research questions for global warming

News from the Columbia Climate School

Six Tough Questions About Climate Change

Whenever the focus is on climate change, as it is right now at the  Paris climate conference , tough questions are asked concerning the costs of cutting carbon emissions, the feasibility of transitioning to renewable energy, and whether it’s already too late to do anything about climate change. We posed these questions to Laura Segafredo , manager for the Deep Decarbonization Pathways Project . The decarbonization project comprises energy research teams from 16 of the world’s biggest greenhouse gas emitting countries that are developing concrete strategies to reduce emissions in their countries. The Deep Decarbonization Pathways Project is an initiative of the Sustainable Development Solutions Network .

• Will the actions we take today be enough to forestall the direct impacts of climate change? Or is it too little too late?

There is still time and room for limiting climate change within the 2˚C limit that scientists consider relatively safe, and that countries endorsed in Copenhagen and Cancun. But clearly the window is closing quickly. I think that the most important message is that we need to start really, really soon, putting the world on a trajectory of stabilizing and reducing emissions. The temperature change has a direct relationship with the cumulative amount of emissions that are in the atmosphere, so the more we keep emitting at the pace that we are emitting today, the more steeply we will have to go on a downward trajectory and the more expensive it will be.

Today we are already experiencing an average change in global temperature of .8˚. With the cumulative amount of emissions that we are going to emit into the atmosphere over the next years, we will easily reach 1.5˚ without even trying to change that trajectory.

Two degrees might still be doable, but it requires significant political will and fast action. And even 2˚ is a significant amount of warming for the planet, and will have consequences in terms of sea level rise, ecosystem changes, possible extinctions of species, displacements of people, diseases, agriculture productivity changes, health related effects and more. But if we can contain global warming within those 2˚, we can manage those effects. I think that’s really the message of the Intergovernmental Panel on Climate Change reports—that’s why the 2˚ limit was chosen, in a sense. It’s a level of warming where we can manage the risks and the consequences. Anything beyond that would be much, much worse.

• Will taking action make our lives better or safer, or will it only make a difference to future generations?

It will make our lives better and safer for sure. For example, let’s think about what it means to replace a coal power plant with a cleaner form of energy like wind or solar. People that live around the coal power plant are going to have a lot less air pollution, which means less asthma for children, and less time wasted because of chronic or acute diseases. In developing countries, you’re talking about potentially millions of lives saved by replacing dirty fossil fuel based power generation with clean energy.

It will also have important consequences for agricultural productivity. There’s a big risk that with the concentration of carbon and other gases in the atmosphere,   agricultural yields will be reduced, so preventing that means more food for everyone.

And then think about cities. If you didn’t have all that pollution from cars, we could live in cities that are less noisy, where the air’s much better, and have potentially better transportation. We could live in better buildings where appliances are more efficient. And investing in energy efficiency would basically leave more money in our pockets. So there are a lot of benefits that we can reap almost immediately, and that’s without even considering the biggest benefit—leaving a planet in decent condition for future generations.

• How will measures to cut carbon emissions affect my life in terms of cost?

To build a climate resilient economy, we need to incorporate the three pillars of energy system transformation that we focus on in all the deep decarbonization pathways. Number one is improving energy efficiency in every part of the economy—buildings, what we use inside buildings, appliances, industrial processes, cars…everything you can think of can perform the same service, but using less energy. What that means is that you will have a slight increase in the price in the form of a small investment up front, like insulating your windows or buying a more efficient car, but you will end up saving a lot more money over the life of the equipment in terms of decreased energy costs.

The second pillar is making electricity, the power sector, carbon-free by replacing dirty power generation with clean power sources. That’s clearly going to cost a little money, but those costs are coming down so quickly. In fact there are already a lot of clean technologies that are at cost parity with fossil fuels— for example, onshore wind is already as competitive as gas—and those costs are only coming down in the future. We can also expect that there are going to be newer technologies. But in any event, the fact that we’re going to use less power because of the first pillar should actually make it a wash in terms of cost.

The Australian deep decarbonization teams have estimated that even with the increased costs of cleaner cars, and more efficient equipment for the home, etc., when the power system transitions to where it’s zero carbon, you still have savings on your energy bills compared to the previous situation.

The third pillar that we think about are clean fuels, essentially zero-carbon fuels. So we either need to electrify everything— like cars and heating, once the power sector is free of carbon—or have low-carbon fuels to power things that cannot be electrified, such as airplanes or big trucks. But once you have efficiency, these types of equipment are also more efficient, and you should be spending less money on energy.

Saving money depends on the three pillars together, thinking about all this as a whole system.

• Given that renewable sources provide only a small percentage of our energy and that nuclear power is so expensive, what can we realistically do to get off fossil fuels as soon as possible?

There are a lot of studies that have been done for the U.S. and for Europe that show that it’s very realistic to think of a power sector that is almost entirely powered by renewables by 2050 or so. It’s actually feasible—and this considers all the issues with intermittency, dealing with the networks, and whatever else represents a technological barrier—that’s all included in these studies. There’s also the assumption that energy storage, like batteries, will be cheaper in the future.

That is the future, but 2050 is not that far away. 35 years for an energy transition is not a long time. It’s important that this transition start now with the right policy incentives in place. We need to make sure that cars are more efficient, that buildings are more efficient, that cities are built with more public transit so less fossil fuels are needed to transport people from one place to another.

I don’t want people to think that because we’re looking at 2050, that means that we can wait—in order to be almost carbon free by 2050, or close to that target, we need to act fast and start now.

• Will the remedies to climate change be worse than the disease? Will it drive more people into poverty with higher costs?

I actually think the opposite is true. If we just let climate go the way we are doing today by continuing business as usual, that will drive many people into poverty. There’s a clear relationship between climate change and changing weather patterns, so more significant and frequent extreme weather events, including droughts, will affect the livelihoods of a large portion of the world population. Once you have droughts or significant weather events like extreme precipitation, you tend to see displacements of people, which create conflict, and conflict creates disease.

I think Syria is a good example of the world that we might be going towards if we don’t do anything about climate change. Syria is experiencing a once-in-a-century drought, and there’s a significant amount of desertification going on in those areas, so you’re looking at more and more arid areas. That affects agriculture, so people have moved from the countryside to the cities and that has created a lot of pressure on the cities. The conflict in Syria is very much related to the drought, and the drought can be ascribed to climate change.

And consider the ramifications of the Syrian crisis: the refugee crisis in Europe, terrorism, security concerns and 7 million-plus people displaced. I think that that’s the world that we’re going towards. And in a world like that, when you have to worry about people being safe and alive, you certainly cannot guarantee wealth and better well-being, or education and health.

• So finally, doing what needs to be done to combat climate change all comes down to political will?

The majority of the American public now believe that climate change is real, that it’s human induced and that we should do something about it.

But there’s seems to be a disconnect between what these numbers seem to indicate and what the political discourse is like… I can’t understand it, yet it seems to be the situation.

I’m a little concerned because other more immediate concerns like terrorism and safety always come first. Because the effects of climate change are going to be felt a little further away, people think that we can always put it off. The Department of Defense, its top-level people, have made the connection between climate change and conflict over the next few decades. That’s why I would argue that Syria is actually a really good example to remind us that if we are experiencing security issues today, it’s also because of environmental problems. We cannot ignore them.

The reality is that we need to do something about climate change fast—we don’t have time to fight this over the next 20 years. We have to agree on this soon and move forward and not waste another 10 years debating.

Read the Deep Decarbonization Pathways Project 2015 report . The full report will be released Dec. 2.

Laura Segafredo was a senior economist at the ClimateWorks Foundation, where she focused on best practice energy policies and their impact on emission trajectories. She was a lead author of the 2012 UNEP Emissions Gap Report and of the Green Growth in Practice Assessment Report. Before joining ClimateWorks, Segafredo was a research economist at Electricité de France in Paris.

She obtained her Ph.D. in energy studies and her BA in economics from the University of Padova (Italy), and her MSc in economics from the University of Toulouse (France).

Related Posts

Solar Geoengineering To Cool the Planet: Is It Worth the Risks?

Army Veteran and Environmental Advocate: A Sustainability Science Student’s Journey to Columbia

Sustainable Development Program Hosts Annual Alumni Career Conversations Panel

Celebrate over 50 years of Earth Day with us all month long! Visit our Earth Day website for ideas, resources, and inspiration.

Many find low wages prohibits saving. Changing personal vehicles and heating systems costs. Will there be financial support for people on low wages?

The energy innovation and dividend bill has already been introduced in the house. It’s a carbon fee and dividend plan. The carbon fee rises every year and 100% of it goes back directly into the hands of the people by a check each month. This helps offset rising costs, especially for lower income folks.

81 cosponsors now Tell your rep in Congress to support this HR 763!

Results show that yields for all four crops grown at levels of carbon dioxide remaining at 2000 levels would experience severe declines in yield due to higher temperatures and drier conditions. But when grown at doubled carbon dioxide levels, all four crops fare better due to increased photosynthesis and crop water productivity, partially offsetting the impacts from those adverse climate changes. For wheat and soybean crops, in terms of yield the median negative impacts are fully compensated, and rice crops recoup up to 90 percent and maize up to 60 percent of their losses.

When is Russia, China, and Mexico going to work toward a better environment instead of the United States trying to do it all? They continue to pollute like they have for years. Who is going to stop the deforestation of the rain forest?

I’m curious if climate change has any effect on seismic activity. It seems with ice melting on the poles and increasing water dispersement and temp of that water, it might cause the plates to shift to compensate. Is there any evidence of this?

this isn’t because of doldrums or jet streams. the pattern keeps having the same action. we must save trees :3

How long do we have, before it’s too late?

Climate Change isn’t nearly as big of a deal as everyone makes it out to be. Meaning no disrespect to the author, but I really don’t see how this is something that we should be worrying about given that one human recycling their soda cans or getting their old phone refurbished rather than dumping it isn’t going to restore the polar ice caps or lower the temperature of the planet. And supposedly agriculture is the problem, but I point-blank refuse to give up my beef night, or bacon and eggs for breakfast on Saturdays. Also, nuclear power is supposed to be a solution, but the building of the power plants is going to add more greenhouse gases than the plant will take out. The whole planet needs a reality check. Earth isn’t going to explode because it’s slightly hotter than it used to be!

Thank you and I need in your help

Get the Columbia Climate School Newsletter →

• Newsletters

Site search

• Israel-Hamas war
• Home Planet
• 2024 election
• Supreme Court
• TikTok’s fate
• All explainers
• Future Perfect

Filed under:

• 9 questions about climate change you were too embarrassed to ask

Basic answers to basic questions about global warming and the future climate.

Share this story

• Share this on Facebook
• Share this on Twitter
• Share this on Reddit
• Share All sharing options

Share All sharing options for: 9 questions about climate change you were too embarrassed to ask

This explainer was updated by Umair Irfan in December 2018 and draws heavily from a card stack written by Brad Plumer in 2015. Brian Resnick contributed the section on the Paris climate accord in 2017.

There’s a vast and growing gap between the urgency to fight climate change and the policies needed to combat it.

In 2018, the United Nations’ Intergovernmental Panel on Climate Change found that it is possible to limit global warming to 1.5 degrees Celsius this century, but the world may have as little as 12 years left to act. The US government’s National Climate Assessment , with input from NASA, the Environmental Protection Agency, and the Pentagon, also reported that the consequences of climate change are already here, ranging from nuisance flooding to the spread of mosquito-borne viruses into what were once colder climates. Left unchecked, warming will cost the US economy hundreds of billions of dollars.

However, these facts have failed to register with the Trump administration, which is actively pushing policies that will increase the emissions of heat-trapping gases.

Ever since he took office, President Donald Trump has rejected or undermined President Barack Obama’s signature climate achievements: the Paris climate agreement; the Clean Power Plan , the main domestic policy for limiting greenhouse gas emissions; and fuel economy standards , which target transportation, the largest US source of greenhouse gases.

At the same time, the Trump administration has aggressively boosted fossil fuels: opening unprecedented swaths of public lands to mining and drilling , attempting to bail out foundering coal power plants , and promoting hydrocarbon exploitation at climate change conferences .

Trump has also appointed climate change skeptics to key positions. Quietly, officials at these and other science agencies have been removing the words “climate change” from government websites and press releases.

Yet the evidence for humanity’s role in changing the climate continues to mount, and its consequences are increasingly difficult to ignore. Atmospheric carbon dioxide concentrations now top 408 parts per million, a threshold the planet hasn’t seen in millions of years . Greenhouse gas emissions reached a record high in 2018. Disasters worsened by climate change have taken hundreds of lives, destroyed thousands of homes, and cost billions of dollars.

The big questions now are how these ongoing changes in the climate will reverberate throughout the rest of the world, and what we should do about them. The answers bridge decades of research across geology, economics, and social science, which have been confounded by uncertainty and obscured by jargon. That’s why it can be a bit daunting to join the discussion for the first time, or to revisit the conversation after a hiatus.

To help, we’ve provided answers to some fundamental questions about climate change you may have been afraid to ask.

1) What is global warming?

In short: The world is getting hotter, and humans are responsible.

Yes, the planet’s temperature has changed before, but it’s the rise in average temperature of the Earth's climate system since the late 19th century, the dawn of the Industrial Revolution, that’s important here. Temperatures over land and ocean have gone up 0.8° to 1° Celsius (1.4° to 1.8° Fahrenheit), on average, in that span:

Many people use the term “climate change” to describe this rise in temperatures and the associated effects on the Earth's climate. (The shift from the term “global warming” to “climate change” was also part of a deliberate messaging effort by a Republican pollster to undermine support for environmental regulations.)

Like detectives solving a murder, climate scientists have found humanity’s fingerprints all over the planet’s warming, with the overwhelming majority of the evidence pointing to the extra greenhouse gases humans have put into the atmosphere by burning fossil fuels. Greenhouse gases like carbon dioxide trap heat at the Earth’s surface, preventing that heat from escaping back out into space too quickly. When we burn coal, natural gas, or oil for energy, or when we cut down forests that usually soak up greenhouse gases, we add even more carbon dioxide to the atmosphere, so the planet warms up.

Global warming also refers to what scientists think will happen in the future if humans keep adding greenhouse gases to the atmosphere.

Though there is a steady stream of new studies on climate change, one of the most robust aggregations of the science remains the Intergovernmental Panel on Climate Change’s fifth assessment report from 2013. The IPCC is convened by the United Nations, and the report draws on more than 800 expert authors. It projects that temperatures could rise at least 2°C (3.6°F) by the end of the century under many plausible scenarios — and possibly 4°C or more. A more recent study by scientists in the United Kingdom found a narrower range of expected temperatures if atmospheric carbon dioxide doubled, rising between 2.2°C and 3.4°C.

Many experts consider 2°C of warming to be unacceptably high , increasing the risk of deadly heat waves, droughts, flooding, and extinctions. Rising temperatures will drive up global sea levels as the world’s glaciers and ice sheets melt. Further global warming could affect everything from our ability to grow food to the spread of disease.

That’s why the IPCC put out another report in 2018 comparing 2°C of warming to a scenario with 1.5°C of warming . The researchers found that this half-degree difference is actually pretty important, since every bit of warming matters. Between the two outlooks, less warming means fewer people will have to move from coastal areas, natural weather events will be less severe, and economies will take a smaller hit.

However, limiting warming would likely require a complete overhaul of our energy system. Fossil fuels currently provide just over 80 percent of the world’s energy. To zero out emissions this century, we’d have to replace most of that with low-carbon sources like wind, solar, nuclear, geothermal, or carbon capture.

Beyond that, we may have to electrify everything that uses energy and start pulling greenhouse gases straight from the air. And to get on track for 1.5°C of warming, the world would have to halve greenhouse gas emissions from current levels by 2030.

That’s a staggering task, and there are huge technological and political hurdles standing in the way. As such, the world's nations have been slow to act on global warming — many of the existing targets for curbing greenhouse gas emissions are too weak , yet many countries are falling short of even these modest goals.

2) How do we know global warming is real?

The simplest way is through temperature measurements. Agencies in the United States, Europe, and Japan have independently analyzed historical temperature data and reached the same conclusion: The Earth’s average surface temperature has risen roughly 0.8° Celsius (1.4° Fahrenheit) since the early 20th century.

But that’s not the only clue. Scientists have also noted that glaciers and ice sheets around the world are melting. Satellite observations since the 1970s have shown warming in the lower atmosphere. There’s more heat in the ocean, causing water to expand and sea levels to rise. Plants are flowering earlier in many parts of the world. There’s more humidity in the atmosphere. Here’s a summary from the National Oceanic and Atmospheric Administration:

These are all signs that the Earth really is getting warmer — and that it’s not just a glitch in the thermometers. That explains why climate scientists say things like , “Warming in the climate system is unequivocal.” They’re really confident about this one.

3) How do we know humans are causing global warming?

Climate scientists say they are more than 95 percent certain that human influence has been the dominant cause of global warming since 1950. They’re about as sure of this as they are that cigarette smoke causes cancer.

Why are they so confident? In part because they have a good grasp of how greenhouse gases can warm the planet, in part because the theory fits the available evidence, and in part because alternate theories have been ruled out. Let's break it down in six steps:

1) Scientists have long known that greenhouse gases in the atmosphere — such as carbon dioxide, methane, or water vapor — absorb certain frequencies of infrared radiation and scatter them back toward the Earth. These gases essentially prevent heat from escaping too quickly back into space, trapping that radiation at the surface and keeping the planet warm.

2) Climate scientists also know that concentrations of greenhouse gases in the atmosphere have grown significantly since the Industrial Revolution. Carbon dioxide has risen 45 percent . Methane has risen more than 200 percent . Through some relatively straightforward chemistry and physics , scientists can trace these increases to human activities like burning oil, gas, and coal.

3) So it stands to reason that more greenhouse gases would lead to more heat. And indeed, satellite measurements have shown that less infrared radiation is escaping out into space over time and instead returning to the Earth’s surface. That’s strong evidence that the greenhouse effect is increasing.

4) There are other human fingerprints that suggest increased greenhouse gases are warming the planet. For instance, back in the 1960s, simple climate models predicted that global warming caused by more carbon dioxide would lead to cooling in the upper atmosphere (because the heat is getting trapped at the surface). Later satellite measurements confirmed exactly that . Here are a few other similar predictions that have also been confirmed.

5) Meanwhile, climate scientists have ruled out other explanations for the rise in average temperatures over the past century. To take one example: Solar activity can shift from year to year, affecting the Earth's climate. But satellite data shows that total solar irradiance has declined slightly in the past 35 years, even as the Earth has warmed.

6) More recent calculations have shown that it’s impossible to explain the temperature rise we’ve seen in the past century without taking the increase in carbon dioxide and other greenhouse gases into account. Natural causes, like the sun or volcanoes, have an influence, but they’re not sufficient by themselves.

Ultimately, the Intergovernmental Panel on Climate Change concluded that most of the warming since 1951 has been due to human activities. The Earth’s climate can certainly fluctuate from year to year due to natural forces (including oscillations in the Pacific Ocean, such as El Niño ). But greenhouse gases are driving the larger upward trend in temperatures.

And as the Climate Science Special Report , released by 13 US federal agencies in November 2017, put it, “For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.”

More: This chart breaks down all the different factors affecting the Earth’s average temperature. And there’s much more detail in the IPCC’s report , particularly this section and this one .

4) How has global warming affected the world so far?

Here’s a list of ongoing changes that climate scientists have concluded are likely linked to global warming, as detailed by the IPCC here and here .

Higher temperatures: Every continent has warmed substantially since the 1950s. There are more hot days and fewer cold days, on average, and the hot days are hotter.

Heavier storms and floods : The world’s atmosphere can hold more moisture as it warms. As a result, the overall number of heavier storms has increased since the mid-20th century, particularly in North America and Europe (though there’s plenty of regional variation). Scientists reported in December that at least 18 percent of Hurricane Harvey’s record-setting rainfall over Houston in August was due to climate change.

Heat waves: Heat waves have become longer and more frequent around the world over the past 50 years, particularly in Europe, Asia, and Australia.

Shrinking sea ice: The extent of sea ice in the Arctic, always at its maximum in winter, has shrunk since 1979, by 3.3 percent per decade. Summer sea ice has dwindled even more rapidly, by 13.2 percent per decade. Antarctica has seen recent years with record growth in sea ice, but it’s a very different environment than the Arctic, and the losses in the north far exceed any gains at the South Pole, so total global sea ice is on the decline:

Global, Arctic and Antarctic Sea Ice Area Spiral February 2018 #GlobalWarming #ClimateChange pic.twitter.com/gayoLFSJ5u — Kevin Pluck (@kevpluck) March 1, 2018

Shrinking glaciers and ice sheets : Glaciers around the world have, on average, been losing ice since the 1970s. In some areas, that is reducing the amount of available freshwater. The ice sheet on Greenland, which would raise global sea levels by 25 feet if it all melted, is declining, with some sections experiencing a sudden surge in the melt rate. The Antarctic ice sheet is also getting smaller, but at a much slower rate .

Sea level rise: Global sea levels rose 9.8 inches (25 centimeters) in the 19th and 20th centuries, after 2,000 years of relatively little change , and the pace is speeding up . Sea level rise is caused by both the thermal expansion of the oceans — as water warms up, it expands — and the melting of glaciers and ice sheets (but not sea ice).

Food supply: A hotter climate can be both good for crops (it lengthens the growing season, and more carbon dioxide can increase photosynthesis) and bad for crops (excess heat can damage plants). The IPCC found that global warming was currently benefiting crops in some high-latitude areas but that negative effects are becoming increasingly common worldwide. In areas like California, crop yields are estimated to decline 40 percent by 2050.

Shifting species: Many land and marine species have had to shift their geographic ranges in response to warmer temperatures. So far, several extinctions have been linked to global warming, such as certain frog species in Central America.

Warmer winters: In general, winters are warming faster than summers . Average low temperatures are rising all over the world. In some cases, these temperatures are climbing above the freezing point of water. We’re already seeing massive declines in snow accumulation in the United States, which can paradoxically increase flood, drought, and wildfire risk — as water that would ordinarily dispatch slowly over the course of a season instead flows through a region all at once.

Debated impacts

Here are a few other ways the Earth’s climate has been changing — but scientists are still debating whether and how they’re linked to global warming:

Droughts have become more frequent and more intense in some parts of the world — such as the American Southwest, Mediterranean Europe, and West Africa — though it’s hard to identify a clear global trend. In other parts of the world, such as the Midwestern United States and Northwestern Australia, droughts appear to have become less frequent. A recent study shows that, globally, the time between droughts is shrinking and more areas are affected by drought and taking longer to recover from them.

Hurricanes have clearly become more intense in the North Atlantic Ocean since 1970, the IPCC says. But it’s less clear whether global warming is driving this. 2017 was an exceptionally bad year for Atlantic hurricanes in terms of strength and damage. And while scientists are still uncertain whether they were a fluke or part of a trend, they are warning we should treat it as a baseline year. There doesn’t yet seem to be any clear trajectory for tropical cyclones worldwide.

5) What impacts will global warming have in the future?

It depends on how much the planet actually heats up. The changes associated with 4° Celsius (or 7.2° Fahrenheit) of warming are expected to be more dramatic than the changes associated with 2°C of warming.

Here’s a basic rundown of big impacts we can expect if global warming continues, via the IPCC ( here and here ).

Hotter temperatures: If emissions keep rising unchecked, then global average surface temperatures will be at least 2°C higher (3.6°F) than preindustrial levels by 2100 — and possibly 3°C or 4°C or more.

Higher sea level rise: The expert consensus is that global sea levels will rise somewhere between 0.2 and 2 meters by the end of the century if global warming continues unchecked (that’s between 0.6 and 6.6 feet). That’s a wide range, reflecting some of the uncertainties scientists have in how ice will melt. In specific regions like the Eastern United States, sea level rise could be even higher, and around the world, the rate of rise is accelerating .

Heat waves: A hotter planet will mean more frequent and severe heat waves .

Droughts and floods: Across the globe, wet seasons are expected to become wetter, and dry seasons drier. As the IPCC puts it , the world will see “more intense downpours, leading to more floods, yet longer dry periods between rain events, leading to more drought.”

Hurricanes: It’s not yet clear what impact global warming will have on tropical cyclones. The IPCC said it was likely that tropical cyclones would get stronger as the oceans heat up, with faster winds and heavier rainfall. But the overall number of hurricanes in many regions was likely to “either decrease or remain essentially unchanged.”

Heavier storm surges: Higher sea levels will increase the risk of storm surges and flooding when storms do hit.

Agriculture: In many parts of the world, the mix of increased heat and drought is expected to make food production more difficult. The IPCC concluded that global warming of 1°C or more could start hurting crop yields for wheat, corn, and rice by the 2030s, especially in the tropics. (This wouldn’t be uniform, however; some crops may benefit from mild warming, such as winter wheat in the United States.)

Extinctions: As the world warms, many plant and animal species will need to shift habitats at a rapid rate to maintain their current conditions. Some species will be able to keep up; others likely won’t. The Great Barrier Reef, for instance, may not be able to recover from major recent bleaching events linked to climate change. The National Research Council has estimated that a mass extinction event “could conceivably occur before the year 2100.”

Long-term changes: Most of the projected changes above will occur in the 21st century. But temperatures will keep rising after that if greenhouse gas levels aren’t stabilized. That increases the risk of more drastic longer-term shifts. One example: If West Antarctica’s ice sheet started crumbling, that could push sea levels up significantly. The National Research Council in 2013 deemed many of these rapid climate surprises unlikely this century but a real possibility further into the future.

6) What happens if the world heats up more drastically — say, 4°C?

The risks of climate change would rise considerably if temperatures rose 4° Celsius (7.2° Fahrenheit) above preindustrial levels — something that’s possible if greenhouse gas emissions keep rising at their current rate.

The IPCC says 4°C of global warming could lead to “substantial species extinctions,” “large risks to global and regional food security,” and the risk of irreversibly destabilizing Greenland’s massive ice sheet.

One huge concern is food production: A growing number of studies suggest it would become significantly more difficult for the world to grow food with 3°C or 4°C of global warming. Countries like Bangladesh, Egypt, Vietnam, and parts of Africa could see large tracts of farmland turn unusable due to rising seas. Scientists are also concerned about crops getting less nutritious due to rising CO2.

Humans could struggle to adapt to these conditions. Many people might think the impacts of 4°C of warming will simply be twice as bad as those of 2°C. But as a 2013 World Bank report argued, that’s not necessarily true. Impacts may interact with each other in unpredictable ways. Current agriculture models, for instance, don’t have a good sense of what will happen to crops if increased heat waves, droughts, new pests and diseases, and other changes all start to combine.

“Given that uncertainty remains about the full nature and scale of impacts,” the World Bank report said, “there is also no certainty that adaptation to a 4°C world is possible.” Its conclusion was blunt: “The projected 4°C warming simply must not be allowed to occur.”

7) What do climate models say about the warming that could actually happen in the coming decades?

That depends on your faith in humanity.

Climate models depend on not only complicated physics but the intricacies of human behavior over the entire planet.

Generally, the more greenhouse gases humanity pumps into the atmosphere, the warmer it will get. But scientists aren’t certain how sensitive the global climate system is to increases in greenhouse gases. And just how much we might emit over the coming decades remains an open question, depending on advances in technology and international efforts to cut emissions.

The IPCC groups these scenarios into four categories of atmospheric greenhouse gas concentrations known as Representative Concentration Pathways . They serve as standard benchmarks for evaluating climate models, but they also have some assumptions baked in .

RCP 2.6, also called RCP 3PD, is the scenario with very low greenhouse gas concentrations in the atmosphere. It bets on declining oil use, a population of 9 billion by 2100, increasing energy efficiency, and emissions holding steady until 2020, at which point they’ll decline and even go negative by 2100. This is, to put it mildly, very optimistic.

The next tier up is RCP 4.5, which still banks on ambitious reductions in emissions but anticipates an inflection point in the emissions rate around 2040. RCP 6 expects emissions to increase 75 percent above today’s levels before peaking and declining around 2060 as the world continues to rely heavily on fossil fuels.

The highest tier, RCP 8.5, is the pessimistic business-as-usual scenario, anticipating no policy changes nor any technological advances. It expects a global population of 12 billion and triple the rate of carbon dioxide emissions compared to today by 2100.

Here’s how greenhouse gas emissions under each scenario stack up next to each other:

And here’s what that means for global average temperatures, assuming that a doubling of carbon dioxide concentrations in the atmosphere leads to 3°C of warming:

As you can see, RCP 3PD is the only trajectory that keeps the planet below 2°C of warming. Recall what it would take to keep emissions in line with this pathway and you’ll understand the enormity of the challenge of meeting this goal.

8) How do we stop global warming?

The world’s nations would need to cut their greenhouse gas emissions by a lot. And even that wouldn’t stop all global warming.

For example, let’s say we wanted to limit global warming to below 2°C. To do that, the IPCC has calculated that annual greenhouse gas emissions would need to drop at least 40 to 70 percent by midcentury.

Emissions would then have to keep falling until humans were hardly emitting any extra greenhouse gases by the end of the century. We’d also have to remove carbon dioxide from the atmosphere .

Cutting emissions that sharply is a daunting task. Right now, the world gets 87 percent of its primary energy from fossil fuels: oil, gas, and coal. By contrast, just 13 percent of the world’s primary energy is “low carbon”: a little bit of wind and solar power, some nuclear power plants, a bunch of hydroelectric dams. That’s one reason global emissions keep rising each year.

To stay below 2°C, that would all need to change radically. By 2050, the IPCC notes, the world would need to triple or even quadruple the share of clean energy it uses — and keep scaling it up thereafter. Second, we’d have to get dramatically more efficient at using energy in our homes, buildings, and cars. And stop cutting down forests. And reduce emissions from agriculture and from industrial processes like cement manufacturing.

The IPCC also notes that this task becomes even more difficult the longer we put it off, because carbon dioxide and other greenhouse gases will keep piling up in the atmosphere in the meantime, and the cuts necessary to stay below the 2°C limit become more severe.

9) What are we actually doing to fight climate change?

A global problem requires global action, but with climate change, there is a yawning gap between ambition and action.

The main international effort is the 2015 Paris climate accord, of which the United States is the only country in the world that wants out . The deal was hammered out over weeks of tense negotiations and weighs in at 31 pages . What it does is actually pretty simple.

The backbone is the global target of keeping global average temperatures from rising 2°C (compared to temperatures before the Industrial Revolution) by the end of the century. Beyond 2 degrees, we risk dramatically higher seas, changes in weather patterns, food and water crises, and an overall more hostile world.

Critics have argued that the 2-degree mark is arbitrary, or even too low , to make a difference. But it’s a starting point, a goal that, before Paris, the world was on track to wildly miss.

Paris is voluntary

To accomplish this 2-degree goal, the accord states that countries should strive to reach peak emissions “as soon as possible.” (Currently, we’re on track to hit peak emissions around 2030 or later , which will likely be too late.)

But the agreement doesn’t detail exactly how these countries should do that. Instead, it provides a framework for getting momentum going on greenhouse gas reduction, with some oversight and accountability. For the US, the pledge involves 26 to 28 percent reductions by 2025. (Under Trump’s current policies, that goal is impossible .)

There’s also no defined punishment for breaking it. The idea is to create a culture of accountability (and maybe some peer pressure) to get countries to step up their climate game.

In 2020, delegates are supposed to reconvene and provide updates about their emission pledges and report on how they’re becoming more aggressive on accomplishing the 2-degree goal.

However, many countries are already falling behind on their climate change commitments, and some, like Germany, are giving up on their near-term targets.

Paris asks richer countries to help out poorer countries

There’s a fundamental inequality when it comes to global emissions. Rich countries have plundered and burned huge amounts of fossil fuels and gotten rich from them. Poor countries seeking to grow their economies are now being admonished for using the same fuels. Many low-lying poor countries also will be among the first to bear the worst impacts of climate change.

The main vehicle for rectifying this is the Green Climate Fund , via which richer countries, like the US, are supposed to send $100 billion a year in aid and financing by 2020 to the poorer countries. The United States’ share was $3 billion , but with President Trump’s decision to withdraw from the Paris accord, this goal is unlikely to be met.

The agreement matters because we absolutely need momentum on this issue

The Paris agreement is largely symbolic, and it will live on even though Trump is aiming to pull the US out. But, as Jim Tankersley wrote for Vox , “the accord will be weakened, and, much more importantly, so will the fragile international coalition” around climate change.

We’re already seeing the Paris agreement lose steam. At a follow-up climate meeting this year in Katowice, Poland , negotiators forged an agreement on measuring and verifying their progress in cutting greenhouse gases, but left many critical questions of how to achieve these reductions unanswered.

But the Paris accord isn’t the only international climate policy game in town

There are regional international climate efforts like the European Union’s Emissions Trading System . However, the most effective global policy at keeping warming in check to date doesn’t have to do with climate change, at least on the surface.

The 1987 Montreal Protocol , which was convened by countries to halt the destruction of the ozone layer, had a major side effect of averting warming. In fact, it’s been the single most effective effort humanity has undertaken to fight climate change. Since many of the substances that eat away at the ozone layer are potent heat-trappers, limiting emissions of gases like chlorofluorocarbons has an outsize effect.

And the Trump administration doesn’t appear as hostile to Montreal as it does to Paris. The White House may send the 2016 Kigali Amendment to the Montreal Protocol to the Senate for ratification, giving the new regulations the force of law. If implemented, the amendment would avert 0.5°C of warming by 2100.

Regardless of what path we choose, the key thing to remember is that we are going to pay for climate change one way or another. We have the opportunity now to address warming on our own terms, with investments in clean energy, moving people away from disaster-prone areas, and regulating greenhouse gas emissions. Otherwise, we’ll pay through diminished crop harvests, inundated coastlines, destroyed homes, lost lives, and an increasingly unlivable planet. Ignoring or stalling on climate change chooses the latter option by default. Our choices do matter, but we’re running out of time to make them.

F urther reading:

Avoiding catastrophic climate change isn’t impossible yet. Just incredibly hard.

Reckoning with climate change will demand ugly tradeoffs from environmentalists — and everyone else

Show this cartoon to anyone who doubts we need huge action on climate change

It’s time to start talking about “negative” carbon dioxide emissions

A history of the 2°C global warming target

Scientists made a detailed “roadmap” for meeting the Paris climate goals. It’s eye-opening.

Will you support Vox today?

We believe that everyone deserves to understand the world that they live in. That kind of knowledge helps create better citizens, neighbors, friends, parents, and stewards of this planet. Producing deeply researched, explanatory journalism takes resources. You can support this mission by making a financial gift to Vox today. Will you join us?

We accept credit card, Apple Pay, and Google Pay. You can also contribute via

In This Stream

Trump withdraws the us from paris climate agreement.

• The rumors that Trump was changing course on the Paris climate accord, explained

Next Up In Science

Sign up for the newsletter today, explained.

Understand the world with a daily explainer plus the most compelling stories of the day.

Thanks for signing up!

Check your inbox for a welcome email.

Oops. Something went wrong. Please enter a valid email and try again.

The AI grift that can literally poison you

Everything’s a cult now

We could be heading into the hottest summer of our lives

How today’s antiwar protests stack up against major student movements in history

What the backlash to student protests over Gaza is really about

You need $500. How should you get it?

We're moving!

Understanding our planet to benefit humankind

News & features.

What Is Climate Change?

How do we know climate change is real, why is climate change happening, what are the effects of climate change, what is being done to solve climate change, earth science in action.

More to Explore

Ask nasa climate.

People Profiles

Images of Change

Before-and-after images of earth, climate change resources, an extensive collection of global warming resources for media, educators, weathercasters, and public speakers..

• Images of Change Before-and-after images of Earth
• Global Ice Viewer Climate change's impact on ice
• Earth Minute Videos Animated video series illustrating Earth science topics
• Climate Time Machine Climate change in recent history
• Multimedia Vast library of images, videos, graphics, and more
• En español Creciente biblioteca de recursos en español
• For Educators Student and educator resources
• For Kids Webquests, Climate Kids, and more

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: 09 February 2024

Globally representative evidence on the actual and perceived support for climate action

• Peter Andre   ORCID: orcid.org/0000-0002-8213-527X 1 ,
• Teodora Boneva   ORCID: orcid.org/0000-0002-4227-3686 2 ,
• Felix Chopra   ORCID: orcid.org/0000-0002-7621-1045 3 &
• Armin Falk   ORCID: orcid.org/0000-0002-7284-3002 2  

Nature Climate Change volume  14 ,  pages 253–259 ( 2024 ) Cite this article

51k Accesses

2 Citations

1248 Altmetric

Metrics details

• Climate-change mitigation
• Psychology and behaviour

Mitigating climate change necessitates global cooperation, yet global data on individuals’ willingness to act remain scarce. In this study, we conducted a representative survey across 125 countries, interviewing nearly 130,000 individuals. Our findings reveal widespread support for climate action. Notably, 69% of the global population expresses a willingness to contribute 1% of their personal income, 86% endorse pro-climate social norms and 89% demand intensified political action. Countries facing heightened vulnerability to climate change show a particularly high willingness to contribute. Despite these encouraging statistics, we document that the world is in a state of pluralistic ignorance, wherein individuals around the globe systematically underestimate the willingness of their fellow citizens to act. This perception gap, combined with individuals showing conditionally cooperative behaviour, poses challenges to further climate action. Therefore, raising awareness about the broad global support for climate action becomes critically important in promoting a unified response to climate change.

Similar content being viewed by others

The economic commitment of climate change

Worldwide divergence of values

Climate damage projections beyond annual temperature

The world’s climate is a global common good and protecting it requires the cooperative effort of individuals across the globe. Consequently, the ‘human factor’ is critical and renders the behavioural science perspective on climate change indispensable for effective climate action. Despite its importance, limited knowledge exists regarding the willingness of the global population to cooperate and act against climate change 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 . To fill this gap, we designed and conducted a globally representative survey in 125 countries, with the aim of examining the potential for successful global climate action. The central question we seek to answer is to what extent are individuals around the globe willing to contribute to the common good, and how do people perceive other people’s willingness to contribute (WTC)?

Drawing on a multidisciplinary literature on the foundations of cooperation, our study focuses on four aspects that have been identified as critical in promoting cooperation in the context of common goods: the individual willingness to make costly contributions, the approval of pro-climate norms, the demand for political action and beliefs about the support of others. We start with exploring the individual willingness to make costly contributions to act against climate change, which is particularly relevant given that cooperation is costly and involves free-rider incentives 9 . Using a behaviourally validated measure, we assess the extent to which individuals around the globe are willing to contribute a share of their income, and which factors predict the observed cross-country variation.

Furthermore, the provision of common goods crucially depends on the existence and enforcement of social norms. These norms prescribe cooperative behaviour 10 , 11 , 12 , 13 , 14 , 15 and affect behaviour either through internalization (shame and guilt 16 ) or the enforcement of norms by fellow citizens (sanctions and approval 17 ). In our survey, we elicit support for pro-climate social norms and examine the extent to which such norms have emerged globally.

It is widely recognized that addressing common-good problems effectively necessitates institutions and concerted political action 18 , 19 , 20 . In democracies, the implementation of effective climate policies relies on popular support, and even in non-democratic societies, leaders remain attentive to prevailing political demands. Therefore, we also elicit the demand for political action as a critical input in the fight against climate change 21 .

Previous research in the behavioural sciences has shown that many individuals can be characterized as conditional cooperators 22 , 23 , 24 , 25 , 26 . This means that individuals are more likely to contribute to the common good when they believe others also contribute. We test this central psychological mechanism of cooperation using our data on actual and perceived WTC. Moreover, we investigate whether beliefs about others’ WTC are well calibrated or whether they are systematically biased. If beliefs are overly pessimistic, this would imply that the world is in a state of pluralistic ignorance 27 , where systematic misperceptions about others’ WTC hinder cooperation and reinforce further pessimism. In such an equilibrium, correcting beliefs holds tremendous potential for fostering cooperation 28 , 29 , 30 , 31 .

The global survey

To obtain globally representative evidence on the willingness to act against climate change, we designed the Global Climate Change Survey. The survey was administered as part of the Gallup World Poll 2021/2022 in a large and diverse set of countries ( N  = 125) using a common sampling and survey methodology ( Methods ). The countries included in this study account for 96% of the world’s greenhouse gas (GHG) emissions, 96% of the world’s gross domestic product (GDP) and 92% of the global population. To ensure national representativeness, each country sample is randomly selected from the resident population aged 15 and above. Interviews were conducted via telephone (common in high-income countries) or face to face (common in low-income countries), with randomly drawn phone numbers or addresses. Most country samples include approximately 1,000 respondents, and the global sample comprises a total of 129,902 individuals.

To assess respondents’ willingness to incur a cost to act against climate change, we elicit their willingness to contribute a fraction of their income to climate action. More specifically, we ask respondents whether they would be ‘willing to contribute 1% of [their] household income every month to fight global warming’ (answered yes or no), and, if not, whether they would be willing to contribute a smaller amount (yes or no). To account for the substantial variation in income levels across countries, the question is framed in relative terms. Respondents’ answers thus reflect how strongly they value climate action relative to alternative uses of their income. The figure of 1% is deliberately chosen as it falls within the range of plausible previously reported estimates of climate change mitigation costs 32 , 33 .

Our WTC measure has been empirically validated and shown to predict incentivized pro-climate donation decisions ( Methods ). In a representative US sample 30 , respondents who state they would be willing to contribute 1% of their monthly income donate 43% more money to a climate charity ( P  < 0.001 for a two-sided t -test, N  = 1,993; Supplementary Fig. 1 ) and are 21–39 percentage points more likely to avoid fossil-fuel-based means of transport (car and plane), restrict their meat consumption, use renewable energy or adapt their shopping behaviour (all P  < 0.001 for two-sided t -tests, N  = 1,996; Supplementary Table 1 ).

To measure respondents’ beliefs about other people’s WTC, we first tell respondents that we are surveying many other individuals in their country about their willingness to contribute 1% of their household income every month to fight global warming. We then ask respondents to estimate how many out of 100 other individuals in their country would be willing to contribute this amount, that is, possible answers range from 0 to 100.

To assess individual approval of pro-climate social norms, we ask respondents to indicate whether they think that people in their country ‘should try to fight global warming’ (answered yes or no). Following recent research on social norms 15 , 34 , the item elicits respondents’ views about what other people should do, that is, what kind of behaviour they consider normatively appropriate (so-called injunctive norms 10 ).

Finally, we measure demand for political action by asking respondents whether they think that their ‘national government should do more to fight global warming’ (answered yes or no). This item assesses the extent to which individuals regard their government’s current efforts as insufficient and sheds light on the potential for increased political action in the future.

The approval of pro-climate norms and the demand for political action are deliberately measured in a general manner to account for the fact that suitable concrete mitigation strategies may differ across countries. Our general measures strongly correlate with the approval of specific pro-climate norms and the demand for concrete policy measures ( Methods ). In a representative US sample, individuals who approve of the general norm to act against climate change are substantially more likely to state that individuals ‘should try to’ avoid fossil-fuel-based means of transport (car and plane), restrict their meat consumption, use renewable energy or adapt their shopping behaviour (correlation coefficients ρ between 0.35 and 0.51, all P  < 0.001 for two-sided t -tests, N  = 1,994; Supplementary Table 2 ). Similarly, the general demand for more political action is strongly correlated with demand for specific climate policies, such as a carbon tax on fossil fuels, regulatory limits on the CO 2 emissions of coal-fired plants, or funding for research on renewable energy ( ρ between 0.49 and 0.59, all P  < 0.001 for two-sided t -tests, N  = 1,996; Supplementary Table 3 ).

To ensure comparability across countries and cultures, professional translators translated the survey into the local languages following best practices in survey translation by using an elaborate multi-step translation procedure. The survey was extensively pre-tested in multiple countries of diverse cultural heritage to ensure that respondents with different cultural, economic and educational backgrounds could comprehend the questions in a comparable way. We deliberately refer to ‘global warming’ rather than ‘climate change’ throughout the survey to prevent confusion with seasonal changes in weather 35 , 36 , and provide all respondents with a brief definition of global warming to ensure a common understanding of the term.

A list of variables, definitions and sources is available in Methods . In all analyses, we use Gallup’s sampling weights, which were calculated by Gallup in multiple stages. A probability weight factor (base weight) was constructed to correct for unequal selection probabilities resulting from the stratified random sampling procedure. At the next step, the base weights were post-stratified to adjust for non-response and to match the weighted sample totals to known population statistics. The standard demographic variables used for post-stratification are age, gender, education and region. When describing the data at the supranational level, we also weight each country sample by its share of the world population.

Widespread global support for climate action

The globally representative data reveal strong support for climate action around the world. First, a large majority of individuals—69%—state they would be willing to contribute 1% of their household income every month to fight global warming (Fig. 1a ). An additional 6% report they would be willing to contribute a smaller fraction of their income, and 26% state they would not be willing to contribute any amount. The proportion of respondents willing to contribute 1% of their income varies considerably across countries (Fig. 1b ), ranging from 30% to 93%. In the vast majority of countries (114 of 125) the proportion is greater than 50%, and in a large number of countries (81 of 125) the proportion is greater than two-thirds.

a , c , e , The global average proportions of respondents willing to contribute income ( a ), approving of pro-climate social norms ( c ) and demanding political action ( e ). Population-adjusted weights are used to ensure representativeness at the global level. b , d , f , World maps in which each country is coloured according to its proportion of respondents willing to contribute 1% of income ( b ), approving of pro-climate social norms ( d ) and demanding political action ( f ). Sampling weights are used to account for the stratified sampling procedure. Supplementary Table 4 presents the data. GW, global warming.

Second, we document widespread approval of pro-climate social norms in almost all countries. Overall, 86% of respondents state that people in their country should try to fight global warming (Fig. 1c ). In 119 of 125 countries, the proportion of supporters exceeds two-thirds (Fig. 1d ).

Third, we identify an almost universal global demand for intensified political action. Across the globe, 89% of respondents state that their national government should do more to fight global warming (Fig. 1e ). In more than half the countries in our sample, the demand for more government action exceeds 90% (Fig. 1f ).

Stronger willingness to contribute in vulnerable countries

Although the approval of pro-climate social norms and the demand for intensified political action is substantial in almost all countries (Fig. 1d,f ), there is considerable variation in the proportion of individuals willing to contribute 1% across countries (Fig. 1b ) and world regions (Supplementary Tables 4 and 5) . What explains the cross-country variation in individual WTC? Two patterns stand out.

First, there is a negative relationship between country-level WTC and (log) GDP per capita ( ρ  = −0.47; 95% confidence interval (CI), [−0.60, −0.32]; P  < 0.001 for a two-sided t -test; N  = 125; Fig. 2a ). To illustrate, in the wealthiest quintile of countries, the average proportion of people willing to contribute 1% is 62%, whereas it is 78% in the least wealthy quintile of countries. A country’s GDP per capita reflects its resilience, that is, its economic capacity to cope with climate change. Put differently, in countries that are most resilient, individuals are least willing to contribute 1% of their income to climate action. At the same time, a country’s GDP is strongly related to its current dependence on GHG emissions 37 . For the countries studied here, the correlation coefficient between log GDP and log GHG emissions is 0.87. From a behavioural science perspective, this pattern is consistent with the interpretation that individuals are less willing to contribute if they perceive the adaptation costs as too high, that is, when the required lifestyle changes are perceived as too drastic.

a – c , Binned scatter plots of the country-level proportion of individuals willing to contribute 1% of their income and log average GDP (per capita, purchasing power parity (PPP) adjusted) for 2010–2019 ( a ), annual average temperature (°C) for 2010–2019 ( b ) and the vulnerability index used in the IPCC Sixth Assessment Report (AR6) ( c ) 41 , 42 . The vulnerability index ranges from 0 to 100, with higher values indicating higher vulnerability. Correlation coefficients are calculated from the unbinned country-level data. We use sampling weights to derive the country-level WTC. Number of bins, 20; 6–7 countries per bin; derived from x axis. The red line represents linear regression.

Second, we find a positive relationship between country-level WTC and country-level annual average temperature ( ρ  = 0.35; 95% CI, [0.18, 0.49]; P  < 0.001 for a two-sided t -test, N  = 125; Fig. 2b ). The average proportion of people who are willing to contribute increases from 64% among the coldest quintile of countries to 77% among the warmest quintile of countries. Average annual temperature captures how exposed a country is to global warming risks 38 , 39 . Countries with higher annual temperatures have already experienced greater damage due to global warming, potentially making future threats from climate change more salient to their residents 40 .

Both results replicate in a joint multivariate regression and are robust to the inclusion of continent fixed effects and other economic, political, cultural or geographic factors (Supplementary Tables 6 – 9 ). Focusing on North America, we also find a significantly positive association between WTC and average temperature on the subnational level (Supplementary Fig. 2 ). Moreover, as low GDP and high temperatures constitute two important aspects of vulnerability to climate change, we also draw on a more comprehensive summary measure of vulnerability, derived for the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report 41 , 42 . In addition to national income and poverty levels, the index also takes into account non-economic factors, such as the quality of public infrastructure, health services and governance. It captures a country’s general lack of resilience and adaptive capacity, and it is highly correlated with log GDP ( ρ  = −0.93) and temperature ( ρ  = 0.62). Figure 2c confirms that people living in more vulnerable countries report a stronger WTC.

The country-level variation in pro-climate norms and demand for intensified political action is much smaller than that for the WTC. Nevertheless, we find that higher temperature predicts stronger norms and support for more political action. We do not detect a significant relationship with GDP (Supplementary Table 10 ).

Beliefs and systematic misperceptions

In line with previous research 11 , 22 , 23 , 24 , 25 , 26 , our data support the importance of conditional cooperation at the global level. Figure 3a shows a strong and positive correlation between the country-level proportions of individuals willing to contribute 1% and the corresponding average perceived proportions of fellow citizens willing to contribute 1% ( ρ  = 0.73; 95% CI, [0.64, 0.81]; P  < 0.001 for a two-sided t -test; N  = 125).

a , Binned scatter plots of the country-level proportions of individuals willing to contribute 1% of their income and the average perceived proportions of others who are willing to contribute 1% of their income. We use sampling weights to derive the country-level WTC and perceived WTC. Number of bins, 20; 6–7 countries per bin; derived from x axis. The red line shows the linear regression. b , Gap between the global and country proportions of respondents who are willing to contribute 1% of their income (circles) and the global and country average perceived proportions of others willing to contribute (triangles). The reported significance levels result from two-sided t -tests testing whether the proportion of individuals who are willing to contribute is equal to the average perceived proportion. We use population-adjusted weights to derive the global averages and the standard sampling weights otherwise. We derive the averages based on all available data, that is, we exclude missing responses separately for each question. See Supplementary Figure 4 for additional descriptive statistics for the perceived WTC (median, 25–75% quartile range).

We document the same pattern at the individual level. In a univariate linear regression analysis, a 1-percentage-point increase in the perceived proportion of others’ WTC is associated with a 0.46-percentage-point increase in one’s own probability of contributing (95% CI, [0.41, 0.50]; P  < 0.001; N  = 111,134; Supplementary Table 11 ). This effect size aligns closely with the degree of conditional cooperation that has been documented in the laboratory 26 .

The critical role of beliefs raises the question of whether beliefs are well calibrated. In fact, Fig. 3b reveals sizeable and systematic global misperceptions. At the global level, there is a 26-percentage-point gap (95% CI, [25.6, 26.0]; P  < 0.001 for a two-sided t -test; N  = 125; Supplementary Table 4 ) between the actual proportion of respondents who report being willing to contribute 1% of their income towards climate action (69%) and the average perceived proportion (43%). Put differently, individuals around the globe strongly underestimate their fellow citizens’ actual WTC to the common good. At the country level, the vast majority of respondents underestimate the actual proportion in their country (81%), and a large proportion of respondents underestimate the proportion by more than 10 percentage points (73%). This pattern holds for each country in our sample (Fig. 3b ). In all 125 countries, the average perceived proportion is lower than the actual proportion, significantly so in all but one country (two-sided t -tests, actual versus perceived WTC). If we limit the analysis to those respondents for whom we have non-missing data for both the actual and the perceived WTC, the global perception gap is estimated to be 29 percentage points (95% CI, [27.2, 30.0]; P  < 0.001 for a two-sided t -test; N  = 125; Supplementary Table 12 ), and the average perceived proportion is estimated to be significantly lower than the actual proportion in all 125 countries (Supplementary Fig. 3 ).

Although the perception gap is positive in all countries, we note that the size of the perception gap varies across countries (s.d. = 8.7 percentage points). Examining the same country-level characteristics as before, we find that the gap is significantly larger in countries with higher annual temperatures and significantly smaller in countries with high GDP (Supplementary Table 13 ). These results are largely robust to the inclusion of other economic, political or cultural factors, which we do not find to be significantly related to the perception gap. These findings are robust to only using respondents for whom we have non-missing data for both the actual and perceived WTC.

Climate scientists have stressed that immediate, concerted and determined action against climate change is necessary 32 , 41 , 43 , 44 . Against this backdrop, our study sheds light on people’s willingness to contribute to climate action around the world. What sets our study apart from existing cross-cultural studies on climate change perceptions 1 , 2 , 3 , 4 and policy views 4 , 5 , 6 is its globally representative coverage and its behavioural science perspective.

The results are encouraging. About two-thirds of the global population report being willing to incur a personal cost to fight climate change, and the overwhelming majority demands political action and supports pro-climate norms. This indicates that the world is united in its normative judgement about climate change and the need to act.

The four aspects of cooperation discussed in this article are likely to interact with one another. For example, consensus on pro-climate norms is likely to strengthen individuals’ WTC and vice versa 13 . Similarly, the enactment of climate policies is likely to strengthen climate norms and vice versa 45 . We find a strong positive correlation between the WTC, pro-climate norms, policy support and beliefs about others’ WTC across countries (Supplementary Table 14 ). Moreover, countries with a stronger approval of pro-climate social norms have passed significantly more climate-change-related laws and policies ( ρ  = 0.20; 95% CI, [0.02, 0.36]; P  = 0.028 for a two-sided t -test; N  = 122). These positive interactions suggest that a change in one factor can unlock potent, self-reinforcing feedback cycles, triggering social-tipping dynamics 46 , 47 . Our findings can inform system dynamics models and social climate models that explicitly take into account the interaction of human behaviour with natural, physical systems 48 , 49 .

The widespread willingness to act against climate change stands in contrast to the prevailing global pessimism regarding others’ willingness to act. The world is in a state of pluralistic ignorance, which occurs when people systematically misperceive the beliefs or attitudes held by others 27 , 28 , 29 , 30 , 31 , 50 . The reasons underlying this perception gap are probably multifaceted, encompassing factors such as media and public debates disproportionately emphasizing climate-sceptical minority opinions 51 , and the influence of interest groups’ campaigning efforts 52 , 53 . Moreover, during periods of transition, individuals may erroneously attribute the inadequate progress in addressing climate change to a persistent lack of individual support for climate-friendly actions 54 .

Importantly, these systematic perception gaps can form an obstacle to climate action. The prevailing pessimism regarding others’ support for climate action can deter individuals from engaging in climate action, thereby confirming the negative beliefs held by others. Therefore, our results suggest a potentially powerful intervention, that is, a concerted political and communicative effort to correct these misperceptions. In light of a global perception gap of 26 percentage points (Fig. 3b ) and the observation that a 1-percentage-point increase in the perceived proportion of others willing to contribute 1% is associated with a 0.46-percentage-point increase in one’s own probability to contribute (Supplementary Table 11 ), such an intervention may yield quantitatively large, positive effects. Rather than echoing the concerns of a vocal minority that opposes any form of climate action, we need to effectively communicate that the vast majority of people around the world are willing to act against climate change and expect their national government to act.

Sampling approach

The survey was carried out as part of the Gallup World Poll 2021/2022 in 125 countries, with a median total response duration of 30 min. The four questions were included towards the end of the Gallup World Poll survey and were timed to take about 1.5 min.

Each country sample is designed to be representative of the resident population aged 15 and above. The geographic coverage area from which the samples are drawn generally includes the entire country. Exceptions relate to areas where the safety of the surveyors could not be guaranteed or—in some countries—islands with a very small population.

Interviews are conducted in one of two modes: computer-assisted telephone interviews via landline or mobile phone or face to face (mostly computer assisted). Telephone interviews were used in countries with high telephone coverage, countries in which it is the customary survey methodology and countries in which the coronavirus disease 2019 pandemic ruled out a face-to-face approach. There is one exception: paper-and-pencil interviews had to be used in Afghanistan for 73% of respondents to minimize security concerns.

The selection of respondents is probability based. The concrete procedure depends on the survey mode. More details are available in the documentation of the Gallup World Poll ( https://news.gallup.com/poll/165404/world-poll-methodology.aspx ) 55 .

Telephone interviews involved random-digit dialling or sampling from nationally representative lists of phone numbers. If contacted via landline, one household member aged 15 or older is randomly selected. In countries with a landline or mobile telephone coverage of less than 80%, this procedure is also adopted for mobile telephone calls to improve coverage.

For face-to-face interviews, primary sampling units are identified (cluster of households, stratified by population size or geography). Within those units, a random-route strategy is used to select households. Within the chosen households, respondents are randomly selected.

Each potential respondent is contacted at least three (for face-to-face interviews) or five (telephone) times. If the initially sampled respondent can not be interviewed, a substitution method is used. The median country-level response rate corresponds to 65% for face-to-face interviews and 9% for telephone interviews. These response rates are comparatively high considering that survey participants are not offered financial incentives for participating in the Gallup World Poll. For telephone interviews, the Pew Research Center reports a response rate of 6% in the United States in 2019 ( https://pewrsr.ch/2XqxgTT ). For face-to-face interviews, ref. 56 found a non-response rate of 23.7% even in a country with very high levels of trust, such as Denmark.

The median and most common sample size is 1,000 respondents. An overview of survey modes and sample sizes can be found in Supplementary Table 15 .

Sampling weights

Although the sampling approach is probability based, some groups of respondents are more likely to be sampled by the sampling procedure. For instance, residents in larger households are less likely to be selected than residents in smaller households because both small and large households have an equal chance of being chosen. For this reason, Gallup constructs a probability weight factor (base weight) to correct for unequal selection probabilities. In a second step, the base weights are post-stratified to adjust for non-response and to match known population statistics. The standard demographic variables used for post-stratification are age, gender, education and region. In some countries, additional demographic information is used based on availability (for example, ethnicity or race in the United States). The weights range from 0.12 to 6.23, with a 10–90% quantile range of 0.28 to 2.10, ensuring that no observation is given an excessively disproportionate weight. Of all weights, 93% are between 0.25 and 4. More details are available in the documentation of the Gallup World Poll ( https://news.gallup.com/poll/165404/world-poll-methodology.aspx ) 55 .

We use these weights in our main analyses in two ways: first, when deriving national averages, we weight individual responses with Gallup’s sampling weights; and, second, when conducting individual-level regression analyses, we weight respondents with Gallup’s sampling weights.

We note that this weighting approach does not take into account the fact that some countries have a larger population than others. At the global level, the approach would effectively weight countries by their sample size and not their population size. Therefore, we also derive population-adjusted weights that render the data representative of the global population (aged ≥15) that is covered by our survey. The population-adjusted weight of individual i in country c is derived as

where w i c denotes the original Gallup sampling weight, I c the set of all respondents in country c , s c the country’s share of the global population aged ≥15 and n the total sample size of 129,902 respondents. Division by \({\sum }_{{I}_{c}}{w}_{ic}\) ensures that countries with a larger sample size (Supplementary Table 15 ) do not receive a larger weight. Multiplication with s c ensures that the total weight of a country sample is proportional to its population share. Multiplication with the constant n ensures that the total sum of the population-adjusted weights equals n , but is inconsequential for the results.

Although the two approaches yield very similar results (Supplementary Table 16 ), we use these population-adjusted weights wherever we present global statistics or statistics for supranational world regions. Supplementary Table 16 also shows that we obtain almost identical results if we do not use weights at all.

Global pre-test

A preliminary version of the survey was extensively pre-tested in 2020 in six countries of diverse cultural heritage—Colombia, Egypt, India, Indonesia, Kenya and Ukraine—to ensure that subjects from different cultural and economic backgrounds interpret the questions adequately. In each country, cognitive interviews were conducted by trained interviewers in local languages. The objectives of the pre-test were threefold, that is, to collect feedback, test whether the survey questions were understandable and check whether they were interpreted homogeneously across cultures. Each survey question was followed by additional probing questions that investigated respondents’ understanding of central terms and the overall logic of the question. Moreover, respondents were invited to express any comprehension difficulties. In response to the feedback, several minor adjustments to the survey were made. Most importantly, we switched to the term global warming instead of climate change to prevent confusion with seasonal changes in weather.

Survey items

The US English version of the questionnaire can be found below. Square brackets indicate information that is adjusted to each country. Parentheses indicate that a response option was available to the interviewer but not read aloud to the interviewee. The frequencies of missing data are summarized in Supplementary Table 17 .

Introduction to global warming

Now, on a different topic… The following questions are about global warming. Global warming means that the world’s average temperature has considerably increased over the past 150 years and may increase more in the future.

Willingness to contribute

Question 1 : Would you be willing to contribute 1% of your household income every month to fight global warming? This would mean that you would contribute [$1] for every [$100] of this income.

Responses : Yes, No, (DK), (Refused)

Coding : Binary dummy for Yes. (DK) and (Refused) are coded as missing data.

Question 2 (asked only if ‘No’ was selected in Question 1) : Would you be willing to contribute a smaller amount than 1% of your household income every month to fight global warming?

Responses : Yes, No, I would not contribute any income, (DK), (Refused)

Coding : We classify respondents into three categories based on their responses to both questions. Willing to contribute (at least) 1%, willing to contribute between 0% and 1%, not willing to contribute. We conservatively code (DK) and (Refused) in Question 2 as ‘Not willing to contribute’.

Beliefs about others’ willingness to contribute

Question : We are asking these questions to 100 other respondents in [the United States]. How many do you think are willing to contribute at least 1% of their household income every month to fight global warming?

Responses : 0–100, (DK), (Refused)

Coding : 0–100, (DK) and (Refused) are coded as missing data.

Social norms

Question : Do you think that people in [the United States] should try to fight global warming?

Demand for political action

Question : Do you think the national government should do more to fight global warming?

Note : We were not allowed to field this question in Myanmar, Saudi Arabia and the United Arab Emirates.

Implementation errors

In two countries, an implementation error was made for the question on WTC a proportion of income.

In Kyrgyzstan, 4 of 1,001 respondents answered the survey in the language Uzbek. To these four respondents, the second sentence of question 1 was not read. The other respondents in Kyrgyzstan were interviewed in a different language and were not affected.

In Mongolia, respondents were asked whether they are willing to contribute less than 1% in question 1. Of these respondents, 93.1% answered yes. We approximate the proportion of Mongolian respondents who are willing to contribute 1% as follows. The implementation error should not affect the proportion of respondents who answer no to both questions (4.4%). Moreover, we know that in most countries 5–6% of respondents are not willing to contribute 1% but are willing to contribute a positive amount smaller than 1%. This is also true in neighbouring countries of Mongolia (China, 6.0%; Kazakhstan, 4.9%; Russia, 5.6%). Therefore, we derive the proportion of Mongolian respondents who are willing to contribute 1% as 100% − 4.4% − 6% = 89.6%, which is close to the uncorrected proportion of 93.1%. Results are virtually unchanged if we exclude observations from Mongolia.

Translation

The translation process of the US English original version into other languages followed the TRAPD model, first developed for the European Social Survey 57 . The acronym TRAPD stands for translation, review, adjudication, pre-testing and documentation. It is a team-based approach to translation and has been found to provide more reliable results than alternative procedures, such as back-translation. The following procedure is implemented:

Translation: a local professional translator conducts the first translation.

Review: the translation is reviewed by another professional translator from an independent company. The reviewer identifies any issues, suggests alternative wordings and explains their comments in English.

Adjudication: the original translator receives this feedback and can accept or reject the suggestions. In the latter case, he provides an English explanation for his decision and a third expert adjudicates the disputed translation, which often involves further exchange with the translators.

Pre-testing: a pilot test with at least ten respondents per language is conducted.

Documentation: translations and commentary (Gallup internal) are documented.

The study was approved by the ethics committee of the Gallup World Poll. Informed consent was obtained from all human research participants.

Our main measures of support for climate action are deliberately measured in a general manner to account for the fact that suitable concrete strategies to act against climate change can differ widely across the globe. However, in previous work, we collected both the general measures and additional specific measures for the different facets of climate cooperation. We conducted a survey with a diverse sample of respondents that is representative of the US population in terms of the sociodemographic characteristics of age, gender, education and region 30 . Specifically, we first elicit respondents’ WTC, demand for political action and approval of pro-climate change norms. In a second step, respondents can allocate money between themselves and a pro-climate charity (incentivized). We also elicit whether respondents have engaged in a set of specific climate-friendly behaviours in the previous 12 months (answered yes or no). We further elicit whether they think that people in the United States should engage in these specific climate-friendly behaviours (yes or no). Finally, we measure support for specific climate-change-related policies and regulations using a four-point Likert scale. Supplementary Tables 1 – 3 show that our general measures are strongly correlated with concrete climate-friendly behaviours, concrete climate-friendly norms and support for specific climate-change-related policies and regulation. More details on these data can be found in ref. 30 .

The data in ref. 30 also allow us to investigate whether we obtain similar results using two different survey methodologies. The Gallup World Poll relies on computer-assisted telephone interviews (landline and mobile) and random sampling via random-digit dialling. In ref. 30 , an online survey was conducted and quota-based sampling was used. Reassuringly, we obtain very similar results for the proportion of the population willing to contribute 1% of their household income, supporting pro-climate norms and demanding more political action (Table 1 ).

Additional data sources

Annual temperature.

This is the annual average temperature (in degrees Celsius) from 2010 to 2019. The data are available from the World Bank Group’s Climate Change Knowledge Portal ( https://climateknowledgeportal.worldbank.org/download-data ) and derived from the CRU TS v.4.05 data ( https://crudata.uea.ac.uk/cru/data/hrg/ ).

A set of indicators for whether a country belongs to one of the following five continents: (1) Africa, (2) Americas, (3) Asia, (4) Europe and (5) Oceania.

Economic growth

The average GDP growth rate between 2000 and 2019, obtained by averaging the year-on-year change in real GDP per capita (in constant US dollars) across years (World Bank WDI database, https://databank.worldbank.org/source/world-development-indicators/Series/NY.GDP.PCAP.PP.KD ).

The average national GDP per capita from 2010 to 2019 in constant US dollars, adjusted for differences in purchasing power. To derive the percentage of world GDP that our survey represents, we take national GDP data from 2019. The data for each country are available from the World Bank WDI database ( https://databank.worldbank.org/source/world-development-indicators/Series/NY.GDP.PCAP.PP.KD ). For Taiwan and Venezuela, the World Bank does not provide GDP estimates. Instead, we use data from the International Monetary Fund World Economic Outlook Database ( https://www.imf.org/en/Publications/WEO/weo-database/2022/October ).

GHG emissions

The per-capita GHG emissions expressed in equivalent metric tons of CO 2 averaged from 2010 to 2019. To derive the percentage of world GHG emissions that our survey represents, we take national GHG data from 2019. GHGs include CO 2 (fossil only), CH 4 , N 2 O and F gases. Data are obtained from EDGAR v.7.0 (ref. 58 ).

Individualism–collectivism

This refers to a country’s location on the individualism–collectivism spectrum, which we standardize 59 .

Kinship tightness

This refers to the extent to which people are embedded in large, interconnected extended family networks. The measure is derived from the data of the Ethnographic Atlas in ref. 60 and is available at https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/JX1OIU .

Regional temperature

The population-weighted regional mean temperature in degrees Celsius (between 2010 and 2019). Regions are defined by Gallup and often coincide with the first administrative unit below the national level. We use temperature data from the Climatic Research Unit ( https://crudata.uea.ac.uk/cru/data/hrg/ ) and population data from the LandScan database ( https://www.ornl.gov/project/landscan ) to construct this variable.

Scientific articles

The average number of scientific articles (per capita) from 2009 to 2018. The annual data for each country are available from the World Bank WDI database and normalized with annual population data from the Maddison Project Database 2020 ( https://www.rug.nl/ggdc/historicaldevelopment/maddison/releases/maddison-project-database-2020 ).

Secondary and tertiary education

This refers to the proportion of the population with secondary or tertiary education as the highest level of education. The Gallup World Poll includes respondent-level information on whether the highest level of educational attainment is secondary and tertiary education, which we aggregate to national proportion by using Gallup’s sampling weights.

Survival versus self-expression values

The extent to which people in a country hold survival versus self-expression values, which we standardize. We obtain the data from the axes of the Inglehart–Welzel Cultural Map ( https://www.worldvaluessurvey.org/WVSNewsShow.jsp?ID=467 ) 61 .

Traditional versus secular values

The extent to which people in a country hold traditional versus secular values, which we standardize. We obtain the data from the axes of the Inglehart–Welzel Cultural Map ( https://www.worldvaluessurvey.org/WVSNewsShow.jsp?ID=467 ) 61 .

Vulnerability index

This measure captures a country’s vulnerability as defined in the IPCC Sixth Assessment Report 41 , 42 . Specifically, the measure is the average of the vulnerability subcomponent of the INFORM Risk Index and the WorldRiskIndex. The INFORM Risk Index consists of 32 indicators related to vulnerability and coping capacity. The vulnerability component of the WorldRiskIndex encompasses 23 indicators, which cover susceptibility, absence of coping ability and lack of adaptive capability. For example, the subcomponents include indicators of extreme poverty, food security, access to basic infrastructure, access to health care, health status and governance. The data and documentation are available at https://ipcc-browser.ipcc-data.org/browser/dataset?id=3736 .

Quality of governance standard data set 2021

The following variables are compiled from the Quality of Governance Standard Data Set 2021 ( https://www.gu.se/en/quality-government ) 62 .

Concentration of political power

This variable is based on the Political Constraints Index III from the Political Constraint Index (POLCON) Dataset ( https://mgmt.wharton.upenn.edu/faculty/heniszpolcon/polcondataset/ ), which we standardize.

A binary measure of democracy, obtained from ref. 63 .

Electricity from fossil fuels

The proportion of electricity produced from oil or coal (World Bank WDI database).

Perceived corruption

We use the Corruption Perception Index (0–100) from Transparency International ( https://www.transparency.org/en/cpi/ ), which we standardize.

The size of the population aged 15 or higher in 2019. The data are taken from the World Bank WDI database.

Property rights

The standardized score of the degree to which a country’s laws protect private property rights and the degree to which those laws are enforced (Heritage Foundation’s Index of Economic Freedom dataset; http://www.heritage.org/index/explore ).

Quality of Governance Environmental Indicators Dataset 2021

The following variables are compiled from the Quality of Governance Environmental Indicators Dataset 2021 ( https://www.gu.se/en/quality-government ) 64 .

Annual precipitation

The long-run average of annual precipitation (in mm per year) (World Bank WDI database).

Climate change executive policies

The cumulative number of climate-change-related policies or other executive provisions (from 1946 until 2020), which were published or decreed by the government, president or an equivalent executive authority ( https://climate-laws.org/ ) 65 .

Climate change laws and legislations

The cumulative number of climate-change-related laws and legislations (from 1946 until 2020) that were passed by the parliament or an equivalent legislative authority 65 .

Distance to coast

The average distance to the nearest ice-free coast (in 1,000 km) 66 .

Terrain ruggedness index

An index of the terrain ruggedness (as of 2012) originally developed to measure topographic variation 67 and modified by ref. 66 .

Reporting summary

Further information on research design is available in the Nature Portfolio Reporting Summary linked to this article.

Data availability

The data of the Global Climate Change Survey are available at https://doi.org/10.15185/gccs.1 . References to and the documentation of external and proprietary data, such as the Gallup World Poll data, are available in the Supplementary Information .

Code availability

The analysis code is available at https://doi.org/10.15185/gccs.1 .

Capstick, S., Whitmarsh, L., Poortinga, W., Pidgeon, N. & Upham, P. International trends in public perceptions of climate change over the past quarter century. Wiley Interdiscip. Rev. Clim. Change 6 , 35–61 (2015).

Article   Google Scholar  

Eom, K., Kim, H. S., Sherman, D. K. & Ishii, K. Cultural variability in the link between environmental concern and support for environmental action. Psychol. Sci. 27 , 1331–1339 (2016).

Article   PubMed   Google Scholar  

Lee, T. M., Markowitz, E. M., Howe, P. D., Ko, C.-Y. & Leiserowitz, A. A. Predictors of public climate change awareness and risk perception around the world. Nat. Clim. Change 5 , 1014–1020 (2015).

Article   ADS   Google Scholar  

Leiserowitz, A. et al. International Public Opinion on Climate Change. (Yale Program on Climate Change Communication and Facebook Data for Good, 2021).

Dechezleprêtre, A. et al. Fighting Climate Change: International Attitudes toward Climate Policies . OECD Economics Department Working Paper 1714 (OECD Publishing, 2022).

Fabre, A., Douenne, T. & Mattauch, L. International Attitudes toward Global Policies . Berlin School of Economics Discussion Papers 22 (Berlin School of Economics, 2023).

Tam, K.-P. & Milfont, T. L. Towards cross-cultural environmental psychology: a state-of-the-art review and recommendations. J. Environ. Psychol. 71 , 101474 (2020).

Cort, T. et al. Rising Leaders on Social and Environmental Sustainability. (Yale Center for Business and the Environment and Yale Program on Climate Change Communication, 2022).

Hardin, G. The tragedy of the commons. Science 162 , 1243–1248 (1968).

Article   ADS   CAS   PubMed   Google Scholar  

Cialdini, R. B., Reno, R. R. & Kallgren, C. A. A focus theory of normative conduct: recycling the concept of norms to reduce littering in public places. J. Pers. Soc. Psychol. 58 , 1015–1026 (1990).

Ostrom, E. Collective action and the evolution of social norms. J. Econ. Perspect. 14 , 137–158 (2000).

Bicchieri, C. The Grammar of Society: The Nature and Dynamics of Social Norms (Cambridge Univ. Press, 2006).

Google Scholar  

Nyborg, K. et al. Social norms as solutions. Science 354 , 42–43 (2016).

Fehr, E. & Schurtenberger, I. Normative foundations of human cooperation. Nat. Hum. Behav. 2 , 458–468 (2018).

Constantino, S. M. et al. Scaling up change: a critical review and practical guide to harnessing social norms for climate action. Psychol. Sci. Public Interest 23 , 50–97 (2022).

Elster, J. Social norms and economic theory. J. Econ. Perspect. 3 , 99–117 (1989).

Fehr, E. & Gächter, S. Cooperation and punishment in public goods experiments. Am. Econ. Rev. 90 , 980–994 (2000).

Ostrom, E. Governing the Commons: The Evolution of Institutions for Collective Action (Cambridge Univ. Press, 2015).

Dietz, T., Ostrom, E. & Stern, P. C. The struggle to govern the commons. Science 302 , 1907–1912 (2003).

Besley, T. & Persson, T. The political economics of green transitions. Q. J. Econ. 138 , 1863–1906 (2023).

Nowakowski, A. & Oswald, A. J. Do Europeans Care About Climate Change? An Illustration of the Importance of Data on Human Feelings . IZA Discussion Paper 13660 (IZA Institute of Labor Economics, 2020).

Fischbacher, U., Gächter, S. & Fehr, E. Are people conditionally cooperative? Evidence from a public goods experiment. Econ. Lett. 71 , 397–404 (2001).

Fehr, E. & Fischbacher, U. Social norms and human cooperation. Trends Cogn. Sci. 8 , 185–190 (2004).

Gächter, S. in Economics and Psychology: A Promising New Cross-Disciplinary Field (eds Frey, B. S. & Stutzer, A.) Ch. 2 (MIT Press, 2007).

Rustagi, D., Engel, S. & Kosfeld, M. Conditional cooperation and costly monitoring explain success in forest commons management. Science 330 , 961–965 (2010).

Gächter, S. in The Oxford Handbook of Behavioral Economics and the Law (eds Zamir, E. & Teichman, D.) 28–60 (Oxford Univ. Press, 2014).

Allport, F. H. Social Psychology (Houghton Mifflin, 1924).

Geiger, N. & Swim, J. Climate of silence: pluralistic ignorance as a barrier to climate change discussion. J. Environ. Psychol. 47 , 79–90 (2016).

Mildenberger, M. & Tingley, D. Beliefs about climate beliefs: the importance of second-order opinions for climate politics. Br. J. Polit. Sci. 49 , 1279–1307 (2019).

Andre, P., Boneva, T., Chopra, F. & Falk, A. Misperceived Social Norms and Willingness to Act Against Climate Change . ECONtribute Discussion Paper 101 (ECONtribute, 2022).

Sparkman, G., Geiger, N. & Weber, E. U. Americans experience a false social reality by underestimating popular climate policy support by nearly half. Nat. Commun. 13 , 4779 (2022).

Article   ADS   CAS   PubMed   PubMed Central   Google Scholar  

IPCC Climate Change 2022: Mitigation of Climate Change (eds Shukla, P. R. et al.) (Cambridge Univ. Press, 2022).

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).

Bursztyn, L., González, A. L. & Yanagizawa-Drott, D. Misperceived social norms: women working outside the home in Saudi Arabia. Am. Econ. Rev. 110 , 2297–3029 (2020).

Lorenzoni, I., Leiserowitz, A., de Franca Doria, M., Poortinga, W. & Pidgeon, N. F. Cross-national comparisons of image associations with ‘global warming’ and ‘climate change’ among laypeople in the United States of America and Great Britain. J. Risk Res. 9 , 265–281 (2006).

Whitmarsh, L. What’s in a name? Commonalities and differences in public understanding of ‘climate change’ and ‘global warming’. Public Understand. Sci. 18 , 401–420 (2009).

Azomahou, T., Laisney, F. & Nguyen Van, P. Economic development and CO 2 emissions: a nonparametric panel approach. J. Public Econ. 90 , 1347–1363 (2006).

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

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

Zaval, L., Keenan, E. A., Johnson, E. J. & Weber, E. U. How warm days increase belief in global warming. Nat. Clim. Change 4 , 143–147 (2014).

IPCC Climate Change 2022: Impacts, Adaptation and Vulnerability (eds Pörtner, H.-O. et al.) (Cambridge Univ. Press, 2022).

Birkmann, J. et al. Understanding human vulnerability to climate change: a global perspective on index validation for adaptation planning. Sci. Total Environ. 803 , 150065 (2022).

Hoegh-Guldberg, O. et al. The human imperative of stabilizing global climate change at 1.5°C. Science 365 , eaaw6974 (2019).

Article   CAS   PubMed   Google Scholar  

IPCC Special Report on Global warming of 1.5° C (eds Masson-Delmotte, V. et al.) (Cambridge University Press, 2018).

Sunstein, C. R. On the expressive function of law. U. Pa. L. Rev. 144 , 2021 (1996).

Milkoreit, M. et al. Defining tipping points for social–ecological systems scholarship—an interdisciplinary literature review. Environ. Res. Lett. 13 , 033005 (2018).

Otto, I. M. et al. Social tipping dynamics for stabilizing Earth’s climate by 2050. Proc. Natl Acad. Sci. USA 117 , 2354–2365 (2020).

Beckage, B. et al. Linking models of human behaviour and climate alters projected climate change. Nat. Clim. Change 8 , 79–84 (2018).

Beckage, B., Moore, F. C. & Lacasse, K. Incorporating human behaviour into Earth system modelling. Nat. Hum. Behav. 6 , 1493–1502 (2022).

Miller, D. T. & McFarland, C. Pluralistic ignorance: when similarity is interpreted as dissimilarity. J. Pers. Soc. Psychol. 53 , 298–305 (1987).

Boykoff, M. T. & Boykoff, J. M. Balance as bias: global warming and the US prestige press. Glob. Environ. Change 14 , 125–136 (2004).

Oreskes, N. & Conway, E. M. Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming (Bloomsbury, 2010).

Supran, G., Rahmstorf, S. & Oreskes, N. Assessing ExxonMobil’s global warming projections. Science 379 , eabk0063 (2023).

Ross, L. The intuitive psychologist and his shortcomings: distortions in the attribution process. Adv. Exp. Soc. Psychol. 10 , 173–220 (1977).

Worldwide Research: Methodology and Codebook (Gallup, 2021).

Christensen, A. I., Ekholm, O., Glümer, C. & Juel, K. Effect of survey mode on response patterns: comparison of face-to-face and self-administered modes in health surveys. Eur. J. Public Health 24 , 327–332 (2013).

ESS Round 9 Translation Guidelines (European Social Survey, 2018).

Branco, A. et al. Emissions Database for Global Atmospheric Research, version v7.0_ft_2021 (European Commission, 2022).

Beugelsdijk, S. & Welzel, C. Dimensions and dynamics of national culture: synthesizing Hofstede with Inglehart. J. Cross Cult. Psychol. 49 , 1469–1505 (2018).

Article   PubMed   PubMed Central   Google Scholar  

Enke, B. Kinship, cooperation, and the evolution of moral systems. Q. J. Econ. 134 , 953–1019 (2019).

Inglehart, R. & Welzel, C. The Inglehart–Welzel world cultural map—World Values Survey 7. http://www.worldvaluessurvey.org/ (2023).

Teorell, J. et al. The Quality of Government Standard Dataset, version Jan22 (Univ. of Gothenburg: The Quality of Government Institute, 2022).

Boix, C., Miller, M. & Rosato, S. Boix–Miller–Rosato dichotomous coding of democracy, 1800–2015. https://doi.org/10.7910/DVN/FJLMKT (Harvard Dataverse, 2018).

Povitkina, M., Alvarado Pachon, N. & Dalli, C. M. The Quality of Government Environmental Indicators Dataset, version Sep21 (Univ. of Gothenburg: The Quality of Government Institute, 2021).

Grantham Research Institute on Climate Change and the Environment & Sabin Center for Climate Change Law. Climate Change Laws of the World Database . https://www.lse.ac.uk/granthaminstitute/legislation (2021).

Nunn, N. & Puga, D. Ruggedness: the blessing of bad geography in Africa. Rev. Econ. Stat. 94 , 20–36 (2012).

Riley, S. J., DeGloria, S. D. & Elliot, R. A terrain ruggedness index that quantifies topographic heterogeneity. Intermt. J. Sci. 5 , 23–27 (1999).

Download references

Acknowledgements

We thank S. Gächter, I. Haaland, L. Henkel, A. Oswald, C. Roth, E. Weber and J. Wohlfart for valuable comments. We thank M. Antony for his support in collecting and managing the Global Climate Change Survey data, and J. König, L. Michels, T. Reinheimer and U. Zamindii for excellent research assistance. Funding by the Institute on Behavior and Inequality (briq) (A.F.) and the Deutsche Forschungsgemeinschaft (DFG; through Excellence Strategy EXC 2126/1 390838866 (P.A., T.B. and A.F.) and through CRC TR 224) is gratefully acknowledged (P.A. and A.F.). The activities of the Center for Economic Behavior and Inequality (CEBI) are financed by the Danish National Research Foundation, grant DNRF134 (F.C.). We gratefully acknowledge research support from the Leibniz Institute for Financial Research SAFE (P.A.).

Author information

Authors and affiliations.

SAFE and Goethe University Frankfurt, Frankfurt, Germany

Peter Andre

University of Bonn, Bonn, Germany

Teodora Boneva & Armin Falk

University of Copenhagen and CEBI, Copenhagen, Denmark

Felix Chopra

You can also search for this author in PubMed   Google Scholar

Contributions

All authors (P.A., T.B., F.C. and A.F.) contributed equally to all activities, including the design of the survey, data analysis and writing of the article.

Corresponding author

Correspondence to Armin Falk .

Ethics declarations

Competing interests.

The authors declare no competing interests.

Peer review

Peer review information.

Nature Climate Change thanks Kimin Eom, Adrien Fabre and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

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

Supplementary information

Supplementary information.

Supplementary Figs. 1–4 and Tables 1–17.

Reporting Summary

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 license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license 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 license, visit http://creativecommons.org/licenses/by/4.0/ .

Reprints and permissions

About this article

Cite this article.

Andre, P., Boneva, T., Chopra, F. et al. Globally representative evidence on the actual and perceived support for climate action. Nat. Clim. Chang. 14 , 253–259 (2024). https://doi.org/10.1038/s41558-024-01925-3

Download citation

Received : 13 July 2023

Accepted : 04 January 2024

Published : 09 February 2024

Issue Date : March 2024

DOI : https://doi.org/10.1038/s41558-024-01925-3

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

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.

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, food safety and nutrition.

Climate Change Science: An Analysis of Some Key Questions (2001)

Chapter: summary.

Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise. Temperatures are, in fact, rising. The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability. Human-induced warming and associated sea level rises are expected to continue through the 21st century. Secondary effects are suggested by computer model simulations and basic physical reasoning. These include increases in rainfall rates and increased susceptibility of semi-arid regions to drought. The impacts of these changes will be critically dependent on the magnitude of the warming and the rate with which it occurs.

The mid-range model estimate of human induced global warming by the Intergovernmental Panel on Climate Change (IPCC) is based on the premise that the growth rate of climate forcing 1 agents such as carbon dioxide will accelerate. The predicted warming of 3°C (5.4°F) by the end of the 21st century is consistent with the assumptions about how clouds and atmospheric relative humidity will react to global warming. This estimate is also consistent with inferences about the sensitivity 2 of climate drawn from comparing the sizes of past temperature swings between ice ages and intervening warmer periods with the corresponding changes in the climate forcing. This predicted temperature increase is sensitive to assumptions concerning future concentrations of greenhouse gases and aerosols. Hence, national policy decisions made now and in the longer-term future will influence the extent of any damage suffered by vulnerable human populations and ecosystems later in this century. Because there is considerable uncertainty in current understanding of how the climate system varies naturally and reacts to emissions of greenhouse gases and aerosols, current estimates of the magnitude of future warming should be regarded as tentative and subject to future adjustments (either upward or downward).

Reducing the wide range of uncertainty inherent in current model predictions of global climate change will require major advances in understanding and modeling of both (1) the factors that determine atmospheric concentrations of greenhouse gases and aerosols, and (2) the so-called “feedbacks” that determine the sensitivity of the climate system to a prescribed increase in greenhouse gases. There also is a pressing need for a global observing system designed for monitoring climate.

The committee generally agrees with the assessment of human-caused climate change presented in the IPCC Working Group I (WGI) scientific report, but seeks here to articulate more clearly the level of confidence that can be ascribed to those assessments and the caveats that need to be attached to them. This articulation may be helpful to policy makers as they consider a variety of options for mitigation and/or adaptation. In the sections that follow, the committee provides brief responses to some of the key questions related to climate change science. More detailed responses to these questions are located in the main body of the text.

What is the range of natural variability in climate?

The range of natural climate variability is known to be quite large (in excess of several degrees Celsius) on local

1 A climate forcing is defined as an imposed perturbation of Earth's energy balance. Climate forcing is typically measured in watts per square meter (W/m2).

2 The sensitivity of the climate system to a prescribed forcing is commonly expressed in terms of the global mean temperature change that would be expected after a time sufficiently long for both the atmosphere and ocean to come to equilibrium with the change in climate forcing.

and regional spatial scales over periods as short as a decade. Precipitation also can vary widely. For example, there is evidence to suggest that droughts as severe as the “dust bowl” of the 1930s were much more common in the central United States during the 10th to 14th centuries than they have been in the more recent record. Mean temperature variations at local sites have exceeded 10°C (18°F) in association with the repeated glacial advances and retreats that occurred over the course of the past million years. It is more difficult to estimate the natural variability of global mean temperature because of the sparse spatial coverage of existing data and difficulties in inferring temperatures from various proxy data. Nonetheless, evidence suggests that global warming rates as large as 2°C (3.6°F) per millennium may have occurred during retreat of the glaciers following the most recent ice age.

Are concentrations of greenhouse gases and other emissions that contribute to climate change increasing at an accelerating rate, and are different greenhouse gases and other emissions increasing at different rates? Is human activity the cause of increased concentrations of greenhouse gases and other emissions that contribute to climate change?

The emissions of some greenhouse gases are increasing, but others are decreasing. In some cases the decreases are a result of policy decisions, while in other cases the reasons for the decreases are not well understood.

Of the greenhouse gases that are directly influenced by human activity, the most important are carbon dioxide, methane, ozone, nitrous oxide, and chlorofluorocarbons (CFCs). Aerosols released by human activities are also capable of influencing climate. ( Table 1 lists the estimated climate forcing due to the presence of each of these “climate forcing agents” in the atmosphere.)

Concentrations of carbon dioxide (CO 2 ) extracted from ice cores drilled in Greenland and Antarctica have typically ranged from near 190 parts per million by volume (ppmv) during the ice ages to near 280 ppmv during the warmer “interglacial” periods like the present one that began around 10,000 years ago. Concentrations did not rise much above 280 ppmv until the Industrial Revolution. By 1958, when systematic atmospheric measurements began, they had reached 315 ppmv, and they are currently ~370 ppmv and rising at a rate of 1.5 ppmv per year (slightly higher than the rate during the early years of the 43-year record). Human activities are responsible for the increase. The primary source, fossil fuel burning, has released roughly twice as much carbon dioxide as would be required to account for the observed increase. Tropical deforestation also has contributed to carbon dioxide releases during the past few decades. The excess carbon dioxide has been taken up by the oceans and land biosphere.

Like carbon dioxide, methane (CH 4 ) is more abundant in Earth's atmosphere now than at any time during the 400,000 year long ice core record, which dates back over a number of glacial/interglacial cycles. Concentrations increased rather smoothly by about 1% per year from 1978, until about 1990. The rate of increase slowed and became more erratic during the 1990s. About two-thirds of the current emissions of methane are released by human activities such as rice growing, the raising of cattle, coal mining, use of land-fills, and natural gas handling, all of which have increased over the past 50 years.

A small fraction of the ozone (O 3 ) produced by natural processes in the stratosphere mixes into the lower atmosphere. This “tropospheric ozone” has been supplemented during the 20th century by additional ozone, created locally by the action of sunlight upon air polluted by exhausts from motor vehicles, emissions from fossil fuel burning power plants, and biomass burning.

Nitrous oxide (N 2 O) is formed by many microbial reactions in soils and waters, including those acting on the increasing amounts of nitrogen-containing fertilizers. Some synthetic chemical processes that release nitrous oxide have also been identified. Its concentration has increased approximately 13% in the past 200 years.

Atmospheric concentrations of CFCs rose steadily following their first synthesis in 1928 and peaked in the early 1990s. Many other industrially useful fluorinated compounds (e.g., carbon tetrafluoride, CF 4 , and sulfur hexafluoride, SF 6 ), have very long atmospheric lifetimes, which is of concern, even though their atmospheric concentrations have not yet produced large radiative forcings. Hydrofluorocarbons (HFCs), which are replacing CFCs, have a greenhouse effect, but it is much less pronounced because of their shorter atmospheric lifetimes. The sensitivity and generality of modern analytical systems make it quite unlikely that any currently significant greenhouse gases remain to be discovered.

What other emissions are contributing factors to climate change (e.g., aerosols, CO, black carbon soot), and what is their relative contribution to climate change?

Besides greenhouse gases, human activity also contributes to the atmospheric burden of aerosols, which include both sulfate particles and black carbon (soot). Both are unevenly distributed, owing to their short lifetimes in the atmosphere. Sulfate particles scatter solar radiation back to space, thereby offsetting the greenhouse effect to some degree. Recent “clean coal technologies” and use of low sulfur fuels have resulted in decreasing sulfate concentrations, especially in North America, reducing this offset. Black carbon aerosols are end-products of the incomplete combustion of fossil fuels and biomass burning (forest fires and land clearing). They impact radiation budgets both directly and indirectly; they are believed to contribute to global warming, although their relative importance is difficult to quantify at this point.

How long does it take to reduce the buildup of greenhouse gases and other emissions that contribute to climate change? Do different greenhouse gases and other emissions have different draw down periods?

3 A removal time of 100 years means that much, but not all, of the substance would be gone in 100 years. Typically, the amount remaining at the end of 100 years is 37%; after 200 years 14%; after 300 years 5%; after 400 years 2%

Is climate change occurring? If so, how?

Weather station records and ship-based observations indicate that global mean surface air temperature warmed between about 0.4 and 0.8°C (0.7 and 1.5°F) during the 20th century. Although the magnitude of warming varies locally, the warming trend is spatially widespread and is consistent with an array of other evidence detailed in this report. The ocean, which represents the largest reservoir of heat in the climate system, has warmed by about 0.05°C (0.09°F) averaged over the layer extending from the surface down to 10,000 feet, since the 1950s.

The observed warming has not proceeded at a uniform rate. Virtually all the 20th century warming in global surface air temperature occurred between the early 1900s and the 1940s and during the past few decades. The troposphere warmed much more during the 1970s than during the two subsequent decades, whereas Earth's surface warmed more during the past two decades than during the 1970s. The causes of these irregularities and the disparities in the timing are not completely understood. One striking change of the past 35 years is the cooling of the stratosphere at altitudes of ~13 miles, which has tended to be concentrated in the wintertime polar cap region.

Are greenhouse gases causing climate change?

The IPCC's conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue. The stated degree of confidence in the IPCC assessment is higher today than it was 10, or even 5 years ago, but uncertainty remains because of (1) the level of natural variability inherent in the climate system on time scales of decades to centuries, (2) the questionable ability of models to accurately simulate natural variability on those long time scales, and (3) the degree of confidence that can be placed on reconstructions of global mean temperature over the past millennium based on proxy evidence. Despite the uncertainties, there is general agreement that the observed warming is real and particularly strong within the past 20 years. Whether it is consistent with the change that would be expected in response to human activities is dependent upon what assumptions one makes about the time history of atmospheric concentrations of the various forcing agents, particularly aerosols.

By how much will temperatures change over the next 100 years and where?

Climate change simulations for the period of 1990 to 2100 based on the IPCC emissions scenarios yield a globally-averaged surface temperature increase by the end of the century of 1.4 to 5.8°C (2.5 to 10.4°F) relative to 1990. The wide range of uncertainty in these estimates reflects both the different assumptions about future concentrations of greenhouse gases and aerosols in the various scenarios considered by the IPCC and the differing climate sensitivities of the various climate models used in the simulations. The range of climate sensitivities implied by these predictions is generally consistent with previously reported values.

The predicted warming is larger over higher latitudes than over low latitudes, especially during winter and spring, and larger over land than over sea. Rainfall rates and the frequency of heavy precipitation events are predicted to increase, particularly over the higher latitudes. Higher evaporation rates would accelerate the drying of soils following rain events, resulting in lower relative humidities and higher daytime temperatures, especially during the warm season. The likelihood that this effect could prove important is greatest in semi-arid regions, such as the U.S. Great Plains. These predictions in the IPCC report are consistent with current understanding of the processes that control local climate.

In addition to the IPCC scenarios for future increases in greenhouse gas concentrations, the committee considered a scenario based on an energy policy designed to keep climate change moderate in the next 50 years. This scenario takes into account not only the growth of carbon emissions, but also the changing concentrations of other greenhouse gases and aerosols.

Sufficient time has elapsed now to enable comparisons between observed trends in the concentrations of carbon dioxide and other greenhouse gases with the trends predicted

in previous IPCC reports. The increase of global fossil fuel carbon dioxide emissions in the past decade has averaged 0.6% per year, which is somewhat below the range of IPCC scenarios, and the same is true for atmospheric methane concentrations. It is not known whether these slowdowns in growth rate will persist.

How much of the expected climate change is the consequence of climate feedback processes (e.g., water vapor, clouds, snow packs)?

The contribution of feedbacks to the climate change depends upon “climate sensitivity,” as described in the report. If a central estimate of climate sensitivity is used, about 40% of the predicted warming is due to the direct effects of greenhouse gases and aerosols. The other 60% is caused by feedbacks. Water vapor feedback (the additional greenhouse effect accruing from increasing concentrations of atmospheric water vapor as the atmosphere warms) is the most important feedback in the models. Unless the relative humidity in the tropical middle and upper troposphere drops, this effect is expected to increase the temperature response to increases in human induced greenhouse gas concentrations by a factor of 1.6. The ice-albedo feedback (the reduction in the fraction of incoming solar radiation reflected back to space as snow and ice cover recede) also is believed to be important. Together, these two feedbacks amplify the simulated climate response to the greenhouse gas forcing by a factor of 2.5. In addition, changes in cloud cover, in the relative amounts of high versus low clouds, and in the mean and vertical distribution of relative humidity could either enhance or reduce the amplitude of the warming. Much of the difference in predictions of global warming by various climate models is attributable to the fact that each model represents these processes in its own particular way. These uncertainties will remain until a more fundamental understanding of the processes that control atmospheric relative humidity and clouds is achieved.

What will be the consequences (e.g., extreme weather, health effects) of increases of various magnitude?

In the near term, agriculture and forestry are likely to benefit from carbon dioxide fertilization and an increased water efficiency of some plants at higher atmospheric CO 2 concentrations. The optimal climate for crops may change, requiring significant regional adaptations. Some models project an increased tendency toward drought over semi-arid regions, such as the U.S. Great Plains. Hydrologic impacts could be significant over the western United States, where much of the water supply is dependent on the amount of snow pack and the timing of the spring runoff. Increased rainfall rates could impact pollution run-off and flood control. With higher sea level, coastal regions could be subject to increased wind and flood damage even if tropical storms do not change in intensity. A significant warming also could have far reaching implications for ecosystems. The costs and risks involved are difficult to quantify at this point and are, in any case, beyond the scope of this brief report.

Health outcomes in response to climate change are the subject of intense debate. Climate is one of a number of factors influencing the incidence of infectious disease. Cold-related stress would decline in a warmer climate, while heat stress and smog induced respiratory illnesses in major urban areas would increase, if no adaptation occurred. Over much of the United States, adverse health outcomes would likely be mitigated by a strong public health system, relatively high levels of public awareness, and a high standard of living.

Global warming could well have serious adverse societal and ecological impacts by the end of this century, especially if globally-averaged temperature increases approach the upper end of the IPCC projections. Even in the more conservative scenarios, the models project temperatures and sea levels that continue to increase well beyond the end of this century, suggesting that assessments that examine only the next 100 years may well underestimate the magnitude of the eventual impacts.

Has science determined whether there is a “safe” level of concentration of greenhouse gases?

The question of whether there exists a “safe” level of concentration of greenhouse gases cannot be answered directly because it would require a value judgment of what constitutes an acceptable risk to human welfare and ecosystems in various parts of the world, as well as a more quantitative assessment of the risks and costs associated with the various impacts of global warming. In general, however, risk increases with increases in both the rate and the magnitude of climate change.

What are the substantive differences between the IPCC Reports and the Summaries?

The committee finds that the full IPCC Working Group I (WGI) report is an admirable summary of research activities in climate science, and the full report is adequately summarized in the Technical Summary. The full WGI report and its Technical Summary are not specifically directed at policy. The Summary for Policymakers reflects less emphasis on communicating the basis for uncertainty and a stronger emphasis on areas of major concern associated with human-induced climate change. This change in emphasis appears to be the result of a summary process in which scientists work with policy makers on the document. Written responses from U.S. coordinating and lead scientific authors to the committee indicate, however, that (a) no changes were made without the consent of the convening lead authors (this group represents a fraction of the lead and contributing authors) and (b) most changes that did occur lacked significant impact.

It is critical that the IPCC process remain truly representative of the scientific community. The committee's concerns

focus primarily on whether the process is likely to become less representative in the future because of the growing voluntary time commitment required to participate as a lead or coordinating author and the potential that the scientific process will be viewed as being too heavily influenced by governments which have specific postures with regard to treaties, emission controls, and other policy instruments. The United States should promote actions that improve the IPCC process while also ensuring that its strengths are maintained.

What are the specific areas of science that need to be studied further, in order of priority, to advance our understanding of climate change?

Making progress in reducing the large uncertainties in projections of future climate will require addressing a number of fundamental scientific questions relating to the buildup of greenhouses gases in the atmosphere and the behavior of the climate system. Issues that need to be addressed include (a) the future usage of fossil fuels, (b) the future emissions of methane, (c) the fraction of the future fossil-fuel carbon that will remain in the atmosphere and provide radiative forcing versus exchange with the oceans or net exchange with the land biosphere, (d) the feedbacks in the climate system that determine both the magnitude of the change and the rate of energy uptake by the oceans, which together determine the magnitude and time history of the temperature increases for a given radiative forcing, (e) details of the regional and local climate change consequent to an overall level of global climate change, (f) the nature and causes of the natural variability of climate and its interactions with forced changes, and (g) the direct and indirect effects of the changing distributions of aerosols. Maintaining a vigorous, ongoing program of basic research, funded and managed independently of the climate assessment activity, will be crucial for narrowing these uncertainties.

In addition, the research enterprise dealing with environmental change and the interactions of human society with the environment must be enhanced. This includes support of (a) interdisciplinary research that couples physical, chemical, biological, and human systems, (b) an improved capability of integrating scientific knowledge, including its uncertainty, into effective decision support systems, and (c) an ability to conduct research at the regional or sectoral level that promotes analysis of the response of human and natural systems to multiple stresses.

An effective strategy for advancing the understanding of climate change also will require (1) a global observing system in support of long-term climate monitoring and prediction, (2) concentration on large-scale modeling through increased, dedicated supercomputing and human resources, and (3) efforts to ensure that climate research is supported and managed to ensure innovation, effectiveness, and efficiency.

The warming of the Earth has been the subject of intense debate and concern for many scientists, policy-makers, and citizens for at least the past decade. Climate Change Science: An Analysis of Some Key Questions , a new report by a committee of the National Research Council, characterizes the global warming trend over the last 100 years, and examines what may be in store for the 21st century and the extent to which warming may be attributable to human activity.

READ FREE ONLINE

Welcome to OpenBook!

You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

Do you want to take a quick tour of the OpenBook's features?

Show this book's table of contents , where you can jump to any chapter by name.

...or use these buttons to go back to the previous chapter or skip to the next one.

Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

Switch between the Original Pages , where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

To search the entire text of this book, type in your search term here and press Enter .

Share a link to this book page on your preferred social network or via email.

View our suggested citation for this chapter.

Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

Get Email Updates

Do you enjoy reading reports from the Academies online for free ? Sign up for email notifications and we'll let you know about new publications in your areas of interest when they're released.

There is unequivocal evidence that Earth is warming at an unprecedented rate. Human activity is the principal cause.

• While Earth’s climate has changed throughout its history , the current warming is happening at a rate not seen in the past 10,000 years.
• According to the Intergovernmental Panel on Climate Change ( IPCC ), "Since systematic scientific assessments began in the 1970s, the influence of human activity on the warming of the climate system has evolved from theory to established fact." 1
• Scientific information taken from natural sources (such as ice cores, rocks, and tree rings) and from modern equipment (like satellites and instruments) all show the signs of a changing climate.
• From global temperature rise to melting ice sheets, the evidence of a warming planet abounds.

The rate of change since the mid-20th century is unprecedented over millennia.

Earth's climate has changed throughout history. Just in the last 800,000 years, there have been eight cycles of ice ages and warmer periods, with the end of the last ice age about 11,700 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth’s orbit that change the amount of solar energy our planet receives.

The current warming trend is different because it is clearly the result of human activities since the mid-1800s, and is proceeding at a rate not seen over many recent millennia. 1 It is undeniable that human activities have produced the atmospheric gases that have trapped more of the Sun’s energy in the Earth system. This extra energy has warmed the atmosphere, ocean, and land, and widespread and rapid changes in the atmosphere, ocean, cryosphere, and biosphere have occurred.

Earth-orbiting satellites and new technologies have helped scientists see the big picture, collecting many different types of information about our planet and its climate all over the world. These data, collected over many years, reveal the signs and patterns of a changing climate.

Scientists demonstrated the heat-trapping nature of carbon dioxide and other gases in the mid-19th century. 2 Many of the science instruments NASA uses to study our climate focus on how these gases affect the movement of infrared radiation through the atmosphere. From the measured impacts of increases in these gases, there is no question that increased greenhouse gas levels warm Earth in response.

Scientific evidence for warming of the climate system is unequivocal.

Intergovernmental Panel on Climate Change

Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that Earth’s climate responds to changes in greenhouse gas levels. Ancient evidence can also be found in tree rings, ocean sediments, coral reefs, and layers of sedimentary rocks. This ancient, or paleoclimate, evidence reveals that current warming is occurring roughly 10 times faster than the average rate of warming after an ice age. Carbon dioxide from human activities is increasing about 250 times faster than it did from natural sources after the last Ice Age. 3

The Evidence for Rapid Climate Change Is Compelling:

Global Temperature Is Rising

The planet's average surface temperature has risen about 2 degrees Fahrenheit (1 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide emissions into the atmosphere and other human activities. 4 Most of the warming occurred in the past 40 years, with the seven most recent years being the warmest. The years 2016 and 2020 are tied for the warmest year on record. 5 Image credit: Ashwin Kumar, Creative Commons Attribution-Share Alike 2.0 Generic.

The Ocean Is Getting Warmer

The ocean has absorbed much of this increased heat, with the top 100 meters (about 328 feet) of ocean showing warming of 0.67 degrees Fahrenheit (0.33 degrees Celsius) since 1969. 6 Earth stores 90% of the extra energy in the ocean. Image credit: Kelsey Roberts/USGS

The Ice Sheets Are Shrinking

The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery and Climate Experiment show Greenland lost an average of 279 billion tons of ice per year between 1993 and 2019, while Antarctica lost about 148 billion tons of ice per year. 7 Image: The Antarctic Peninsula, Credit: NASA

Glaciers Are Retreating

Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska, and Africa. 8 Image: Miles Glacier, Alaska Image credit: NASA

Snow Cover Is Decreasing

Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and the snow is melting earlier. 9 Image credit: NASA/JPL-Caltech

Sea Level Is Rising

Global sea level rose about 8 inches (20 centimeters) in the last century. The rate in the last two decades, however, is nearly double that of the last century and accelerating slightly every year. 10 Image credit: U.S. Army Corps of Engineers Norfolk District

Arctic Sea Ice Is Declining

Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades. 11 Credit: NASA's Scientific Visualization Studio

Extreme Events Are Increasing in Frequency

The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events. 12 Image credit: Régine Fabri,  CC BY-SA 4.0 , via Wikimedia Commons

Ocean Acidification Is Increasing

Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30%. 13 , 14 This increase is due to humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the ocean. The ocean has absorbed between 20% and 30% of total anthropogenic carbon dioxide emissions in recent decades (7.2 to 10.8 billion metric tons per year). 1 5 , 16 Image credit: NOAA

1. IPCC Sixth Assessment Report, WGI, Technical Summary . B.D. Santer et.al., “A search for human influences on the thermal structure of the atmosphere.” Nature 382 (04 July 1996): 39-46. https://doi.org/10.1038/382039a0. Gabriele C. Hegerl et al., “Detecting Greenhouse-Gas-Induced Climate Change with an Optimal Fingerprint Method.” Journal of Climate 9 (October 1996): 2281-2306. https://doi.org/10.1175/1520-0442(1996)009<2281:DGGICC>2.0.CO;2. V. Ramaswamy, et al., “Anthropogenic and Natural Influences in the Evolution of Lower Stratospheric Cooling.” Science 311 (24 February 2006): 1138-1141. https://doi.org/10.1126/science.1122587. B.D. Santer et al., “Contributions of Anthropogenic and Natural Forcing to Recent Tropopause Height Changes.” Science 301 (25 July 2003): 479-483. https://doi.org/10.1126/science.1084123. T. Westerhold et al., "An astronomically dated record of Earth’s climate and its predictability over the last 66 million years." Science 369 (11 Sept. 2020): 1383-1387. https://doi.org/10.1126/science.1094123

2. In 1824, Joseph Fourier calculated that an Earth-sized planet, at our distance from the Sun, ought to be much colder. He suggested something in the atmosphere must be acting like an insulating blanket. In 1856, Eunice Foote discovered that blanket, showing that carbon dioxide and water vapor in Earth's atmosphere trap escaping infrared (heat) radiation. In the 1860s, physicist John Tyndall recognized Earth's natural greenhouse effect and suggested that slight changes in the atmospheric composition could bring about climatic variations. In 1896, a seminal paper by Swedish scientist Svante Arrhenius first predicted that changes in atmospheric carbon dioxide levels could substantially alter the surface temperature through the greenhouse effect. In 1938, Guy Callendar connected carbon dioxide increases in Earth’s atmosphere to global warming. In 1941, Milutin Milankovic linked ice ages to Earth’s orbital characteristics. Gilbert Plass formulated the Carbon Dioxide Theory of Climate Change in 1956.

3. IPCC Sixth Assessment Report, WG1, Chapter 2 Vostok ice core data; NOAA Mauna Loa CO2 record O. Gaffney, W. Steffen, "The Anthropocene Equation." The Anthropocene Review 4, issue 1 (April 2017): 53-61. https://doi.org/abs/10.1177/2053019616688022.

4. https://www.ncei.noaa.gov/monitoring https://crudata.uea.ac.uk/cru/data/temperature/ http://data.giss.nasa.gov/gistemp

5. https://www.giss.nasa.gov/research/news/20170118/

6. S. Levitus, J. Antonov, T. Boyer, O Baranova, H. Garcia, R. Locarnini, A. Mishonov, J. Reagan, D. Seidov, E. Yarosh, M. Zweng, " NCEI ocean heat content, temperature anomalies, salinity anomalies, thermosteric sea level anomalies, halosteric sea level anomalies, and total steric sea level anomalies from 1955 to present calculated from in situ oceanographic subsurface profile data (NCEI Accession 0164586), Version 4.4. (2017) NOAA National Centers for Environmental Information. https://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/index3.html K. von Schuckmann, L. Cheng, L,. D. Palmer, J. Hansen, C. Tassone, V. Aich, S. Adusumilli, H. Beltrami, H., T. Boyer, F. Cuesta-Valero, D. Desbruyeres, C. Domingues, A. Garcia-Garcia, P. Gentine, J. Gilson, M. Gorfer, L. Haimberger, M. Ishii, M., G. Johnson, R. Killick, B. King, G. Kirchengast, N. Kolodziejczyk, J. Lyman, B. Marzeion, M. Mayer, M. Monier, D. Monselesan, S. Purkey, D. Roemmich, A. Schweiger, S. Seneviratne, A. Shepherd, D. Slater, A. Steiner, F. Straneo, M.L. Timmermans, S. Wijffels. "Heat stored in the Earth system: where does the energy go?" Earth System Science Data 12, Issue 3 (07 September 2020): 2013-2041. https://doi.org/10.5194/essd-12-2013-2020.

7. I. Velicogna, Yara Mohajerani, A. Geruo, F. Landerer, J. Mouginot, B. Noel, E. Rignot, T. Sutterly, M. van den Broeke, M. Wessem, D. Wiese, "Continuity of Ice Sheet Mass Loss in Greenland and Antarctica From the GRACE and GRACE Follow-On Missions." Geophysical Research Letters 47, Issue 8 (28 April 2020): e2020GL087291. https://doi.org/10.1029/2020GL087291.

8. National Snow and Ice Data Center World Glacier Monitoring Service

9. National Snow and Ice Data Center D.A. Robinson, D. K. Hall, and T. L. Mote, "MEaSUREs Northern Hemisphere Terrestrial Snow Cover Extent Daily 25km EASE-Grid 2.0, Version 1 (2017). Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/MEASURES/CRYOSPHERE/nsidc-0530.001 . http://nsidc.org/cryosphere/sotc/snow_extent.html Rutgers University Global Snow Lab. Data History

10. R.S. Nerem, B.D. Beckley, J. T. Fasullo, B.D. Hamlington, D. Masters, and G.T. Mitchum, "Climate-change–driven accelerated sea-level rise detected in the altimeter era." PNAS 15, no. 9 (12 Feb. 2018): 2022-2025. https://doi.org/10.1073/pnas.1717312115.

11. https://nsidc.org/cryosphere/sotc/sea_ice.html Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS, Zhang and Rothrock, 2003) http://psc.apl.washington.edu/research/projects/arctic-sea-ice-volume-anomaly/ http://psc.apl.uw.edu/research/projects/projections-of-an-ice-diminished-arctic-ocean/

12. USGCRP, 2017: Climate Science Special Report: Fourth National Climate Assessment, Volume I [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, https://doi.org/10.7930/j0j964j6 .

13. http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F

14. http://www.pmel.noaa.gov/co2/story/Ocean+Acidification

15. C.L. Sabine, et al., “The Oceanic Sink for Anthropogenic CO2.” Science 305 (16 July 2004): 367-371. https://doi.org/10.1126/science.1097403.

16. Special Report on the Ocean and Cryosphere in a Changing Climate , Technical Summary, Chapter TS.5, Changing Ocean, Marine Ecosystems, and Dependent Communities, Section 5.2.2.3. https://www.ipcc.ch/srocc/chapter/technical-summary/

Header image shows clouds imitating mountains as the sun sets after midnight as seen from Denali's backcountry Unit 13 on June 14, 2019. Credit: NPS/Emily Mesner Image credit in list of evidence: Ashwin Kumar, Creative Commons Attribution-Share Alike 2.0 Generic.

Discover More Topics From NASA

Explore Earth Science

Earth Science in Action

Earth Science Data

Facts About Earth

An official website of the United States government

Here’s how you know

Official websites use .gov A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS A lock ( Lock A locked padlock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

JavaScript appears to be disabled on this computer. Please click here to see any active alerts .

Climate Change Research

Fifth national climate assessment.

It's Earth Month!

Check out NCA5, the most comprehensive analysis of the state of climate change in the United States.

Explore NCA5

EPA’s Climate Change Research seeks to improve our understanding of how climate change impacts human health and the environment.

Air Quality

Researching how changes in climate can affect air quality.

Community Resilience

Research to empower communities to become more resilient to climate change.

Ecosystems & Water Quality

Research to understand how climate change is affecting these resources now and in the future.

Researching how energy production will impact climate and the environment.

Human Health

Research to understand how a changing climate will impact human health.

Tools & Resources

Decision support tools, models & databases, research grants, outreach, and educational resources.

More Resources

• Publications, Presentations, and Other Research Products in Science Inventory
• Climate Change Research Milestones
• EPA's Climate Change Homepage
• EPA's Climate Adaptation Plan

• Show search

Climate Change Stories

Climate Change FAQs

You asked. Our scientists answered. Use this guide to have the best info about climate change and how we can solve it together.

December 09, 2018 | Last updated November 13, 2023

Top Question: What Can I Do About Climate Change?

• Start a conversation. Talking about climate change is the best way to kickstart action , says Chief Scientist Kath arine Hayhoe.
• Vote at the ballot box (and the store). At every level, elected leaders have influence on policies that affect us all. And support companies taking climate action.
• Take personal action. Calculate your carbon footprint and share what you’ve learned to make action contagious.

Climate Change Basics

Click items to expand answers.

Each of these terms describes parts of the same problem—the fact that the average temperature of Earth is rising. As the planet heats up (global warming), we see broad impacts on Earth’s climate, such as shifting seasons, rising sea level, and melting ice.

As the impacts of climate change become more frequent and more severe, they will create—and in many cases they already are creating—crises for people and nature around the world. Many types of extreme weather, including heatwaves, heavy downpours, hurricanes and wildfires are becoming stronger and more dangerous.

Left unchecked, these impacts will spread and worsen, affecting our homes and cities, economies, food and water supplies as well as the species, ecosystems, and biodiversity of this planet we all call home.

All of these terms are accurate, and there’s no perfect one that will make everyone realize the urgency of action. Whatever you choose to call it, the most important thing is that we act to stop it.

Yes, scientists agree that the warming we are seeing today is entirely human-caused.

Climate has changed in the past due to natural factors such as volcanoes, changes in the sun’s energy and the way the Earth orbits the sun.  In fact, these natural factors should be cooling the planet. However, our planet is warming.

Scientists have known for centuries that the Earth has a natural blanket of greenhouse or heat-trapping gases. This blanket keeps the Earth more than 30 degrees Celsius (over 60 degrees Fahrenheit) warmer than it would be otherwise. Without this blanket, our Earth would be a frozen ball of ice.

Greenhouse gases, which include carbon dioxide and methane, trap some of the Earth’s heat that would otherwise escape to space. The more heat-trapping gases in the atmosphere, the thicker the blanket and the warmer it gets.

Over Earth’s history, heat-trapping gas levels have gone up and down due to natural factors. Today, however, by burning fossil fuels, causing deforestation ( forests are key parts of the planet’s natural carbon management systems), and operating large-scale industrial agriculture, humans are rapidly increasing levels of heat-trapping gases in the atmosphere.

The human-caused increase in carbon dioxide in the atmosphere is much greater than any observed in the paleoclimate history (i.e. ancient climate data measured through ice sheets, tree rings, sediments and more) of the earth. As a result, temperature in the air and ocean is now increasing faster than at any time in human history.

Scientists have looked at every other possible reason why climate might be changing today, and their conclusions are clear. There’s no question: it’s us.

One of the main reasons scientists are so worried about climate change is the speed at which it is occurring. In many cases, these changes are happening faster than animals, plants, and ecosystems can safely adapt to – and the same is true for human civilization.

We’ve never seen climate change this quickly, and it is putting our food and water systems, our infrastructure, and even our economies at risk. In some places, these changes are already crossing safe levels for ecosystems and humans.

That’s why, the more we do to mitigate these risks, the better off we will all be.

Effects of Climate Change

Climate change is affecting our planet in many ways. Average temperatures are increasing; rainfall patterns are shifting; snow lines are retreating; glaciers and ice sheets are melting; permafrost is thawing; sea levels are rising ; and severe weather is becoming more frequent.

In particular, heatwaves are becoming more frequent and more intense. Tropical cyclones like hurricanes, typhoons, and cyclones are intensifying faster and dumping more rain. Wildfires are burning greater area, and in many areas around the world, heavy rainfall is becoming more frequent and droughts are getting stronger.

All of these impacts are concerning because they can harm and even potentially lead to the collapse of ecosystems and human systems. And it’s clear that they become more severe  the more heat-trapping gases we produce.

Rapid changes in climate can directly and indirectly impact animals across the world. Many species are approaching—or have already reached—the limit of where they can go to find hospitable climates. In the polar regions, animals like polar bears that live on sea ice are now struggling to survive as that ice melts.

It’s not just how climate change affects an animal directly; it’s about how the warming climate affects the ecosystem and food chain to which an animal has adapted. For example, in the U.S. and Canada, moose are being affected by an increase in ticks and parasites that are surviving the  shorter, milder winters .

In western North America, salmon rely on steady-flowing cold rivers to spawn. As climate change alters the temperature and flow of these waterways, some salmon populations are dwindling. This change in salmon population affects many species that rely on salmon like orcas or grizzly bears.

Changes in temperature and moisture are causing some species to migrate in search of new places to live. For instance, in North America, species are shifting their ranges an average of 11 miles north and 36 feet higher in elevation each decade to find more favorable conditions. The Central Appalachians are one resilient climate escape route  that may help species adapt to changing conditions.

There are some natural places with enough topographical diversity such that, even as the planet warms, they can be  resilient strongholds for plant and animal species . These strongholds serve as breeding grounds and seed banks for many plants and animals that otherwise may be unable to find habitat due to climate change. However, strongholds are not an option for all species, and some plants and animals are blocked from reaching these areas by human development like cities, highways and farmland.

Here at The Nature Conservancy, we use science to identify such locations and work with local partners and communities to do everything we can to protect them.

From reducing agricultural productivity to threatening livelihoods and homes, climate change is affecting people everywhere. You may have noticed how  weather patterns near you are shifting  or how more frequent and severe storms are developing in the spring. Maybe your community is experiencing more severe flooding or  wildfires .

Many areas are even experiencing “sunny day flooding” as rising sea levels cause streets to flood during high tides. In Alaska, some entire coastal communities are being moved because the sea level has risen and what used to be permanently frozen ground has thawed to the point where their original location is no longer habitable.

Climate change also  exacerbates the threat of human-caused conflict  resulting from a scarcity of resources like food and water that become less reliable as growing seasons change and rainfall patterns become less predictable.

Many of these impacts are disproportionately affecting low-income, Indigenous, or marginalized communities. For example, in large cities in North America, low-income communities are often hotter during heatwaves, more likely to flood during heavy downpours, and the last to have their power restored after storms.

Around the globe, many of the poorest nations are being impacted first and most severely by climate change, even though they have contributed far less to the carbon pollution that has caused the warming in the first place. Climate change affects us all, but it doesn’t affect us all equally: and that’s not fair.

Whether you live close to a coast or far from one, what happens in oceans matters to our lives .

Earlier, we described how greenhouse gases trap heat around the planet. Only a small fraction of the extra heat being trapped by the carbon pollution blanket is going into heating up the atmosphere. Almost 90% of the heat is going into the ocean, causing the ocean to warm.

Warmer water takes up more space, causing sea level to rise. As land-based ice melts, this addition of water from land to the ocean causes the ocean to rise even faster.

Warmer oceans can drive fish migrations and lead to coral bleaching and die off.

As the ocean surface warms, it’s less able to mix with deep, nutrient-rich water, which limits the growth of phytoplankton (little plants that serve as the base of the marine food web and that also produce a lot of the oxygen we breathe). This in turn affects the whole food chain.

In addition to taking up heat, the oceans are also absorbing about a quarter of the carbon pollution that humans produce. In addition to warming the air and water of our planet, some of this extra carbon dioxide is being absorbed by the ocean, making our oceans more acidic. In fact, the rate of ocean acidification is the highest it has been in 300 million years!

This acidification negatively impacts many marine habitats and animals, but is a particular threat to shellfish, which struggle to grow shells as water becomes more acidic.

There’s also evidence that warming surface waters may contribute to slowing ocean currents. These currents act like a giant global conveyor belt that transports heat from the tropics toward the poles. This conveyor belt is critical for bringing nutrient-rich waters towards the surface near the poles where giant blooms of food web-supporting phytoplankton occur (this is why the Arctic and Antarctic are known for having such high abundance of fish and marine mammals). With continued warming, these processes may be at risk.

Climate change is disrupting weather patterns, leading to more extreme and frequent heatwaves, droughts, and flooding events that directly threaten harvests. Warmer seasons are also contributing to rising populations of insect pests that eat a higher share of crop yields, and higher carbon dioxide levels are causing plants to grow faster, while decreasing their nutritional content.

Flooding, drought, and heatwaves have decimated crops in China. In Bangladesh, rising sea levels are threatening rice crops. In the midwestern United States, more frequent and intense rains have caused devastating spring flooding, which delays—and sometimes prevents—planting activities.

These impacts make it more difficult for farmers to grow crops and sustain their livelihoods. Globally, one recent study finds that staple crop yield failures will be 4.5 times higher by 2030 and 25 times higher by mid-century. That means a major rice or wheat failure every other year, and higher probabilities of soybean and maize failures.

However, farmers are poised to play a significant role in addressing climate change. Agricultural lands are among the Earth’s largest natural reservoirs of carbon , and when farmers use soil health practices like cover crops, reduced tillage, and crop rotations, they can draw carbon out of the atmosphere .

These practices also help to improve the soil’s water-holding capacity, which is beneficial as water can be absorbed from the soil by crops during times of drought, and during heavy rainfalls, soil can help reduce flooding and run-off by slowing the release of water into streams.

Healthier soils can also improve crop yields, boost farmers’ profitability, and reduce erosion and fertilizer runoff from farm fields, which in turn means cleaner waterways for people and nature. That’s why climate-smart agriculture is a win-win!

Solutions to Climate Change

Yes, deforestation, land use change, and agricultural emissions are responsible for about a quarter of heat-trapping gas emissions from human activities. Agricultural emissions include methane from livestock digestion and manure, nitrous oxide from fertilizer use, and carbon dioxide from land use change.

Forests are one of our most important types of natural carbon storage , so when people cut down forests, they lose their ability to store carbon. Burning trees—either through wildfires or controlled burns-- releases even more carbon into the atmosphere.

Forests are some of the best natural climate solutions we have on this planet. If we can slow or stop deforestation , manage natural land so that it is healthy, and use other natural climate solutions such as climate-smart agricultural practices, we could achieve up to one third of the emission reductions needed by 2030 to keep global temperatures from rising more than 2°C (3.6°F). That’s the equivalent of the world putting a complete stop to burning oil.

When it comes to climate change, there’s no one solution that will fix it all. Rather, there are many solutions that, together, can address this challenge at scale while building a safer, more equitable, and greener world.

First, we need to reduce our heat-trapping gas emissions as much as possible, as soon as possible. Through efficiency and behavioral change, we can reduce the amount of energy we need.

At the same time, we have to  transition all sectors of our economy away from fossil fuels  that emit carbon, through increasing our use of clean energy sources like wind and solar. This transition will happen much faster and more cost-effectively if governments enact an economy-wide price on carbon.

Second, we need to harness the power of nature to capture carbon and deploy agricultural practices and technologies that capture and store carbon. Our research shows that proper land management of forests and farmlands, also called natural climate solutions, can provide up to one-third of the emissions reductions necessary to reach the Paris Climate Agreement’s goal.

The truth, however, is that even if we do successfully reach net zero carbon emissions by 2050, we will still have to address harmful climate impacts. That’s why there is a third category of climate solutions that is equally important: adaptation to the impacts of global warming.

Adaptation consists of helping our human and natural systems prepare for the impacts of a warming planet. Greening urban areas helps protect them from heat and floods; restoring coastal wetlands helps protect from storm surge; increasing the diversity of ecosystems helps them to weather heat and drought; growing super-reefs helps corals withstand marine heatwaves. There are many ways we can use technology, behavioral change, and nature to work together to make us more resilient to climate impacts.

Climate change affects us all, but it doesn’t affect us all equally or fairly. We see how sea level rise threatens communities of small island states like Kiribati and the Solomon Islands and of low-lying neighborhoods in coastal cities like Mumbai, Houston and Lagos. Similarly, people living in many low-income neighborhoods in urban areas in North America are disproportionately exposed to heat and flood risk due to a long history of racist policies like redlining.

Those who have done the least to contribute to this problem often bear the brunt of the impacts and have the fewest resources to adapt. That’s why it is particularly important to help vulnerable communities adapt and become more resilient to climate change.

We need to  increase renewable energy at least nine-fold  from where it is today to meet the goals of the Paris Agreement and avoid the worst climate change impacts. Every watt that we can reduce through efficiency or shift from fossil fuel to renewables like wind power or solar power is a step in the right direction.

The best science we have tells us that to avoid the worst impacts of global warming, we must globally achieve net-zero carbon emissions no later than 2050. To do this, the world must immediately identify pathways to reduce carbon emissions from all sectors: transportation, agriculture, electricity, and industry. This cannot be achieved without a major shift to renewable energy.

Clean energy and technological innovation are not only helping mitigate climate change, but also helping create jobs and support economic growth in communities across the world. Renewable energy such as wind and solar have experienced remarkable growth and huge cost improvements over the past decade with no signs of slowing down.

Prices are declining rapidly, and renewable energy is becoming increasingly competitive with fossil fuels all around the world. In some places, new renewable energy is already cheaper than continuing to operate old, inefficient, and dirty fossil fuel-fired power plants.

However, it’s important that renewable energy development isn’t built at the expense of protecting unique ecosystems or important agricultural lands. Without proactive planning, renewable energy developments could displace up to 76 million acres of farm and wildlife habitat—an area the size of Arizona.

Fortunately, TNC studies have found that  we can meet clean energy demand 17 times over  without converting more natural habitat. The key is to deploy new energy infrastructure on the wealth of previously converted areas such as agricultural lands, mine sites, and other transformed terrain, at a  lower cost .

Thoughtful planning is required at every step. For instance, much of the United States’ wind potential is in the Great Plains, a region with the best remaining grassland habitat on the continent. TNC has mapped out the right places to site wind turbines  in this region in order to catalyze renewable energy responsibly, and we’re doing the same analysis for India and Europe as well.

There can also be unique interventions to protect wildlife where clean energy has already been developed. In Kenya, for instance, a wind farm employs biodiversity monitors to watch for migrating birds , and can order individual turbines to shut down in less than a minute.

The Nature Conservancy is committed to tackling the dual crises of climate change and biodiversity loss. These two crises are, as our chief scientist says, two sides of the same coin .

What we do between now and 2030 will determine if we get on track to meet the targets of the Paris Agreement while also conserving enough land and water to slow accelerated species loss. That’s why we have ambitious 2030 goals that focus on people and the planet.

We're combatting these dual crises by:

• Enhancing nature’s ability to draw down and store carbon across forests, farmlands and wetlands by  accelerating the deployment of natural climate solutions .
• Mobilizing action for a clean energy future  and new, low-carbon technologies in harmony with nature.
• Supporting the leadership of Indigenous Peoples and local communities .
• Building resilience through natural defenses such as restored reefs, mangroves and wetlands that reduce the impact of storms and floods.
• Restoring and bolstering the resilience of vulnerable ecosystems like coral reefs and coastal wetlands.
• Helping countries around the globe, like India and Croatia , implement and enhance their commitments to the Paris Agreement.

Visit  Our Goals for 2030  to learn more about TNC’s actions and partnerships to tackle climate change this decade.

Why We Must Urgently Act on Climate

Some amount of change has already occurred, and some future changes are inevitable due to our past choices. However, the good news is that we know what causes it and what to do to stop it. It will take courage, ambition, and a push to create change, but it can be done.

Reaching net zero carbon emissions by 2050 is an ambitious goal, one that’s going to require substantial effort across every sector of the economy. We don’t have a lot of time, but if we are prepared to act now, and act together, we can substantially reduce the rate of global warming and prevent the worst impacts of climate change from coming to pass.

The even better news is that the low carbon economy that we need to create will also give us cleaner air, more abundant food and water, more affordable energy choices, and safer cities. Likewise, many of the solutions to even today’s climate change impacts benefit both people and nature.

When we really understand the benefits of climate action—how it will lead us to a world that is safer and healthier, more just and equitable—the only question we have left is: What are we waiting for?

Scientific studies show that climate change, if unchecked, would overwhelm our communities and pose an existential threat to certain ecosystems.

These catastrophic impacts include sea level rise from melting ice sheets in Greenland and Antarctica that would flood most major global coastal cities; increasingly common and more severe storms, droughts, and heatwaves; massive crop failures and water shortages; and the large-scale destruction of habitats and ecosystems, leading to species extinctions .

To avoid the worst of climate change, the Intergovernmental Panel on Climate Change (IPCC) says that “every bit of warming matters.” When it comes to limiting climate change, there’s no magic threshold: the faster we reduce our emissions, the better off we will be.

In 2015, all the countries in the world came together and signed the Paris Agreement . It’s a legally binding international treaty in which signatories agree to hold “the increase in the global average temperature to well below 2°C (3.5° F) above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C (2.7°F) above pre-industrial levels.”

Every day that goes by, we are releasing carbon into the atmosphere and increasing our planetary risk. Scientists agree that we need to begin reducing carbon emissions  RIGHT NOW .

To reach the goal of the Paris Agreement, the world must make significant progress toward decarbonization (reducing carbon from the atmosphere and replacing fossil fuels in our economies) by 2030 and commit ourselves to reaching net zero carbon emissions by 2050. This is no small feat and will require a range of solutions applied together, to reach the goal.

As the IPCC says, “every action matters.” You can be part of the climate change solution and you can activate others, too.

It’s really important that we use our voices for climate action.  Tell your policy makers that you care about climate change  and want to see them enact laws and policies that address greenhouse gas emissions and climate impacts.

One of the simplest—and most important—things that everyone can do is to  talk about climate change with family and friends . We know these conversations can seem like a recipe for discord and hard feelings. It starts with meeting people where they are. TNC has resources to help you break the climate silence and pave the way for action on global warming.

You can also talk about climate change where you work, and with any other organization you’re part of. Join an organization that shares your values and priorities, to help amplify your voice. Collective change begins with understanding the risks climate change poses and the actions that can be taken together to reduce emissions and build resilience.

Lastly, you can calculate your carbon footprint  and take actions individually or with your family and friends to lower it. You might be surprised which of your activities are emitting the most heat-trapping gases. But don’t forget to talk about the changes you’ve made, to help make them contagious —contagious in a good way, of course!

Stay connected for the latest news from nature.

Get global conservation stories, news and local opportunities near you. Check out a sample Nature News email.

Please provide a valid email address

You’ve already signed up with this email address. To review your email preferences, please visit nature.org/emailpreferences

We may have detected a typo. Please enter a valid email address (formatted as [email protected]). Did you mean to type ?

We are sorry, but there was a problem processing the reCAPTCHA response. Please contact us at [email protected] or try again later.

Talking About Climate

COP28: Your Guide to the 2023 UN Climate Change Conference in UAE

COP28 takes place November 30-December 12, 2023 in United Arab Emirates. This guide will tell you what to expect at COP28, why TNC will be there, and what it all means for you.

Food, Climate and Nature FAQs: Understanding the Food System’s Role in Healing Our Planet

You've got questions about food, farming, climate and nature. We've got answers and easy ways you can support regenerative food systems that help the planet.

Renewable Energy Transition

We no longer need to choose between abundant energy and a cleaner environment. A renewable energy revolution is happening across the globe.

Quick links

• Climate change
• COVID-19 research
• Staff profiles

Climate change questions and answers

Why is our climate changing? What are the impacts? Here we address some of the common questions raised about the changing climate and the science involved in studying it.

What is climate change?

Climate change refers to any long-term trends or shifts in climate over many decades.

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.

Why do sea levels change?

Sea levels can change for a variety of reasons over a range of different time scales.

How are large scale climate processes responding in a changing climate?

Large-scale climate processes, such as El Niño and the Indian Ocean Dipole, affect Australia’s climate. Climate change may make the impacts of these processes more extreme.

How is climate likely to change in the future?

The Earth's future climate will depend on whether the world manages to slow or reduce greenhouse gas emissions, but warming is likely to continue.

How do greenhouse gases warm the planet?

The greenhouse effect keeps the Earth’s climate liveable, but human activities have increased the amounts of carbon dioxide and other greenhouse gases in the air, warming the planet and changing our climate.

What are the sources of carbon dioxide in the atmosphere?

About 90 per cent of the world’s carbon emissions comes from the burning of fossil fuels, and most of Australia’s emissions also comes from energy production, followed by transport, agriculture, and industrial processes.

How are greenhouse gases measured, estimated, and reported?

The Australian Government uses a ‘bottom-up’ approach to estimate the country’s greenhouse emissions, which is complemented by CSIRO measurements to provide ‘top-down’ estimates.

How can we address the causes of climate change?

We need to address climate change through mitigation and adaptation. Mitigation addresses the cause of climate change, primarily through emissions reductions.

How can we adapt to climate change?

Adaption to climate change can prepare communities, industries and infrastructure for the future. Adaptation can build resilience and reduce the risks posed by climate change, but there are barriers and limits. Some risks are unavoidable.

How does CSIRO contribute to climate change knowledge?

Our climate researchers contribute significantly to the international effort of weather and climate understanding.

What are the impacts of extreme weather and climate events?

Increases in extreme climate events pose challenges for Australia now and in the future.

How will climate extremes change Australia?

Australia experiences many different climate types across its large area, including a range of climate extremes from freezing mountains to scorching deserts. As climate changes, Australia’s weather and climate extremes will also change.

How fast is the climate changing?

While our climate has always changed, it is now changing at a rate that is unprecedented for many thousands of years and is due to human activities that emit greenhouse gases into the air.

How confident are we about the science of climate change?

The main impacts and mechanisms of physical climate change are scientifically well-understood, but specific estimates of these impacts are uncertain.

Where can I find more information about climate change?

Check where information comes from to ensure it is based on reliable and quality-assured sources of climate change science, such as peer-reviewed papers.

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.

ENCYCLOPEDIC ENTRY

Global warming.

The causes, effects, and complexities of global warming are important to understand so that we can fight for the health of our planet.

Earth Science, Climatology

Tennessee Power Plant

Ash spews from a coal-fueled power plant in New Johnsonville, Tennessee, United States.

Photograph by Emory Kristof/ National Geographic

Global warming is the long-term warming of the planet’s overall temperature. Though this warming trend has been going on for a long time, its pace has significantly increased in the last hundred years due to the burning of fossil fuels . As the human population has increased, so has the volume of fossil fuels burned. Fossil fuels include coal, oil, and natural gas, and burning them causes what is known as the “greenhouse effect” in Earth’s atmosphere.

The greenhouse effect is when the sun’s rays penetrate the atmosphere, but when that heat is reflected off the surface cannot escape back into space. Gases produced by the burning of fossil fuels prevent the heat from leaving the atmosphere. These greenhouse gasses are carbon dioxide , chlorofluorocarbons, water vapor , methane , and nitrous oxide . The excess heat in the atmosphere has caused the average global temperature to rise overtime, otherwise known as global warming.

Global warming has presented another issue called climate change. Sometimes these phrases are used interchangeably, however, they are different. Climate change refers to changes in weather patterns and growing seasons around the world. It also refers to sea level rise caused by the expansion of warmer seas and melting ice sheets and glaciers . Global warming causes climate change, which poses a serious threat to life on Earth in the forms of widespread flooding and extreme weather. Scientists continue to study global warming and its impact on Earth.

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.

February 21, 2024

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

Numbers, Facts and Trends Shaping Your World

Read our research on:

Full Topic List

Regions & Countries

• Publications
• Our Methods
• Short Reads
• Tools & Resources

Read Our Research On:

• In Response to Climate Change, Citizens in Advanced Economies Are Willing To Alter How They Live and Work

Many doubt success of international efforts to reduce global warming

Table of contents.

• Acknowledgments
• Methodology

This analysis focuses on attitudes toward global climate change around the world. For this report, we conducted nationally representative Pew Research Center surveys of 16,254 adults from March 12 to May 26, 2021, in 16 advanced economies. All surveys were conducted over the phone with adults in Canada, Belgium, France, Germany, Greece, Italy, the Netherlands, Spain, Sweden, the UK, Australia, Japan, New Zealand, Singapore, South Korea and Taiwan.

In the United States, we surveyed 2,596 U.S. adults from Feb. 1 to 7, 2021. Everyone who took part in the U.S. survey is a member of the Center’s American Trends Panel (ATP), an online survey panel that is recruited through national, random sampling of residential addresses. This way nearly all adults have a chance of selection. The survey is weighted to be representative of the U.S. adult population by gender, race, ethnicity, partisan affiliation, education and other categories.

This study was conducted in countries where nationally representative telephone surveys are feasible. Due to the coronavirus outbreak, face-to-face interviewing is not currently possible in many parts of the world.

Here are the questions used for the report, along with responses. See our methodology database for more information about the survey methods outside the U.S. For respondents in the U.S., read more about the ATP’s methodology .

A new Pew Research Center survey in 17 advanced economies spanning North America, Europe and the Asia-Pacific region finds widespread concern about the personal impact of global climate change. Most citizens say they are willing to change how they live and work at least some to combat the effects of global warming, but whether their efforts will make an impact is unclear.

Citizens offer mixed reviews of how their societies have responded to climate change, and many question the efficacy of international efforts to stave off a global environmental crisis.

Conducted this past spring, before the summer season ushered in new wildfires , droughts , floods and stronger-than-usual storms , the study reveals a growing sense of personal threat from climate change among many of the publics polled. In Germany, for instance, the share that is “very concerned” about the personal ramifications of global warming has increased 19 percentage points since 2015 (from 18% to 37%).

In the study, only Japan (-8 points) saw a significant decline in the share of citizens deeply concerned about climate change. In the United States, views did not change significantly since 2015.

Young adults, who have been at the forefront of some of the most prominent climate change protests in recent years, are more concerned than their older counterparts about the personal impact of a warming planet in many publics surveyed. The widest age gap is found in Sweden, where 65% of 18- to 29-year-olds are at least somewhat concerned about the personal impacts of climate change in their lifetime, compared with just 25% of those 65 and older. Sizable age differences are also found in New Zealand, Australia, the U.S., France and Canada.

Public concern about climate change appears alongside a willingness to reduce its effects by taking personal steps. Majorities in each of the advanced economies surveyed say they are willing to make at least some changes in how they live and work to address the threat posed by global warming. And across all 17 publics polled, a median of 34% are willing to consider “a lot of changes” to daily life as a response to climate change.

Generally, those on the left of the political spectrum are more open than those on the right to taking personal steps to help reduce the effects of climate change. This is particularly true in the U.S., where citizens who identify with the ideological left are more than twice as willing as those on the ideological right (94% vs. 45%) to modify how they live and work for this reason. Other countries where those on the left and right are divided over whether to alter their lives and work in response to global warming include Canada, the Netherlands, Australia and Germany.

Beyond individual actions, the study reveals mixed views on the broader, collective response to climate change. In 12 of the 17 publics polled, half or more think their own society has done a good job dealing with global climate change. But only in Singapore (32%), Sweden (14%), Germany (14%), New Zealand (14%) and the United Kingdom (13%) do more than one-in-ten describe such efforts as “very good.” Meanwhile, fewer than half in Japan (49%), Italy (48%), the U.S. (47%), South Korea (46%) and Taiwan (45%) give their society’s climate response favorable marks.

Abroad, the U.S. response to climate change is generally seen as wanting. Among the 16 other advanced economies surveyed, only Singaporeans are slightly positive in their assessment of American efforts (53% say the U.S. is doing a “good job” of addressing climate change). Elsewhere judgments are harsher, with six-in-ten or more across Australia, New Zealand and many of the European publics polled saying the U.S. is doing a “bad job” of dealing with global warming. However, China fares substantially worse in terms of international public opinion: A median of 78% across 17 publics describe China’s handling of climate change as “bad,” including 45% who describe the Chinese response as “very bad.” That compares with a cumulative median of 61% who judge the American response as “bad.”

At the cross-national level, the European Union’s response to climate change is viewed favorably by majorities in each of the advanced economies surveyed, except Germany where opinion is split (49% good job; 47% bad job). However, there is still room for improvement, as only a median of 7% across the publics polled describe the EU’s efforts as “very good.” The United Nations’ actions to address global warming are also generally seen in a favorable light: A median of 56% say the multilateral organization is doing a good job. But again, the reviews are tempered, with just 5% describing the UN’s response to climate change as “very good.”

Publics in the advanced economies surveyed are divided as to whether actions by the international community can successfully reduce the effects of global warming. Overall, a median of 52% lack confidence that a multilateral response will succeed, compared with 46% who remain optimistic that nations can respond to the impact of climate change by working together. Skepticism of multilateral efforts is most pronounced in France (65%), Sweden (61%) and Belgium (60%), while optimism is most robust in South Korea (68%) and Singapore (66%).

These are among the findings of a new Pew Research Center survey, conducted from Feb. 1 to May 26, 2021, among 18,850 adults in 17 advanced economies.

People concerned climate change will harm them during their lifetimes

Many people across 17 advanced economies are concerned that global climate change will harm them personally at some point in their lifetime. A median of 72% express at least some concern that they will be personally harmed by climate change in their lifetimes, compared with medians of 19% and 11% who say they are not too or not at all concerned, respectively. The share who say they are very concerned climate change will harm them personally ranges from 15% in Sweden to 57% in Greece.

Roughly two-thirds of Canadians and six-in-ten Americans are worried climate change will harm them in their lifetimes. Only 12% of Canadians and 17% of Americans are not at all concerned about the personal impact of global climate change.

Publics in Europe express various degrees of concern for potential harm caused by climate change. Three-quarters or more of those in Greece, Spain, Italy, France and Germany say they are concerned that climate change will harm them at some point during their lives. Only in Sweden does less than a majority of adults express concern about climate change harming them. Indeed, 56% of Swedes are not concerned about personal harm related to climate change.

In general, Asia-Pacific publics express more worry about climate change causing them personal harm than not. The shares who express concern range from 64% in Australia to 88% in South Korea. About one-third or more in South Korea, Singapore and Australia say they are very concerned climate change will harm them personally.

The share who are very concerned climate change will harm them personally at some point during their lives has increased significantly since 2015 in nearly every country where trend data is available. In Germany, for example, the share who say they are very concerned has increased 19 percentage points over the past six years. Double-digit changes are also present in the UK (+18 points), Australia (+16), South Korea (+13) and Spain (+10). The only public where concern for the harm from climate change has decreased significantly since 2015 is Japan (-8 points).

While many worry climate change will harm them personally in the future, there is widespread sentiment that climate change is already affecting the world around them. In Pew Research Center surveys conducted in 2019 and 2020, a median of 70% across 20 publics surveyed said climate change is affecting where they live a great deal or some amount. And majorities in most countries included as part of a 26-nation survey in 2018 thought global climate change was a major threat to their own country (the same was true across all 14 countries surveyed in 2020 ).

Those who place themselves on the left of the ideological spectrum are more likely than those who place themselves on the right to be concerned global climate change will harm them personally during their lifetime. This pattern is present across all 14 nations where ideology is measured. In 10 of these 14, though, majorities across the ideological left, center and right are concerned climate change will harm them personally.

The difference is starkest in the U.S.: Liberals are 59 percentage points more likely than conservatives to express concern for this possibility (87% vs. 28%, respectively). However, large ideological differences are also present in Australia (with liberals 41 points more likely to say this), the Netherlands (+35), Canada (+30), Sweden (+30) and New Zealand (+23).

Women are more concerned than men that climate change will harm them personally in many of the publics polled. In Germany, women are 13 points more likely than men to be concerned that climate change will cause them harm (82% vs 69%, respectively). Double-digit differences are also present across several publics, including the U.S., Sweden, the UK, South Korea, Singapore, Taiwan, Australia and the Netherlands.

When this question was first asked in 2015 , women were also more likely to express concern than their male counterparts that climate change will harm them in the U.S., Germany, Canada, Japan, Spain and Australia.

Young people have been at the forefront of past protests seeking government action on climate change. In eight places surveyed, young adults ages 18 to 29 are more likely than those 65 and older to be concerned climate change will harm them during their lifetime. The difference is greatest in Sweden, home of youth climate activist Greta Thunberg . Young Swedes are 40 points more likely than their older counterparts to say they are concerned about harm from climate change. Large age gaps are also present in New Zealand (with younger adults 31 points more likely to say this), Australia (+30) and Singapore (+20). And young Americans, French, Canadians and Brits are also more likely to say that climate change will personally harm them in their lifetimes.

While large majorities across every age group in Greece and South Korea are concerned climate change will harm them personally, those ages 65 and older are more likely to hold this sentiment than those younger than 30.

Many across the world willing to change how they live and work to reduce effects of climate change

Many across the publics surveyed say they are willing to make at least some changes to the way they live and work to reduce the effects of climate change. A median of 80% across 17 publics say they would make at least some changes to their lives to reduce the effects of climate change, compared with a median of 19% who say they would make a few changes or no changes at all. The share willing to make a lot of changes ranges from 8% in Japan to 62% in Greece.

In North America, about three-quarters or more of both Canadians and Americans say they are willing to make changes to reduce the effects of climate change.

Large majorities across each of the European publics surveyed say they are willing to change personal behavior to address climate change, but the share who say they are willing to make a lot of changes varies considerably. About half or more in Greece, Italy and Spain say they would make a lot of changes, while fewer than a third in Belgium, Germany and the Netherlands say the same.

Majorities in each of the Asia-Pacific publics polled say they would make some or a lot of changes to how they live and work to combat the effects of climate change, including more than three-quarters in South Korea, Singapore, Australia and New Zealand. But in Japan, fully 44% say they are willing to make few or no changes to how they live and work to address climate change, the largest share of any public surveyed.

In eight countries surveyed, those ages 18 to 29 are more likely than those 65 and older to say they are willing to make at least some changes to how they live and work to help reduce the effects of climate change. In France, for example, about nine-in-ten of those younger than 30 are willing to make changes in response to climate change, compared with 62% of those 65 and older.

Ideologically, those on the left are more likely than those on the right to express willingness to change their behavior to help reduce the effects of global climate change. The ideological divide is widest in the U.S., where 94% of liberals say they are willing to make at least some changes to how they live and work to help reduce the effects of climate change, compared with 45% of conservatives. Large ideological differences are also present between those on the left and the right in Canada (a difference of 26 percentage points), the Netherlands (25 points), Australia (23 points) and Germany (22 points).

In most publics, those with more education are more likely than those with less education to say they are willing to adjust their lifestyles in response to the impact of climate change. 1 In Belgium, for example, those with a postsecondary degree or higher are 14 points more likely than those with a secondary education or below to say they are willing to make changes to the way they live. Double-digit differences are also present between those with more education and less education in France, Germany, New Zealand, the Netherlands and Australia.

And in most places surveyed, those with a higher-than-median income are more likely than those with a lower income to express willingness to make at least some changes to reduce the effects of climate change. For example, in Belgium, about three-quarters (76%) of those with a higher income say they would make changes to their lives, compared with 66% of those with a lower income.

Many are generally positive about how their society is handling climate change

Respondents give mostly positive responses when asked to reflect on how their own society is handling climate change. Around half or more in most places say they their society is doing at least a somewhat good job, with a median of 56% saying this across the 17 advanced economies.

Roughly two-thirds (64%) of Canadians say their country is doing a good job, while nearly half of Americans say the same.

In most of the European publics surveyed, majorities believe their nation’s climate change response is at least somewhat good. Those in Sweden and the UK are especially optimistic, with around seven-in-ten saying their society is doing a good job dealing with climate change. In Europe, Italians are the most critical of their country’s performance: 20% say their society is doing a very bad job, the largest share among all publics surveyed.

Around eight-in-ten in Singapore and New Zealand say their publics are doing a good job – the highest levels among all societies surveyed. This includes around a third (32%) in Singapore who say they are doing a very good job. Adults in the other Asia-Pacific publics surveyed are more circumspect; about half or fewer say their society is doing a good job.

Political ideology plays a role in how people evaluate their own public’s handling of climate change. For adults in 10 countries, those on the right tend to rate their country’s performance with regard to climate change more positively. The difference is most stark in Australia: 69% of those on the right say Australia is handling climate change well, compared with just 19% of those on the left – a 50-point difference. A striking difference also appears in the U.S., where conservatives are 41 points more likely than liberals to say the U.S. is doing a good job dealing with climate change.

Evaluations are also tied to how people view governing parties. In 10 of 17 publics surveyed, people who see the governing party positively are more likely than those with a negative view of the party to think climate change is being handled well. The opposite is true in the U.S., where only 33% of Democrats and Democratic-leaning independents say the U.S. is handling climate change well, compared with 61% of those who do not support the Democratic Party.

Mixed views on whether action by the international community can reduce the effects of climate change

Only a median of 46% across the publics polled are confident that actions taken by the international community will significantly reduce the effects of climate change. A median of 52% are not confident these actions will reduce the effects of climate change.

Canadians are generally divided on whether international climate action can reduce the impact of climate change. And 54% of Americans are not confident in the international community’s response to the climate crisis.

In Europe, majorities in Germany and the Netherlands express confidence that international climate action can significantly address climate change. However, majorities in France, Sweden, Belgium and Italy are not confident in climate actions taken by the international community.

South Koreans and Singaporeans say they are confident in international climate action, but elsewhere in the Asia-Pacific region, public opinion is either divided or leans toward pessimism about international efforts.

Opinion of international organizations, like the United Nations, is linked to confidence that actions taken by the international community will significantly reduce the effects of global climate change. Those with a favorable view of the UN are more confident that actions taken by the international community will significantly reduce the effects of climate change than those with an unfavorable view of the UN. This difference is largest in the U.S., where 61% with a favorable view of the UN say international action will reduce the effects of climate change, compared with just 22% of those with an unfavorable view of the organization. Double-digit differences are present in every public polled.

Similarly, in every EU member state included in the survey, those with favorable views of the bloc are more likely to have confidence in international efforts to combat climate change than those with unfavorable views.

Little consensus on whether international climate action will harm or benefit domestic economies

Relatively few in the advanced economies surveyed think actions taken by the international community to address climate change, such as the Paris climate agreement, will mostly benefit or harm their own economy. A median of 31% across 17 publics say these actions will be good for their economy, while a median of 24% believe such actions will mostly harm their economy. A median of 39% say actions like the Paris climate agreement will have no economic impact.

In Sweden, about half (51%) feel international climate actions will mostly benefit their economy. On the other hand, only 18% in France say their public will benefit economically from international climate agreements.

In no public do more than a third say international action on climate change will harm their economy. But in the U.S., which pulled out of the Paris climate agreement under former President Donald Trump and has just recently rejoined the accord under President Joe Biden, a third say international climate agreements will harm the economy. (For more on how international publics view Biden’s international policy actions, see “ America’s Image Abroad Rebounds With Transition From Trump to Biden .”)

The more widespread sentiment among those surveyed is that climate actions will have no impact on domestic economies. In eight publics, four-in-ten or more hold this opinion, including half in France. And in two places – Japan and Taiwan – one-in-five or more offer no opinion.

Those on the left of the ideological spectrum are more likely than those on the right to say international action to address climate change – such as the Paris Agreement – will mostly benefit their economies. U.S. respondents are particularly divided by ideology. Roughly half (53%) of liberals feel international actions related to climate change will benefit the U.S. economy, compared with just 12% of conservatives. The next largest difference is in Canada, where those on the left are 24 percentage points more likely than those on the right to think this type of international action will benefit their economy.

Those on the right in many publics are, in turn, more likely than those on the left to think international actions such as the Paris Agreement will mostly harm their economies. Here again, ideological divisions in the U.S. are much larger than those in other publics: 65% of conservatives say international climate change actions will harm the American economy, compared with 12% of liberals who say the same.

In several advanced economies, those who say their current economic situation is good are more likely to say that actions taken by the international community to address climate change will mostly benefit their economies than those who say the economic situation is bad. In Sweden, for example, a majority (55%) of those who say the current economic situation is good also believe international action like the Paris Agreement will benefit the Swedish economy, compared with 31% who are more negative about the state of the economy.

Evaluating the climate change response from the EU, UN, U.S. and China

In addition to reflecting on their own public, respondents were asked to evaluate how four international organizations or countries are handling global climate change. Of the entities asked about, the European Union receives the best ratings, with a median of 63% across the 17 publics surveyed saying the EU is doing a good job handling climate change. A median of 56% say the same for the United Nations. Far fewer believe the U.S. or China – the two leading nations in carbon dioxide emissions – are doing a good job.

EU handling of climate change receives high marks in and outside of Europe

Majorities in all but two of the publics surveyed think the EU is doing a good job addressing climate change. However, this positivity is tempered, with most respondents saying the EU’s effort is somewhat good, but few saying it is very good.

Praise for the bloc’s response to climate change is common among the European countries surveyed. In Spain and Greece, around seven-in-ten say the EU is doing at least a somewhat good job, and about six-in-ten or more in the UK, Italy, Sweden and France agree. The Dutch and Germans have more mixed feelings about how the EU is responding to climate change. Notably, only about one-in-ten say the EU is doing a very bad job handling climate change in every European country surveyed but Sweden, where only 5% say so.

Seven-in-ten Canadians believe the EU is doing a good job dealing with climate change, and 62% in the U.S. express the same view.

The Asia-Pacific publics surveyed report similarly positive attitudes on the EU’s climate plans. Around seven-in-ten Australians and Singaporeans consider the EU’s response to climate change at least somewhat good. About six-in-ten or more in New Zealand, South Korea, Japan and Taiwan echo this sentiment.

Climate change actions by UN seen positively among most surveyed

Majorities in most publics also consider the UN response to climate change to be good. A median of 49% across all publics surveyed say that the UN’s actions are somewhat good, and a median of 5% say the actions are very good.

Canadians evaluate the UN’s performance on climate more positively than Americans do. In Canada, roughly six-in-ten say the multilateral organization is doing at least a somewhat good job handling climate change. About half of those in the U.S. agree with that evaluation, with 43% of Americans saying the UN is doing a bad job of dealing with climate change.

In Europe, majorities in Spain, Sweden, the UK, Greece and Italy approve of how the UN is dealing with climate change. Fewer than half of adults in the Netherlands, France and Belgium agree with this evaluation, and only about a third in Germany say the same.

Singaporeans stand out as the greatest share of adults among those surveyed who see the UN’s handling of climate change as good. This includes 14% who say the UN response is very good, which is at least double the share in all other societies surveyed. Majorities in Australia and New Zealand similarly say that the UN is doing a good job.

Many critical of U.S. approach to climate change

In most publics surveyed, adults who say the U.S. is doing a good job of handling climate change are in the minority. A median of 33% say the U.S. is doing a somewhat good job, and a median of just 3% believe the U.S. is doing a very good job.

About half of Americans say their own country is doing a good job in dealing with global climate change, but six-in-ten Canadians say their southern neighbor is doing a bad job.

Across Europe, most think the U.S. is doing a bad job of addressing climate change, including 75% of Germans and Swedes. And at least a quarter in all European nations surveyed except the UK and Greece say the U.S. is doing a very bad job.

Singaporeans offer the U.S. approach to climate change the most praise in the Asia-Pacific region and across all publics surveyed; around half say they see the U.S. strategy positively. New Zealanders are the most critical in the Asia-Pacific region: Only about a quarter say the U.S. is doing at least a somewhat good job.

Political ideology is linked to evaluations of the U.S. climate strategy. In 12 countries, those on the right of the political spectrum are significantly more likely than those on the left to say the U.S. is doing a good job dealing with global climate change. The difference is greatest in Australia, Canada and Italy.

Few give China positive marks for handling of climate change

The publics surveyed are unenthusiastic about how China is dealing with climate change. A median of 18% across the publics say China is doing a good job, compared with a median of 78% who say the opposite. Notably, a median of 45% say that China is doing a very bad job handling climate change.

Just 18% of Americans and Canadians believe China is doing a good job handling climate change.

Similarly, few in Europe think China is dealing effectively with climate change. In fact, more than four-in-ten in nearly all European countries polled say China is doing a very bad job with regards to climate change. Criticism is less common in Greece, where a third give China positive marks for its climate change action.

Adults in the Asia-Pacific region also generally give China poor ratings for dealing with climate change. South Koreans are exceptionally critical; about two-thirds say China is doing a very bad job, the highest share in all publics surveyed. About four-in-ten or more in New Zealand, Japan and Australia concur. Singaporeans stand out, as half say China is doing a good job, nearly 20 percentage points higher than the next highest public.

In nine countries surveyed, those with less education are more positive toward China’s response to climate change than those with more education. Likewise, those with lower incomes are more inclined to provide positive evaluations of China’s climate change response. Those with less education or lower incomes are also less likely to provide a response in several publics.

CORRECTION (Oct. 13, 2021): In the chart “Publics are divided over the economic impact of international actions to address global climate change,” the “Don’t Know” column has been edited to reflect updated percentages to correct for a data tabulation error. These changes did not affect the report’s substantive findings.

• For the purpose of comparing educational groups across publics, education levels are standardized based on the UN’s International Standard Classification of Education (ISCED). The “less education” category is secondary education or below and the “more education” category is postsecondary or above in Australia, Belgium, Canada, Denmark, France, Germany, Italy, Japan, Netherlands, New Zealand, Singapore, South Korea, Spain, Sweden, Taiwan, UK and U.S. ↩

Sign up for our weekly newsletter

Fresh data delivery Saturday mornings

Sign up for The Briefing

Weekly updates on the world of news & information

• China Global Image
• Environment & Climate
• European Union
• Issue Priorities
• U.S. Global Image
• United Nations

How people in Hong Kong view mainland China and their own identity

In east asia, many people see china’s power and influence as a major threat, u.s.-germany relationship remains solid, but underlying policy differences begin to show, how views of the u.s., china and their leaders have changed over time, comparing views of the u.s. and china in 24 countries, most popular, report materials.

• American Trends Panel Wave 82
• Spring 2021 Survey Data

1615 L St. NW, Suite 800 Washington, DC 20036 USA (+1) 202-419-4300 | Main (+1) 202-857-8562 | Fax (+1) 202-419-4372 |  Media Inquiries

Research Topics

• Age & Generations
• Coronavirus (COVID-19)
• Economy & Work
• Family & Relationships
• Gender & LGBTQ
• Immigration & Migration
• International Affairs
• Internet & Technology
• Methodological Research
• News Habits & Media
• Non-U.S. Governments
• Other Topics
• Politics & Policy
• Race & Ethnicity
• Email Newsletters

ABOUT PEW RESEARCH CENTER  Pew Research Center is a nonpartisan fact tank that informs the public about the issues, attitudes and trends shaping the world. It conducts public opinion polling, demographic research, media content analysis and other empirical social science research. Pew Research Center does not take policy positions. It is a subsidiary of  The Pew Charitable Trusts .

Copyright 2024 Pew Research Center

Terms & Conditions

Privacy Policy

Cookie Settings

Reprints, Permissions & Use Policy

April 27, 2024

Climate Leaders Debate Goal for Controlling Global Warming

A new U.N. program highlights the disconnect between climate messaging and the growing possibility of overshooting a key global warming threshold

By Chelsea Harvey & E&E News

Chair of the United Nations Sustainable Development Group Achim Steiner speaks during an exclusive interview in Istanbul, Turkiye on March 21, 2024.

Hakan Akgun/Anadolu via Getty Images

CLIMATEWIRE | NEW YORK — The United Nations Development Programme launched a new program Tuesday that aims to galvanize countries around stronger climate action — and keep global warming below 1.5 degrees Celsius.

Known as Climate Promise 2025, the plan centers on strengthening the carbon-cutting pledges that countries will update next year under the Paris climate agreement. It’s the latest stage of UNDP’s Climate Promise program , which worked with 128 countries on the 2020 round of pledges — known as nationally determined contributions, or NDCs.

“The next two years stand as one of the best chances we have as a global community to course correct our collective path and ensure warming stays below 1.5 degrees Celsius, staving off the worst effects of climate change,” said Achim Steiner, UNDP administrator, at an event launching the initiative in New York on Tuesday.

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing . By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

Yet scientists warn that the 1.5-degree target — the Paris Agreement’s most ambitious goal — is already all but out of reach. Global efforts to reduce greenhouse gas emissions aren’t happening fast enough, and many experts say it’s virtually certain that the world will at least temporarily overshoot that threshold.

It’s the latest example of a growing divide between the public messaging from many world leaders and the warnings from scientists that a breach of the 1.5-degree target is already imminent. The disconnect raises questions about how — and whether — world leaders should communicate the growing possibility of an overshoot.

“Sooner or later, policymakers will have to embrace the ‘overshoot story’ if they want to stick to 1.5C,” said Oliver Geden, a climate policy expert at the German Institute for International and Security Affairs, in an email to POLITICO's E&E News.

If world leaders accept the likelihood of an overshoot, they can begin to consider ways to reverse it, Geden added. It’s possible for the world to temporarily exceed the 1.5-degree target and later use technological means to bring global temperatures back down — for instance, by drawing carbon dioxide back out of the atmosphere, in a strategy known as “negative emissions.”

Most potential global cooling strategies are still unproven at large scales, making them an uncertain solution. It’s not clear any of the technologies will ever be feasible at all, Geden said.

But "negative emissions" strategies are among the only methods that could keep the 1.5-degree target alive after an overshoot.

That means policymakers “would need to plan for and to communicate that the world needs to reach net-negative CO2 emissions after reaching net-zero around 2050,” Geden said.

But other experts argue that public messaging around the 1.5-degree target shouldn’t change, even if overshoot becomes unavoidable. The world must still continue to rapidly reduce greenhouse gas emissions to keep as close to the original target as possible.

“You need to do the same things whether you're aiming for 1.5 or for 2 [degrees],” said Laura Pereira, a researcher at the University of the Witwatersrand in South Africa. “It’s just that if you act now and do it rapidly enough, you can do 1.5.”

Some experts also worry that declaring an overshoot inevitable could also potentially hamper the momentum of global climate action plans.

“As soon as you throw your hands up in the air and say, 'Oh, we’re going to overshoot,' you're not going to have those hard discussions about what really needs to change,” Pereira said.

‘Becoming inevitable’

The debate is likely to intensify as the 1.5 degree threshold draws closer.

Global emissions would have to peak by 2025 and then fall a staggering 42 percent by 2030 in order to keep warming below 1.5 degrees, according to the U.N.’s Intergovernmental Panel on Climate Change, the world’s top authority on global warming. The world would then need to hit net-zero emissions around 2050.

“Regarding the reachability of the 1.5ºC target, truly transformative action is needed to still be able to achieve the 1.5ºC goal without an at least temporary overshoot,” said Nico Wunderling, a scientist at the Potsdam Institute for Climate Impact Research in Germany, in an email.

Human societies can only emit a limited amount of additional carbon without overshooting the target, Wunderling added, and research suggests the planet is likely to burn through that budget within the next five years if greenhouse gas emissions don’t swiftly and dramatically drop.

So while it’s not impossible, he said, it’s “extremely ambitious” for the world to reach net-zero emissions in time to avoid 1.5 degrees of warming.

The world could still limit warming to 1.5 degrees after a short period of overshooting the target, he said. But the impacts of climate change worsen with every fraction of a degree the planet warms. And some consequences, like sea-level rise or plant and animal extinctions, can’t be easily reversed once they’ve happened, even if global temperatures later fall.

So if the world does blow through 1.5 degrees, scientists say, it’s crucial to limit the overshoot as much as possible.

That’s a growing concern among climate experts. Scientists have quietly warned for years that the world is unlikely to meet the 1.5-degree target . But their message has grown more urgent in the last few years.

Scientists were candid about the impending risks during their presentation of the third and final installment of the IPCC’s most recent major assessment report in April 2022.

“It is almost inevitable that we will at least temporarily overshoot 1.5,” Jim Skea, an energy expert at Imperial College London and co-chair of the IPCC working group that prepared the report, said at a 2022 virtual presentation of the findings.

Another U.N. report in 2022 warned that countries' carbon-cutting pledges were too weak and, as of that moment, there was “no credible pathway” to 1.5 C . And the 2023 emissions gap report , released in November, reiterated that failing to sufficiently reduce emissions over the next six years will make it “impossible to limit warming to 1.5C with no or limited overshoot.”

In December, leading international scientists presented an annual report to the U.N. on the year’s top climate insights. It concluded that overshooting the 1.5-degree target is “becoming inevitable.”

Immediate, radical and transformative action could technically still keep the target alive, the report noted. But the diminishing probability means that world leaders must also work to minimize overshoot as much as possible.

“Governments, corporations and other actors must now focus on minimizing the magnitude and duration of overshoot, while still acting to avoid it,” the report warns.

Keeping the target alive

U.N. messaging remains focused on staying below 1.5 degrees — period.

“We believe it is worth trying to bring the world together through nationally determined contributions to a scenario where 1.5 C remains at least within the realm of possibility,” said Steiner, UNDP’s administrator, at Tuesday’s Climate Promise launch.

The new initiative aspires to bring the next round of national pledges in line with the IPCC’s requirements for staying under 1.5 degrees. The plan takes a three-pronged approach, aiming to help countries scale up their ambition, accelerate their progress and increase the inclusivity of their climate plans, acknowledging the disproportionate impacts of global warming on Indigenous communities and other vulnerable populations.

“It’s make or break for the 1.5-degree limit,” said U.N. Secretary-General António Guterres at Tuesday’s launch event. “Today, humanity spews out over 40 gigatons of carbon dioxide every year. At this rate, the planet will soon be pushed past the 1.5-degree limit. Countries’ ambitious new national climate plans — which are due next year — are essential to avert this calamity.”

When the Paris Agreement was first adopted in 2015, scientists estimated that the world was on track for about 3.5 degrees of global warming, said Cassie Flynn, UNDP’s global director of climate change, at Tuesday’s launch. But the world has made progress since then — the current Paris climate pledges are consistent with warming of around 2.5 degrees.

The next round of national contributions could still bring that trajectory down by another degree, she said.

Technically speaking, the world could cut emissions in line with keeping global warming under 1.5 degrees. But that would require a Herculean overhaul of the global economy in record time, an unprecedented feat in human history.

Many scientists say that scenario is unlikely. But the fact that hitting the target is still technically feasible — at least for a few more years — keeps the idea of avoiding overshoot alive for now.

“The goal of staying under 1.5 degrees is alive until overshoot,” Pereira said. “You can always change things fundamentally.”

Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2024. E&E News provides essential news for energy and environment professionals.

• Share full article

Advertisement

Subscriber-only Newsletter

Climate Forward

Your most pressing climate questions.

Introducing Ask NYT Climate, where we’ll explore how climate intersects with your everyday life.

By Ryan McCarthy

I’m the new editor of the Climate Forward newsletter.

Are traffic circles better for the environment than four-way stops? Will the oceans be too hot for fish to survive? Is green hydrogen a thing?

Over the past few years, we here at the Climate desk have received hundreds of smart, often highly specific, questions from our readers about what they can do in their daily lives to affect climate change. To answer some of these questions, this week we’ve launched “ Ask NYT Climate ,” which is dedicated to exploring how climate intersects with your life.

Our first edition is about the perhaps counterintuitive idea that buying stuff online can actually be better for the planet than driving to a store. And if you’ve got a question you want us to answer, send it via the form at the bottom of this page .

To get a sense of how the biggest issues in the climate world intertwine with our lives, I also turned to our reporters and asked them two things: “What’s the most common question you hear from readers?” and “What are the biggest questions your sources are trying to answer right now?”

Our warming planet

“When I tell people I write about science and the natural world, the questions, I think, kind of stop,” said Raymond Zhong . He was only half-joking.

He writes about what climate scientists are thinking and researching. But on the core issues of climate change, he pointed out, the science is largely settled.

“A lot of the most basic questions people have about climate change were answered by scientists long ago,” Zhong said. We know what’s warming the earth: emissions of carbon dioxide, largely from human sources. And we know stopping global warming requires moving away from fossil fuels.

That said, the question he most often gets is some version of “What can I do?” (These are the kinds of tricky questions — which kinds of personal choices matter more than others — that will be a focus of Ask NYT Climate.)

Many of Zhong’s sources in the scientific community are investigating a somewhat different question: What role have we all played in this year’s record-breaking heat, and what that might tell us about the future? To answer that, some of them are looking back to the ancient world .

“The question, broadly, is: Has something deeper in the climate system changed?” Zhong said. We know many of the reasons the planet was so hot last year, but scientists are trying to discern the exact effect of other variables, including El Niño, or of aerosols emitted from ships’ smokestacks, which in a twist can have a cooling effect on the planet.

“Is 2023 the harbinger of something worse? That’s a deep question,” he said, “and it’s challenging the notion that we’ve already solved all the big questions.”

The scale of the problem

Coral Davenport , who covers climate change policy from Washington, also says she gets the “What can I do?” question a lot. In fact, it’s the most common thing our reporters hear from readers.

Individual actions can add up, of course. For example, food choices do have consequences. Earlier, we answered your questions about the climate implications of what we eat .

But Davenport said she often has to remind people of the sheer scope of climate change. Moving the global energy system away from fossil fuels is a gargantuan undertaking.

“As a problem, as a policy issue,” Davenport said, “it is arguably the most gigantic problem in the world.”

Climate change, she said, “absolutely cannot be solved unless it’s by gigantic entities working together. It has to be massive and global.” Davenport has recently covered things like the Biden administration’s pause on building a new natural gas export terminal , Republican attacks on electric vehicles and drilling regulations .

What do Davenport’s sources want to know? Many say they simply want to understand what the government’s rules will be. “I hear a lot of frustration,” Davenport said, “from companies caught in a regulatory whiplash” between Democratic and Republican administrations.

Automakers and electric utilities in particular, she said, tend to complain about climate rules that come and go as political winds change in Washington. But those changes, and those complaints, have become more extreme than in the past, she said.

How to protect nature

“One question I get is, ‘Is there any hope?’” said Catrin Einhorn , who covers biodiversity, wildlife ecosystems and nature. She’s covered things like ocean protection treaties , vanishing kestrels and the decline of California salmon .

The Climate desk has written about the hope vs. despair debate extensively over the past few years . We’re coming off the hottest year on record , but there are growing reasons to think the world can make significant progress, perhaps even quickly. “There are many pathways, spelled out by rigorous research. Each has tradeoffs,” wrote Somini Sengupta in our interactive Climate FAQ, which is built around the questions people ask of it.

Many of Einhorn’s sources, meanwhile, are focused on quantifying biodiversity loss and finding ways to slow it down. Globally, the rate of species extinction is currently at least tens to hundreds of times higher than the average over the past 10 million years. “Climate change is actually an easier problem to solve than biodiversity loss,” Einhorn said. “Biodiversity loss is even more sprawling and also harder to measure than greenhouse gas emissions.”

And, she says, her sources are obsessed with the big question of how we can reorient our economy — and a growing population that consumes more and more — in ways that don’t take as severe a toll on the natural world.

Three places where change is happening

Glaciers are shrinking , coral reefs are in crisis and last year was the hottest on record . Atmospheric concentrations of carbon dioxide , the main greenhouse gas, have passed a dangerous new threshold as people continue to burn fossil fuels. Is anyplace making progress on climate change?

The short answer is: It’s complicated, but yes.

Uruguay has pivoted in less than a decade to generating almost all its electricity from a diverse mix of renewables.

In China, an electric car that costs just $5,000 is suddenly one of the biggest sellers.

Paris is transforming itself into a city of bikes. The percentage of trips taken by bicycle within Paris more than doubled between 2020 and 2024, from 5 to 11 percent , thanks in part to new bike lanes set up during the coronavirus pandemic.

Steps like these, taken individually, aren’t enough to avoid the most serious consequences of climate change — worsening droughts, intensified storms and human suffering. Still, they show how some places are pulling off significant local changes very quickly. Read more here. — Delger Erdenesanaa

More climate news

The Cadillac Lyriq is the new darling of the E.V. industry, Bloomberg reports .

Ecuador is considering more debt-for-nature swaps after last year’s record-breaking $1.6 billion swap deal, Reuters reports .

Heatmap News examines why pollsters may be underestimating climate change as a political issue.

Rooftop solar generates so much electricity in California that on certain days gigawatts of power are “curtailed,” or essentially thrown away, per The Washington Post .

Thanks for being a subscriber.

Read past editions of the newsletter here .

If you’re enjoying what you’re reading, please consider recommending it to others. They can sign up here . Browse all of our subscriber-only newsletters here . And follow The New York Times on Instagram , Threads , Facebook and TikTok at @nytimes.

Reach us at [email protected] . We read every message, and reply to many!

Learn More About Climate Change

Have questions about climate change? Our F.A.Q. will tackle your climate questions, big and small .

Paris is becoming a city of bikes. Across China, people are snapping up $5,000 electric cars. Here’s a look at a few bright spots  for emission reductions.

In theory, online shopping can be more efficient  than driving to the store. But you may still want to think before you add to cart.

“Buying Time,” a new series from The New York Times, looks at the risky ways  humans are starting to manipulate nature  to fight climate change.

Big brands like Procter & Gamble and Nestlé say a new generation of recycling plants will help them meet environmental goals, but the technology is struggling to deliver .

Did you know the ♻ symbol doesn’t mean something is actually recyclable ? Read on about how we got here, and what can be done.

Warming Arctic reduces dust levels in parts of the planet

Research finds antidesertification measures needed in tandem with emission reductions.

Dust can have a huge impact on local air quality, food security, energy supply and public health. Previous studies have found that dust levels are decreasing across India, particularly northern India, the Persian Gulf Coast and much of the Middle East, but the reason has remained unclear. SEAS researchers found that the decrease in dust can be attributed to the Arctic warming much faster than the rest of the planet, a phenomenon known as Arctic amplification. This process destabilizes the jet stream and changes storm tracks and wind patterns over the major sources of dust in West and South Asia.

Ironically, the best-case scenario for emissions -- carbon neutrality -- could have the worst impact for dust because if humans reduce emissions enough to slow or stop Arctic amplification, then the jet stream and wind patterns would likely return to pre-warming states, which would lead to an increase in dust. The researchers find that as the global community works to reduce greenhouse emissions, local governments should simultaneously be working to address dust reduction.

Climate change is a global phenomenon, but its impacts are felt at a very local level.

Take, for example, dust. Dust can have a huge impact on local air quality, food security, energy supply and public health. Yet, little is known about how global climate change is impacting dust levels.

Previous studies have found that dust levels are actually decreasing across India, particularly northern India, the Persian Gulf Coast and much of the Middle East, but the reason has remained unclear. Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) are working to understand how global climate change is impacting dust levels in the region.

In a paper published in the Proceedings of the National Academy of Sciences , a team of researchers led by Michael B. McElroy, the Gilbert Butler Professor of Environmental Studies at SEAS, found that the decrease in dust can be attributed to the Arctic warming much faster than the rest of the planet, a phenomenon known as Arctic amplification. This process destabilizes the jet stream and changes storm tracks and wind patterns over the major sources of dust in West and South Asia -- namely the Arabian Peninsula and the Thar Desert between India and Pakistan.

"Local land management, rapid urbanization and industrialization certainly contribute to dust levels West and South Asia but the novel insight from our study is the increasingly dominant influence of circulation change on the broader global climate context," said McElroy. "Changes in atmospheric circulation patterns, driven by global climate dynamics shifts, have emerged as the principal driver behind the observed recent dust reductions in West and South Asia."

What does that mean for the future of dust in the region? It all depends on how we curb emissions. Ironically, the best-case scenario for emissions -- carbon neutrality -- could have the worst impact for dust. If humans can reduce emissions enough to slow or stop Arctic amplification, then the jet stream and wind patterns would likely return to pre-warming states, which would lead to an increase in dust.

Of course, that doesn't mean we shouldn't pursue carbon neutrality, said McElroy. But as the global community works to reduce greenhouse emissions, local governments should simultaneously be working to address dust reduction.

"At the local level, we need to be thinking about stronger anti-desertification actions such as reforestation and irrigation management and how to better monitor urban-level dust concentrations, in concert with broad climate mitigation strategies," said McElroy.

The research was co-authored by Fan Wang, Yangyang Xu, Piyushkumar N. Patel, Ritesh Gautam, Meng Gao, Cheng Liu, Yihui Ding, Haishan Chen, Yuanjian Yang, Yuyu Zhou and Gregory R. Carmichael. The research was supported by grants from National Key Research and Development Program of China (2022YFC3700103), National Natural Science Foundation of China (Project Nos. 42322902 and 42375095), and the Research Grants Council of the Hong Kong Special Administrative Region, China (Project Nos. C2002- 22Y, 22201820, and 12202021).

• Global Warming
• Environmental Issues
• Environmental Policy
• Severe Weather
• Air Pollution
• Environmental Awareness
• Gulf Stream
• Arctic Circle
• Global warming

Story Source:

Materials provided by Harvard John A. Paulson School of Engineering and Applied Sciences . Original written by Leah Burrows. Note: Content may be edited for style and length.

Journal Reference :

• Fan Wang, Yangyang Xu, Piyushkumar N. Patel, Ritesh Gautam, Meng Gao, Cheng Liu, Yihui Ding, Haishan Chen, Yuanjian Yang, Yuyu Zhou, Gregory R. Carmichael, Michael B. McElroy. Arctic amplification–induced decline in West and South Asia dust warrants stronger antidesertification toward carbon neutrality . Proceedings of the National Academy of Sciences , 2024; 121 (14) DOI: 10.1073/pnas.2317444121

Cite This Page :

Explore More

• Mice Given Mouse-Rat Brains Can Smell Again
• New Circuit Boards Can Be Repeatedly Recycled
• Collisions of Neutron Stars and Black Holes
• Advance in Heart Regenerative Therapy
• Bioluminescence in Animals 540 Million Years Ago
• Profound Link Between Diet and Brain Health
• Loneliness Runs Deep Among Parents
• Food in Sight? The Liver Is Ready!
• Acid Reflux Drugs and Risk of Migraine
• Do Cells Have a Hidden Communication System?

Trending Topics

Strange & offbeat.