41586-024-07219-0

Download citation

Received : 25 January 2023

Accepted : 21 February 2024

Published : 17 April 2024

Issue Date : 18 April 2024

DOI : https://doi.org/10.1038/s41586-024-07219-0

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

By submitting a comment you agree to abide by our Terms and Community Guidelines . If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Quick links

• Explore articles by subject
• Guide to authors
• Editorial policies

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Talk to our experts

1800-120-456-456

• Global Warming Essay

Essay on Global Warming

The last few decades have been monumental when it comes to technological development. Humans have developed systems and machines that make our lives easier. Especially during the early modern period from the early 16th century to as far as the late 18the century, also commonly referred to as “The Scientific Revolution” or “The Enlightenment”, modern technology leapt ahead in development in such a short time frame compared to all of history.

However, with the development of society, there has been a severe detriment to the quality of Earth’s environment. One of the most massive threats to the condition of the planet is climate change. Inadequate research and reckless misuse of natural resources are some of the core reasons for the deteriorating condition of the planet.

To understand the concept of Global Warming and its causes and effects, we need to take an in-depth look into many factors that affect the temperature of the planet and what that means for the future of the world. Here is an objective look at the topic of Global Warming and other important related topics.

What is Climate Change?

Ever since the industrial and scientific revolution, Earth is slowly being used up for its resources. Moreover, the onset of the exponential increase in the world’s population is also very taxing on the environment. 

Simply put, as the need for consumption of the population increases, both the utilisation of natural resources and the waste generated from the use of said resources have also increased massively. 

One of the main results of this over the many years has become climate change. Climate change is not just the rise or fall of temperature of different areas of the world; it is also a change in the rain cycles, wind patterns, cyclone frequencies, sea levels, etc. It affects all major life groups on the planet in some way or the other.  

What is Global Warming?

Global Warming is often considered an effect of Climate change. Global Warming is the rapid increase in the temperature of the Earth’s environment that is causing many life-threatening issues to arise.

Global Warming is a dangerous effect on our environment that we are facing these days. Rapid industrialization, increase in the population growth and pollution are causing a rise in Global Warming. Global Warming refers to the increase in the average temperature of the earth's surface during the last century. One of the reasons why Global Warming is dangerous is because it disturbs the overall ecology of the planet. This results in floods, famine, cyclones and other issues. There are many causes and results of this warming and is a danger for the existence of life on earth.

The sign of Global Warming is already visible with many natural phenomena happening around globally, affecting each living species.

Here is some data that can help to give a more precise understanding of the reality of Global Warming in the last few years:

On average, the world’s temperature is about 1.5°C higher than during the start of the industrial revolution in the late 1700s. That may not seem a lot to you, but that is an average estimate. This number is only increasing. Many parts of the world face far more severe changes in temperature that affect the planet’s overall health.

In 1950, the world’s CO 2 emissions were at 6 billion tonnes which had quadrupled in volume until 1990, just 40 years later to 22 billion tonnes. Not only that, unchecked CO 2 emissions today have reached a whopping 35 billion tonnes.

The most evident causes of Global Warming are industrialization, urbanization, deforestation, and sophisticated human activities. These human activities have led to an increase in the emission of Greenhouse Gases, including CO₂, Nitrous Oxide, Methane, and others.

Causes of Global Warming

A variety of reasons causes Global Warming. Some of which can be controlled personally by individuals but others are only expected to be solved by communities and the world leaders and activists at the global level.

Many scientists believe the main four reasons for Global Warming, according to recent studies, are:

Greenhouse gases

Deforestation

Per capita carbon emissions

Global Warming is certainly an alarming situation, which is causing a significant impact on life existence. Extreme Global Warming is resulting in natural calamities, which is quite evident happening around. One of the reasons behind Global Warming is the extreme release of greenhouse gases stuck on the earth surface, resulting in the temperature increase.

Similarly, volcanoes are also leading to Global Warming because they spew too much CO₂ in the air. One of the significant causes behind Global Warming is the increase in the population. This increase in the population also results in air pollution. Automobiles release a lot of CO₂, which remains stuck in the earth.

This increase in the population is also leading to deforestation, which further results in Global Warming. More and more trees are being cut, increasing the concentration of CO₂.

The greenhouse is the natural process where the sunlight passes through the area, thus warming the earth's surface. The earth surface releases energy in the form of heat in the atmosphere maintaining the balance with the incoming energy. Global Warming depletes the ozone layer leading to the doom's day.

There is a clear indication that the increase in Global Warming will lead to the complete extinction of life from the earth surface.

Solution for Global Warming

Global Warming can not be blamed on individuals; however, it can be tackled and maintained from worsening starting at the individual level. Of course, industries and multinational conglomerates have higher carbon emissions levels than an average citizen. Still, activism and community effort are the only feasible ways to control the worsening state of Global Warming.

Additionally, at the state or government level, world leaders need to create concrete plans and step programmes to ensure that no further harm is being caused to the environment in general. 

Although we are almost late in slowing down the Global Warming rate, it is crucial to find the right solution. From individuals to governments, everyone has to work upon a solution for Global Warming. Controlling pollution, population and use of natural resources are some of the factors to consider. Switching over to the electric and hybrid car is the best way to bring down the carbon dioxide.

As a citizen, it is best to switch over to the hybrid car and to use public transport. This will reduce pollution and congestion. Another significant contribution you can make is to minimize the use of plastic. Plastic is the primary cause of Global Warming taking years to recycle.

Deforestation is another thing to consider that will help in controlling Global Warming. Planting of more trees should be encouraged to make the environment go green.

Industrialization should be under certain norms. The building of industries should be banned in green zones affecting plants and species. Hefty penalties should be levied on such sectors contributing towards Global Warming.

Effects of Global Warming

Global Warming is a real problem that many want to prove as a hoax for their political benefit. However, as aware citizens of the world, we must make sure only the truth is presented in the media.

Various parts of the environment, both flora and fauna, are directly adversely affected by the damages caused by Global Warming. Wildlife being in danger is ultimately a serious threat to the survival of humanity as we know it and its future.

The effect of Global Warming is widely seen in this decade. Glacier retreat and arctic shrinkage are the two common phenomena seen. Glaciers are melting in a fast way. These are pure examples of climate change.

Rise in sea level is another significant effect of Global Warming. This sea-level rise is leading to floods in low-lying areas. Extreme weather conditions are witnessed in many countries. Unseasonal rainfall, extreme heat and cold, wildfires and others are common every year. The number of these cases is increasing. This will indeed imbalance the ecosystem bringing the result of the extinction of species.

Similarly, marine life is also widely getting affected due to the increase in Global Warming. This is resulting in the death of marine species and other issues. Moreover, changes are expected in coral reefs, which are going to face the end in coming years.

These effects will take a steep rise in coming years, bringing the expansion of species to a halt. Moreover, humans too will witness the negative impact of Global Warming in the end.

FAQs on Global Warming Essay

1. What Global Warming will Cause?

Global warming will have a massive impact on our earth in the end. Flood, extreme weather conditions, famine, wildfire and many more will be the result. There will be hotter days, which will also increase the wildfire and famine. In the past years, many meteorological bureaus have added purple and magenta to the forecast.

Another impact of global warming will be rising sea levels. Increased ocean temperatures will lead to the melting of glaciers and ice caps. Increase in the sea level will lead to floods in many low-lying areas.

The overall ecosystem of nature will be an imbalance. This will affect nature in the long-term.

2. Why Does Global Warming Happen?

There are many reasons for the cause of global warming. There are certain gases in the atmosphere called greenhouse gases. The energy then radiates from the surface; the greenhouse gases trap longwave radiation. We humans have added to the atmospheric blanket of greenhouse affecting the living species. Warming of air, oceans, and land is how global warming happens.