good research questions on climate change

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

Rising Wheat Prices and Unprecedented Demonstrations: Pakistani Protestors Demand Autonomy

In the Jersey Suburbs, a Search for Rocks To Help Fight Climate Change

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

Congratulations to our Columbia Climate School MA in Climate & Society Class of 2024! Learn about our May 10 Class Day  celebration. #ColumbiaClimate2024

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

Thesis Helpers

Find the best tips and advice to improve your writing. Or, have a top expert write your paper.

Top 100 Climate Change Topics To Write About

Climate change issues have continued to increase over the years. That’s because human activities like fossil fuel usage, excavation, and greenhouse emissions continue to drastically change the climate negatively. For instance, burning fossil fuels continues to release greenhouse emissions and carbon dioxide in large quantities. And the lower atmosphere of the earth traps these gasses thereby affecting the global climate. To enhance their awareness of the impact of global warming, educators ask learners to write academic papers and essays on different climate change topics.

According to statistics, global warming affects the climate in different ways. However, the earth has experienced a general temperature increase of 0.85 degrees centigrade over the last 100 years. Such statistics show that this increase will eventually pass the acceptable thresholds in the next 10 years or less. And this will have dire consequences on human health and the global climate. As such, writing a paper about a topic on climate change is a great way to educate the masses.

However, some learners have difficulties choosing topics for their papers and essays on climate change. That’s because this is a relatively new subject. Nevertheless, students that are pursuing ecology, political, and biology studies are conversant with this subject. If struggling to decide what to write about, consider this list of topics related to climate change.

Climate Change Topics for Short Essays

Perhaps, your educator has asked you to write a short essay on climate change. Maybe you’re yet to decide what to write about because every topic you think about seems to have been written about. In that case, use this list of climate change topics for inspiration. You can write about one of these topics or develop it to make it more unique.

• How climate change is responsible for the disappearing rainforest
• The effects of global warming on air quality within the urban areas
• Global warming and greenhouse emissions- Possible health risks
• Is climate change responsible for irregular weather patterns?
• How has climate change affected the food chain?
• The negative effects of climate change on human wellbeing
• How global warming affects agriculture
• How climate change works
• Why is climate change dangerous to human health?
• How to minimize global warming effects on human health
• How global warming affects the healthcare
• Effects of climate change of life quality in rural and urban areas
• How warmer temperatures support allergy-related illnesses
• How climate change is a risk to life on earth
• How climate change and natural disasters correlate
• How climate change affects the population of the earth
• How climate change relates to global warming
• How global warming has caused extreme heating in most urban areas
• How wildfires relate to climate change
• How ocean acidification and climate change affect the world’s habitat

These climate change essay topics cover different aspects of human activities and their effects on the earth’s ecosystem. As such, writing a research paper or essay on any of these topics requires extensive research and analysis of information. That’s the only way you can come up with a solid paper that will impress the educator to award you the top grade.

Climate Change Issues that Make for Good Topics

Maybe you want to research issues that relate to climate change. Most people may have not considered such issues but they are worthy of climate change debate topics. In that case, consider these issues when choosing your climate topics for papers and essays.

• Climate change and threat to natural biodiversity are equally important
• Climate change in Miami and Saudi Arabia- How the effects compare
• Climate change as a human activity’s effect on the environment
• Preventing climate change by protecting forests
• Climate change in China- How the country has declined to head to the global call about saving Mother Nature
• Common causes of climate change
• Common effects of climate change
• The definition of climate change
• What is anthropogenic climate change
• Describe climate change
• What drives climate change?
• Renewable energy sources and climate change
• Human and economics induced climate change
• Climate change biology
• Climate change and business
• Science, Spin, and climate change
• Climate change- How global warming affects populations
• Climate change and social concepts
• Extreme weather and climate change- How they relate
• Global warming as a complex issue in climate change

These are great climate change topics for research papers and essays. However, writing about these topics requires extensive research. You should also be ready to spend energy and time finding relevant and latest sources of information before you write about these topics.

Interesting Climate Change Topics for Papers and Essays

Perhaps, you want to write an essay or paper about something interesting. In that case, consider this list of interesting climate change research paper topics.

• Climate change across the globe- What experts say
• Development, climate change, and disaster reduction
• Critical review- Climate change and agriculture
• Schools should include climate change as a subject in geography courses
• Consumption and climate change- How the wind blows in Indiana
• How the United Nations responds to climate change
• Snowpack and climate change
• How climate change threatens global security
• The effects of climate change on coastal areas’ tourism
• How climate change relates to Queensland Australia’s floods
• How climate change affects the tourism and hospitality industry
• Possible strategies for addressing the effects of climate change on urban areas
• How climate change affects indigenous people
• How to avoid the threats of climate change
• How climate change affects coral triangle turtles
• Climate change drivers in the Asian countries
• Economic discourse analysis methodology in climate change
• How climate change affects New Hampshire businesses
• How climate change affects the life of an individual
• The economic cost of the effects of climate change

These are fantastic climate change paper topics to explore. Nevertheless, you must be ready to research your topic extensively before you start writing your academic paper or essay.

Major Topics on Climate Change for Academic Writing

Perhaps, you’re looking for topics related to climate change that you write major papers about. In that case, you should consider these global climate change topics.

• Early science on climate change
• How the world can manage the effects of climate change
• Environmental issues relating to climate change
• Views comparison about the climate change problem
• Asset-based community development and climate change
• Experts’ evaluation of climate change
• How science affects climate change
• How climate change affects the ocean life
• Scotland’s vulnerability to climate change
• How energy conservation can solve the climate change problem
• How climate change affects the world economy
• International collaboration and climate change
• International relations view on climate change
•  How transportation affects climate change
• Climate change and technology
• Climate change policies and human rights
• Climate change from an anthropological perspective
• Climate change as an international security issue
• Role of the United Nations in addressing climate change
• Climate change and pollution

This category has some of the best climate change thesis topics. That’s because most people will be interested in reading papers on such topics due to their global perspectives. Nevertheless, you should prepare to spend a significant amount of time researching and writing about any of these topics on climate change.

Climate Change Topics for Presentation

Perhaps, you want to write papers on topics related to climate change for presentation purposes. In that case, you need topics that most people can resonate with. Here is a list of topics about climate change that will interest most people.

• How can humans stop global warming in the next ten years
• Could humans have stopped global warming a decade ago?
• How has the environment changed over the years and how has this change caused global warming?
• How did the Obama administration try to limit climate change?
• What is the influence of chemical engineering on global warming?
• How is urbanization connected to climate change?
• Theories that explain why some nations ignore climate change
• How global warming affects the rising sea levels
• How anthropogenic and natural climate change differ
• How the war against terrorism differs from the war on climate change
• How atmospheric change influences global climate change
• Negative effects of global climate change on Minnesota
• The greenhouse effect and ozone depletion
• How greenhouse affects the earth’s environment
• How can individuals reduce the emissions of greenhouse gasses
• How climate change will affect humans in their lifetime
• What are the social, physical, and economic effects of climate change
• Problems and solutions to climate change on the Pacific Ocean
• How climate change relates to species’ extinction
• How the phenomenon of denying climate change affects animals

This list prepared by our  research helpers has some of the best essay topics on climate change. Pick one of these ideas, research it, and then compose a winning paper.

Make PhD experience your own

Leave a Reply Cancel reply

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

Explore your training options in 10 minutes Get Started

• Graduate Stories
• Partner Spotlights
• Bootcamp Prep
• Bootcamp Admissions
• University Bootcamps
• Coding Tools
• Software Engineering
• Web Development
• Data Science
• Tech Guides
• Tech Resources
• Career Advice
• Online Learning
• Internships
• Apprenticeships
• Tech Salaries
• Associate Degree
• Bachelor's Degree
• Master's Degree
• University Admissions
• Best Schools
• Certifications
• Bootcamp Financing
• Higher Ed Financing
• Scholarships
• Financial Aid
• Best Coding Bootcamps
• Best Online Bootcamps
• Best Web Design Bootcamps
• Best Data Science Bootcamps
• Best Technology Sales Bootcamps
• Best Data Analytics Bootcamps
• Best Cybersecurity Bootcamps
• Best Digital Marketing Bootcamps
• Los Angeles
• San Francisco
• Browse All Locations
• Digital Marketing
• Machine Learning
• See All Subjects
• Bootcamps 101
• Full-Stack Development
• Career Changes
• View all Career Discussions
• Mobile App Development
• Cybersecurity
• Product Management
• UX/UI Design
• What is a Coding Bootcamp?
• Are Coding Bootcamps Worth It?
• How to Choose a Coding Bootcamp
• Best Online Coding Bootcamps and Courses
• Best Free Bootcamps and Coding Training
• Coding Bootcamp vs. Community College
• Coding Bootcamp vs. Self-Learning
• Bootcamps vs. Certifications: Compared
• What Is a Coding Bootcamp Job Guarantee?
• How to Pay for Coding Bootcamp
• Ultimate Guide to Coding Bootcamp Loans
• Best Coding Bootcamp Scholarships and Grants
• Education Stipends for Coding Bootcamps
• Get Your Coding Bootcamp Sponsored by Your Employer
• GI Bill and Coding Bootcamps
• Tech Intevriews
• Our Enterprise Solution
• Connect With Us
• Publication
• Reskill America
• Partner With Us

• Resource Center
• Bachelor’s Degree
• Master’s Degree

The Top 10 Most Interesting Climate Change Research Topics

Finishing your environmental science degree may require you to write about climate change research topics. For example, students pursuing a career as environmental scientists may focus their research on environmental-climate sensitivity or those studying to become conservation scientists will focus on ways to improve the quality of natural resources.

Climate change research paper topics vary from anthropogenic climate to physical risks of abrupt climate change. Papers should focus on a specific climate change research question. Read on to learn more about examples of climate change research topics and questions.

Find your bootcamp match

What makes a strong climate change research topic.

A strong climate change research paper topic should be precise in order for others to understand your research. You must use research methods to find topics that discuss a concern about climate issues. Your broader topic should be of current importance and a well-defined discourse on climate change.

Tips for Choosing a Climate Change Research Topic

• Research what environmental scientists say. Environmental scientists study ecological problems. Their studies include the threat of climate change on environmental issues. Studies completed by these professionals are a good starting point.
• Use original research to review articles for sources. Starting with a general search is a good place to get ideas. However, as you begin to refine your search, use original research papers that have passed through the stage of peer review.
• Discover the current climatic conditions of the research area. The issue of climate change affects each area differently. Gather information on the current climate and historical climate conditions to help bolster your research.
• Consider current issues of climate change. You want your analyses on climate change to be current. Using historical data can help you delve deep into climate change effects. First, however, it needs to back up climate change risks.
• Research the climate model evaluation options. There are different approaches to climate change evaluation. Choosing the right climate model evaluation system will help solidify your research.

What’s the Difference Between a Research Topic and a Research Question?

A research topic is a broad area of study that can encompass several different issues. An example might be the key role of climate change in the United States. While this topic might make for a good paper, it is too broad and must be narrowed to be written effectively.

A research question narrows the topic down to one or two points. The question provides a framework from which to start building your paper. The answers to your research question create the substance of your paper as you report the findings.

How to Create Strong Climate Change Research Questions

To create a strong climate change research question, start settling on the broader topic. Once you decide on a topic, use your research skills and make notes about issues or debates that may make an interesting paper. Then, narrow your ideas down into a niche that you can address with theoretical or practical research.

Top 10 Climate Change Research Paper Topics

1. climate changes effect on agriculture.

Climate change’s effect on agriculture is a topic that has been studied for years. The concern is the major role of climate as it affects the growth of crops, such as the grains that the United States cultivates and trades on the world market. According to the scientific journal Nature , one primary concern is how the high levels of carbon dioxide can affect overall crops .

2. Economic Impact of Climate Change

Climate can have a negative effect on both local and global economies. While the costs may vary greatly, even a slight change could cost the United States a loss in the Global Domestic Product (GDP). For example, rising sea levels may damage the fiber optic infrastructure the world relies on for trade and communication.

3. Solutions for Reducing the Effect of Future Climate Conditions

Solutions for reducing the effect of future climate conditions range from reducing the reliance on fossil fuels to reducing the number of children you have. Some of these solutions to climate change are radical ideas and may not be accepted by the general population.

4. Federal Government Climate Policy

The United States government’s climate policy is extensive. The climate policy is the federal government’s action for climate change and how it hopes to make an impact. It includes adopting the use of electric vehicles instead of gas-powered cars. It also includes the use of alternative energy systems such as wind energy.

5. Understanding of Climate Change

Understanding climate change is a broad climate change research topic. With this, you can introduce different research methods for tracking climate change and showing a focused effect on specific areas, such as the impact on water availability in certain geographic areas.

6. Carbon Emissions Impact of Climate Change

Carbon emissions are a major factor in climate change. Due to the greenhouse effect they cause, the world is seeing a higher number of devastating weather events. An increase in the number and intensity of tsunamis, hurricanes, and tornados are some of the results.

7. Evidence of Climate Change

There is ample evidence of climate change available, thanks to the scientific community. However, some of these implications of climate change are hotly contested by those with poor views about climate scientists. Proof of climate change includes satellite images, ice cores, and retreating glaciers.

8. Cause and Mitigation of Climate Change

The causes of climate change can be either human activities or natural causes. Greenhouse gas emissions are an example of how human activities can alter the world’s climate. However, natural causes such as volcanic and solar activity are also issues. Mitigation plans for these effects may include options for both causes.

9. Health Threats and Climate Change

Climate change can have an adverse effect on human health. The impacts on health from climate change can include extreme heat, air pollution, and increasing allergies. The CDC warns these changes can cause respiratory threats, cardiovascular issues, and heat-related illnesses.

10. Industrial Pollution and the Effects of Climate Change

Just as car emissions can have an adverse effect on the climate, so can industrial pollution. It is one of the leading factors in greenhouse gas effects on average temperature. While the US has played a key role in curtailing industrial pollution, other countries need to follow suit to mitigate the negative impacts it causes.

Other Examples of Climate Change Research Topics & Questions

Climate change research topics.

• The challenge of climate change faced by the United States
• Climate change communication and social movements
• Global adaptation methods to climate change
• How climate change affects migration
• Capacity on climate change and the effect on biodiversity

Climate Change Research Questions

• What are some mitigation and adaptation to climate change options for farmers?
• How do alternative energy sources play a role in climate change?
• Do federal policies on climate change help reduce carbon emissions?
• What impacts of climate change affect the environment?
• Do climate change and social movements mean the end of travel?

Choosing the Right Climate Change Research Topic

Choosing the correct climate change research paper topic takes continuous research and refining. Your topic starts as a general overview of an area of climate change. Then, after extensive research, you can narrow it down to a specific question.

You need to ensure that your research is timely, however. For example, you don’t want to address the effects of climate change on natural resources from 15 or 20 years ago. Instead, you want to focus on views about climate change from resources within the last five years.

Climate Change Research Topics FAQ

A climate change research paper has five parts, beginning with introducing the problem and background before moving into a review of related sources. After reviewing, share methods and procedures, followed by data analysis . Finally, conclude with a summary and recommendations.

A thesis statement presents the topic of your paper to the reader. It also helps you as you begin to organize your paper, much like a mission statement. Therefore, your thesis statement may change during writing as you start to present your arguments.

According to the US Forest Service, climate change issues are related to topics regarding forest management, biodiversity, and species distribution. Climate change is a broad focus that affects many topics.

To write a research paper title, a good strategy is not to write the title right away. Instead, wait until the end after you finish everything else. Then use a short and to-the-point phrase that summarizes your document. Use keywords from the paper and avoid jargon.

About us: Career Karma is a platform designed to help job seekers find, research, and connect with job training programs to advance their careers. Learn about the CK publication .

What's Next?

Get matched with top bootcamps

Ask a question to our community, take our careers quiz.

Leave a Reply Cancel reply

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

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 .

Frequently Asked Questions About Climate Change

Below are answers to some frequently asked questions about climate change. For information about evidence of climate change, the greenhouse effect, and the human role in climate change, please see EPA Climate Science .

On this page:

What is the difference between weather and climate?

What is climate change, what is the difference between global warming and climate change, what is the difference between climate change and climate variability, why has my town experienced record-breaking cold and snowfall if the climate is warming, is there scientific consensus that people are causing today’s climate change, do natural variations in climate contribute to today’s climate change, why be concerned about a degree or two change in the average global temperature, how does climate change affect people’s health, who is most at risk from the impacts of climate change, how can people reduce the risks of climate change, what are the benefits of taking action now.

Some of the following links exit the site.

"Weather" refers to the day-to-day state of the atmosphere such as the combination of temperature, humidity, rainfall, wind, and other factors. "Climate" describes the weather of a place averaged over a period of time, often 30 years. Think about it this way: climate is something that can be expected to happen in general, like a cold winter season, whereas weather is what a person might experience on any given day, like a snowstorm in January or a sunny day in July.

Climate change involves significant changes in average conditions—such as temperature, precipitation, wind patterns, and other aspects of climate—that occur over years, decades, centuries, or longer. Climate change involves longer-term trends, such as shifts toward warmer, wetter, or drier conditions. These trends can be caused by natural variability in climate over time, as well as human activities that add greenhouse gases to the atmosphere like burning fossil fuels for energy.

The terms "global warming" and "climate change" are sometimes used interchangeably, but global warming is just one of the ways in which climate is affected by rising concentrations of greenhouse gases. "Global warming" describes the recent rise in the global average temperature near the earth's surface, which is caused mostly by increasing concentrations of greenhouse gases (such as carbon dioxide and methane) in the atmosphere from human activities such as burning fossil fuels for energy.

Climate change occurs over a long period of time, typically over decades or longer. In contrast, climate variability includes changes that occur within shorter timeframes, such as a month, season, or year. Climate variability explains the natural variability within the system. For example, one unusually cold or wet year followed by an unusually warm or dry year would not be considered a sign of climate change.

Today’s Climate Change

Even though the planet is warming, some areas may be experiencing extra cold or snowy winters. These cold spells are due to variability in local weather patterns, which sometimes lead to colder-than-average seasons or even colder-than-average years at the local or regional level. In fact, a warmer climate traps more water vapor in the air, which may lead to extra snowy winters in some areas. As long as it is still cold enough to snow, a warming climate can lead to bigger snowstorms.

Yes. Climate scientists overwhelmingly agree that people are contributing significantly to today’s climate change, primarily by releasing excess greenhouse gases into the atmosphere from activities such as burning fossil fuels for energy, cultivating crops, raising livestock, and clearing forests. The Intergovernmental Panel on Climate Change's Sixth Assessment Report , which represents the work of hundreds of leading experts in climate science, states that "it is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere, and biosphere have occurred.”

The 2018 National Climate Assessment , developed by the U.S. Global Change Research Program—which is composed of 13 federal scientific agencies—concluded that scientific evidence consistently points to human activities, rather than natural climate trends, as the “dominant cause” behind the rapid global temperature increase of 1.8°F from 1901 to 2016 (see Figure 1). Hundreds of independent and governmental scientific organizations have released similar statements, both in the United States and worldwide, including the World Meteorological Organization , the American Meteorological Society , and the American Geophysical Union .

The earth does go through natural cycles of warming and cooling caused by factors such as changes in the sun or volcanic activity. For example, there were times in the distant past when the earth was warmer than it is now. However, natural variations in climate do not explain today’s climate change. Most of the warming since 1950 has been caused by human emissions of greenhouse gases that come from a variety of activities, including burning fossil fuels.

A degree or two change in average global temperature might not sound like much to worry about, but relatively small changes in the earth’s average temperature can mean big changes in local and regional climate, creating risks to public health and safety , water resources , agriculture , infrastructure , and ecosystems . Among the many examples cited by the 2018 National Climate Assessment are an increase in heat waves and days with temperatures above 90°F; more extreme weather events such as storms, droughts, and floods; and a projected sea level rise of 1 to 4 feet by the end of this century, which could put certain areas of the country underwater.

Climate change poses many threats to people’s health and well-being. Among the health impacts cited by the 2018 National Climate Assessment are the following:

• Atmospheric warming has the potential to increase ground-level ozone in many regions, which can cause multiple health issues (e.g., bronchitis, emphysema, and asthma) and worsen lung function.
• Higher summer temperatures are linked to an increased risk of heat-related illnesses and death . Older adults, pregnant women, and children are at particular risk, as are people living in urban areas because of the additional heat associated with urban heat islands .
• Climate change is expected to expose more people to ticks that carry Lyme disease or other bacterial and viral agents, and to mosquitoes that transmit West Nile and other viruses.
• More frequent extreme weather events such as droughts , hurricanes , floods , and wildfires will not only put people’s lives at risk, but can also worsen underlying medical conditions, increase stress, and lead to adverse mental health effects.
• Rising temperatures and extreme weather have the potential to disrupt the availability, safety, and nutritional quality of food.

See EPA’s Climate Indicators website for more information about the effects of climate change in the United States.

Everyone will be affected by climate change, but some people may be more affected than others. Among the most vulnerable people are those in overburdened, underserved, and economically distressed communities. Three key factors influence a person’s vulnerability to the impacts of climate change:

• Exposure . Some people are more at risk simply because they are more exposed to climate change hazards where they live or work. For example, people who live on the coast can be more vulnerable to sea level rise, coastal storms, and flooding.
• Sensitivity . Some people are more sensitive to the impacts of climate change, such as children, pregnant women, and those with pre-existing medical conditions such as asthma.
• Adaptability . Older adults, those with disabilities, those with low income, and some indigenous people may have more difficulty than others in adapting to climate change hazards.

In addition, there is a wide range of other factors that influence people’s vulnerability. For example, people with less access to healthcare, adequate housing, and financial resources are less likely to rebound from climate disasters. People who are excluded from planning processes, experience racial and ethnic discrimination, or have language barriers are also more vulnerable to and less able to prepare for and avoid the risks of climate change.

Learn more about the connections between climate change and human health .

People can reduce the risks of climate change by making choices that reduce greenhouse gas emissions and by preparing for the changes expected in the future. Decisions that people make today will shape the world for decades and even centuries to come. Communities can also prepare for the changes in the decades ahead by identifying and reducing their vulnerabilities and considering climate change risks in planning and development . Such actions can ensure that the most vulnerable populations —such as young children, older adults, and people living in poverty—are protected from the health and safety threats of climate change.

The longer people wait to act on climate change, the more damaging its effects will become on the planet and people’s health. If people fail to take action soon, more drastic and costly measures to prevent greenhouse gases from exceeding dangerous levels could be needed later. The most recent National Climate Assessment found that global efforts to reduce greenhouse gas emissions could avoid tens of thousands of deaths per year in the United States by the end of the century, as well as billions of dollars in damages related to water shortages, wildfires, agricultural losses, flooding, and other impacts. There are many actions that people can take now to help reduce the risk of climate change while also improving the natural environment, community infrastructure and transportation systems, and overall health.

• Frequently Asked Questions

5 ways NOAA scientists are answering big questions about climate change

• April 20, 2021
• Download Cover Image

From warmer ocean temperatures to longer and more intense droughts and heat waves, climate change is affecting our entire planet. Scientists at NOAA have long worked to track, understand and predict how climate change is progressing and impacting ecosystems, communities and economies. This Earth Day, take a look at five ways scientists are studying this far-reaching global trend.

1. Tracking greenhouse gas levels in the atmosphere

To understand climate change, scientists need an accurate, up-to-date record of how greenhouse gas levels in the atmosphere have changed over time. Enter: NOAA Global Monitoring Laboratories’ Global Greenhouse Gas Reference Network , which measures the three main long-term drivers of climate change: carbon dioxide (CO2), methane, and nitrous oxide. Four remote atmospheric baseline observatories form the backbone of the monitoring system – the most well-known of which, located in Mauna Loa, Hawaii, is home to the longest record of direct measurements of CO2 in the atmosphere. This year, scientists used data from these observatories to confirm that average global CO2 levels had surged in 2020 to 412.5 parts per million – levels that are higher than at any time in the past 3.6 million years.

2. Understanding ocean warming 

The ocean can absorb and store a lot of heat. In fact, more than 90 percent of the planet’s warming over the past 50 years has occurred in the ocean, making the buoys, floats and other ocean monitoring tools NOAA uses to keep tabs on ocean warming critical. Argo, for instance, is a network of about 4,000 autonomous floats that drift throughout the ocean, gathering critical data on salt content and temperature. Last year, data collected by Argo floats helped scientists determine that the area of ocean regions with long-term warming trends dwarfs that of regions with cooling trends. Deep Argo floats have also found that the coldest waters off of Antarctica are warming three times faster than they were in the 1990s. Tracking ocean warming helps scientists better predict sea level rise, gauge threats to coral reef ecosystems and important fisheries, and build knowledge on how a warmer ocean impacts our weather – including severe weather like hurricanes.  

3. Exploring the link between climate change and hurricanes

Hurricanes draw their strength from warm ocean waters. So as the ocean continues to absorb heat, should we expect to see more intense hurricanes, tropical storms and typhoons? 

Probably, according to recent research led by NOAA scientists . The research, which analyzed findings from over 90 peer-reviewed studies, found that warming of the surface ocean from human-caused climate change is likely fueling more powerful tropical cyclones. And as sea levels rise, the destructive power of tropical cyclones is amplified, as higher sea levels can result in more intense flooding. ⁣NOAA scientists  have also concluded  that climate change has been influencing the pattern of where tropical cyclones have been increasing or decreasing in occurrence. Researchers are still working to understand the link between climate and hurricanes – check out this page for the most up-to-date science.

4. Tracking warming in the Great Lakes

Like the ocean, freshwater is also impacted by Earth’s warming temperatures. In the Great Lakes, scientists who monitor winter ice cover say that, though ice cover tends to be variable from year to year, the data show a long-term trend of ice decline over the last several decades. Research has also shown that the Great Lakes’ deep waters aren’t immune to warming: As climate change has gradually delayed the onset of autumn in the Great Lakes region, the deep waters of Lake Michigan have started showing shorter winter seasons.  Increases in the lakes’ water temperatures can have serious impacts, including disruptions in the food web that could affect fisheries and recreation, which are important parts of the regional economy. 

5. Working towards climate resilience

From sunny day flooding creating hazards for coastal regions in Florida, to summer heat waves posing risks to communities without air conditioning in the Northeast, climate change creates a range of challenges and dangers for communities. NOAA is helping communities become more resilient to these changes. In Utqiaġvik, Alaska, for instance, NOAA Sea Grant and partners are working with the local community  to better understand risks of flooding and shoreline erosion, helping them better prepare for storms. The NOAA Regional Integrated Sciences and Assessments (RISA) program also funds research and engagement to help Americans prepare for climate change. For instance, the Northeast RISA team worked with New York City officials to map out where in the city extreme heat was having the most impact, so that the city could take action to protect at-risk residents. The U.S. Climate Resilience Toolkit also makes it easy for people to learn more about climate-related risks and opportunities in their area, giving them the knowledge they need to make their communities more climate resilient. 

To learn more NOAA’s work on climate change, visit climate.gov , and consider subscribing  to the This Week on Climate.gov newsletter.

Those delicious smells may be impacting air quality

No sign of greenhouse gases increases slowing in 2023

First-of-its-kind experiment illuminates wildfires in unprecedented detail

Meet the women advancing NOAA’s exploration and stewardship of the ocean and Great Lakes 

Popup call to action.

A prompt with more information on your call to action.

Researching Climate Change

Climate change research involves numerous disciplines of Earth system science as well as technology, engineering, and programming. Some major areas of climate change research include water, energy, ecosystems, air quality, solar physics, glaciology, human health, wildfires, and land use.

To have a complete picture of how the climate changes and how these changes affect the Earth, scientists make direct measurements of climate using weather instruments. They also look at proxy data that gives us clues about climate conditions from prehistoric times. And they use models of the Earth system to predict how the climate will change in the future.

Measurements of modern climate change

Because climate describes the weather conditions averaged over a long period of time (typically 30 years), much of the same information gathered about weather is used to research climate. Temperature is measured every day at thousands of locations around the world. This data is used to calculate average global temperatures . Changes in temperature patterns are a strong indicator of how much the climate is changing. Because we have thousands of temperature measurements, we know that record high temperatures are increasing across the globe, which is a sign that the climate is warming. Climatologists also look at changes in precipitation, the length and frequency of drought, as well as the number of days that rivers are at flood stage to understand how the climate is changing. Winds and other direct measures of climate contribute to climate change research as well.

This map shows the location of weather stations across the Earth. Continuous data from thousands of stations is important for climate change research.

Using proxy data to understand climate change in the past

Throughout Earth's 4.6 billion years, the climate has changed drastically, including periods that were much colder and much warmer than the climate today. But how do we know about the climate from prehistoric times ? Researchers decipher clues within the Earth to help reconstruct past environments based on our understanding of environments today. Proxy data can take the form of fossils, sediment layers, tree rings , coral, and ice cores. These proxies contain evidence of past environments. For example, marine fossils and ocean seafloor sediment preserved in rock layers from around 80 million years ago (the Cretaceous Period) indicate that North America was mostly covered in water. The high sea levels were due to a much warmer climate when all of the polar ice sheets had melted. We also find fossil vegetation and pollen records indicating that forests covered the polar regions during this same time period. The existence of multiple types of proxy data from different locations, often from overlapping time periods, strengthens our understanding of past climates.

Ice core drilling in the Arctic provides proxy evidence of paleoclimate conditions.

National Snow and Ice Data Center

Using models to project future climate change

Scientists use models of the Earth to figure out how climate will likely change in the future. These models, which are simulations of Earth, include equations that describe everything from how the winds blow to how sea ice reflects sunlight and how forests take up carbon dioxide. In-depth knowledge of how each part of the Earth functions is needed to write the equations that represent each part within the model. Understanding climate change in both the present and the past helps to create computational models that can predict how the climate system might change in the future.

While scientists work hard to ensure that climate models are as accurate as possible, the models are unable to predict exactly how the climate will change in the future because some things are unknown, namely how much humans will change (or not change) behaviors that contribute to climate warming. Scientists run the models with different scenarios to account for a range of possibilities. For example, running the models to show how the climate will respond if we reduce fossil fuel emissions by different amounts can help us prepare for the many impacts that a changing climate has on the Earth.

Climate models keep track of how parameters change from place to place using a grid pattern on the Earth’s surface. The environmental conditions within each hexagon-shaped area are programmed into the model. More detailed models have smaller hexagons.

Studying the impacts of climate change

From monitoring changes in tropical coral reefs to changes in glacial ice, keeping track of how climate change is affecting the planet is important for adapting to the future. Scientists who monitor the environment report stronger and more frequent storms, changing weather patterns, a longer growing season in some locations, and changes in the distribution of plants and migratory animals. Monitoring how climate change is affecting our world can help identify new threats to human health as the ranges of insect-borne diseases change and as drought-prone regions expand.

Many different areas of research, from meteorology to oceanography, epidemiology to agriculture, and even fields such as sociology and economics, have a role to play in terms of researching both how the climate is changing and the impacts of climate change.

The average length of the growing season in the lower 48 states has increased by almost two weeks since the late 1800s, a result of the changing climate. Researchers study how this change in the growing season impacts humans and the Earth. Credit: EPA

© 2021 UCAR

• How Climate Works
• History of Climate Science Research
• Investigating Past Climates
• Climate Modeling
• Fast Computers and Complex Climate Models
• Visualizing Weather and Climate
• IPCC: The Intergovernmental Panel on Climate Change
• From Dog Walking To Weather And Climate
• Satellite Signals from Space: Smart Science for Understanding Weather and Climate

• Mission, Facts and Figures
• Deans, Chairs and Staff
• Leadership Council
• Dean in the News
• Get Involved
• DEIB Mission
• Message from DEIB Associate Dean
• News and Media
• Reading Lists
• The Yale and Slavery Research Project
• Photo Gallery
• Winslow Medal
• Coat of Arms & Mace
• $50 Million Challenge
• For Pandemic Prevention and Global Health
• For Understanding the Health Impacts of Climate Change
• For Health Equity and Justice
• For Powering Health Solutions through Data Science
• For Future Leaders
• For Faculty Leaders
• For Transformational Efforts
• An abiding love for Yale turns into a lasting gift – in 15 minutes
• Endowed Professorship Created at Critical Time for Yale School of Public Health
• Brotherly encouragement spurs gift to support students
• Prestipino creates opportunities for YSPH students, now and later
• Alumna gives back to the school that “opened doors” in male-dominated field
• For Public Health, a Broad Mission and a Way to Amplify Impact
• Couple Endows Scholarship to Put Dreams in Reach for YSPH Students
• A Match Made at YSPH
• A HAPPY Meeting of Public Health and the Arts
• Generous Gift Bolsters Diversity & Inclusion
• Alumni Donations Aid Record Number of YSPH Students
• YSPH’s Rapid Response Fund Needs Donations – Rapidly
• Podiatric Medicine and Orthopedics as Public Health Prevention
• Investing in Future Public Health Leaders
• Support for Veterans and Midcareer Students
• Donor Eases Burden for Policy Students
• A Personal Inspiration for Support of Cancer Research
• Reducing the Burden of Student Debt
• Learning About Global Health Through Global Travel
• A Meeting in Dubai, and a Donation to the School
• Rapid Response Fund
• Planned Giving
• Testimonials
• Faculty, Postdoc Jobs
• For the Media
• Issues List
• PDF Issues for Download
• Editorial Style Guide
• Social Media
• Shared Humanity Podcast
• Health & Veritas Podcast
• Accreditation
• Faculty Directory by Name
• Career Achievement Awards
• Annual Research Awards
• Teaching Spotlights
• Biostatistics
• Chronic Disease Epidemiology
• Climate Change and Health Concentration
• Environmental Health Sciences
• Epidemiology of Microbial Diseases
• Global Health
• Health Policy and Management
• Maternal and Child Health Promotion Track
• Public Health Modeling Concentration
• Regulatory Affairs Track
• Social & Behavioral Sciences
• U.S. Health Justice Concentration
• Why Public Health at Yale
• Events and Contact
• What Does it Take to be a Successful YSPH Student?
• How to Apply and FAQs
• Incoming Student Gateway
• Traveling to Yale
• Meet Students and Alumni
• Past Internship Spotlights
• Student-run Organizations
• MS and PhD Student Leaders
• Staff Spotlights
• Life in New Haven
• Libraries at Yale
• The MPH Internship Experience
• Practicum Course Offerings
• Summer Funding and Fellowships
• Downs Fellowship Committee
• Stolwijk Fellowship
• Climate Change and Health
• Career Management Center
• What You Can Do with a Yale MPH
• MPH Career Outcomes
• MS Career Outcomes
• PhD Career Outcomes
• Employer Recruiting
• Tuition and Expenses
• External Funding and Scholarships
• External Fellowships for PhD Candidates
• Alumni Spotlights
• Bulldog Perks
• Stay Involved
• Board of Directors
• Emerging Majority Affairs Committee
• Award Nomination Form
• Board Nomination Form
• Alumni Engagement Plus
• Mentorship Program
• The Mentoring Process
• For Mentors
• For Students
• Recent Graduate Program
• Transcript and Verification Requests
• Applied Practice and Student Research
• Competencies and Career Paths
• Applied Practice and Internships
• Student Research
• Seminar and Events
• Competencies and Career paths
• Why the YSPH Executive MPH
• Message from the Program Director
• Two-year Hybrid MPH Schedule
• The Faculty
• Student Profiles
• Newsletter Articles
• Approved Electives
• Physicians Associates Program
• Joint Degrees with International Partners
• MS in Biostatistics Standard Pathway
• MS Implementation and Prevention Science Methods Pathway
• MS Data Sciences Pathway
• Internships and Student Research
• Competencies
• Degree Requirements - Quantitative Specialization
• Degree Requirements - Clinical Specialization
• Degree Requirements- PhD Biostatistics Standard Pathway
• Degree Requirements- PhD Biostatistics Implementation and Prevention Science Methods Pathway
• Meet PhD Students in Biostatistics
• Meet PhD Students in CDE
• Degree Requirements and Timeline
• Meet PhD Students in EHS
• Meet PhD Students in EMD
• Meet PhD Students in HPM
• Degree Requirements - PhD in Social and Behavioral Sciences
• Degree Requirements - PhD SBS Program Maternal and Child Health Promotion
• Meet PhD Students in SBS
• Differences between MPH and MS degrees
• Academic Calendar
• Translational Alcohol Research Program
• Molecular Virology/Epidemiology Training Program (MoVE-Kaz)
• For Public Health Practitioners and Workforce Development
• Course Description
• Instructors
• Registration
• Coursera Offerings
• Non-degree Students
• International Initiatives & Partnerships
• NIH-funded Summer Research Experience in Environmental Health (SREEH)
• Summer International Program in Environmental Health Sciences (SIPEHS)
• 2022 Student Awards
• APHA Annual Meeting & Expo
• National Public Health Week (NPHW)
• Leaders in Public Health
• YSPH Dean's Lectures
• The Role of Data in Public Health Equity & Innovation Conference
• Innovating for the Public Good
• Practice- and community-based research and initiatives
• Practice and community-based research and initiatives
• Activist in Residence Program
• Publications
• Health Care Systems and Policy
• Heart Disease and Stroke
• SalivaDirect™
• COVID Net- Emerging Infections Program
• Panels, Seminars and Workshops (Recordings)
• Public Health Modeling Unit Projects
• Rapid Response Fund Projects
• HIV-AIDS-TB
• The Lancet 2023 Series on Breastfeeding
• 'Omics
• News in Biostatistics
• Biostatistics Overview
• Seminars and Events
• Seminar Recordings
• Statistical Genetics/Genomics, Spatial Statistics and Modeling
• Causal Inference, Observational Studies and Implementation Science Methodology
• Health Informatics, Data Science and Reproducibility
• Clinical Trials and Outcomes
• Machine Learning and High Dimensional Data Analysis
• News in CDE
• Nutrition, Diabetes, Obesity
• Maternal and Child Health
• Outcomes Research
• Health Disparities
• Women's Health
• News in EHS
• EHS Seminar Recordings
• Climate change and energy impacts on health
• Developmental origins of health and disease
• Environmental justice and health disparities
• Enviromental related health outcomes
• Green chemistry solutions
• Novel approaches to assess environmental exposures and early markers of effect
• 1,4 Dioxane
• Reproducibility
• Tissue Imaging Mass Spectrometry
• Alcohol and Cancer
• Olive Oil and Health
• Lightning Talks
• News in EMD
• Antimicrobial Resistance
• Applied Public Health and Implementation Science
• Emerging Infections and Climate Change
• Global Health/Tropical Diseases
• HIV and Sexually Transmitted Infections
• Marginalized Population Health & Equity
• Pathogen Genomics, Diagnostics, and Molecular Epidemiology
• Vector-borne and Zoonotic Diseases
• Disease Areas
• EMD Research Day
• News in HPM
• Health Systems Reform
• Quality, Efficiency and Equity of Healthcare
• Substance Abuse and Mental Health
• Modeling: Policy, Operations and Disease
• Pharmaceuticals, Vaccines and Medical Devices
• Health and Wellbeing
• News in SBS
• Aging Health
• Community Engagement
• Health Equity
• Mental Health
• Reproductive Health
• Sexuality and Health
• Nutrition, Exercise
• Stigma Prevention
• Community Partners
• For Public Health Practitioners
• Reports and Publications
• Fellows Stipend Application
• Agency Application
• Past Fellows
• PHFP in the News
• Frequently Asked Questions
• International Activity
• Research Publications
• Grant Listings
• Modeling Analyses
• 3 Essential Questions Series

INFORMATION FOR

• Prospective Students
• Incoming Students
• myYSPH Members

3 Essential Questions: Climate Change and Health

• Climate Change

Kai Chen, Ph.D., assistant professor in the Department of Environmental Health Sciences, studies the relationship between climate change, air pollution and human health. He applies multidisciplinary approaches in climate and air pollution sciences, exposure assessment and environmental epidemiology to better understand how climate change is affecting human health. Much of this work has been done in China, Europe and the United States.

Why is climate change regarded as the greatest public health challenge of the 21st century?

KC: This summer, we have witnessed deadly extreme weather events occurring across the United States, such as the record-breaking heat wave in the Pacific Northwest, the raging wildfires in the West, and the devastating hurricanes and flooding in the East. All of these extreme weather events are exacerbated by climate change. But the currently reported direct death toll during these events is only the tip of the iceberg. Extreme temperatures and weather events can adversely affect a comprehensive spectrum of diseases, leading to increased mortality and morbidity.

At Yale, our research at the Yale Center on Climate Change and Health (YCCCH) shows that heat can increase the risk of cardiovascular diseases such as heart attack and stroke, respiratory diseases, diabetes, unintentional injuries and mental disorders. Recent global burden-of-disease studies found that around 2 million to 5 million deaths per year can be attributable to extreme temperature globally.

Climate change can also indirectly impact our health through worsening water quality, air pollution, increased transmission of infectious diseases, and decreased crop yields and nutrients. For example, air pollution accounts for nearly seven million premature deaths per year. Our YCCCH’s recent research also shows that air pollution is linked to increased hospital admissions of cardiovascular, kidney and mental illness.

Why is the Paris Agreement goal to keep global warming well below 2° C so important to our health?

Recent global burden-of-disease studies found that around 2 million to 5 million deaths per year can be attributable to extreme temperature globally. Kai Chen

KC: Any increase in global warming will primarily adversely affect human health. Our research shows that heat-related morbidity and mortality are projected to increase at 1.5 °C of warming and increase further at 2 °C or 3 °C. Ground-level ozone, a potent air pollutant, will increase when global warming exceeds 2 °C, resulting in a higher ozone-related mortality burden. As the climate changes, the world’s population is also growing older. Population aging will substantially amplify the projected mortality burden of temperature and air pollution under a warming climate.

What is the legacy of COVID-19 in addressing climate change?

KC: One big legacy of the COVID-19 response is a leap forward to a sustainable and healthier world. During the COVID-19 pandemic, lockdowns have given us the opportunity to see clean and blue skies across the world. Our study finds that in China, the first nationwide lockdown in early 2020 sharply reduced the country’s often-severe air pollution and brought substantial human health benefits in non-COVID-19 deaths. This dramatic change has shown us a glimpse of what a healthier world with strong clean air policies could be. But air pollution reduction and its associated health benefits during COVID-19 lockdowns are temporary. Moving forward, a more sustainable and healthier society will require increased investment in clean and renewable energy, low-carbon infrastructure, active transportation and climate-friendly lifestyles.

At the Yale Center on Climate Change and Health, our Climate, Health and Environment Nexus Lab aims to apply multidisciplinary approaches to produce policy-relevant knowledge that can be used to advance climate change mitigation and adaptation in a manner that promotes health and protects vulnerable populations.

3 Essential Questions is a recurring feature that explores vital topics in public health. Read earlier versions of 3 Essential Questions on cancer and antibiotic resistance .

MEDIA CONTACT: Michael Greenwood at [email protected]

Featured in this article

• Kai Chen, PhD Assistant Professor of Epidemiology (Environmental Health); Director of Research, Climate Change and Health; Deputy Faculty Director, Climate Change and Health; Affiliated Faculty, Yale Institute for Global Health

• Newsletters

Site search

• Israel-Hamas war
• Home Planet
• 2024 election
• Supreme Court
• 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.

So, what was the point of John Mulaney’s live Netflix talk show?

UFOs, God, and the edge of understanding

Israel’s other war

What we know about the police killing of Black Air Force member Roger Fortson

Inside the bombshell scandal that prompted two Miss USAs to step down

How to listen to Today, Explained on the radio

Climate change: Answers to your most asked questions

• Published 24 May 2019

During the last worldwide school strikes in March, BBC News asked for your questions on climate change.

Since then, thousands of you have been talking to our climate change chatbot on Facebook Messenger.

Below are some of the topics that came up many times - with some answers from science and our climate team.

You can chat to our climate bot here .

You asked: Can we adapt to climate change instead of fighting it?

Humans are already adapting. In South Korea, farmers are growing different crops to future-proof themselves against changing temperatures.

London's Thames Barrier was designed to help the city deal with an increasing risk of flooding.

And the United Nations has made adaptation a key part of its strategy, alongside measures to curb rising global average temperatures.

Under the Paris climate agreement, richer countries have agreed to help poorer nations by providing "climate finance" to help them adapt.

You asked: Should I change my diet?

Avoiding meat and dairy products is one of the biggest ways to reduce your environmental impact.

Cutting these from your diet could reduce an individual's carbon footprint from food by two-thirds, according to one Oxford study .

• Climate change food calculator: What's your diet's carbon footprint?

Beef and lamb have a big environmental impact, as the digestive systems of livestock produce methane - a powerful greenhouse gas.

The UN says we need to eat more locally-sourced seasonal food, and throw less of it away.

How and where your food is produced is also important, as the same food can have very different impacts.

For example, beef cattle raised on deforested land is responsible for 12 times more emissions than cows reared on natural pastures.

You asked: What can I do?

Lots. The UN Intergovernmental Panel on Climate Change (IPCC) says the world cannot meet its emissions targets without changes by individuals.

• Buy less meat, milk, cheese and butter and more locally sourced seasonal food - and throw less of it away
• Change how you get around. Drive electric cars but walk or cycle short distances. Take trains and buses instead of planes
• Use video-conferencing instead of business travel
• Use a washing line instead of a tumble dryer
• Insulate homes
• Demand low carbon in every consumer product

Research reported by the IPCC also said people tend to overestimate the energy-saving potential of lighting, and underestimate the energy used to heat water.

It also says people don't think a lot about the energy used for the creation of products they buy.

You asked: Why has so much changed in food labelling for personal health but not planet health?

In 2013, the government set out plans for a consistent "traffic light" food labelling system to help people easily understand what's in their food.

But we don't have a similar system for the carbon footprint or environmental impact.

It would involve considering things such as air freight versus importing food by sea, the use of water in food production, as well as the impact on land and forests.

Tesco did try it in 2007 - it started calculating the carbon footprint of every one of its 70,000 products.

But five years later the supermarket gave up, saying it was "a minimum of several months' work" for each product.

In 2007, Walkers Crisps was the first UK firm to put carbon footprint figures on its products. But the company confirmed to the BBC that it has since removed them.

You asked: What about the world's increasing population?

Human-induced climate change is happening. And the UN estimates the world has added approximately one billion humans since 2005.

But depending on where in the world you live - and your lifestyle - a person's emissions can be very different.

Generally, people living in countries like the UK depend heavily on fossil fuels.

According to one study , having one fewer child is the single most effective thing you can do to reduce your emissions.

But this result is contentious and leads to many philosophical and ethical questions which we're not going to wade into here.

Like, if you are responsible for your children's emissions, are your parents responsible for yours?

You asked: What are governments doing on climate change?

Individual governments are choosing to tackle climate change in various ways.

But the one thing that has pulled the world together is the Paris agreement.

• What is in the Paris climate agreement?
• 'Trump effect' threatens Paris agreement

The deal has united nearly 200 countries in a single agreement on tackling climate change for the first time ever.

Nations pledged to keep global temperatures "well below" 2.0C (3.6F) above pre-industrial times and "endeavour to limit" them even more, to 1.5C.

However, scientists point out that the agreement must be stepped up if it is to have any chance of curbing dangerous climate change.

You asked: How much hotter has the world got - and how hot will it get?

Global temperatures rises are generally compared to "pre-industrial times". Many researchers define that as 1850-1900 - before the world was chugging out greenhouse gases on a global scale.

The world is now about 1C warmer than it was back then, according to the IPCC.

For decades, researchers argued the global temperature rise must be kept below 2C by the end of this century to avoid the worst impacts.

But scientists now argue that keeping below 1.5C is a far safer limit for the world.

• What does 1.5C mean in a warming world?

It's hard to know much hotter the world will get. But if current trends continue, the World Meteorological Organization says temperatures may rise by 3-5C by 2100.

You asked: Why doesn't BBC News do more on climate change?

Covering climate change and its impact on people around the world is a top priority for BBC News.

We know climate change is an increasingly important subject. Younger audiences in particular tell us they would like to see more journalism on the issue, the BBC says.

There has been a significant increase in the number and range of stories across our output.

This includes prominent coverage of the latest scientific research, extreme weather events, climate protests, how climate change is affecting people's lives and the search for solutions to this enormous global challenge.

These stories are resonating with our audiences and it is a subject we are committed to covering in depth across BBC News.

You asked: What if I can't afford to change my way of life?

Being climate conscious can often feel very expensive, from changing your food habits to buying an electric car.

But there are some things that will save you money - like eating wonky vegetables instead of red meat and cycling to work instead of driving.

And making your home more energy efficient should actually bring down your bills.

Chat to our climate change bot on Facebook Messenger

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.

• 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.

Climate Change

Frequently asked questions about climate change.

The Earth’s climate is changing. Rising temperatures are already driving changes in climate around the globe, including changes in precipitation patterns and the frequency or intensity of extreme events such as storms, floods, droughts, and heat waves.The warmer climate has also led to rising sea levels, changes in snow and ice cover, longer growing seasons, and impacts on infrastructure, public health, and ecosystems. Many of these observed changes are linked to the rising levels of carbon dioxide and other greenhouse gases in our atmosphere, caused by human activities.  [1]  

See the frequently asked questions below to learn more about the causes of climate change, why it matters, and what we can do about it.

Climate refers to average weather conditions over many years. For example, the climate in Minnesota is cold and snowy in the winter, while the climate in Hawai'i is warm and humid all year long. Weather, in contrast, refers to a specific event or condition that happens over a period of hours or days. For example, a thunderstorm, a snowstorm, and today's temperature all describe weather. 

Climate change involves significant changes, over several decades or longer, in temperature, precipitation, wind patterns, and other aspects of climate. Weather varies naturally from year to year, so one unusually cold or wet year followed by an unusually warm or dry year would not be considered a sign of climate change. Climate change involves longer-term trends, such as a gradual shift toward warmer, wetter, or drier conditions. 

“Global Warming” vs. “Climate Change”

Global warming is just one aspect of climate change. It’s a term used to describe the recent rise in the global average temperature near Earth's surface, which is caused mostly by increasing concentrations of greenhouse gases (such as carbon dioxide and methane) in the atmosphere. The terms “global warming” and “climate change” are sometimes used interchangeably, but warming is only one of the ways in which climate is affected by rising concentrations of greenhouse gases.

Hundreds of independent lines of evidence confirm that our climate is changing. For example, scientists have documented long-term changes around the world in temperature , precipitation , sea level , and the amount of heat stored in the ocean . Especially dramatic changes are underway in the Arctic , where warming is amplified by powerful feedbacks. Reductions in sea ice , land-based ice, and snow cover, along with the thawing of permafrost, are having profound impacts in the Arctic and beyond. Rising sea levels, caused mainly by the expansion of seawater as it warms, along with billions of tons of water added to the ocean each year from melting glaciers , ice caps, and ice sheets, are affecting coastal communities in many parts of the world, including places like South Florida, Chesapeake Bay, and low-lying communities along the Gulf Coast in the United States. Changes in the length of growing seasons and pollen seasons , the timing of bird migrations , and range shifts in plants and wildlife provide still more evidence for recent changes in climate.

The Greenhouse Effect

Greenhouse gases, such as CO 2 , methane, and nitrous oxide, act like a blanket around the planet. They trap energy in the atmosphere and cause it to warm. This phenomenon, called the greenhouse effect, is natural and necessary to support life on Earth: without it the Earth’s average temperature would be around 0°F. But scientists agree that the continuing buildup of greenhouse gases in the atmosphere—caused mainly by the burning of fossil fuels for energy—will upset the natural energy balance and change Earth's climate, with potentially dangerous risks to human health, infrastructure, the economy, and ecosystems. 

Climate scientists have concluded that humans are largely responsible for the climate change that has occurred since the 1950s. [1]  Human activities—such as burning fossil fuels for energy, cultivating crops, raising livestock, and clearing forests—are releasing greenhouse gases into the atmosphere . These greenhouse gases are being emitted faster than forests and the oceans can remove them, causing them to build up in the atmosphere. 

The atmospheric concentration of carbon dioxide (CO 2 ) has increased by more than 40% since pre-industrial times, and the current CO 2  level is higher than it has been in at least 800,000 years. [1] We know that human activities are the cause of this increase because the CO 2  emitted by burning fossil fuels carries a distinct chemical fingerprint that’s detectable in the atmosphere. [2]

Scientists have known since the 1800s that greenhouse gases trap heat, preventing it from escaping to space. The warming effect of greenhouse gases is amplified by feedbacks, especially from water vapor (a powerful and plentiful natural greenhouse gas), leading to more warming and changes in climate. [1] Natural influences on climate, such as changes in solar radiation, natural cycles, volcanic eruptions, and the climate’s normal year-to-year variability, can‘t fully explain the current warming trend. [1]  The climate changes observed in recent decades follow a number of patterns—such as cooling at high altitudes and more warming at night than during the day—that are consistent with what scientists would expect from an increase in greenhouse gases rather than changes in solar variability or other natural causes. [1]

The Earth’s average temperature has risen by 1.5°F over the past century, and climate scientists estimate it will rise another 0.5 to 8.6°F by the end of this century, depending, in part, on future emissions. [1]  That may not sound like much to worry about, since most of us experience much greater temperature changes over the course of a day or from season to season. But the global average temperature during the height of the last ice age was only 5 to 9°F cooler than it is today. [3]  Relatively small changes in the planet’s average temperature can mean big changes in local and regional climate , creating risks to public health and safety [4] ,  water resources , agriculture , infrastructure , and ecosystems . [5]  Following are some examples:  [5]

• Increasing heat waves: Heat waves have become more frequent in the United States in recent decades. Climate scientists expect the number of days with temperatures above 90°F to increase in the United States as the climate changes, especially toward the end of this century. 
• More extreme weather: In addition to heat waves, changes in precipitation patterns, including extreme precipitation events, storms, and floods, are becoming more common and more severe in many regions, and this is expected to continue. 
• Intensified droughts: Higher temperatures lead to increased rates of evaporation and can lead to more rapid drying of soils. Without reductions in global greenhouse gas emissions, longer-term droughts are expected to intensify in much of the Southwest, the Great Plains, and the Southeast.
• Impacts on crops: Over the past 40 years, climate disruptions to agricultural production have increased, and this is expected to continue.
• Impacts on health: Climate change is increasing our exposure to extreme temperatures, extreme weather events; degraded air quality; diseases transmitted through food, water, and insects; and stresses to mental health and well-being. These threats to human health are expected to increase with continued climate change.
• More wildfires: The area burned by wildfire in parts of western North America is expected to double (or more) for each 1.8°F increase in global average temperature. [6]
• Rising sea levels: Global sea level has risen by about eight inches since the late 1800s, and is projected to rise another 1 to 4 feet by the end of this century. Flooding is becoming more frequent along the U.S. coastline, especially in the Mid-Atlantic region where the land is simultaneously sinking.

Climate change endangers our health by affecting our food and water sources, the air we breathe, the weather we experience, and our interactions with the built and natural environments. As the climate continues to change, the risks to human health continue to grow.

Although every American is vulnerable to the health impacts associated with climate change, some populations are disproportionately vulnerable , including those with low income, some communities of color, immigrant groups (including those with limited English proficiency), Indigenous peoples, children and pregnant women, older adults, vulnerable occupational groups, persons with disabilities, and persons with preexisting or chronic medical conditions. [4]

By making choices that reduce greenhouse gas pollution , and preparing for the changes expected in the future, we can reduce risks from climate change. Our decisions today will shape the world we live in and the world we leave to our children and grandchildren. 

Due to time lags in the climate system and the fact that CO 2 stays in the atmosphere for hundreds or thousands of years, the climate will continue to warm until at least mid-century regardless of what we do today to reduce emissions (see graph below). If we fail to make substantial cuts to greenhouse gas emissions, the Earth will keep warming for centuries to come. [1]

But it is not too late to address climate change and reduce the risks of impacts in the second half of this century and beyond. Doing so will require substantial cuts in greenhouse emissions. This will require stepping up improvements in energy efficiency, reducing waste, slowing deforestation, and shifting to cleaner energy sources. 

Communities can also prepare for the changes in the decades ahead by identifying and reducing their vulnerabilities and incorporating consideration of climate change risks into planning and development. Such actions can ensure that the most vulnerable populations—such as young children, older adults, and people living in poverty—are protected from health and safety threats from climate change.

Economic studies suggest that the longer we wait to act on climate change, the more expensive it will be. There are many technologies already available, and actions we can take today, that will help us reduce our risks. Many of the actions that we can take to address climate change will have immediate benefits, such as cleaner, healthier air, as well as significant future climate benefits. A recent EPA study found that global efforts to reduce greenhouse gas emissions could avoid tens of thousands of deaths annually in the U.S. by the end of the century and avoid billions of dollars in damages related to water shortages, agricultural losses, flooding, and other impacts.

Yes – small actions really add up! There are many actions that individuals and business can take to reduce their carbon footprint and act on climate change. Simple actions such as using energy-efficient light bulbs, looking for the ENERGY STAR label on appliances and other products, recycling and composting, purchasing green power, using public transit, and bicycling or walking instead of driving can make a difference by reducing your household’s carbon footprint.

As thousands of households and businesses have already discovered, improving energy efficiency in our homes and products can reduce greenhouse gas emissions and also save money. EPA’s ENERGY STAR program, a voluntary initiative that drives more widespread use of energy-efficient products and practices, has saved U.S. businesses, organizations, and consumers more than $362 billion in energy costs since 1992 while avoiding more than 2 billion metric tons of greenhouse gas emissions.

• EPA’s Climate Change site provides details on the science and impacts of climate change, sources of emissions, a household emissions calculator, and much more.
• What You Can Do about Climate Change  on EPA's Climate Change site offers suggestions for what you can do at home, at the office, at school, and on the road to reduce your greenhouse gas emissions.
• Climate.gov , run by the National Oceanic and Atmospheric Administration, serves as a source for news and features on U.S. and global climate, maps and data, and resources for teachers.
• NASA’s Global Climate Change site provides news, educational information, apps, images, multimedia, and other resources.
• The U.S. Global Change Research Program conducts the U.S. National Climate Assessment and conducts a wide range of other research on climate change.
• Climate Change Evidence and Causes , a report by the National Academy of Sciences, looks at 20 common questions about climate change and provides authoritative answers from leading climate scientists. 

Top of Page

1. IPCC (2013). Summary for Policymakers. In:  Climate Change 2013: The Physical Science Basis.  Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change .  Intergovernmental Panel on Climate Change. 2. IPCC (2007). Climate Change 2007: The Physical Science Basis. Frequently Asked Questions . FAQ 7.1. Intergovernmental Panel on Climate Change. 3. IPCC (2007). Climate Change 2007: The Physical Science Basis. Executive Summary. Intergovernmental Panel on Climate Change. 4.​ USGCRP (2016). The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment .  Crimmins, A., J. Balbus, J.L. Gamble, C.B. Beard, J.E. Bell, D. Dodgen, R.J. Eisen, N. Fann, M.D. Hawkins, S.C. Herring, L. Jantarasami, D.M. Mills, S. Saha, M.C. Sarofim, J. Trtanj, and L. Ziska, Eds. U.S. Global Change Research Program. 5. USGCRP (2014). Climate Change Impacts in the United States: The Third National Climate Assessment . Melillo, Jerry M., Theres (T.C.) Richmond, and Gary W. Yohe, Eds., U.S. Global Change Research Program. 6. National Research Council (2011). Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millenia. National Academies Press.

Contact Us to ask a question, provide feedback, or report a problem.

• Basic Information
• What EPA is Doing
• What You Can Do
• Greenhouse Gas Emissions
• Students' Site

Have Climate Questions? Get Answers Here.

By The New York Times Climate Desk Updated Sept. 6, 2023

• Share full article

Illustration by Maria Chimishkyan

Climate change is tremendously complex — and we’re here to help. The climate desk at The Times has been collecting reader questions and has started answering them here.

Type your question in the search box to see if we’ve covered it yet. If you don’t find an answer, don’t worry: We’re following your great questions and will add more in time.

Ask your question here:

This tool uses machine learning to suggest relevant answers on this page. Read about our methodology here .

Or browse the questions below: the science, how do we know climate change is really happening.

There’s overwhelming evidence that the world has been warming since the late 19th century, when the burning of fossil fuels became widespread and resulted in large-scale emissions of heat-trapping carbon dioxide into the atmosphere. This evidence is largely in the form of data from weather stations, buoys, ships, satellites and other sources. The most basic measurements of temperature show that the world has been steadily getting warmer. On average, surface temperatures are 1.2 degrees Celsius (2.2 degrees Fahrenheit) warmer than a century and a half ago. And the rate of warming has accelerated in recent decades. Temperatures in the top layer of the world’s oceans have increased as well. The oceans have absorbed much of the heat trapped in the atmosphere. There is also plenty of evidence showing the consequences of this warming. Tide gauges and other instruments show that sea levels have risen by about half an inch per decade since 1900 (mostly because water expands as it warms). Satellites that measure gravitational changes show that trillions of tons of ice have melted from the world’s ice sheets and glaciers. Rainfall data shows that heavy downpours have increased in the United States and elsewhere, because warmer air holds more moisture. And not all of the evidence comes from instruments. Scientists doing field research around the world have documented other effects of climate change. Ornithologists, for instance, have shown that warming is affecting many bird species — changing when they nest, breed and migrate, and even where they are able to live and thrive. Botanists see similar signs of the effects of climate change on crops, forests and other vegetation. — Henry Fountain

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

How do we know humans are to blame for climate change?

Over many decades, thousands of scientists have studied the warming planet. They’ve reached an overwhelming consensus: The burning of fossil fuels by humans is the primary cause of global warming today. Even scientists employed by oil companies have come to this conclusion . One scientific study put it this way: The odds of current global warming occurring without human-caused greenhouse gas emissions are less than 1 in 100,000. Here’s how the science arrived at this place. First, it’s important to understand the main forces affecting climate. The big ones are the sun (whose energy can fluctuate over time), ocean circulation patterns (which can change how heat is distributed around the planet), volcanic activity (which pumps material into the sky that can have either warming or cooling effects) and the overall amount of greenhouse gases in the atmosphere. Each of these forces has played a role at different times in history. For example, 56 million years ago, a giant burst of greenhouse gases from volcanoes or vast deposits of methane (or both) abruptly warmed the planet by at least 9 degrees Fahrenheit, triggering mass extinctions. About 12,000 years ago, major changes in Atlantic Ocean circulation plunged the Northern Hemisphere into a frigid state. And 300 years ago, a combination of reduced solar output and increased volcanic activity cooled parts of the planet enough that Londoners regularly ice-skated on the Thames River. Volcanoes can have a cooling effect when they shoot out stuff that blocks solar radiation. In studying the cause of today’s climate changes, scientists have looked at all of these factors. The first three (solar energy, ocean patterns and volcanic activity) haven’t varied enough in the last 150 years to account for today’s rapidly rising temperatures. That’s especially true in the second half of the 20th century, when solar output actually declined and volcanoes had a cooling effect. Rather, scientists have found that the warming is best explained by rising concentrations of greenhouse gases in the atmosphere, put there by humans burning vast amounts of fossil fuels like coal, oil and gas since the start of the Industrial Revolution. From having studied bubbles of ancient air trapped in ice, scientists know that before 1750, the concentration of carbon dioxide in the atmosphere was roughly 280 parts per million. That number is now above 420 parts per million. Carbon dioxide acts like a blanket in the atmosphere, trapping the sun’s heat and warming the planet. — Julia Rosen

How will climate change affect biodiversity?

Climate change is already harming plant and animal life in ways that scientists are racing to understand. Warmer oceans are killing corals. Rising sea levels are threatening the beaches that sea turtles need for nesting. Summers are becoming longer, and winters shorter — seasonal shifts that endanger countless animal and plant species by disrupting food supplies, mating seasons and other variables. And then there are the polar bears, long symbols of what could be lost in a warming world. One study predicted sudden die-offs , with large segments of ecosystems collapsing in waves as the world warms. The phenomenon has already started in coral reefs, scientists say, and could begin in tropical forests by the 2040s. However, despite these grim predictions, climate change isn’t currently the biggest driver of biodiversity loss. On land, the largest factor is the reshaping of the terrain itself, as people have created farms and ranches, towns and cities, roads and mines on what was once habitat for myriad species. At sea, the main cause of biodiversity loss is overfishing. These issues — habitat loss, overfishing and climate change — are interlinked. For example, ecosystems like peatlands and forests not only support a wide variety of life but also pull carbon dioxide out of the air and store it in plants and in the ground. Destroying them both harms biodiversity and complicates the fight against climate change. — Catrin Einhorn

Read more: Animals Are Running Out of Places to Live

What are tipping points, and why should we care?

A climate “tipping point” refers to a threshold beyond which small changes to global temperatures can have big, irreversible effects. For example, you’ve probably heard that scientists are concerned about the melting of the huge ice sheet that covers Greenland. If the world isn’t able to rein in global warming, the melting will eventually become self-sustaining and irreversible, researchers have determined. That’s a tipping point. If this threshold is crossed, the melting could raise sea levels by as much as 23 feet over the course of several centuries, swamping coastal cities around the world. The idea of climate tipping points has been around for decades, although there is debate about how many there are and at what temperatures they will be reached. The big ones, however, are generally accepted to include the melting of the ice sheets in Antarctica and Greenland; the thawing of Arctic permafrost; the collapse of a major ocean circulation system; and the shrinking of the Amazon rainforest. Recent research suggests that some of these changes may start to occur once global warming reaches between 1.5 and 2 degrees Celsius (2.7 and 3.6 degrees Fahrenheit) above preindustrial average temperatures. And the world is already 1.2 degrees Celsius warmer than it was in the 19th century. — Henry Fountain

Read more: Failure to Slow Warming Will Set Off Climate ‘Tipping Points,’ Scientists Say

Do volcanoes affect climate change?

The effect of volcanic eruptions on warming is minimal. Volcanic activity generates between 130 million tons to 440 million tons of carbon dioxide per year, according to the United States Geological Survey. Human activity generates far more, about 35 billion tons of carbon dioxide per year — 80 times as much as the high end of the estimate for volcanic activity, and 270 times as much as the low end estimate. And that’s just carbon dioxide. Human activity also releases other greenhouse gases into the atmosphere, like methane, in far greater quantities than volcanoes do. Here’s one way to think about it. The largest volcanic eruption in the past century was the 1991 eruption of Mount Pinatubo in the Philippines. If an explosion of that size happened every day, NASA has calculated, it would still release only half as much carbon dioxide as daily human activity does. Volcanoes can also have a short-term cooling effect, when they blast material into the atmosphere that blocks the sun’s energy. But regardless, there is no evidence that volcanic activity has increased over the past 200 years. There have been more reports of eruptions. But researchers at the Global Volcanism Program of the Smithsonian Institution have attributed that increase not to a rise in actual eruptions, but to increased reports from the growing number of people who live near a volcano. In 2013, the Intergovernmental Panel on Climate Change found that the climatic effects of volcanic activity were “inconsequential” over the scale of a century. You can read the findings on Page 56 of the IPCC’s report . — Maggie Astor

What’s happening to the oceans?

Talk of global warming usually focuses on rising temperatures in the atmosphere. But most warming is actually occurring in the oceans. That’s because the oceans are an enormous heat sink. They cover two-thirds of the Earth’s surface, and water can absorb much more heat than air, so about 90 percent of the excess heat trapped in the atmosphere by greenhouse gases is taken up by the oceans. Without the oceans, the atmosphere would have warmed far more than the 1.2 degrees Celsius (2.2 degrees Fahrenheit) it has since the late 19th century. And currents distribute the ocean’s heat around the globe, playing a critical role in regulating the climate. But warming of the oceans has caused its own problems. Water expands when it warms, which contributes to rising sea levels. Warming oceans cause coral reefs to die, add energy to hurricanes, making them more destructive, and melt the leading edges of ice sheets in Greenland and Antarctica from underneath. And just as with land-based life, warming in the oceans has affected the range and distribution of many species of fish and shellfish. Oceans don’t just absorb heat; they also take up carbon dioxide. This, again, is not all bad — the huge current that encircles Antarctica removes much carbon dioxide that would otherwise stay in the atmosphere and trap more heat. But as the carbon dioxide concentration of the oceans increases, the water becomes more acidic. This change in water chemistry harms many small ocean organisms that are a fundamental part of the marine food chain. — Henry Fountain

Read more: Warning on Mass Extinction of Sea Life: ‘An Oh My God Moment’

How does ranching and animal agriculture affect climate change?

Raising animals to feed people has a significant effect on climate change (and the environment in general), and it’s not just about belching cows. Cattle get a lot of the attention because of their burps: The specialized digestive system of cattle (and other ruminants, including sheep) produces methane that is released into the atmosphere, mostly through belching. The United Nations Food and Agriculture Organization estimates that digestion accounts for about 40 percent of the emissions from animal agriculture. However, a wide range of other emissions are related to the production of feed, animal transportation and other activities. Overall, the U.N. agency estimates that, globally, the raising of livestock of all kinds is responsible for nearly 15 percent of all emissions related to human activity. Cattle raised for meat and milk account for about two-thirds of total emissions, and pig production accounts for about 10 percent. Buffalo, chicken (for meat and eggs) and other animals like sheep account for smaller amounts. When measured by unit of protein produced, beef has by far the largest carbon footprint. The production and processing of animal feed — forage crops like hay, as well as corn and other grains — accounts for even more emissions than digestion. Some of these come from the burning of fossil fuels (to run agricultural equipment and heat or cool barns and other facilities), some from activities like fertilizer production and some from the land-use changes that often accompany the expansion of the beef industry and other enterprises. An analysis by Our World in Data, a scientific publication affiliated with the University of Oxford, found that agricultural land use could be reduced by 75 percent , to one billion hectares from four billion, if the world adopted a plant-based diet. When a rancher or beef producer clears a forest to create grazing land, large amounts of carbon in the felled trees is released, either quickly, through burning, or more slowly, through decay. With worldwide demand for beef and other meats rising, this kind of deforestation is increasing in some parts of the world, notably in the Amazon rainforest in South America. Brazil is the perennial leader in acres of tropical forest lost to deforestation, according to the World Resources Institute. Two other significant, if smaller, sources of emissions are manure and the processing and transportation of the finished animal products. — Henry Fountain

What are El Niño and La Niña?

These are the names of two different but related climate phenomena that originate in the equatorial Pacific Ocean and come and go every few years, influencing weather around the world. An El Niño period tends to bring rainier, cooler conditions to much of the Southern United States, and warmer conditions to other parts of North America. Elsewhere around the world, El Niño can create warm, dry conditions in Asia, Australia and the Indian subcontinent. Parts of Africa and South America can be affected as well. In 2023, scientists announced the start of the latest El Niño. With it comes increased chances for hotter-than-normal temperatures in 2024. Then there’s La Niña, its opposite. La Niña often brings warmer and drier conditions in the Southern United States, and cooler, wetter weather in parts of the North, especially the Pacific Northwest. Parts of Australia and Asia can be wetter than normal. La Niña can also lead to more hurricanes in the North Atlantic. Both El Niño and La Niña occur on average about every two to seven years. They can last the better part of the year, though sometimes longer. Some research suggests that exceptionally strong episodes will occur more frequently than they do now as the world continues to warm from emissions of greenhouse gases. Both are defined by changes in sea-surface temperatures in the equatorial Pacific, as well as changes in atmospheric high-pressure and low-pressure zones. When sea-surface temperatures there are about 1 degree Fahrenheit or more above average, El Niño can develop. When temperatures are below average, La Niña can form. (When temperatures are at or near average, neither develops.) The temperature changes are also accompanied by differences in atmospheric air pressure that can influence powerful trade winds, affecting rainfall and temperatures far and wide.

Read more: El Niño and La Niña, Explained

What are climate “models” and are they any good?

Simply put, climate models are computer programs that simulate part or all of the world’s climate. They help scientists better understand what might happen in the future — in this case, how the global climate may change over time. But climate models are far from simple. The software has to replicate, as closely as possible, the physics of climate elements like the atmosphere, the ocean, land surfaces and ice sheets. Even more critically, it must accurately simulate how all of these elements interact over time. The simulations combine actual data (temperature, precipitation, humidity and other real-world observations) with tweakable elements like carbon dioxide levels in the atmosphere or variations in the sun’s intensity. This allows scientists to explore various what-ifs — for example, what might happen to sea levels if greenhouse gas emissions increase or decrease. No computer model, of the climate or anything else, is perfect. No computer can do enough calculations fast enough to show how the climate will change every minute in every cubic inch of the world for the next 50 years. But computer models can be extremely useful, and they’re steadily improving. And even older and less complex models have proven over time to be accurate at forecasting climate change. — Henry Fountain

Is there a connection between climate change and earthquakes?

Short answer: Maybe. But it’s hard to know for sure, and the effects would likely be small. Here’s a longer answer. Earthquakes occur because of changes in the stresses along a fault line — a fracture between blocks of rock underground. Anything that causes changes in stress levels could push a stable fault to the point where the blocks suddenly move past each other. That’s an earthquake. Stresses in a fault build up naturally, a result of the slow movement of Earth’s large crustal plates. But stresses can be affected in other ways as well. For example, injection of wastewater from oil drilling into wells in Oklahoma was found to have caused many earthquakes, most of them small. And anything that alters the mass above a fault — impounding of water behind a dam, for example — can potentially alter stresses. Extraction of gas from a large natural gas field in Soviet Uzbekistan is thought to have triggered large earthquakes in 1976 and 1984. Faults are far enough underground that the warming of the atmosphere and the oceans from emissions of greenhouse gases wouldn’t affect them. But global warming may affect earthquakes indirectly. More intense and frequent droughts could result in more evaporation of water from the ground, potentially changing fault stresses. The melting of ice sheets and glaciers, which are extremely heavy, might alter stresses below them as well. But since the effects likely would be small, and since scientists don’t precisely know pre-quake stress conditions within faults, no one is able yet to confidently say whether such indirect warming-related effects pushed a given fault past the breaking point and caused an earthquake. — Henry Fountain

What can I do?

What can the average person do about climate change.

This is one of the most common and vexing questions: Can one person’s actions really make a difference? The problem is so big that the fix has to come from powerful nations and policymakers, right? First of all, it’s impossible to separate the two things: Personal actions and international cooperation are inextricably linked. The answer also depends on whose actions we’re talking about. The actions of a middle-class American matter a lot more than the actions of, say, a farmer in Bangladesh. Why? Because people in wealthy countries consume much more than people in poor countries, and so their choices matter more to global emissions. What can individuals do? Here’s a detailed guide . A few examples: ∙ Transit: What car a person buys — or whether a person even owns a car — matters tremendously, because transportation is the single biggest source of emissions in most American cities. ∙ Air travel: Long-haul and first-class trips in particular increase a person’s carbon footprint. ∙ Food: If people were to simply waste less food, it would make a significant difference in emissions. ∙ Stuff: Avoid the disposable. Purchase things that last. In our homes, one of the most effective (but sometimes complicated) things that can help is to replace gas heaters with electric heat pumps . Gas stoves, too, contribute to warming , although to a lesser degree, but also have other negative health effects . Changing what you do can also influence others. Research shows, for instance, that people tend to conserve more electricity when their utility bills show how their power use compares with their neighbors’. And it’s worth noting that individual action is a prerequisite for collective action. Without individual activists getting together, there would be no Sunrise Movement camping out in the halls of Congress. And, of course, voting is an individual action that can be an important force for change. On the whole, though, humans tend to be bad at altering their behavior today to address risks tomorrow. This “present bias,” as cognitive scientists call it, makes it hard for us, as individuals, to carry out lifestyle changes now to prevent a catastrophe down the road. Because the world has deferred climate action for so long, it must now cut greenhouse gas emissions drastically and swiftly. It can be hard to imagine how those cuts can be made without ambitious government policies. Still, it’s not too late to make a difference. While it’s true that we have already dangerously warmed the planet by burning fossil fuels for generations, the future isn’t set in stone. Many futures remain possible. It’s up to us to decide which one plays out. — Somini Sengupta

Are we doomed?

If you’re asking whether the climate has already changed and is already causing grievous harm to millions of people, the answer is yes. If you’re asking whether humanity is destined to some vague and awful fate, the answer is no. Unequivocally no. Much is being done to slow the pace of warming. More can be done. That’s what scientists implore policymakers to do. “It’s never too late to stop punching ourselves in the face,” as Adam Levy, an atmospheric physicist, says in this video (while punching himself). Let’s first look at where we are. The average global temperature is about 1.2 degrees Celsius higher today than it was at the start of the industrial age, mainly because of the burning of fossil fuels. Thanks to all the greenhouse gases that have already accumulated in the atmosphere, the planet will heat up more in the coming decades. How much more? That depends on the actions of the countries that emit the most (essentially, the 20 largest economies, led by the United States and China). There are ways to keep planetary warming on a safe trajectory. The shorthand for this, established by global scientific consensus, is to limit global average temperature increases to well below 2 degrees Celsius, compared with preindustrial times. Until recently, we were on a very bad trajectory: The global average temperature was on track to warm by more than 4 degrees Celsius by 2100. That’s no longer the case, thanks to ambitious policies spurred by public pressure, technological advances and the rapidly falling cost of renewable energy. The pace can still be slowed a lot more. It requires slashing the burning of fossil fuels. It requires plugging leaks of methane (an extremely potent greenhouse gas) from oil and gas facilities. It requires growing food without mowing down more forests. There are many pathways, spelled out by rigorous research. Each has tradeoffs. For some of us, it might be easier to subscribe to doomism. It lets us off the hook to change how we do things. Or to imagine how the world might function differently. Nihilism is cheap. Don’t buy it. — Somini Sengupta

How should I think about my diet?

By some estimates, the world’s food system is responsible for one-quarter of humanity’s greenhouse gas emissions . It happens because forests get cleared to make room for farms and livestock. Cows and rice paddies emit methane, a potent greenhouse gas. Fossil fuels are burned to power farm machinery, make fertilizer and ship food. Anyone focused on the climate effects of diet should keep a few broad things in mind. First, beef, lamb and cheese tend to have the biggest effects on emissions by far — creating the most greenhouse gases per gram of protein — in part because cows and other ruminants are more resource-intensive to raise. Pork, chicken, eggs and many types of fish typically have smaller effects on emissions (though they can create other environmental concerns ). Plant-based foods usually produce the fewest emissions of all. So the most straightforward way of reducing diet-related emissions is to consume less meat and dairy and more plants. It’s especially the case if you live in the United States, where red meat consumption is much higher than in many parts of the world. According to a World Resources Institute analysis , if the average American simply replaced a third of the beef they eat with lower-emissions pork or poultry or legumes, their food-related emissions would fall 13 percent. Moreover, a number of studies have found that people who currently eat a meat-heavy diet could shrink their food-related footprint by one-third or more by going vegetarian. It sounds like a no-brainer, but the other big way to shrink the climate effect of your diet is simply to waste less food. According to some estimates , Americans throw out roughly 20 percent of the food they buy. Other popular strategies are less clear-cut, at least when it comes to greenhouse gas emissions. Studies differ on whether grass-fed beef, for instance, is any more climate friendly than conventional feedlot beef, although some argue it’s better for animal welfare. Organic crops tend to require more land than traditional crops, which could lead to more emissions if such farming results in more deforestation. As for debates over locally grown produce, or paper vs. plastic bags, those are relatively small in the grand scheme of things, since transportation and packaging are a sliver of food’s climate effects. And, of course, there are other concerns besides climate change. For example, when compared with meat, wild fish can be a lower-emissions option. But that comes with a caveat: The world is already catching about as much wild fish as it possibly can. Most fisheries are being fished at their maximum sustainable level, while others are being overexploited . So more people switching to fish could require, among other actions, increasing the number of sustainable fish farms worldwide. — Brad Plumer

Read more: Your Questions About Food and Climate Change, Answered

What about non-dairy milks like almond milk?

The Times has written extensively about food, diet and climate change — including what you might want to know about almond milks and soy milks — in this guide . Here’s an excerpt with the gist of it: “Almond, oat and soy milk all have a smaller greenhouse gas footprint than cow’s milk does. But, as always, there are caveats and trade-offs to consider. Almonds require a lot of water to grow, and this has been a problem in places like California. Soy milk tends to be fairly low-impact, as long as the soy is sustainably farmed.” In addition, we’ve written a separate entry in this F.A.Q. about how to think about your diet generally.

Where’s the safest place for me to live?

This is one of the most common lines of questioning we see: Should I move? Is one place safer than another? The simple fact is that no place is invulnerable to climate change. And although some parts of the world might be better than others, better isn’t perfect, because global warming has effects everywhere. Experts point to two major factors when you’re considering whether another place would be better suited for dealing with climate change than wherever you live now. The first is geography. Consider this example from the United States. The Midwest is inland, away from rising sea levels and warming ocean waters that will cause more flooding and intensified hurricanes. Midwestern states are also farther north than many others, which means naturally lower temperatures than places to the south. The Great Lakes region, and surrounding rivers, have the potential to provide reliable sources of water, offsetting some of the worst effects of drought. These factors also apply to much of the Northeast United States and the northern Great Plains and, outside the U.S., parts of Canada, Russia and Scandinavia. The second factor is the ability of a place to accommodate new arrivals. Does an area have enough housing or can it support more? Are residents welcoming to newcomers? Are local and regional governments preparing for population increases? If the answer to at least some of these questions is yes, you may have identified a potential destination. Some cities in the U.S. meet these standards. Detroit, Cincinnati and Buffalo, N.Y., are common examples. They are in regions with more climate-friendly geography. And they have another thing in common: Their populations have shrunk by the hundreds of thousands since the 1950s. Overall, relocating in the face of climate change is a profoundly complicated problem that the world is only beginning to fully understand. For one thing, many people, particularly in poorer countries or regions, can’t afford to move even if they wanted to. Despite that, some communities may be uprooted by disaster, forcing climate migration and the social, political and economic upheaval that can entail. The bottom line is that the planet will continue warming in the coming decades, according to the most recent projections. And even wealthier places aren’t always prepared for climate extremes. That makes it all the more important to consider points like geography, and a community’s preparedness for the future, when thinking about relocating. — German Lopez

Read more: Finding Climate Havens

Should I have kids?

Now we’re getting personal. First of all, if you’re trying to work through the climate consequences of bringing new life into the world, you’re in good company . It is our modern take on a question that’s probably been around since the dawn of humanity: Will my children have a safe and fulfilling life? If you’re worried about the future your child will grow up into, that’s a legitimate concern. Climate change affects people unfairly and unequally , starting at pregnancy . But whether we are rich or poor, the social and economic tumult the world faces as the planet warms is all but certain to touch us. If your concern is with the actual climate toll of child-rearing, researchers have tried to tackle that question. One study found that having a family does indeed take a significant environmental toll, though, as you can imagine, it’s a complex thing to try to put a number to. But here’s an important point to consider. More people in the world doesn’t necessarily mean more greenhouse gas emissions, if the world can find a way to stop burning fossil fuels. That cuts to the very heart of the world’s climate crisis: Can, and will, the world do what needs to be done in time for future generations? Ultimately, the choice to have a child or not comes down to the act of balancing a host of profound moral and individual considerations, starting perhaps with: Does parenthood deeply interest you? Because the right decision can’t be just about numbers, or carbon-dioxide-equivalent emissions, or the uncertainties of an unknowable future. As we all know, it’s easy to find friends, relatives — perhaps even (we hope!) our own parents — who will declare raising their children to be one of the most important and satisfying choices they’ve made. And it’s also easy to find folks who are living the richest of lives while choosing not to have a family.

Read more: The Population Question

How bad is the plastic problem and what can be done about it?

Plastic is a technological marvel that has transformed the human experience. We have plastic to thank for our cellphones, sippy cups, automobiles, surgical gloves, elastic underwear bands and countless other things. It’s also responsible for some 4 percent of global emissions . That’s more than what’s produced by all of the world’s airplanes combined . Plastic is, after all, usually made from fossil fuels. And it’s more than a climate problem: Plastic litter is killing marine life. And pollution (not only in the form of plastic) is one of the main drivers of biodiversity loss. Plastic-related chemicals can disrupt human metabolism and inhibit hormones. And they’re related to diseases . Research shows that more than 40 percent of the plastic we use comes in the form of packaging, generally single-use, and a lot of it isn’t recyclable. In fact, only about 9 percent of all plastic ever made has been recycled , according to the United Nations Environment Program. Recycling is notoriously difficult, starting with the little “recycling” symbol we’re all familiar with — the three arrows forming a triangle. Many people assume it means something is recyclable. But guess what: It doesn’t mean that. More on this big problem here . What plastic isn’t recycled ends up going to landfills, or it becomes litter, or it gets burned, polluting the atmosphere. The fossil fuel industry, worried about declining demand for oil, is trying to pivot to making even more of the stuff. Plastic waste going into waterways is set to more than double , perhaps even triple, by 2040. Some governments are creating laws to put the burden on companies to handle plastic waste, and are banning some single-use plastics. There is also movement toward a global treaty with a goal of getting nations to agree on a legally binding plan to improve recycling, clean up waste and curb production. How to do that, though, is up for debate . — Manuela Andreoni

Read more: Trash Or Recycling? How Plastic Keeps Us Guessing

Should I bother recycling?

It’s worth the effort. But the key word here, unfortunately, is “effort.” Figuring out whether something is recyclable — or simply whether anyone near you actually accepts recyclables — is far too confusing. You can’t even trust the familiar recycling symbol (those three little arrows forming a triangle) because it doesn’t actually mean a thing is recyclable. But there’s hope! America’s big recycling companies do want your recycling, or at least some of it. For starters, we built a game to explain how you can figure out if various pieces of plastic are actually recyclable. In order to know what you should throw in the bin, it can help to think like the recyclers. Recycling, after all, is not a public service in many places — it’s a business. So whether a material gets recycled depends on whether money can be made from it. Materials like glass and metals have a long history of recycling and can be endlessly reprocessed. The United States also has good infrastructure for recycling paper products like cardboard, which has a recycling rate above 90 percent. Plastic is different. One of the biggest barriers is that it’s often cheaper to simply make new plastic. That said, there is a good market for rigid plastics, the kinds marked “1” and “2” in the triangular symbol. These represent items like milk jugs and detergent tubs, and nearly 30 percent of these are recycled. One set of items must almost always go into the trash: flexible, or soft, plastics like shopping bags, bubble mailers or foil-lined chip bags. For one thing because they can jam up machines at sorting plants. So, yes, try to recycle clean paper products, metals, rigid plastics and glass, if it’s accepted in your local recycling program. To improve recycling, environmentalists say it can help to support legislation such as bottle bills , laws that incentivize companies to make products more recyclable or measures aimed at reducing single-use products. — Winston Choi-Schagrin

Does composting help?

Reducing food waste can definitely make a difference. The United Nations Environment Program says food waste accounts for 8 to 10 percent of greenhouse gas emissions globally. And that’s not to mention the emissions associated with food production, which add up to about 30 percent of the global total. But when tossing food or scraps simply can’t be avoided, composting can play a role. Composting can reduce greenhouse gases “by improving carbon sequestration in the soil and by preventing methane emissions through aerobic decomposition,” according to the Environmental Protection Agency . That’s because methane-producing microbes aren’t active in the presence of oxygen, the E.P.A. explains. Organic material decomposing in a landfill, on the other hand, produces lots of methane, a powerful greenhouse gas. Some cities and states are trying to make composting easier. Municipal brown bins can be found in parts of New York City, and California has a law requiring every jurisdiction to provide “organic waste collection.” Around the world, lawmakers have started to tackle the problem and the related issue of hunger. If your local government hasn’t set up a program, you can sometimes find community gardens or farmers’ markets that will accept compost. And we’ve written a guide on how you can compost inside your home , even without a yard. To answer the big question right up front: It doesn’t smell. While we have you on the topic of food waste, another thing to consider is what you buy, and where. We’ve written about apps that help connect you with unsold food for cheap. Think of those perfectly edible peaches and tomatoes that get passed up because they’re not pretty enough. If you find yourself thinking, “I’m just one person, what’s the point?” you might be inspired by this story of Domingo Morales . A New Yorker from the Bronx, Mr. Morales created a program to bring composting to public housing, home to as many as 600,000 New Yorkers. And if you still have more questions, check out the entries in this F.A.Q. about diet and animal agriculture .

Should I give up my gas stove?

People sure do love their gas stoves. But they have their downsides, particularly compared to induction cooktops , which are far more efficient and also don’t release pollutants into the home from the burning gas. Here’s how to think about making a change. First of all, if you’re looking to reduce household emissions of greenhouse gases, there may be more effective things that you could do before ditching the stove. The best thing to start with is an energy assessment, which is when you bring in a licensed professional to look over the home and identify the biggest ways to reduce energy use. ( This government site has information about finding one.) Often they will suggest things like fixing leaky windows or doors, which can save a surprising amount of money over time. If your home has a gas- or oil-burning furnace, replacing it with a heat pump would have a far bigger impact on household emissions than replacing your stove. That can be a costly project depending on many things, such as the size and age of the house. However, to soften the blow, in the U.S. you may be eligible for financial incentives . But back to your gas stove. Is it time to say goodbye? Evidence of the health risks of gas stoves has grown, including a link to childhood asthma. The reason is that the flames emit various poisonous gases including nitrogen oxide, which is thought to trigger asthma. Stoves can also sometimes leak small amounts of natural gas even when they’re off. There are ways to minimize the risk, such as making sure the range hood is turned on while cooking, or by buying a room air filter. This article has more details. Gas ranges also, obviously, burn gas, which is a fossil fuel and contributes to global warming. If you’re going to switch, induction stoves are the most efficient choice. They can cost a lot more than a traditional electric range, and for technical reasons, only certain kinds of pots and pans will work on the burners. But since induction ranges are powered by electricity they eliminate the issue of indoor pollution from gas. And depending how your local utility generates electricity, they can be much greener. If you decide to do it, you may also be eligible for incentives via the Inflation Reduction Act .

How do I explain climate change to my kid?

Climate change is likely to make your child’s life experience much different than what you’ve known. So even though it might feel like a daunting subject to bring up with your kids, it may also be one of the most important. The first — and most critical — step is to stay positive. Remind your child that they have a role to play as a nature lover and a climate leader, whether it’s in their backyard, their school, their community or beyond. Second, don’t feel daunted by the science. To help, we created this virtual children’s book which explains the basics of climate science, as well as actions we can all take. Third, remember that your approach will largely depend on your child’s age and interests. For young children, one way to start is by inspiring a love of the natural world. Over time, you can try to connect what they are noticing, whether it’s migrating birds or the leaves changing color, with concepts like seasons and weather. By elementary school, kids may have already heard the phrase “climate change,” so it can be important that they don’t start associating it with fear. Explain the basic facts of climate change and the world’s finite resources. (Again, our children’s book might come in handy.) Empower your kids with actions they can take on their own, whether it’s turning off the lights when they leave a room, or home composting , or taking care of a tree in the backyard. Science museums, zoos, and aquariums are great places to explore together, since many now connect their exhibitions with the wider effects of climate change and biodiversity loss in a child-friendly way. For kids who do receive formal instruction on climate change, it will most likely happen in middle school . At home, you might watch for opportunities to connect it with phenomena they are noticing in the community, whether it’s heat waves or changes in local flora or fauna. For teenagers, it might help to familiarize them with videos or stories of young people who are working on solutions. Reassure them that there are still paths forward , and take the opportunity to help them understand about misinformation and the value of reliable sources of information about climate change, but also about the world in general. Finally, let experts do your homework for you. Here are some kid- and teenager-friendly resources that have been vetted by climate scientists and science educators. · CLEAN is a database of resources supported by the National Oceanic and Atmospheric Administration. · Subject to Climate offers news articles and lesson plans written for fifth graders and up. · And of course The New York Times’s Learning Network curates kid-friendly material that’s designed for teachers but may also be helpful for parents. — Winston Choi-Schagrin

Read more: A Climate Change Guide for Kids

What can I do about climate anxiety?

Eco-anxiety, climate grief, despair, dread, anger. This is a serious phenomenon, and we’ve written about how climate change has entered the therapy room . Therapy can indeed be a helpful way to work through feelings like these related to the climate crisis, although sometimes it can be costly for a person without insurance to cover it. This article about support networks describes some useful, affordable resources. As one Times guide explains , action can also be an antidote to anxiety. And you might be inspired by this article about a growing chorus of young people trying to focus more on solutions to counterbalance the seeming drumbeat of gloomy news on climate change. Or this profile of teen climate activists and what they’re doing and why. This F.A.Q. also covers the topic elsewhere, from a slightly different angle, in our answer to the question, “ Are we doomed? ” We also have an entry on how to talk to kids about climate change.

Read more: How to Calm Your Climate Anxiety

How can I identify or rebut bad information when I see it?

There’s a whole lot of climate misinformation out there, thanks to deniers, special-interest groups and also the numerous people who buy into it not realizing that it’s bad information. “The climate has always changed.” “It’s snowing outside, gotcha!” “Sunspots are to blame and volcanoes too.’” These are all flawed arguments or attempts to misrepresent the science, cherry-pick facts or spread conspiracy theories about what’s known or how climate systems work. Once you recognize them, they are pretty simple to dismiss or ignore, and usually the flaws in the arguments are pretty easy to understand. Here are some resources that list examples of these kinds of bad information, and explain what’s wrong with them. ∙ Skeptical Science is a nonprofit website focused on science education that keeps a long list of false claims and rebuttals about climate. ∙ Here’s a short guide written for broadcast meteorologists to help them debunk climate misinformation. ∙ Carbon Brief, a climate news site based in Britain, occasionally writes “fact checks” about spurious claims in the news.

Solutions and geopolitics

Who is most responsible for climate change.

The world’s wealthiest countries have historically contributed the most to global warming. Just two dozen nations , including the United States, Canada, Japan, Australia and much of western Europe, are responsible for 50 percent of all the planet-warming greenhouse gases released from fossil fuels and industry since 1850, despite accounting for just 12 percent of the global population today. That’s because these countries industrialized earlier than much of the rest of the world and therefore have been burning oil, gas and coal for energy for longer than everyone else. When gauging responsibility for current warming, experts look at historical emissions, because once carbon dioxide is in the air it can affect the atmosphere for centuries. Today, China is by far the world’s largest single emitter, accounting for one-third of humanity’s carbon dioxide from energy and industry in 2022. However, it’s responsible for just 14 percent of all planet-warming greenhouse gas emissions since 1850. There are other ways to look at responsibility. Even within an individual country, a person’s “carbon footprint” (or the amount of greenhouse gas emissions produced by one’s lifestyle) typically depends on income and wealth. In the United States, according to one analysis , the top 10 percent of earners emits roughly 75 tons of carbon dioxide per person per year, while the bottom 50 percent emit about 10 tons per person. For comparison: In China, the top 10 percent emits about 36 tons per person, while the bottom half averages 3 tons per person. Some environmentalists prefer to focus on the fossil-fuel producers themselves. One oft-cited analysis found that more than 70 percent of global emissions since 1998 could be traced back to oil, gas and coal sold by just 100 companies, including China Coal, Saudi Aramco and oil giants like Exxon and Shell. But others point out that these companies hardly acted alone — the world bought and burned their products. — Brad Plumer

Read more: Who Has The Most Historical Responsibility for Climate Change?

What are the most critical steps to take soon?

To limit warming to just 1.5 degrees Celsius above preindustrial times — the more ambitious of the two climate goals endorsed by world leaders in the Paris agreement — emissions need to fall roughly in half by 2030 and countries need to stop adding carbon dioxide to the atmosphere by around 2050. That is a daunting task. In 2021, the International Energy Agency compiled a long list of steps to get there. There’s no silver bullet, but here are a few of the main recommendations: · Countries should immediately stop approving new coal plants unless they can trap the plants’ emissions and bury them underground (a technology barely in use). · By 2025, governments should start banning the sale of new oil and gas furnaces to heat buildings, shifting instead to electric heat pumps . · By 2030, electric vehicles should make up 60 percent of new car sales globally. · Worldwide, the annual pace of installing solar and wind power needs to quadruple between now and the early 2030s. Other short-term measures could make a big difference, such as curtailing emissions of methane , a potent greenhouse gas, from oil and gas operations, farms and landfills. Finding ways to conserve energy, such as improving insulation in homes, could also be a fast way to cut emissions. — Brad Plumer

Read more: To Cut Emissions to Zero, U.S. Needs to Make Big Changes in Next 10 Years

Can you give me some good news, please?

There has been some good news on climate change. Not enough. But good news nonetheless. First of all, over the past decade or so, several major economies including the United States have shifted away from burning coal to generate electricity. Coal is the dirtiest of fossil fuels, and historically speaking a major contributor to greenhouse gas emissions. There are still coal power plants being built in the world, but the overall trend away from coal toward cleaner options, like solar, is progress. The cost to build solar power plants has fallen enough that, in some cases, it is now one of the most price-competitive options for generating electricity. This is a significant financial milestone. Cars that burn gas are a major contributor to planet-warming greenhouse emissions, but in the past few years some of the world’s largest automakers have launched aggressive efforts to pivot to making more electric vehicles while phasing out gasoline models. The importance of a significant polluting industry embracing this change, and competing with one another to be better at it, can’t be underestimated. Car buyers have been responding. As recently as a half-decade or so ago, electric-car sales were negligible in many parts of the world, but have risen rapidly since. Electric vehicles aren’t perfect of course, but as a general rule they’re cleaner than gasoline cars. (If you’re interested in reading more about that, see the entry in this F.A.Q. for “ How green are electric cars? ”) The spread of electric vehicles also means that some of the difficulties of owning one (for example, finding charging stations nearby) will likely resolve themselves more quickly as demand grows from drivers. That, in turn, could encourage sales. In 2022 the United States passed new legislation, the Inflation Reduction Act, that is widely considered the most important legislative effort to fight climate change in the nation’s history by encouraging a transition to cleaner energy and offering a range of incentives to businesses and individuals to clean up their act. ( This Times guide explains how you might be able to claim some of that money by, for instance, buying an electric car or installing a heat pump.) Lastly, here’s a big one: For reasons like the above, in the past decade or so the world has made significant progress toward slowing global warming and avoiding particularly extreme consequences from climate change. Not nearly enough progress, mind you, but significant nonetheless. Specifically, before the 2015 Paris Agreement, some estimates put the world on track to warm in the range of 3.6 degrees Celsius above preindustrial times. Scientists widely agree that if average global temperatures were to increase that much, it would be devastating socially and economically. Now, however, according to a United Nations report in 2022, the world is on track to heat between 2.1 degrees and 2.9 degrees by 2100. That’s still very dangerous. However, if the nations of the world act as aggressively as they promise, there remains a chance to hold that increase to below 2 degrees Celsius, according to scientists. That’s a big “if,” of course. It would require a tremendous amount of work by the nations of the world, on an extremely swift timetable over the next decade or two, to hit the lower targets for limiting global warming. However, since you asked about good news, let’s keep it positive. Even if there’s a lot of hard work to do, progress has been made on important fronts. There’s now even a movement, “ OK Doomer ,” that basically says, stop it with the gloomy takes and focus on things that will fix the problem.

How did climate change become so political if the science is clear?

In the 1970s, caring for the environment wasn’t such a partisan issue in the United States. Consider that back then Democrats and Republicans worked together to create the Clean Water Act, the Clean Air Act and the Environmental Protection Agency. But when it comes to tackling climate change today, that kind of cooperation seems hard to imagine. Research by the Pew Research Center in 2022, for example, showed that 9 percent of registered Republican voters considered climate change to be “very important” to their vote in the congressional elections, compared with 68 percent of registered Democrat voters. That divide didn’t come from nowhere. Fossil fuel companies and political interest groups have long funded efforts to try to cast doubt on overwhelming scientific evidence that climate change is happening and as a result of human activity, namely the burning of fossil fuels. That message has been successful with many conservative politicians and voters. The science is clear: Even scientists for Exxon, the oil giant, made remarkably accurate projections of how burning fossil fuels would warm the planet. Yet, for years, Exxon and others publicly cast doubt on climate science. Supporters of the fossil fuel industry have included the Koch family, billionaires based in Kansas who donated heavily to groups that helped politicize the science of climate change over the years. President Donald J. Trump mocked climate science, withdrew the United States from the Paris agreement and weakened many government policies that were designed to curb emissions. In the aftermath of the Trump presidency, something of a regrouping occurred among Republicans. Party leaders increasingly acknowledged the science, and some started policy platforms they said would address climate change. However, many of the proposals remained largely opposed to the solution that scientists say is needed: moving away from fossil fuel energy. — Lisa Friedman

What can be done about the biodiversity crisis?

The diversity of the world’s plant and animal life is under threat worldwide for many reasons — development, overfishing, climate change. Scientists know how to solve the biodiversity crisis, at least theoretically. The problem is, the solutions would involve transformative changes in how people live. A 2022 global agreement on biodiversity laid out a path forward, starting with conservation of places that are home to high biodiversity, restoring some degraded areas and putting more of the planet under protection. The targets also include: · Manage wild species so people can hunt and fish without depleting them. · Make agriculture, fisheries and forestry sustainable by using practices that are friendly to biodiversity. · Have companies and financial institutions monitor and disclose how their activities affect biodiversity. · Cut global food waste in half. Eliminating subsidies for agricultural and industrial practices that harm biodiversity would be another significant tool. Doing so would not only reduce damage to species but also free up money for governments to spend on biodiversity protection. Many of these changes would require regulators or elected officials to act. But individuals can also do their part. Limiting meat and dairy intake, and consuming only sustainably managed fish are important steps because overfishing and agriculture related to livestock are major drivers of biodiversity loss. An analysis by Our World in Data, a scientific publication affiliated with the University of Oxford, found that agricultural land use could be reduced by 75 percent , to one billion hectares from four billion hectares, if the world adopted a plant-based diet. (That would help with climate change, too.) — Catrin Einhorn

Read more: ">A ‘Crossroads’ for Humanity: Earth’s Biodiversity Is Still Collapsing

Are offsets legitimate?

Great question. We’ve written about airline offsets here . What’s a “carbon offset,” exactly? Offsets seek to compensate for emissions — for example, from passenger airplanes — by funding emission reductions or carbon removal somewhere else, like by planting forests or supporting renewable energy projects. But a joint investigation by the Guardian and other outlets found that 90 percent of offsets approved by a leading certifier are “ largely worthless and could make global heating worse .” We’ve written about how tree-planting is booming, and how that could either help or harm the planet , depending on how it’s done. The New York Times Magazine explored how the task of planting the number of trees required to make a difference is easier said than done . Don’t get us wrong, there are lots of great reasons to plant trees. For example, trees can help reduce urban-heat-island effects and heat-related deaths . You may also be interested in reading about how tree species will or won’t hold up against climate change , and how people can help forests adapt. A parting thought on offsets: Be wary of greenwashing. Here are some tips on how to spot it .

How will the Inflation Reduction Act address climate change, and how quickly?

President Biden’s 2022 Inflation Reduction Act was one of the most consequential pieces of climate legislation in U.S. history. It invests nearly $370 billion over 10 years into clean energy, with the goal of pivoting the nation’s power plants, automobiles and heavy industry away from fossil fuels while jump-starting new markets for things like American-made batteries and hydrogen power. Along the way the Biden administration also vowed to take a chunk out of greenhouse gas emissions and reshape energy policy to make it more beneficial to low-income communities. A lot of that will take time. But some big measures took effect straightaway. Early on, the Department of Energy agreed to a “conditional commitment” of $700 million to develop a lithium mine in Nevada with the aim of building up the domestic supply of lithium for electric car batteries. The Environmental Protection Agency also announced the availability of $100 million in grants to assist communities disproportionately affected by industrial pollution and other hazards. The law provides a number of benefits for homeowners looking to buy an electric vehicle or make their home more sustainable, including rebates for heat pumps, electric stoves, insulation and electric wiring. Through 2032, households can claim a tax credit of 30 percent of the cost of certain energy-efficiency projects, like weatherization and home energy audits, up to $1,200 per year. New rebates for buying electric vehicles also went into effect early on, allowing for a $7,500 credit for a new electric car and up to $4,000 for a used one. To qualify, the automobiles must be assembled in North America. This government site helps navigate the program. — Lisa Friedman

Read more: This Guide Can Help You Save Money and Fight Climate Change

What is the Paris Agreement?

In December 2015, nearly every country in the world agreed to a global treaty aimed at reducing emissions of planet-warming greenhouse gases. It was a landmark achievement in global diplomacy. Some 195 nations signed on to its terms. The idea of the treaty, which is known as the Paris Agreement because it was negotiated in Paris, is that every country, rich or poor, will set goals to curb its emissions in an effort to avert the worst effects of climate change. Individual countries agreed to set timetables for cutting their emissions, and those schedules were to become more ambitious over time. Countries also pledged to work together to help finance global adaptation to the threats of climate change. The agreement set a target of limiting the average increase in global temperatures to well below 2 degrees Celsius (3.6 degrees Fahrenheit) by the end of the century, compared with preindustrial temperatures, and to preferably hold the increase to 1.5 degrees Celsius. Currently, global temperatures have risen about 1.2 degrees Celsius since the late 19th century. And growing scientific evidence suggests that the stricter aim under the Paris accord — limiting warming to 1.5 degrees Celsius — is necessary to avoid a far greater likelihood of devastating consequences like widespread crop failures and the collapse of polar ice sheets. The Paris Agreement has a major shortcoming: It lacks an enforcement mechanism if a country falls short of its commitments. And an analysis by Climate Action Tracker found that, as of 2021, none of the nations with large-scale emissions had instituted climate pledges in keeping with the 1.5-degree target.

Read more: The World Is Falling Short of Its Climate Goals. Four Big Emitters Show Why.

What is the Intergovernmental Panel on Climate Change?

The Intergovernmental Panel on Climate Change is a United Nations body that produces a comprehensive overview of climate science every six to eight years. The I.P.C.C.’s work is widely considered some of the most authoritative climate research available. Each report is thousands of pages long and written by hundreds of experts from around the globe. A summary of each report’s key findings is approved, line-by-line, by nearly 200 world governments before it is released to the public. The most recent I.P.C.C. overview consisted of three reports that were published in 2021 and 2022. The first described scientists’ latest physical understanding of the climate . The second looked at how climate change was affecting human societies and the natural world. The third laid out strategies that countries could pursue to halt global warming . — Raymond Zhong

Read more: A Hotter Future Is Certain, Climate Panel Warns. But How Hot Is Up to Us.

What is COP?

Since 1995, representatives from nearly every nation have gathered once a year to grapple with the threat that affects them all — climate change. The event is known as — take a deep breath — the Conference of the Parties to the United Nations Framework Convention on Climate Change. Mercifully, that gets shortened to “COP.” Tens of thousands of people typically attend the event, including protesters, environmental groups, corporate executives, representatives of fossil fuel companies and, increasingly, celebrities like Leonardo DiCaprio. The two-week event takes on a festival vibe, with delegates wearing native dress rubbing shoulders with government officials in business attire and activists dressed as polar bears. The goals vary from year to year, but, generally, nations try to reach consensus on ways to cut their greenhouse gas emissions. It can be a messy diplomatic scramble because every party must sign off on any final agreement, and nations often have widely different ideas about what those agreements should, or should not, say. In the closing days of the event, negotiations are all but guaranteed to stretch into the night and toward dawn. At 2015’s COP, the Paris Agreement was born — the pact among nations to try to limit the average increase in global temperatures to 2 degrees Celsius (3.6 degrees Fahrenheit) compared with preindustrial levels, and to ideally hold it to 1.5 degrees Celsius. Since then, every COP has given the world a chance to measure its progress against that goal. Like the Olympics, COP changes its location for each event. In 2023, it will be the United Arab Emirates’ turn to host.

About Earth Day: Isn’t every day an earth day?

Short answer: yes. More helpful answer: Technically, according to our calendar apps, Earth Day comes around once a year, on April 22, when people worldwide hold marches and parades, and issue calls to protect the environment. The notion of a special day to celebrate the environment was born more than a half-century ago in the era of acid rain, smog-blanketed cities, dying bald eagles and rivers bubbling with sludge. The basic idea: Humans have only one planet, so we’d better clean up our act. A lot has changed since the first one in 1970 . Back then a main target was pollution. Climate change “was not part of the discussion” at that time, said Denis Hayes, an original Earth Day organizer, in this New York Times profile . That’s no longer the case, of course. Today global warming is a big focus of Earth Day events. The movement sparked historic changes in environmental policy in the United States. The Clean Air Act was one direct result. Here’s a look at 10 of the biggest environmental victories in the decades since the first Earth Day — and also the failures. The bald eagle has bounced back, for one thing. Still there are many new challenges. One last thing: Why was April 22 chosen? Turns out it was picked as a convenient date between spring break and university final exams, making it easier for students to participate. Since then, though, the date has taken on extra meaning. In 2016 the signing of the Paris Accord — the agreement among nations to fight global warming — was symbolically set for April 22.

Extreme weather

Are heat waves getting worse.

In general, scientists have no doubt that heat waves around the world are becoming hotter, more frequent and longer. In June 2023, temperatures around the world were at their highest levels in decades. The spike reflects two factors that are shaping what forecasters say could be a multiyear period of exceptional warmth for the planet: humans’ continued emissions of heat-trapping gases and the return, after three years, of the natural climate pattern known as El Niño. The 2018 National Climate Assessment, a major scientific report by 13 federal agencies, said that the number of hot days was increasing and that the frequency of heat waves in the United States had jumped from an average of two per year in the 1960s to six per year in the 2010s. The report also said that the season for heat waves had lengthened by 45 days since the 1960s. An important caveat: It takes careful scientific analysis to decide whether any single heat wave is attributable to climate change. But, broadly speaking, heat waves are worsening. Global warming also increases the likelihood of drought. Higher temperatures dry out soils and vegetation, making areas more prone to fires. Warming can also cause more precipitation to fall as rain than as snow, which can affect water availability for agriculture if a region relies, say, on snowmelt from mountains upstream for a steady supply of water in the spring or summer.

Is climate change causing more droughts?

Global warming increases the likelihood of drought. Higher temperatures dry out soils and vegetation more quickly. Warming can also cause more precipitation to fall as rain than snow — which matters from a drought perspective because some places rely on snowmelt to provide water during the growing season. In addition, climate change can affect precipitation patterns around the world, making dry areas drier. In recent years, most of the western half of the United States has been in a drought, with conditions ranging from moderate to severe. In the Southwest, the drought has gone on for so long — since 2000 — that it is considered a megadrought. It constitutes the region’s driest two decades in 1,200 years.

Are wildfires getting worse?

There is no doubt: Wildfires in the Western United States are worsening. As we’ve reported , they’re growing larger, becoming more intense, killing a greater number of trees, spreading faster and reaching higher — even generating their own weather . Climate change has its fingerprints all over it. The dryness, higher temperatures and longer fire season are all factors that make fires more extreme, according to experts . It’s a global phenomenon. Continent-spanning wildfires in Canada have sent plumes of smoke to blanket cities and turn the skies pink-gray. The early 2023 Canadian fires triggered health concerns in Quebec and Philadelphia, Toronto and New York. Worldwide, in fact, worsening heat and dryness could lead to a 50 percent rise in devastating fires, according to a 2022 United Nations report , or a “global wildfire crisis.” It’s a health issue, too. Smoke from wildfires has worsened over the past decade, potentially reversing decades of improvements in Western air quality that occurred thanks to the implementation of the Clean Air Act, research shows. If you want to see where fires are currently in the U.S., we have a map that stays updated . If you want to see where homes are at risk, we have a map for that , too. We’ve also written about how, despite fire risks, homes are being built in harm’s way . Here’s some information on how to prepare your home for a fire and how to protect your health . How dangerous is wildfire smoke? We’ve covered that here . Lastly, if you’re interested in solutions, you might like to read about how setting intentional fires — a technique long-used by Indigenous people — can reduce the risk of catastrophic ones. More on other policy solutions toward the end of this article .

How do you measure air quality?

Burning things — whether it’s coal in a power plant, or trees in a wildfire — can create a cocktail of pollution in the air we breathe. A standard way to measure it is the Air Quality Index. Here’s what the index does, and how to interpret it. The A.Q.I. measures the density of five pollutants: ground-level ozone , particulates , carbon monoxide , nitrogen dioxide and sulfur dioxide . It was established by the Environmental Protection Agency in the United States to help communicate the cleanliness of the air people are breathing. The scale runs from zero (very good) to 500 (very bad.) The simplest thing to remember is: If it’s under 100, then pollution is below the level known to cause adverse health effects. A reading of 100 or higher usually serves as a warning to people who have respiratory conditions. Children and some older adults might particularly want to take precautions, as well as people with heart and lung disease. A number above 200 is considered “very unhealthy.” Wildfires are a common cause of extended periods of unhealthy air. Fine particles in the soot, ash and dust can fill the air. When inhaled, these tiny specks can increase the risk of heart attacks, cancer and acute respiratory infections, particularly in children and older adults. The Air Quality Index tracks these fine particles with a measurement called PM 2.5, a reference to particles smaller than 2.5 micrometers. Some research suggests that wildfire smoke may be more toxic to the lungs than standard urban air pollution as it contains a distinct mix of particulates that activate inflammatory cells deep in the lungs while hindering other cells that can dampen the inflammatory response later. Standard N95 masks can help by filtering some of the particulate matter, but they won’t block all wildfire pollutants. — Adeel Hassan

Read more: The Air Quality Index Explained: What It Means and How to Stay Safe

What about hurricanes?

Greenhouse gas emissions aren’t just warming the atmosphere. Oceans are heating up, too, and that’s making hurricanes stronger and wetter. The slightly good news: There’s little evidence that climate change is making hurricanes and typhoons more frequent. In fact, there might even be slightly fewer storms over time, due to shifting wind patterns. But of the hurricanes that do form, research suggests that more of them will be major storms rated Category 3 or higher on the hurricane-force scale. That’s because higher ocean temperatures provide more of the heat energy that fuels these storms as they move across the water. Warmer ocean water can also cause “rapid intensification,” which occurs when a storm becomes much more powerful over a very short period of a single day or even a few hours. A 2019 study in the journal Nature Communications showed that rapid intensification had been increasing. Hurricanes are becoming wetter because warmer air holds more moisture that can then fall as rain. Hurricane Harvey, which stalled over Houston in 2017, produced at least 15 percent more rain than it would have in a world without the human effects on climate.

Read more: What We Know About Climate Change and Hurricanes

Are winters getting weirder?

Climate change isn’t just making the winter season warmer. It is also making it weirder. Winter temperatures have risen over the past several decades. According to a Climate Central analysis , the average winter temperatures have warmed in 97 percent of 238 locations in the United States since 1970. But don’t put your snow gear away. Overall, the average snowfall is decreasing and instead, in many cases, falling as rain. However, at the same time the frequency of extreme snowstorms has risen across the eastern two-thirds of the contiguous United States over the past century, according to the National Centers for Environmental Information . Here’s why. Air that is warmer can hold more water vapor. So as winter temperatures get warmer, the storms have more available water vapor and then can produce more snow. So, while snow across the course of the winter may seem more sparse, the single snowstorms will be more intense, creating more disruption to daily life. And while the average minimum temperatures continue to rise, intense cold spells will undoubtedly exist. According to some scientists , the warming of the Arctic, enhanced by climate change, weakens the polar vortex — a strong band of winds in the stratosphere surrounding the North Pole — knocking it out of kilter and allowing colder Arctic air to spill south into the U.S., Europe and Asia. This data is specific to the United States, but researchers say similar effects are being seen in other parts of the world. While various factors (like local temperature increases, local geography and weather patterns) can change the effects at any given location, seasonal weather patterns work on the same general principles in other parts of the world. And with a large portion of the world’s population living across the mid-latitudes, similar to the United States, people living elsewhere will likely see similar instances of weird winter weather. — Judson Jones

Is flooding getting worse?

Global warming has the potential to worsen flooding because warmer air can hold more water, which can then fall as rain. However, flooding is a complex phenomenon with many contributing causes. Floods can be affected by a range of factors, including land development (are there too many paved roads or parking lots worsening runoff?) and ground conditions. If the ground is already saturated with water from one storm, it can’t absorb more from another. And in a prolonged drought, soils dry out, harden and become less permeable, so less of the water from a heavy rain soaks in. For reasons like these, linking any single flood to global warming requires extensive scientific analysis. That said, the potential for heavier rainfall driven by climate change is an increasingly important part of the mix. For example, scientists have determined that the record rainfall that led to devastating floods in Germany and Belgium in the summer of 2021 was made much more likely by global warming.

Read more: How Is Climate Change Affecting Floods?

Has climate change affected rainfall?

The United States and other parts of the world have seen increases in the frequency of intense rain events. That is likely to continue as warming progresses. The most important reason for this is that warmer air holds more moisture for clouds to release as rain. In California and the Pacific Coast, for instance, storms known as atmospheric rivers have for centuries provided the region with much of its water supplies. But scientists say global warming is now increasing the risk of powerful, weekslong storm sequences that cause flooding and landslides. Scientific analysis can estimate how much climate change worsened any particular downpour. These attribution studies, as they are called, compare two sets of computer simulations of the same storm. One set is staged in a hypothetical world in which there have been no greenhouse gas emissions and thus no global warming. The second simulates the world we live in, complete with global warming. — Raymond Zhong

Read more: The Coming California Megastorm

Does climate change affect tornadoes?

Scientists have not been able to determine whether there is a link between warming and the frequency or strength of tornadoes. That’s because tornadoes are relatively small, short-lived weather events, making them hard to incorporate into scientists’ computer models of the global climate. Researchers do say that tornadoes have become more likely to occur in clusters over the past few decades – there might be fewer days each year with tornadoes, but on each of those days, there are more tornadoes. Other research has found that the region of the United States known as Tornado Alley, where most tornadoes occur, seems to be shifting eastward. The timing of tornado seasons is also becoming more unpredictable, researchers have found, with more early and late starts compared with decades ago. However, the reason for this is unclear. — Raymond Zhong

Read more: What We Know About Tornadoes and Climate Change

What is the climate impact of cryptocurrency and blockchain technology?

Cryptocurrencies and NFTs can be astonishingly energy-intensive. This is because of their underlying technology, known as blockchain, which we’ve explained here . Researchers at Cambridge University have said that the process of creating and maintaining Bitcoin, for example, can consume as much electricity as many countries do. That process is known as “mining,” and it usually takes place in warehouses stacked with computers. Mining has also pushed up electricity prices for homeowners and small businesses. Recognizing the problem, some miners of Bitcoin have tried to reframe their activity as more eco-friendly. Some digital currencies are considered to be less energy-intensive than others. Etherium, for example, switched to a more energy-efficient infrastructure in 2022. But no matter. The climate impact of running all these computers has proven significant. In several places, including New York State, crypto companies have reopened once mothballed coal-burning electrical plants to power their activities, keeping older and dirtier plants pumping out greenhouse gases.

Read more: Bitcoin Uses More Electricity Than Many Countries. How Is That Possible?

How green are electric cars?

Transportation is the single biggest source of emissions in the United States, and the transition to electric vehicles is widely viewed as a key part of the solution. Broadly speaking, modern electric cars generate significantly fewer planet-warming emissions than most cars powered by combustion engines. But the way we produce the electricity that charges up those cars still needs to get cleaner before electric vehicles are truly emissions-free: Coal-burning power plants obviously still generate greenhouse gases. One way to compare the climate effects of various electric and gasoline vehicles is through this interactive tool developed by researchers at the Massachusetts Institute of Technology. It incorporates the major variables, including the emissions involved in manufacturing the car itself and in producing the fuel, whether gas or electricity, that powers it. If you assume electric vehicles are drawing their power from the average grid in the United States, which most often includes a mix of fossil fuel and renewable power plants, then those cars typically produce less than half the emissions of a similarly-sized, gas-powered car. Electric cars are usually more emissions-intensive to manufacture because of their batteries. But over time they more than make up for that because electric motors are more efficient than traditional internal combustion engines. And electric vehicles should get cleaner as utilities continue to close coal-fired power plants. Electric vehicles can have other costs, too. The lithium-ion cells that power most electric vehicles require significant mining — including for lithium, cobalt and other rare earth metals — that can come with serious environmental or human rights concerns. But, of course, drilling for oil has serious environmental effects of its own. Key to the sustainability of electric cars will also be the recyclability of the materials . One last thought before you go: It might sound obvious, but one way to reduce the negative effects of both gas and electric cars would be to reduce dependence on driving, perhaps by focusing on better public transit systems. — Brad Plumer

Read more: How Green Are Electric Vehicles?

Which electric car is best?

“Buying an electric car can be exciting and bewildering.” That’s a line from The Times’s guide to buying an electric vehicle, and it couldn’t be truer. The guide walks through the main considerations when trying to decide what’s the right choice. Will it be primary transportation, or a second car? How and where will it be charged? For readers in the United States, we’ve also got this guide on how to access government money — tax breaks, other things — from the federal climate policies for a variety of purchases including electric cars, which can help defray the cost a bit. Because electric cars are expensive, and that can be a big barrier to many buyers.

What about electric-car batteries?

The Times has reported in detail about how battery recycling will be critical to the sustainability of electric vehicles. Our writers have also covered the environmental cost of battery production — for example, the effects of mining for lithium , which is critical for modern batteries. At the same time, auto makers and battery producers are taking steps to improve the way these huge batteries are built because they are aware of the business advantages that improved technologies would give them. In addition, elsewhere in this F.A.Q. we’ve written a separate entry, “ How green are electric cars? ”

What are the key technologies to tackle climate change? Are they ready?

If the goal is to slash greenhouse gas emissions by burning far less fossil fuel — and it is — then many of the technologies are already well developed. Wind turbines, solar panels, hydro plants and nuclear reactors all generate electricity while producing essentially no carbon dioxide. Solar and wind costs have fallen drastically in recent years, and the technologies are time-tested. For those plants that still burn fossil fuel, there are so-called carbon capture technologies to keep planet-warming carbon dioxide out of the atmosphere, although these have yet to be widely deployed. The basic process involves removing the carbon dioxide that is produced when the fuel is burned and storing it permanently underground. Battery-powered cars and buses are becoming more common, and large trucks are starting to be electrified as well. Many rail networks and transit systems already run on electricity. As power generation moves away from burning coal, and produces fewer emissions, these modes of transportation will become correspondingly cleaner. But sharply cutting emissions from aviation and maritime shipping is more difficult. Planes and ships are becoming more energy-efficient, but, as it stands, even the best batteries don’t provide enough electricity for their weight to power large planes or cargo ships. — Henry Fountain

What should I know about geoengineering?

Geoengineering refers to deliberately intervening in the climate to reduce global warming — by, say, releasing chemicals into the sky to reflect some sunlight. The idea is that those kinds of techniques might buy the world time to eliminate the carbon dioxide emissions that are warming the planet. The proposals generally fall into two categories. One is carbon dioxide removal, which would involve pulling some of the gas from the atmosphere and storing it so that it doesn’t return. While a few companies have made machines for this purpose, and are now removing relatively small amounts of carbon dioxide, many scientists and policymakers think the process is too slow, requiring too many expensive, energy-gobbling machines, to be practical. The other category is solar radiation management, which would aim to reduce the amount of sunlight reaching the Earth’s surface. Few people consider solar radiation management to be benign, and it comes with a lot of opposition. The most widely discussed method would use airplanes or other means to inject a chemical such as sulfur dioxide into the upper atmosphere, where it would form aerosol particles and reflect some sunlight. This would mimic what happens in a huge volcanic eruption. Mount Pinatubo sent so much sulfur dioxide into the atmosphere when it erupted in 1991 that it cooled the planet by more than half a degree Fahrenheit for more than a year. The method would result in a quick fix for warming, and it wouldn’t necessarily be that expensive. But it would do nothing about issues like the increasing acidification of the oceans as carbon dioxide is absorbed into the water, a process that has dire consequences for sea life. Opponents have other concerns as well, including about the possibility of unintended consequences: drier parts of the world turning wetter, for instance, and vice versa. Still, a number of institutions, including the National Academy of Sciences, support cautious research into the idea, given how much the risks of climate change are increasing. — Henry Fountain

Will nuclear fusion save us?

There is no doubt that nuclear fusion is on the horizon. The problem is it’s been on the horizon for a long time. Scientists first realized nearly a century ago that it might be possible to mimic the force that powers the sun — fuse two small atoms at enormous temperatures and pressures to release a huge amount of energy. (Fusion is different from fission, the basis for current nuclear power plants, in which a much larger atom is split to release energy.) Uncontrolled fusion was achieved in 1952 with the detonation of the first hydrogen bomb. To be useful as an energy source, though, fusion must be controlled, and that has proven tremendously difficult. If the released energy could be harnessed, fusion would have many potential advantages over fission. The fuel is more abundant, the process holds far less risk of a radioactive accident and the technology produces less hazardous radioactive waste. The obstacles are great. Until late 2022, no fusion experiment had ever achieved a very basic measure of success: generating more energy than it consumed. That was finally accomplished by a long-running experiment at Lawrence Livermore National Laboratory in California, which uses several hundred laser beams to implode a tiny capsule containing two isotopes of hydrogen. That success was rightly hailed. But creating fusion for an instant or two is a far cry from the continuous fusion needed to generate electricity. It will most likely take decades to commercialize either laser-initiated fusion or the other major fusion technology, which involves confining a high-temperature cloud of ionized atoms through powerful electromagnets in a doughnut-shaped device called a tokamak. Some companies are working on smaller fusion reactors that they claim might lead to the development of a commercial power plant within about a decade. But, for now, fusion power remains on the distant horizon. — Henry Fountain

Deciphering the jargon

Are global warming and climate change the same thing.

The terms “global warming” and “climate change” are often used interchangeably. But they can mean different, though related, things. Global warming refers to how much hotter the world has become since the late 19th century as a result of emissions of carbon dioxide, methane and other greenhouse gases. Most of the emissions have come from the burning of fossil fuels, which became widespread as much of the world industrialized. These gases trap some of the heat that radiates after sunlight strikes the Earth’s surface, making the atmosphere warmer. Already, the atmosphere is about 1.2 degrees Celsius (2.2 degrees Fahrenheit) warmer than it was in the late 1800s. Climate change is a broader term. Higher temperatures are one element of the world’s changing climate, but there are others that have resulted indirectly from the warming. Among these are changes in atmospheric and oceanic circulation patterns and in how much moisture the atmosphere can hold. — Henry Fountain

What are greenhouse gases?

Certain gases in the atmosphere — like carbon dioxide and methane — that trap some of the heat radiated from the Earth’s surface are known as greenhouse gases. The name comes from what happens in a greenhouse: Sunlight passes through the transparent roof and walls, is absorbed by what’s inside the greenhouse, and is then re-emitted as heat. But that heat energy has longer wavelengths than sunlight, so it can’t escape back through the roof and walls. That’s why the inside of a greenhouse warms up when sunlight hits it. In Earth’s atmosphere, greenhouse gases act a little differently, but the effect is the same. They absorb energy at certain wavelengths that correspond to those of the heat energy radiating from Earth. The gas molecules then re-radiate this heat energy, and while some heads off into space, much of it remains in the atmosphere, contributing to global warming. The main greenhouse gas is carbon dioxide. It’s the primary waste gas produced by the burning of fossil fuels like coal and oil. Carbon dioxide makes up about four-fifths of the greenhouse gases emitted by human activities. Methane, from oil and gas production and other sources, is the second most prevalent. It has a greater heat-trapping capacity than carbon dioxide, but persists in the atmosphere for a shorter time. Nitrous oxide is the next most common greenhouse gas. Then there are a slew of others, in very small concentrations, with high heat-trapping capacity, including hydrofluorocarbons, or HFCs. Water vapor is a greenhouse gas as well. And unlike the others mentioned here, it changes from gas to liquid, or vice versa, depending on the temperature of the atmosphere. So as the atmosphere heats up, the concentration of water vapor increases, which amplifies the warming. (Oxygen and nitrogen, which together make up 99 percent of the atmosphere, absorb only shorter-wavelength energy, so they are not greenhouse gases.) Emissions of greenhouse gases from the burning of fossil fuels and other activities have warmed the world by about 1.2 degrees Celsius, or 2.2 degrees Fahrenheit, since the late 19th century. If you want to understand that better, go to the “science” section on this page. We explain how we know climate change is happening, and how we know humans are to blame. — Henry Fountain

What exactly does sustainable mean?

“Sustainable” sure sounds good, and claims of sustainability are ubiquitous. The problem is that the term can be interpreted in many ways, and it’s often not clear what a company or product is claiming. Consider the “Sustainability On-the-Go” gift box, a real product that contains wooden eating utensils and a tumbler wrapped in bamboo, or the toilet paper stand that encourages users to use less by dispensing one sheet at a time (another real product). Without independent verification and an agreed-upon definition, the term is all but meaningless. Worse, it can backfire, as in the case of cotton tote bags , which have proliferated because they have an image as being more sustainable than, say, plastic disposable ones. But organic cotton bags must be reused 20,000 times for them to have a similar environmental impact as their thin plastic counterparts, research has suggested . It’s not just about consumer goods. Pick your industry — airlines, restaurants, banks, fossil fuel companies, you name it — and you’ll find sustainability being marketed, often with little to back up the claims. Is there a right way to do it? The United Nations defines sustainability as “meeting the needs of the present without compromising the ability of future generations to meet their own needs.” That’s the opposite of a marketing buzzword. In fact, it’s a call for bringing humans into balance with the planet and its resources. By that definition, true sustainability requires transformative changes in economies and societies. — Catrin Einhorn

Read more: Where’s the Waste? A ‘Circular’ Food Economy Could Combat Climate Change

What does net zero mean?

This is one of those important climate concepts that has been given a jargon-y name. Scientists have warned that global warming will keep getting worse until humanity reaches “net zero” emissions — that is, the point at which we are no longer increasing the total amount of greenhouse gases in the atmosphere. Getting to “zero” emissions would require stopping every single activity that releases greenhouse gases, but that would be very tough to do. So “net zero” refers to a situation in which some greenhouse gases are still being released, but they’re offset by other activities like planting more trees to pull carbon dioxide out of the air. So the net effect is zero emissions. Net zero. The term is everywhere. In recent years, a growing number of countries and businesses have been making pledges to be net zero by various dates. The United States and China both have net-zero promises. So do Amazon and Apple. In practice, the concept can be abused since it’s not always clear that the offsetting action — the trees being planted or the technologies being promised to remove carbon dioxide from the atmosphere — are as effective as claimed or even technically feasible within the time frames being discussed. And those offsets can be contentious. Trees can absorb carbon dioxide, of course, but they can also burn in wildfires, releasing carbon dioxide. Carbon-removal technology is still in its infancy. Critics worry that leaders and businesses may be using the uncertain promise of such offsets in the future to avoid making deeper cuts in their emissions today. And many corporate net-zero pledges have asterisks. Some companies, for instance, have pledged to clean up their offices but not their broader supply chains. At the same time, many countries’ net-zero pledges are vague and not yet backed by concrete policies to curb emissions as drastically as would be needed. That’s true of both the United States and China. — Brad Plumer

Read more: Searching for Hidden Meaning in Climate Jargon

What is a carbon footprint?

Say you have a nice steak dinner. You might know that cows belch copious amounts of methane, a fact that helps make ranching a sizable source of greenhouse gas emissions worldwide. But that isn’t all: Those glasses of wine, the bottled water for the table and the cheesecake for dessert all generated emissions when they were produced and when they were transported to the restaurant by train, truck or airplane. Those emissions can be described as your dinner’s “carbon footprint,” a measure of its contribution to global warming. Similarly, a tally of emissions related to everything in your life — heating your home, driving to and from work, flying somewhere for the holidays — defines your household’s carbon footprint. Here, “carbon” refers not only to carbon dioxide, the main greenhouse gas, but also to all of the greenhouse gases that the relevant activities might generate. Researchers developed the idea of a carbon footprint in the 1990s as a research tool. It wasn’t invented by an oil company, as some have suggested. However, critics say the fossil fuel industry has embraced the idea as a way to place some of the responsibility for the climate crisis on consumers, shifting attention away from the role of the energy industry or the need for wider structural changes, including a much faster transition to cleaner energy sources. A carbon footprint is a useful concept for comparing the climate consequences of various human activities. It allows us to see, for instance, that the carbon footprint of a typical American is many times that of a person who lives in a poorer country. It also enables examination of companies, industries and even entire nations. And, yes, individual actions matter. Frequent air travel, for example, comes with a huge carbon footprint. So it can help to tread more lightly. — Hiroko Tabuchi

Read more: The Climate Impact of Your Neighborhood, Mapped

What is mitigation?

Mitigation is a term used by both climate scientists and disaster experts — but for completely different scenarios. Which can be confusing. First, climate change. Here, mitigation refers to anything that reduces emissions of planet-warming greenhouse gasses. Think the shift from coal-burning power plants to wind and solar power generation, or the shift to electric cars or to more efficient home appliances like heat pumps and induction stoves. Among disaster experts and people who deal with emergencies — floods, storms, wildfires — mitigation means something else entirely. They use it to talk about protecting people against the effects of storms. (Confusingly, this is what climate experts sometimes refer to as “adaptation.”) One way to know what sort of mitigation is being discussed is to listen for more precise phrases like “disaster mitigation” or “hazard mitigation.” — Christopher Flavelle

What is adaptation?

Adaptation is the counterpart to mitigation. And let’s just say it: None of this language is user-friendly. But experts throw these words around, so we deal with it. Adaptation refers to steps aimed at blunting the current consequences of climate change — intensifying storms, wildfires, heat waves — and preparing for what happens as they worsen over time. Some good examples are adjusting how and where we build houses and roads; helping people move away from places vulnerable to flooding or wildfires; or planting different kinds of crops as weather patterns change. “Adaptation” is sometimes used interchangeably with “resilience,” but the terms have important differences. Resilience means maintaining a way of life, but with better protection. Adaptation means changing a way of life that is becoming too hard to sustain. Think of using a seawall to protect a beach town from hurricanes (resilience) versus helping people move somewhere else (adaptation). Adaptation used to be a dirty word among environmentalists, who viewed the notion as defeatist — an admission of the failure to cut emissions or an invitation not to try. But, as the effects of climate change have worsened, that criticism has faded. The need to adapt, while still trying to cut emissions, has become indisputable. But the term still carries an element of privilege, especially because poorer communities and nations have far less ability to adapt than wealthier people do. — Christopher Flavelle

How does carbon capture work?

The most straightforward way to keep carbon out of the atmosphere is to not burn fossil fuels. But since oil, gas and coal are such entrenched features of modern economies, engineers are exploring strategies to capture or remove the carbon dioxide those fuels produce. Carbon capture generally refers to any technology that can trap the carbon dioxide coming out of a factory or power plant before it escapes into the atmosphere and helps warm the planet. There are about two dozen facilities worldwide that do this. Some use chemical solvents that bind to and absorb carbon dioxide from a plant’s exhaust, allowing the gas to be compressed and shipped off in a pipeline. Once captured, the carbon dioxide can be permanently buried underground, where it will no longer act as a greenhouse gas warming the world. More contentiously, some energy companies have used captured carbon dioxide in what is called “ enhanced oil recovery ”: injecting the gas into depleted oil wells to dislodge deposits of crude oil that are otherwise hard to reach. Critics say this runs counter to the whole point of carbon capture, since the technology is being used to extract more oil, which will be burned, producing more carbon dioxide. Some energy companies, however, say the process can be helpful for helping to fund early carbon capture projects. — Brad Plumer

What is carbon removal and is it effective?

Carbon removal is slightly different from carbon capture — it generally refers to pulling carbon dioxide out of the atmosphere after it has been emitted. Trees can do this naturally. And expanding forest cover can be a form of carbon removal, although there’s only so much land to go around and there’s always the risk that trees will burn in wildfires, releasing the carbon dioxide they’d stored. Recently, many companies have been experimenting with high-tech approaches to carbon removal, such as direct-air capture. A company called Climeworks is doing this at a plant in Iceland , using giant fans and filters to pull carbon dioxide from the sky, allowing it to be pumped underground and locked away permanently. This kind of carbon removal is still in its early stages and faces many obstacles, including extremely high costs to make it work. Some scientists, though, say it may be necessary in order for the world to achieve the equivalent of zero emissions, or for there to be a large-scale effort to reverse at least some of the global warming that humans have caused. — Brad Plumer

What is carbon pricing and how does it work?

Some economists have long argued that “carbon pricing” is an elegant way to tackle climate change: Just give companies and consumers a financial incentive to clean up their acts by charging them for the greenhouse gas emissions they produce. In practice, that gets complicated. There are two main ways to impose carbon pricing. The simplest is a carbon tax, which is typically a flat tax levied on oil, gas or coal. Countries like Canada and Sweden have carbon taxes. However, these taxes sometimes come with exemptions and loopholes. And politicians are often reluctant to set a carbon tax high enough to have a significant effect on behavior, because they fear a backlash from voters. There’s also a cap-and-trade system, which typically works something like this: A government sets a cap on overall emissions and steadily tightens that cap over time. Companies receive permits that allow them to release limited emissions. But polluters have an added incentive to cut emissions because unused permits can be traded at a profit. And, as emissions caps tighten, those prices can rise. Both California and the European Union have versions of cap-and-trade systems, although it can be tricky to design these programs so that they work well. — Brad Plumer

Project Credits

Editing and production by Sarah Graham, Rebecca Lieberman, Claire O’Neill, Mike Peed, Jesse Pesta and Amelia Pisapia.

Research and development contributions by Jack Cook.

Illustration by Maria Chimishkyan.

Reporting contributed by Manuela Andreoni, Maggie Astor, Winston Choi-Schagrin, Catrin Einhorn, Christopher Flavelle, Henry Fountain, Lisa Friedman, Adeel Hassan, Judson Jones, Brad Plumer, Julia Rosen, Somini Sengupta, Hiroko Tabuchi and Raymond Zhong.

Methodology

In 2022 we asked readers what they wanted to know about climate change. Their responses helped guide this resource, which was written and edited by the climate desk at The New York Times.

The search function at the top of the page uses a combination of machine learning and human editing to understand questions and suggest relevant answers. The underlying technology was developed by The New York Times Research and Development team.

If we don’t have an answer to a question you ask, the system takes note so that we can consider adding it. You can also tell us what you want to know using this good old-fashioned form .

Advertisement

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.

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
• Explore content
• About the journal
• Publish with us
• Sign up for alerts

Research articles

Global warming decreases connectivity among coral populations

The authors develop a high-resolution model of coral larval dispersal for the southern Great Barrier Reef. They show that 2 °C of warming decreases larval dispersal distance and connectivity of reefs, hampering post-disturbance recovery and the potential spread of warm-adapted genes.

• Joana Figueiredo
• Christopher J. Thomas
• Emmanuel Hanert

Phenological mismatches between above- and belowground plant responses to climate warming

The authors conduct a meta-analysis to reveal mismatches in above- and belowground plant phenological responses to warming that differ by plant type (herbaceous versus woody). The work highlights a need for further research and consideration of under-represented belowground phenological changes.

• Huiying Liu
• Madhav P. Thakur

Near-term transition and longer-term physical climate risks of greenhouse gas emissions pathways

There is a balance in mitigation pathway design between economic transition cost and physical climate threats. This study provides a comprehensive framework to assess the near- and long-term risks under various warming scenarios globally and in particular regions.

• Ajay Gambhir
• Seth Monteith

Hysteresis of the intertropical convergence zone to CO 2 forcing

In idealized model experiments where CO 2 increases four-fold before returning to its original level, temperature and precipitation show almost linear responses to CO 2 forcing. In contrast, the response of the Intertropical Convergence Zone lags behind CO 2 changes, associated with delayed energy exchanges.

• Jong-Seong Kug
• Jongsoo Shin

Contextualizing cross-national patterns in household climate change adaptation

The context and motivation around adaptation are influenced by local culture and institutions. In the United States, China, Indonesia and the Netherlands, some factors (such as perceived costs) have similar influences on household adaptation to flooding, but others (such as flood experience) differ between countries.

• Brayton Noll
• Tatiana Filatova
• Alessandro Taberna

Ocean warming and accelerating Southern Ocean zonal flow

The remoteness and paucity of historic observations of the Southern Ocean limit understanding of the effects of climate change on circulation. Using observations, CMIP6 and eddy-resolving models, this Article shows that acceleration of its zonal flow emerged in recent decades as a result of uneven ocean warming.

• Jia-Rui Shi
• Lynne D. Talley

Cost and attainability of meeting stringent climate targets without overshoot

Current emissions scenarios include pathways that overshoot the temperature goals set out in the Paris Agreement and rely on future net negative emissions. Limiting overshoot would require near-term investment but would result in longer-term economic benefit.

• Keywan Riahi
• Christoph Bertram
• Behnam Zakeri

Net zero-emission pathways reduce the physical and economic risks of climate change

Mitigation pathways allowing for temperature overshoot often ignore the related climate and macroeconomic impacts. Net-zero pathways with limited overshoot could reduce low-probability high-consequence risks and economic loss.

• Laurent Drouet
• Valentina Bosetti
• Massimo Tavoni

Health co-benefits of climate change mitigation depend on strategic power plant retirements and pollution controls

Climate mitigation policies often provide health co-benefits. Analysis of individual power plants under future climate–energy policy scenarios shows reducing air pollution-related deaths does not automatically align with emission reduction policies and that policy design needs to consider public health.

• Guannan Geng
• Steven J. Davis

Climate action with revenue recycling has benefits for poverty, inequality and well-being

Climate policy analyses often ignore the possibility of progressive redistribution of carbon tax revenues and assume that mitigation cost will burden the poor in the short term. Integrated Assessment Model (IAM) estimation suggests such redistribution could reduce inequality, alleviate poverty and increase well-being globally.

• Mark Budolfson
• Francis Dennig
• Stéphane Zuber

Observed increases in extreme fire weather driven by atmospheric humidity and temperature

Climate change has led to increased fire activity in parts of the globe due to observed increases in fire weather extremes. These trends are driven predominantly by decreasing relative humidity and increasing temperature.

• Piyush Jain
• Dante Castellanos-Acuna
• Mike D. Flannigan

Climate and land-use changes reduce the benefits of terrestrial protected areas

The authors project future rates of temporal and spatial displacement of climate and land-use in protected areas (PAs), and show that more than one-quarter of the world’s PAs are highly threatened, with particular risk to PAs across tropical moist and grassland biomes.

• Ernest F. Asamoah
• Linda J. Beaumont
• Joseph M. Maina

Demand-side solutions to climate change mitigation consistent with high levels of well-being

Evaluation of mitigation actions often focuses on cost and overlooks the direct effects on well-being. This work shows demand-side measures have large mitigation potential and beneficial effects on well-being outcomes.

• Felix Creutzig
• Leila Niamir
• Diana Ürge-Vorsatz

A multi-model analysis of long-term emissions and warming implications of current mitigation efforts

Mitigation pathways tend to focus on an end temperature target and calculate how to keep within these bounds. This work uses seven integrated assessment models to consider current mitigation efforts and project likely temperature trajectories.

• Ida Sognnaes
• Glen P. Peters

Risk transfer policies and climate-induced immobility among smallholder farmers

Smallholder farmers will be impacted substantially by climate change and need to adapt. Agent-based modelling shows that interventions, particularly cash transfer paired with risk transfer mechanisms, lead to increased migration and uptake of cash crops, with higher income and lower inequality.

• Nicolas Choquette-Levy
• Matthias Wildemeersch
• Simon A. Levin

Climatic limit for agriculture in Brazil

Soybean and maize yields in the Amazon-Cerrado region of Brazil are dependent on water from rain. Warming and drying will make the climate less suitable for agricultural production; changes have already moved 28% of croplands out of their optimum climate space.

• Ludmila Rattis
• Paulo M. Brando
• Michael T. Coe

Anthropogenic emissions and urbanization increase risk of compound hot extremes in cities

Heat extremes threaten the health of urban residents with particularly strong impacts from day–night sustained heat. Observation and simulation data across eastern China show increasing risks of compound events attributed to anthropogenic emissions and urbanization.

A systematic global stocktake of evidence on human adaptation to climate change

Determining progress in adaptation to climate change is challenging, yet critical as climate change impacts increase. A stocktake of the scientific literature on implemented adaptation now shows that adaptation is mostly fragmented and incremental, with evidence lacking for its impact on reducing risk.

• Lea Berrang-Ford
• A. R. Siders
• Thelma Zulfawu Abu

Threatened salmon rely on a rare life history strategy in a warming landscape

Highlighting the importance of rare phenotypes in population persistence, the authors show that spring-run Chinook salmon late-migrant juveniles were critical for cohort success in drought and ocean heatwave years. Combined further warming and impassable dams threaten these late migrants’ survival.

• F. Cordoleani
• C. C. Phillis
• R. C. Johnson

Impact of high-speed rail on road traffic and greenhouse gas emissions

Intercity high-speed rail (HSR) can have large climate benefits with its high energy efficiency. This study explores the substitution effects of HSR on road traffic in China, which can be translated to an annual reduction of 14.76 million tons of CO 2 -equivalent emissions.

Quick links

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