causes and solutions of global warming essay

Essay on Global Warming – Causes and Solutions

500+ words essay on global warming.

Global Warming is a term almost everyone is familiar with. But, its meaning is still not clear to most of us. So, Global warming refers to the gradual rise in the overall temperature of the atmosphere of the Earth. There are various activities taking place which have been increasing the temperature gradually. Global warming is melting our ice glaciers rapidly. This is extremely harmful to the earth as well as humans. It is quite challenging to control global warming; however, it is not unmanageable. The first step in solving any problem is identifying the cause of the problem. Therefore, we need to first understand the causes of global warming that will help us proceed further in solving it. In this essay on Global Warming, we will see the causes and solutions of Global Warming.

Causes of Global Warming

Global warming has become a grave problem which needs undivided attention. It is not happening because of a single cause but several causes. These causes are both natural as well as manmade. The natural causes include the release of greenhouses gases which are not able to escape from earth, causing the temperature to increase.

Get English Important Questions here

Further, volcanic eruptions are also responsible for global warming. That is to say, these eruptions release tons of carbon dioxide which contributes to global warming. Similarly, methane is also one big issue responsible for global warming.

So, when one of the biggest sources of absorption of carbon dioxide will only disappear, there will be nothing left to regulate the gas. Thus, it will result in global warming. Steps must be taken immediately to stop global warming and make the earth better again.

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

Global Warming Solutions

As stated earlier, it might be challenging but it is not entirely impossible. Global warming can be stopped when combined efforts are put in. For that, individuals and governments, both have to take steps towards achieving it. We must begin with the reduction of greenhouse gas.

Furthermore, they need to monitor the consumption of gasoline. Switch to a hybrid car and reduce the release of carbon dioxide. Moreover, citizens can choose public transport or carpool together. Subsequently, recycling must also be encouraged.

Read Global Warming Speech here

For instance, when you go shopping, carry your own cloth bag. Another step you can take is to limit the use of electricity which will prevent the release of carbon dioxide. On the government’s part, they must regulate industrial waste and ban them from emitting harmful gases in the air. Deforestation must be stopped immediately and planting of trees must be encouraged.

In short, all of us must realize the fact that our earth is not well. It needs to treatment and we can help it heal. The present generation must take up the responsibility of stopping global warming in order to prevent the suffering of future generations. Therefore, every little step, no matter how small carries a lot of weight and is quite significant in stopping global warming.

हिंदी में ग्लोबल वार्मिंग पर निबंध यहाँ पढ़ें

FAQs on Global Warming

Q.1 List the causes of Global Warming.

A.1 There are various causes of global warming both natural and manmade. The natural one includes a greenhouse gas, volcanic eruption, methane gas and more. Next up, manmade causes are deforestation, mining, cattle rearing, fossil fuel burning and more.

Q.2 How can one stop Global Warming?

A.2 Global warming can be stopped by a joint effort by the individuals and the government. Deforestation must be banned and trees should be planted more. The use of automobiles must be limited and recycling must be encouraged.

Customize your course in 30 seconds

Which class are you in.

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

Leave a Reply Cancel reply

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

Download the App

45,000+ students realised their study abroad dream with us. Take the first step today

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

Verification Code

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

Thanks for your comment !

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

Essay on Global Warming

• Updated on  
• Apr 27, 2024

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

Short Essay on Global Warming and Climate Change?

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

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

Also Read: Essay on Yoga Day

Also Read: Speech on Yoga Day

What is Global Warming?

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

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

Also Read: What is a Natural Disaster?

What are the Causes of Global Warming?

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

• Deforestation 
• Greenhouse emissions
• Carbon emissions per capita

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

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

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

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

Solutions for Global Warming

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

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

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

Also Read: Essay on Pollution

Effects of Global Warming

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

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

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

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

Also Read: Concept of Sustainable Development

Sample Essays on Global Warming

Here are some sample essays on Global Warming:

Essay on Global Warming Paragraph in 100 – 150 words

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

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

Also Read: Social Forestry

Essay on Global Warming in 250 Words

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

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

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

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

Also Read: Types of Water Pollution

Essay on Global Warming in 500 Words

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

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

Essay on Global Warming UPSC

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

Also Read: Essay on Disaster Management

Climate Change and Global Warming Essay

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

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

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

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

Also Read: Essay on Air Pollution

Tips to Write an Essay

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

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

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

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

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

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

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

Relevant Blogs

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

Digvijay Singh

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

Leave a Reply Cancel reply

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

Contact no. *

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

Thank you for the comment!

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

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

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

thank you so much

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

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

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

Leaving already?

8 Universities with higher ROI than IITs and IIMs

Grab this one-time opportunity to download this ebook

Connect With Us

45,000+ students realised their study abroad dream with us. take the first step today..

Resend OTP in

Need help with?

Study abroad.

UK, Canada, US & More

IELTS, GRE, GMAT & More

Scholarship, Loans & Forex

Country Preference

New Zealand

Which English test are you planning to take?

Which academic test are you planning to take.

Not Sure yet

When are you planning to take the exam?

Already booked my exam slot

Within 2 Months

Want to learn about the test

Which Degree do you wish to pursue?

When do you want to start studying abroad.

September 2024

January 2025

What is your budget to study abroad?

How would you describe this article ?

Please rate this article

We would like to hear more.

Search the United Nations

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

Causes and Effects of Climate Change

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

Empowering women and restoring wetlands go hand in hand

Environmentalist and Women Changemaker in the World of Wetlands Cécile Ndjebet says women are crucial for sustainable environmental conservation.

wikiHow teams up with Verified to empower people with climate information

Sacred plant helps forge a climate-friendly future in Paraguay

Facts and figures.

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

Cutting emissions

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

Clean energy

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

Adapting to climate change

• Climate adaptation
• Early warnings for all
• Youth voices

Financing climate action

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

International cooperation

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

• Student Opportunities

About Hoover

Located on the campus of Stanford University and in Washington, DC, the Hoover Institution is the nation’s preeminent research center dedicated to generating policy ideas that promote economic prosperity, national security, and democratic governance. 

• The Hoover Story
• Hoover Timeline & History
• Mission Statement
• Vision of the Institution Today
• Key Focus Areas
• About our Fellows
• Research Programs
• Annual Reports
• Hoover in DC
• Fellowship Opportunities
• Visit Hoover
• David and Joan Traitel Building & Rental Information
• Newsletter Subscriptions
• Connect With Us

Hoover scholars form the Institution’s core and create breakthrough ideas aligned with our mission and ideals. What sets Hoover apart from all other policy organizations is its status as a center of scholarly excellence, its locus as a forum of scholarly discussion of public policy, and its ability to bring the conclusions of this scholarship to a public audience.

• Peter Berkowitz
• Ross Levine
• Michael McFaul
• Timothy Garton Ash
• China's Global Sharp Power Project
• Economic Policy Group
• History Working Group
• Hoover Education Success Initiative
• National Security Task Force
• National Security, Technology & Law Working Group
• Middle East and the Islamic World Working Group
• Military History/Contemporary Conflict Working Group
• Renewing Indigenous Economies Project
• State & Local Governance
• Strengthening US-India Relations
• Technology, Economics, and Governance Working Group
• Taiwan in the Indo-Pacific Region

Books by Hoover Fellows

Economics Working Papers

Hoover Education Success Initiative | The Papers

• Hoover Fellows Program
• National Fellows Program
• Student Fellowship Program
• Veteran Fellowship Program
• Congressional Fellowship Program
• Media Fellowship Program
• Silas Palmer Fellowship
• Economic Fellowship Program

Throughout our over one-hundred-year history, our work has directly led to policies that have produced greater freedom, democracy, and opportunity in the United States and the world.

• Determining America’s Role in the World
• Answering Challenges to Advanced Economies
• Empowering State and Local Governance
• Revitalizing History
• Confronting and Competing with China
• Revitalizing American Institutions
• Reforming K-12 Education
• Understanding Public Opinion
• Understanding the Effects of Technology on Economics and Governance
• Energy & Environment
• Health Care
• Immigration
• International Affairs
• Key Countries / Regions
• Law & Policy
• Politics & Public Opinion
• Science & Technology
• Security & Defense
• State & Local
• Books by Fellows
• Published Works by Fellows
• Working Papers
• Congressional Testimony
• Hoover Press
• PERIODICALS
• The Caravan
• China's Global Sharp Power
• Economic Policy
• History Lab
• Hoover Education
• Global Policy & Strategy
• Middle East and the Islamic World
• Military History & Contemporary Conflict
• Renewing Indigenous Economies
• State and Local Governance
• Technology, Economics, and Governance

Hoover scholars offer analysis of current policy challenges and provide solutions on how America can advance freedom, peace, and prosperity.

• China Global Sharp Power Weekly Alert
• Email newsletters
• Hoover Daily Report
• Subscription to Email Alerts
• Periodicals
• California on Your Mind
• Defining Ideas
• Hoover Digest
• Video Series
• Uncommon Knowledge
• Battlegrounds
• GoodFellows
• Hoover Events
• Capital Conversations
• Hoover Book Club
• AUDIO PODCASTS
• Matters of Policy & Politics
• Economics, Applied
• Free Speech Unmuted
• Secrets of Statecraft
• Capitalism and Freedom in the 21st Century
• Libertarian
• Library & Archives

Support Hoover

Learn more about joining the community of supporters and scholars working together to advance Hoover’s mission and values.

What is MyHoover?

MyHoover delivers a personalized experience at  Hoover.org . In a few easy steps, create an account and receive the most recent analysis from Hoover fellows tailored to your specific policy interests.

Watch this video for an overview of MyHoover.

Log In to MyHoover

Forgot Password

Don't have an account? Sign up

Have questions? Contact us

• Support the Mission of the Hoover Institution
• Subscribe to the Hoover Daily Report
• Follow Hoover on Social Media

Make a Gift

Your gift helps advance ideas that promote a free society.

• About Hoover Institution
• Meet Our Fellows
• Focus Areas
• Research Teams
• Library & Archives

Library & archives

Events, news & press.

Global Warming: Causes And Consequences

The familiar photo of the Earth spinning in the blackness of space that was taken 50 years ago by William Anders, an astronaut on the Apollo 8 lunar mission, starkly illustrated our isolation on this planet. Now we face a crisis as the climate and environmental conditions that support life as we know it become ever more fragile owing to CO 2 -induced global warming. The evidence suggests there is significant risk that areas of the Earth in tropical zones may become uninhabitable and that significant food chains will collapse in this century. 

Spaceship Earth

The familiar photo of the Earth spinning in the blackness of space that was taken 50 years ago by William Anders, an astronaut on the Apollo 8 lunar mission, starkly illustrated our isolation on this planet. Now we face a crisis as the climate and environmental conditions that support life as we know it become ever more fragile owing to CO 2 -induced global warming. The evidence suggests there is significant risk that areas of the Earth in tropical zones may become uninhabitable and that significant food chains will collapse in this century. We agree with those who say that the highest human priority now is to greatly reduce human societies’ reliance on CO 2 -producing oil and coal. However, even the most optimistic projections of reduced CO 2 production and resulting reductions in climatic warming suggest that future generations will face daunting problems. Fortunately, this growing disruption is occurring at a time of unprecedented breakthroughs in science and technology. Although there are many things that can be done to ameliorate individual events, the worldwide effort is uncoordinated and there is widespread resistance from vested economic and political interest groups. Here, we first survey the consequences of the rapid rise in CO 2 emissions and then consider the possibility that new genetic technologies can help mitigate some of the biological consequences of global changes in climate patterns.

Life on Earth has evolved in an interconnected ecology determined by weather patterns, movements of global tectonic plates, and the dynamic surface chemistry of oceans and land. The creatures on Earth—all the humans, animals, plants, bacteria, fungi, and viruses—are dependent on each another as well as on this enveloping ecosystem. Since the Earth is an integrated system, significant changes in any internal component or in external influences induce movement toward a new equilibrium. Throughout the history of the Earth there have been long periods of cooling leading to growth of massive continental ice sheets, interspersed with warm intervals. While the causes of these ice ages are not fully understood, the principal contributing factors have been identified. The composition of the atmosphere, particularly the concentration of carbon dioxide and methane, is important. Also changes in the Earth’s orbit around the sun, changes in the tilt in the Earth’s axis, impacts of large meteorites, and eruptions of super volcanoes. The latter two phenomena can both put massive amounts of particulate matter and carbon dioxide into the atmosphere.

In two instances, biological phenomena have disrupted the composition of the atmosphere with global consequences. One was the Great Oxidation Event or the Oxidation Catastrophe, around 2.45 billion years ago. This occurred after a bacterial species, an ancestor of contemporary cyanobacteria, evolved the ability to produce oxygen as a byproduct of photosynthesis. This event had extraordinary consequences for ocean chemistry and eventually for the slow accumulation of atmospheric oxygen to contemporary levels over an interval of several million years. The newly oxygenated atmosphere was toxic to virtually all the anaerobic organisms that then populated the earth. These organisms died and were replaced by creatures that could thrive in the new oxygenated atmosphere. 1 Now, the current human-induced increase in atmospheric CO 2 is the second biological disruption of atmospheric composition that is producing global warming with credible predictions of ever more dire consequences in coming decades. Consequences we are already seeing include:

Accelerating rise in global sea level owing to irreversible melting of glacial ice in the European Alps, melting of arctic ice, and of greatest concern, melting of the land ice sheets in Greenland and Antarctica.

Large changes in climate patterns that have led to cataclysmic wild fires encouraged by the hottest summers on record and extreme floods stemming from new and disruptive storm patterns.

Acidification and warming of the oceans leading to decimation of coral reefs and other changes that are disrupting the marine food chain.

The global redistribution of bacterial, fungal, and viral pathogens and their vectors out of the tropics and into temperate zones and the emergence of previously unknown pathogens.

As the Earth’s climate continues to warm owing to increasing levels of atmospheric CO 2 the mean sea level will rise. 2 The mean sea level has risen about 8 inches since the late 1800s, and projections suggest an accelerating rise of between 2 and 6 feet by 2100. 3 The predominant contributor to the future sea level increase will be melting of the enormous land-based ice sheets and glaciers on Antarctica and Greenland. The amount of the rise will be strongly dependent on mankind’s success in limiting future CO 2 emissions. However, even the lowest estimates portend devastating consequences: 4 loss of arable land owing to flooding and salt water intrusion (e.g., Vietnam, Bangladesh, California’s Salinas valley 5 ); major population displacements (100 million people will be displaced by a three-foot rise); many coastal areas may have to be abandoned (e.g., South Florida and Miami 6 ).

We are already experiencing changes in global weather patterns. Regions accustomed to temperate temperatures and predictable periods of rainfall are seeing prolonged drought and periods of extreme high temperature, while other regions are experiencing excess rain and snowfall along with lower ambient temperatures. In parts of Australia, drought and peak summer temperatures nearing 116 o F are causing vast wildfires. Simultaneously, U.S. states around the Great Lakes have experienced winter temperatures of -34 o C (-29.2 o F) that are significantly colder than temperatures in the Arctic. This skewing of ambient temperatures in North America is due to changes in the jet stream that have allowed polar air from the Arctic to flow into zones normally buffered against temperature extremes. Global warming contributes to these unusual weather patterns through its influence on the polar vortex, a wide expanse of swirling cold air near the pole. 7 Over a surprisingly short time, the average temperature rise at the north polar region has been higher than in some more southerly areas. While average temperatures across the globe have now increased to 1.2 o C above preindustrial revolution levels, the poles have seen an average increase of 3 o C. During March 2018, temperatures in Siberia were 15 o C (59 o F) above historical averages, and Greenland experienced a period of 61 hours above freezing (three times longer than any previous year), while temperatures were unusually low in Europe. These disruptions in global weather patterns have caused long-term drought conditions in some regions and unprecedented floods in others, leading to loss of arable land and precipitous reductions in agricultural production. Those who deny climate change often point to periods of extreme cold in unexpected regions as evidence supporting their views, without understanding that the large-scale changes in weather patterns are a central consequence of global warming. When the oceans warm, global weather patterns are disrupted in many areas in unexpected ways.

It is important to recognize that these global events are interconnected. For example, consider the consequences of sustained rainfall on degraded farmland: Increased rainfall leads to soil erosion, that in turn results in the release of phosphorous from fertilized soil into rivers and the oceans. That release, in turn can stimulate algal blooms and red tides, further reducing the ocean oxygen levels that are already lowered by warming waters. These phenomena add to the impacts of warming and acidification on food chains in the ocean.

What will be the impact of global warming on our land-based food supply and our ability to maintain the animals and plants we depend on? Warming is already slowing yield gains in most wheat-growing locations, and global wheat production is expected to fall by 6% for each 1°C of further temperature increase while becoming more variable. 8 Global production of corn is similarly at risk. 9 Global warming will alter world food production patterns, with crop productivity reduced in low latitudes and tropical regions but increased somewhat in high latitude regions. This will lead to trade changes with expanded sales of food products from the mid-to-high latitudes to lower latitude regions. 10

Extinction of species owing to expanding human activities around the globe has been accelerating over the last two centuries. Now the onset of changes in the climate is accelerating the rate of extinctions. Disruptions of habitats, loss of food sources, and the spread of infectious diseases are happening at a rate that cannot be accommodated by evolutionary adaptation. The number of species that have gone extinct in the last century alone would have taken between 800 and 1000 years to disappear in previous mass extinctions. 11 During one of these extinctions, the Permian-Triassic extinction 250 million years ago, 12,13 the earth lost 96% of all marine species, 100% of the coral reefs, and 70% of terrestrial vertebrates. In that event, the accumulation of carbon dioxide in the atmosphere led to ocean warming and to ocean acidification that together played a key role in the global loss of life. Recovery from that extinction event took more than 10 million years.

Currently, we are experiencing a 6 th mass extinction, 11 and we are approaching up to 100x higher rates of extinction than the background rate. There are two critical differences now. First, the current rate of change to the earth’s ecosystem is occurring in a few decades rather than over thousands of years as in the previous five extinction periods. Second, the events underlying the current cataclysm are man-made. Metaphorically, we are riding a runaway climate train with no one at the controls.

Effects on the Oceans

In the past there have been few established populations of invasive species identified in the high northern latitudes, that is, the northern coasts of Canada or Russia. With the continuing loss of Arctic sea ice, this situation will change. There has been rapid growth of shipping traffic along the northern coast of Russia in recent years, a large cruise ship went through the Northwest Passage in 2016, and now multiple arctic cruises are advertised each year. We can expect continuing expansion in arctic shipping activities, mineral/energy exploration, fishing, and tourism in future years. These new northern transport routes offer shorter and less expensive connections between northern hemisphere ports, so the shipping traffic will inevitably grow as more ice melts and warmer weather seasons get longer. Introduction of invasive species into these Arctic regions will follow rapidly. This will bring new challenges to the native inhabitants—humans, wildlife, and plants—of these northern ocean and terrestrial habitats. There will be greater competition for food sources and introduction of new infectious diseases. This sequence of events has occurred innumerable times before when alien populations expanded into new regions. 14

Currently, the oceans absorb 93% of the heat trapped by greenhouse gases in the atmosphere, thus slowing warming of land masses. But the resulting rapid warming of the oceans directly impacts marine life and related food chains. Consider, for example, the coral reefs along over 93,000 miles of coastline rimming the oceans—one of the largest ecosystems on the planet.

A thriving coral reef is comprised of groups of millions of identical tiny polyps a few millimeters wide and a few centimeters long, each with a calcite skeleton. Millions of these tiny stony skeletons accumulate over generations to form the large hard coral reefs found along tropical shorelines. Many of the coral species obtain most of their nutrients from photosynthetic algae plants called zooxanthellae . When the sea around them warms excessively, the polyps expel the zooxanthellae and the coral becomes completely white—a condition called coral bleaching. Corals can survive bleaching events and restore the zooxanthellae , if conditions normalize quickly enough. But the bleaching events are highly stressful, and the corals will die if occurrence of bleaching events persists. When this happens, only the dead coral skeletons—which can be immense—are left.

The Great Barrier Reef, 500 feet thick at some points, extends discontinuously for over 1500 miles off the coast of eastern Australia. By 2018, half of the Great Barrier Reef had died from heat stress. Similar damage is occurring in the Caribbean and the rest of the world’s tropical shorelines. 15,16

Loss of the ocean reef ecosystems could substantially compromise the Earths ability to sustain the health and well-being of its inhabitants. Fish populations in the coral reefs are the source of food for hundreds of millions of people. Loss of the reefs disrupts the marine food chain which causes loss of local food supplies, stressed populations, and conflicts over fishing rights.

There is now a global sense of urgency to develop methods to restore and maintain the health of the reefs considering their increasing destruction. Corals can evolve to survive in changed conditions—warmer, more acidic, etc. However, the rate of natural adaptation is too slow relative to the current rate of changes in their ocean environment, so there is widespread devastation of established reefs. This has led to efforts to accelerate the rate of adaptation. In some stressed reefs, small coral colonies are found that have successfully adapted to the local changes in temperature and increased acidity. Reef preservationists have shown that corals harvested from these colonies can be nurtured in coral “farms” and then used to seed new growth in damaged areas. Scientists are also experimenting with selective breeding to develop coral strains better adapted to changed conditions. 17–19

In Indonesia another attempt at coral reef remediation involves attaching optimized coral polyps to metal rods planted within the compromised reefs. The application of a mild electric shock causes minerals in the water to precipitate and adhere to the metal structures, thus stimulating calcification with the goal of creating the more native ‘cement’ of a reef’s exoskeleton, referred to as ‘Biorock.’ 20 The resulting limestone surface increases the growth of the corals under conditions that would normally lead to their death. All these schemes are highly promising, but there are daunting cost and logistical barriers to scaling restoration efforts to address the vast areas of lost reefs.

Global Warming Is Changing the Distribution of Animal and Plant Pathogens

The last century has seen radical changes in the pattern, volume, and speed of transport of people and cargo between widely separated regions on the planet. One consequence has been the increase in direct long-distance human transport of dangerous infectious diseases by person to person transmission. Surveillance of travelers at entry points, coupled with identification, treatment, and when necessary, quarantine of the infected persons and their contacts, has been the response strategy. But diseases that are carried by intermediate vectors, for example, mosquitoes or ticks, present a different and more complex challenge. Any such vector is adapted to thrive in some environmental niche—characterized by a temperature and rainfall range, urban or rural, indoor or outdoor, etc. When a region’s climate warms, it may become hospitable to new vectors, which will then inevitably arrive either by expansion from adjacent territories or as accidental hitchhikers in freight shipments or transport vehicles.

For example, in a remarkably short time, human viruses like Zika, Dengue, Chikungunya, Yellow Fever, and West Nile have spread into regions of the Caribbean, Latin America, and the United States that until recently had ambient temperatures below that required to support their transmission. In addition, fungal infections of food plants, like the blights infecting Cavendish bananas and cocoa trees, have become a global problem. The rapid spread of global disease caused by changes in atmospheric temperature, ocean temperature, erratic and drenching rains, and floods in one geographic location accompanied by droughts in another location is being facilitated by migration of the vectors, such as mosquitoes, ticks, bats, and rats, that carry the pathogens. Insect vectors are exquisitely sensitive to changes in temperature, and warmer temperatures increase their breeding season and life span. Zika, Dengue, Chikungunya, and Yellow Fever viruses soon follow arrival of the common Aedes aegypti mosquito and are then transmitted among humans by the female mosquito. Other mosquito species transmit West Nile virus, the malaria parasite, and the parasitic nematode worm that causes the human disfiguring disease lymphatic filariasis (elephantiasis).

Ticks are another rapidly spreading vector. Although most tick species do not harbor pathogens harmful to humans, Lyme disease is caused by a tick-borne bacterial pathogen, Borrelia burgdorferi . Until recently, ticks were inhibited over much of North America by cold winters, but with increasing average temperatures and milder winters they are becoming established further north. Lyme disease is now endemic in Canada, so the government has recently established tick surveillance networks.

The vector-borne bacterial pathogen Candidatus Liberibacter that causes citrus greening disease is a serious agricultural threat. Liberibacter are transferred to citrus trees by an insect vector, the Asian citrus psyllid or jumping plant lice. The disease causes the decline and death of citrus trees by blocking the flow of nutrients and sugars from the leaves to the roots. Once infected, the tree is doomed. Liberibacter have recently migrated along with the citrus psyllid vector to warming temperate climate zones worldwide, including ten U.S. states. 21 The resulting Citrus Greening infections have devastated the Florida citrus industry and destroyed citrus groves in Asia, Brazil, and the Dominican Republic. In the United States, the damage has been less in states further north than Florida, probably because of their cooler temperatures, but as the climate warms, the citrus greening infections will likely continue moving northward.

Owing to the huge financial impact of citrus greening, there are multiple biology-based efforts underway to disrupt the infection pathway either by eliminating the psyllid vector, by killing the bacterial Liberibacter pathogen, or by developing an infection resistant citrus tree variety. 22 Insect warfare has also been tried by introduction of a wasp that preys specifically on the Asian citrus psyllid. This strategy works, but it only reduces, rather than eliminating, the citrus psyllid population. 23

Each biological approach tried so far has its pros and cons. Insecticides can kill the citrus psyllid, but they may also threaten beneficial insects. Antibiotics may kill the Liberibacter, but their use can also increase bacterial antibiotic resistance and thus loss of antibiotic effectiveness for treating human diseases. This story of the challenges of containing the spread of the citrus greening disease is representative of similar challenges encountered in trying to deal with a myriad of newly encroaching diseases, some carried by other insect vectors. Are there better solutions on the horizon? It may be that recent advances in genetic technology will lead to more effective approaches.

Can New Genetic Technologies Reduce Global Warming Consequences?

Along with the increasing threat of climate change to human health and agriculture, we are experiencing a revolution in genetic engineering technology. Perhaps this will lead to new methods for effective surveillance and for mitigation of the redistribution of vectors that transmit disease.

The new CRISPR Cas9 technology lets us change specific genes in an insect or animal vector, thus making it either unable to serve as a reservoir for a given pathogen (known as a population modification drive) or eliminating the ability of the vector to propagate (known as a suppression drive). A suppression drive targets the reproductive capacity of the insect vector and can lead to a population crash, potentially wiping out a species. A population modification drive does not affect the reproduction capability of the insect, but it prevents the vector from harboring the pathogen or it prevents transmitting the pathogen to the human host. With these technologies, the genetic makeup of a few individuals in a targeted vector species is changed in such a manner that once these individuals are released into the wild, the change spreads rapidly throughout the entire vector population. Gene drives only affect sexually reproducing species, and thus they cannot be used directly on bacterial and viral pathogens.

Malaria transmission has been used as a test case to explore use of a vector gene drive to contain the spread of a disease. The results have been encouraging. In 2015, 200 million people worldwide were infected with malaria and between 500,000 and 700,000 died from the disease. Seventy-two percent of these were children under 5 years of age. In 2016, the number of cases worldwide increased to 216 million. Of 3,500 mosquito species, only those that belong to a subset called Anopheles can transmit the malaria parasite, Plasmodium falciparum , to a human by means of a bite from a female. The Anopheles stephensi mosquito, endemic to India and South Asia, carries the malaria parasite in that region. These mosquitoes were experimentally gene edited so that they could no longer carry the malaria parasite, establishing a population modification gene drive. A key trick in a gene drive is to engineer both copies of the chromosome so that all the offspring of a mating between a normal mosquito and a genetically altered one carry the genetic profile of the desired alteration, rather than just half the offspring, which is normally the case. Under laboratory conditions, it was demonstrated that this population modification drive leads to rapid spread of the desired genetically-altered mosquito and disappearance of the normal mosquitoes. The genetically altered mosquitoes cannot harbor the malaria parasite. This suggests that release of this genetically altered mosquito into the wild would halt the spread of malaria and thus save millions of lives. Eventually the malaria parasite could naturally mutate to overcome the genetic change in its mosquito host allowing it to once again infect humans, but this might not occur for a long time.

Another example is the Anopheles gambiae mosquito, which transmits malaria in sub-Saharan Africa. In another series of gene drive experiments, gene editing was used to change genes that the female mosquito needs for egg production, thereby creating female sterility (a suppression gene drive). In this case, the goal was just to reduce the number of mosquitoes transmitting malaria, but the technique could potentially wipe out the entire population of Anopheles gambiae . The combined challenge of climate change, which is altering the geographic distribution of the vector mosquitoes, and growing resistance to drugs routinely used to treat malaria-infected patients is making gene editing of the insect vectors an increasingly attractive potential solution. However, the notion of eliminating an entire insect species troubles many people.

In another test case, gene drives are being explored as a way of controlling transmission of Lyme disease by ticks on the U.S. island of Nantucket. Owing to recent increases in the population of island ticks, over 40% of the 10,000 inhabitants of Nantucket have, or have had, Lyme disease. Both deer and the white foot mouse can transmit the Lyme disease pathogen, Borrelia burgdorferi bacteria, to ticks, and the pathogen can then be transmitted to humans by the ticks. Ticks feed on the deer or white foot mice carrying Borrelia and the infected ticks bite humans, passing on Lyme disease. A plan was proposed by Kevin Esvelt (MIT) and Sam Telford (Tufts U., Cummings School of Veterinary Medicine) to use a gene drive to reduce the population of white footed mice that are infected with Borrelia . To do this, the mice would be genetically engineered so that they are immune to infection by the Lyme disease bacterial pathogen and thus could not accumulate infectious Borrelia . In this case, there would still be the same number of mice and the same number of ticks, but the number of ticks able to transmit Borrelia would be significantly reduced. Thousands of altered mice would be released on the island. The gene drive would ensure that the genetic alteration would pass down through all following generations of mice on the island, disrupting the cycle of transmission. The plan is to first test the genetically modified mice on an uninhabited island and then, with the concurrence of the inhabitants of both Nantucket Island and Martha’s Vineyard, release the genetically altered mice. The first step will be to get the concurrence and support of the inhabitants of these islands, because the gene drive would be altering the environment shared by all inhabitants.

Recently, a new gene editing application has been developed to alter the response of plants to environmental challenges. The proposed scheme involves spraying a field of plants with millions of insect vectors carrying viruses that are programmed to edit the genome of a plant such as maize to become drought resistant, in one growing season. This technique would be significantly faster than a gene drive. Further, this method would not permanently alter the genetic makeup of future plant generations, as is the case with gene drives. The goal is to engineer drought-resistant and temperature-tolerant plants, thereby securing the food supply during times of climate instability. But there is a catch, as once released into the wild, controlling these insect vectors would be difficult, if not impossible. As a result, this work has been limited so far to the laboratory. There is also concern that the method could be adapted as a biological weapon, enabling destruction of targeted food crops over wide areas by adverse genetic manipulation of the plants’ chromosomes. In addition to controlling mosquito vectors and tick-borne Lyme disease, gene drives are also being devised to control the nematode worms that carry the parasite causing Schistosomiasis.

Gene drives have not yet been released in the wild to mitigate vector-borne transmission of disease as there are critical questions to be resolved as noted above. Although the biology is ready, there are many questions of governance, safety, and ethics to be answered. Caution is important, since once the genetically-altered vectors are released, there is no assured way of controlling them at this point.

In July 2015, the U.S. National Academy of Sciences convened a meeting to discuss “the promise and perils of gene drives.” Critical questions raised at the meeting were:

Will an entire species of vector be wiped out? Methods are being devised to slow the gene drive so that only a portion of the offspring contain the genetically engineered alterations. These “Daisy chain drives,” have been engineered to be self-limiting and eventually disappear from the population.

Have techniques been devised that could control a runaway gene drive? By creating a second gene drive that undoes the genetic alterations of the first gene drive, essentially “a molecular eraser,” it is hoped a gene drive could be reversed, but not before unintended consequences to the ecosystem become apparent.

Can the altered genetic traits be transferred to other insect species ? Unlikely, but possible. If this occurred, the potential for wiping out beneficial insect species would lead to further ecological disruptions, compounding the ravages of climate change.

Global Warming Mitigation Will Require a Coordinated International Effort

Many climate scientists and other thoughtful people have had concerns about the deteriorating global ecosystem for several decades now. The contribution of human activity to this escalating cataclysm is well documented. Predictions of dire consequences have been noted and sporadic attempts by the international community have been made to mitigate the ongoing onslaught of carbon emissions. But global warming is a problem that can only be solved by global cooperation because the world’s ecosystem is an integrated system. The causes of environmental degradation cannot be addressed by a patchwork of uncoordinated responses. We are dependent upon achieving international cooperation to mount a coordinated, science-based response.

In the United States today, political calculations relating to oil and coal interests have halted government acknowledgement of the risks of continuing future emissions of CO 2 into the atmosphere. In December 2018, at a UN Climate Change Conference in Poland, Wells Griffith, Mr. Trump’s international energy and climate adviser, said “We strongly believe that no country should have to sacrifice their economic prosperity or energy security in pursuit of environmental sustainability.” The attendees broke into jeers and mocking laughter. 24 Do not think that the United States is alone in this stance. We are aligned with other major fossil fuel producing nations, including Russia, Saudi Arabia, Kuwait, and Australia. We are now well beyond the time of debating about validity of the predictions about what will happen if climate change is left unaddressed. Rather, we are trying to mitigate what has already happened, while, as a society, summoning the courage and the will to leave fossil fuels in the ground and switch to alternative energy sources. Renewable power resources and improvements in the efficiency of our energy use can be important components of our energy future for the rest of this century. But, practically speaking, nuclear power will probably also have to be a major component of the future energy portfolio in order to meet world energy demands while greatly reducing use of fossil fuels. 25, 26 That too is controversial. These are existential choices that call for an unprecedented level of wisdom and societal responsiveness in the world’s political systems. It does seem likely that achieving the necessary global political response will only come when there is widespread public fear and panic as the realization of the danger percolates into public consciousness. 27 It is extraordinary that the current U.S. national leadership both denies existence of the global warming problem and actively promotes more use of fossil fuels. The longer we delay reduction in global CO 2 emissions, the worse the ultimate catastrophe will be.

Authors’ Note:

We believe the world energy economy must shift rapidly from reliance on fossil fuels—coal, oil, and gas—to cleaner alternatives or our children and grandchildren will suffer dire consequences. We encourage the reader to personally assess the risks and potential solutions. To that end, we have included references for further reading that are openly accessible on the Internet.

Lucy Shapiro is a professor in the Department of Developmental Biology at Stanford University School of Medicine where she holds the Virginia and D. K. Ludwig Chair in Cancer Research and is the director of the Beckman Center for Molecular and Genetic Medicine. Harley McAdams is an emeritus professor at the Department of Developmental Biology at Stanford University School of Medicine.

View the discussion thread.

Join the Hoover Institution’s community of supporters in ideas advancing freedom.

ENCYCLOPEDIC ENTRY

Global warming.

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

Earth Science, Climatology

Tennessee Power Plant

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

Photograph by Emory Kristof/ National Geographic

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

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

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

Media Credits

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

Production Managers

Program specialists, last updated.

February 21, 2024

User Permissions

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

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

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

Interactives

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

Related Resources

Lisa Hupp/USFWS

Arctic Match Live Now!

For a limited time, all gifts are being matched to stop Big Oil from blocking a new once-in-a-lifetime opportunity to protect the Arctic.

Global Warming 101

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

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

Jia Tianyong/China News Service/VCG via Getty Images

• Share this page block

What is global warming?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Related Stories

1.5 Degrees of Global Warming—Are We There Yet?

When Customers and Investors Demand Corporate Sustainability

Liquefied Natural Gas 101

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

• History & Society
• Science & Tech
• Biographies
• Animals & Nature
• Geography & Travel
• Arts & Culture
• Games & Quizzes
• On This Day
• One Good Fact
• New Articles
• Lifestyles & Social Issues
• Philosophy & Religion
• Politics, Law & Government
• World History
• Health & Medicine
• Browse Biographies
• Birds, Reptiles & Other Vertebrates
• Bugs, Mollusks & Other Invertebrates
• Environment
• Fossils & Geologic Time
• Entertainment & Pop Culture
• Sports & Recreation
• Visual Arts
• Demystified
• Image Galleries
• Infographics
• Top Questions
• Britannica Kids
• Saving Earth
• Space Next 50
• Student Center

global warming summary

Learn about the causes and effects of global warming.

global warming , Increase in the global average surface temperature resulting from enhancement of the greenhouse effect, primarily by air pollution . In 2007 the UN Intergovernmental Panel on Climate Change forecast that by 2100 global average surface temperatures would increase 3.2–7.2 °F (1.8–4.0 °C), depending on a range of scenarios for greenhouse gas emissions, and stated that it was now 90 percent certain that most of the warming observed over the previous half century could be attributed to greenhouse gas emissions produced by human activities (i.e., industrial processes and transportation). Many scientists predict that such an increase in temperature would cause polar ice caps and mountain glaciers to melt rapidly, significantly raising the levels of coastal waters, and would produce new patterns and extremes of drought and rainfall, seriously disrupting food production in certain regions. Other scientists maintain that such predictions are overstated. The 1992 Earth Summit and the 1997 Kyoto Protocol to the United Nations Framework Convention on Climate Change attempted to address the issue of global warming, but in both cases the efforts were hindered by conflicting national economic agendas and disputes between developed and developing nations over the cost and consequences of reducing emissions of greenhouse gases.

Global Warming Definition, Causes, Effects, Impacts, Solutions

Global Warming is a long-term increase in average global temperature. Read about Global Warming Definition, Causes, Effects, Impact on Climate Change & Solutions for the UPSC exam.

Table of Contents

What is Global Warming?

Global Warming is a long-term increase in average global temperature. It is considered a natural phenomenon, but anthropogenic activities on earth, particularly post Industrial Revolution , have led to an increase in the rate of this temperature increase. Various Reports published by the International Panel on Climate Change (IPCC) have time and again highlighted that since 1850 human activities have led to an increase of about 1 degree Celsius in average global temperature. Most of this warming has taken place in the second half of the 20th century. The fact that 5 of the hottest recorded year have occurred since 2015 can help us better understand the calamitous impact of anthropogenic activities.

Global Warming Causes

Green House Gases also known as GHGs in the atmosphere trap the solar radiations that are reflected by the earth’s surface. Under normal circumstances, most of these radiations escape into outer space. However, the release of GHGs by anthropogenic activities has increased their concentration in the atmosphere. Thus, the earth is getting hotter and hotter. 

Some of the common GHGs include carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and water vapour, among others. The global warming potential of each GHG is different. For example, methane has a 25-time warming potential than carbon dioxide. Similarly, nitrous oxide has more than 250 times the warming potential than carbon dioxide. The top  anthropogenic activities that are responsible for the release of GHGs are shown below.

Global Warming and Green House Effect

Both phenomena are related to each other. Green House Gases also known as GHGs in the atmosphere trap the solar radiations that are reflected by the earth’s surface. Under normal circumstances, most of these radiations escape into outer space. However, the release of GHGs by anthropogenic activities has increased their concentration in the atmosphere. This is the primary cause of Global Warming . 

Global Warming Effects

Increase in the average temperature of the earth.

According to IPCC reports, human-induced global warming is responsible for nearly 1 degree Celsius temperature rise vis a vis pre-industrial level. Data from NASA suggest that 2016 has been the hottest year on record.

Frequency of Extreme Weather Events is Increasing

Across the globe, extreme weather events have increased in occurrence. For example, forest fires in California have become an annual event. Also, it is increasing in frequency each year. Most recently, we have recorded the phenomena of heat waves in Antarctica. The intensity of cyclones in the Bay of Bengal region has increased. Similarly, the frequency of occurrence of El Niño and La Niña has reduced from once in 8–10 years to once in 3–4 years now. More frequent episodes of floods and drought are being recorded every year across the world.

Melting of Ice

According to IPCC, there is 10% less permafrost in North Hemisphere at present compared to the 1900s. Remote sensing data suggest Arctic ice is melting fast. Experts suggest that not only will the sea level rise with the melting of glaciers, but there is also a danger of new bacteria and viruses being released into the environment which has so far been trapped in ice sheets. This may lead to outbreaks of disease and pandemics which are beyond the control of human medical sciences.

Sea Level Rise and Acidification of Ocean

A report published by WMO, suggests that the rate of sea level rise has doubled for the period between 2013 and 2021 compared to the rate for the period between 1993 and 2002. Earth scientists are suggesting that if this phenomenon continues, many human-inhabited coastal areas will be submerged into the sea in the coming decades. Also, with the concentration of carbon dioxide rising in the atmosphere, oceans are absorbing more of it. This is leading to ocean acidification. The impact of this phenomenon can be disastrous for ocean biodiversity, particularly the coral reefs. 

Adverse Impact on Terrestrial Ecosystems of the Earth

It has been recorded that many flora and fauna species are heading northwards in Northern Hemisphere. Significant changes have been observed in the migratory movements of birds across the world. Early arrival to their summer feeding and breeding grounds is quite evident. Expert biologists suggest that rising temperatures in the tropical and subtropical regions may lead to an outbreak of new diseases, which in turn may render many floral and faunal species extinct.

Social and Economic Impact

A rising number of extreme weather events will have an adverse impact on agriculture and fisheries. Rising global temperatures will have a negative impact on the productivity of human beings, particularly in tropical and subtropical regions of the earth. The impact on life and livelihoods of indigenous people across the world will be even more pronounced. 

Global Warming Solutions

Global cooperation for reduction of emissions.

It is time that the target of containing the global average temperature rise within 1.5 degrees Celsius of pre-industrial levels is taken seriously. Also, global efforts should be based on a spirit of Common But Differentiated Responsibility. This will ensure that historical injustices done to the global south are duly acknowledged, and they have an equal chance to transform themselves into developed countries. Countries must act proactively to achieve Net Zero Emission status at the earliest. 

Transition to Cleaner and Greener Forms of Energy

Thermal power plants based on coal should be made more efficient and inefficient ones should be phased off. Also, mass adoption of renewable forms of energy like solar should be promoted. Similarly, avenues for using hydrogen as energy fuel should be looked into. We must also explore the possibility of Nuclear fusion for energy generation, in addition to making nuclear fission-based energy generation safer.

Changes in Agricultural Practices and Land Use

Agriculture based on the use of nitrogenous fertilizers must be replaced with organic farming techniques. Also, methane gas released from agricultural and cattle waste must be trapped as biogas for domestic usage. Massive afforestation drives must be organized. Urban governments must make it a point to include green spaces in urban planning.

Improving Transportation System

The advent of E-vehicles is a welcome change, but we need to make the batteries used in these vehicles more efficient. Urban planners must make public transportation systems inherent as a benchmark of good urban planning. Also, urban planning should be such that it promotes more walking and cycling habits among the residents. 

Behavioural Changes

All the above discussions will have no meaning if we as individuals are not sensitive enough. We need to make reducing, reusing and recycling a mantra of our living. It should be our civic duty to save water, and wildlife and raise awareness among others. 

Solar Geoengineering

Solar geoengineering, a proposed climate intervention method, aims to counteract global warming by reflecting a portion of the sun’s rays back into space. One prominent approach involves injecting substances like sulphur dioxide into the upper atmosphere to create reflective aerosols. These particles can scatter sunlight, reducing the Earth’s temperature. However, solar geoengineering is a topic of debate, with concerns about its side effects, such as disrupted weather patterns and potential geopolitical risks. Research in this field is ongoing, but it remains a theoretical concept with limited practical implementation.

Can Solar Geoengineering Halt Global Warming?

Solar geoengineering, specifically solar radiation management (SRM), is under scrutiny as a potential method to mitigate global warming. SRM involves reflecting sunlight away from Earth, often by injecting substances like sulphur dioxide into the upper atmosphere to create reflective aerosols. However, its effectiveness remains a subject of debate, with concerns about potential side effects and ethical implications. While research in this field is ongoing, solar geoengineering is currently in a theoretical stage, with limited practical implementation.

Global Warming Conclusion

It is rightly said that “Charity begins at home.” Climate action will be more efficient if we go by this spirit. To begin with, each individual can make sure that what is happening in their house and immediate surroundings is in harmony with the environment. If this can happen, all the policies we are making at the local, national, regional and global levels will give far better results. 

Global Warming UPSC

Each year, we read about rising global temperatures. Also, catching the headlines is the news related to disasters caused by events like cyclones, forest fires, floods and drought. All these phenomena can be attributed to one single cause which is global warming. 

Global Warming is a long-term increase in average global temperature. It is considered a natural phenomenon, but anthropogenic activities on earth, particularly post-Industrial Revolution, have led to an increase in the rate of this temperature increase.

Sharing is caring!

Why is global warming a problem?

Global Warming at present rate can lead to disastrous impacts like rising sea level, out break of new diseases, extreme weather events among others.

What are 3 causes of global warming?

Human induced green house gas emission due to activities like agriculture, industrial emissions, transportation are the top 3 causes of global warming.

What are 5 effects of global warming?

Rising sea level, out break of new diseases, extreme weather events, changes in biodiversity and melting of glaciers are top 5 effects of global warming.

Why global warming is important?

Global warming at its natural rate is important to keep up the temperature of earth within the range that makes it habitable. This makes global warming important.

Can we control global warming?

Number of mitigation measures like shifting to cleaning forms of energy and transportation can be taken to control global warming.

Who help with global warming?

Global Warming is a collective challenge for entire humanity. Citizens, civil societies, governments and businesses must act in unison to address it.

I, Sakshi Gupta, am a content writer to empower students aiming for UPSC, PSC, and other competitive exams. My objective is to provide clear, concise, and informative content that caters to your exam preparation needs. I strive to make my content not only informative but also engaging, keeping you motivated throughout your journey!

Leave a comment

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

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

Trending Event

• TNPSC Group 4 Result 2024
• UPSC ESIC Nursing Officer Result 2024
• UPSC EPFO PA Result 2024
• UPSC CMS Result 2024
• SSC Stenographer Apply Online 2024
• IB SA MTS Final Result 2024

Recent Posts

• UPSC Online Coaching
• UPSC Exam 2024
• UPSC Syllabus 2024
• UPSC Prelims Syllabus 2024
• UPSC Mains Syllabus 2024
• UPSC Exam Pattern 2024
• UPSC Age Limit 2024
• UPSC Calendar 2024
• UPSC Syllabus in Hindi
• UPSC Full Form
• UPPSC Exam 2024
• UPPSC Calendar
• UPPSC Syllabus 2024
• UPPSC Exam Pattern 2024
• UPPSC Application Form 2024
• UPPSC Eligibility Criteria 2024
• UPPSC Admit card 2024
• UPPSC Salary And Posts
• UPPSC Cut Off
• UPPSC Previous Year Paper

BPSC Exam 2024

• BPSC 70th Notification
• BPSC 69th Exam Analysis
• BPSC Admit Card
• BPSC Syllabus
• BPSC Exam Pattern
• BPSC Cut Off
• BPSC Question Papers

SSC CGL 2024

• SSC CGL Exam 2024
• SSC CGL Syllabus 2024
• SSC CGL Cut off
• SSC CGL Apply Online
• SSC CGL Salary
• SSC CGL Previous Year Question Paper
• SSC MTS 2024
• SSC MTS Apply Online 2024
• SSC MTS Syllabus 2024
• SSC MTS Salary 2024
• SSC MTS Eligibility Criteria 2024
• SSC MTS Previous Year Paper

SSC Stenographer 2024

• SSC Stenographer Notfication 2024
• SSC Stenographer Syllabus 2024
• SSC Stenographer Salary 2024

IMPORTANT EXAMS

• Terms & Conditions
• Return & Refund Policy
• Privacy Policy

• ENVIRONMENT

How global warming is disrupting life on Earth

The signs of global warming are everywhere, and are more complex than just climbing temperatures.

Our planet is getting hotter. Since the Industrial Revolution—an event that spurred the use of fossil fuels in everything from power plants to transportation—Earth has warmed by 1 degree Celsius, about 2 degrees Fahrenheit.  

That may sound insignificant, but 2023 was the hottest year on record , and all 10 of the hottest years on record have occurred in the past decade.  

Global warming and climate change are often used interchangeably as synonyms, but scientists prefer to use “climate change” when describing the complex shifts now affecting our planet’s weather and climate systems.  

Climate change encompasses not only rising average temperatures but also natural disasters, shifting wildlife habitats, rising seas , and a range of other impacts. All of these changes are emerging as humans continue to add heat-trapping greenhouse gases , like carbon dioxide and methane, to the atmosphere.

What causes global warming?

When fossil fuel emissions are pumped into the atmosphere, they change the chemistry of our atmosphere, allowing sunlight to reach the Earth but preventing heat from being released into space. This keeps Earth warm, like a greenhouse, and this warming is known as the greenhouse effect .  

Carbon dioxide is the most commonly found greenhouse gas and about 75 percent of all the climate warming pollution in the atmosphere. This gas is a product of producing and burning oil, gas, and coal. About a quarter of Carbon dioxide also results from land cleared for timber or agriculture.  

Methane is another common greenhouse gas. Although it makes up only about 16 percent of emissions, it's roughly 25 times more potent than carbon dioxide and dissipates more quickly. That means methane can cause a large spark in warming, but ending methane pollution can also quickly limit the amount of atmospheric warming. Sources of this gas include agriculture (mostly livestock), leaks from oil and gas production, and waste from landfills.  

What are the effects of global warming?  

One of the most concerning impacts of global warming is the effect warmer temperatures will have on Earth's polar regions and mountain glaciers. The Arctic is warming four times faster than the rest of the planet. This warming reduces critical ice habitat and it disrupts the flow of the jet stream, creating more unpredictable weather patterns around the globe.  

( Learn more about the jet stream. )

A warmer planet doesn't just raise temperatures. Precipitation is becoming more extreme as the planet heats. For every degree your thermometer rises, the air holds about seven percent more moisture. This increase in moisture in the atmosphere can produce flash floods, more destructive hurricanes, and even paradoxically, stronger snow storms.  

The world's leading scientists regularly gather to review the latest research on how the planet is changing. The results of this review is synthesized in regularly published reports known as the Intergovernmental Panel on Climate Change (IPCC) reports.  

A recent report outlines how disruptive a global rise in temperature can be:

• Coral reefs are now a highly endangered ecosystem. When corals face environmental stress, such as high heat, they expel their colorful algae and turn a ghostly white, an effect known as coral bleaching . In this weakened state, they more easily die.  
• Trees are increasingly dying from drought , and this mass mortality is reshaping forest ecosystems.
• Rising temperatures and changing precipitation patterns are making wildfires more common and more widespread. Research shows they're even moving into the eastern U.S. where fires have historically been less common.
• Hurricanes are growing more destructive and dumping more rain, an effect that will result in more damage. Some scientists say we even need to be preparing for Cat 6 storms . (The current ranking system ends at Cat 5.)

How can we limit global warming?  

Limiting the rising in global warming is theoretically achievable, but politically, socially, and economically difficult.  

Those same sources of greenhouse gas emissions must be limited to reduce warming. For example, oil and gas used to generate electricity or power industrial manufacturing will need to be replaced by net zero emission technology like wind and solar power. Transportation, another major source of emissions, will need to integrate more electric vehicles, public transportation, and innovative urban design, such as safe bike lanes and walkable cities.  

( Learn more about solutions to limit global warming. )

One global warming solution that was once considered far fetched is now being taken more seriously: geoengineering. This type of technology relies on manipulating the Earth's atmosphere to physically block the warming rays of the sun or by sucking carbon dioxide straight out of the sky.

Restoring nature may also help limit warming. Trees, oceans, wetlands, and other ecosystems help absorb excess carbon—but when they're lost, so too is their potential to fight climate change.  

Ultimately, we'll need to adapt to warming temperatures, building homes to withstand sea level rise for example, or more efficiently cooling homes during heat waves.  

Related Topics

• CLIMATE CHANGE
• ENVIRONMENT AND CONSERVATION
• POLAR REGIONS

You May Also Like

Why all life on Earth depends on trees

Life probably exists beyond Earth. So how do we find it?

Pizzlies, grolars, and narlugas: Why we may soon see more Arctic hybrids

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

Listen to 30 years of climate change transformed into haunting music

• Interactive Graphic
• Environment
• Paid Content

History & Culture

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

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

• Share full article

You Asked, We Answered: Some Burning Climate Questions

Reporters from the Climate Desk gathered reader questions and are here to help explain some frequent puzzlers.

What’s one thing you want to know about climate change? We asked, and hundreds of you responded.

The topic, like the planet, is vast. Overwhelming. Complex. But there’s no more important time to understand what is happening and what can be done about it.

Why are extreme cold weather events happening if the planet is warming?

I understand that scientists believe that some extreme cold weather events are due to climate change, but I don’t quite understand how, especially if Earth is getting warmer overall. Could you explain this? — Gabriel Gutierrez, West Lafayette, Ind.

By Maggie Astor

The connection between climate change and extreme cold weather involves the polar jet stream in the Northern Hemisphere, strong winds that blow around the globe from west to east at an altitude of 5 to 9 miles. The jet stream naturally shifts north and south, and when it shifts south, it brings frigid Arctic air with it.

A separate wind system, called the polar vortex , forms a ring around the North Pole. When the vortex is temporarily disrupted — sometimes stretched or elongated, and other times broken into pieces — the jet stream tends to take one of those southward shifts. And research “suggests these disruptions to the vortex are happening more often in connection with a rapidly warming, melting Arctic, which we know is a clear symptom of climate change,” said Jennifer A. Francis, a senior scientist at the Woodwell Climate Research Center.

In other words, as climate change makes the Arctic warmer, the polar vortex is being more frequently disrupted in ways that allow Arctic air to escape south. And while temperatures are increasing on average, Arctic air is still frigid much of the time. Certainly frigid enough to cause extreme cold snaps in places like, say, Texas that are not accustomed to or prepared for them.

Where the extreme cold occurs depends on the nature of the disruption to the polar vortex. One type of disruption brings Arctic air into Europe and Asia. Another type brings Arctic air into the United States, and “that’s the type of polar vortex disruption that’s increasing the fastest,” said Judah L. Cohen, the director of seasonal forecasting at Atmospheric and Environmental Research, a private organization that works with government agencies.

It is important to note that these atmospheric patterns are extremely complicated, and while studies have shown a clear correlation between the climate-change-fueled warming of the Arctic and these extreme cold events, there is some disagreement among scientists about whether the warming of the Arctic is directly causing the extreme cold events. Research on that question is ongoing.

How will climate change affect biodiversity?

What impact will climate change have on biodiversity? How are they interlinked? How do the roles of developing versus developed countries differ, for example the United States and India? — A reader in India

By Catrin Einhorn

Warmer oceans are killing corals . Rising sea levels threaten the beaches that sea turtles need for nesting, and hotter temperatures are causing more females to be born. Changing seasons are increasingly out of step with the conditions species have evolved to depend on.

And then there are the polar bears , long a symbol of what could be lost in a warming world.

Climate change is already affecting plants and animals in ways that scientists are racing to understand. One study predicted sudden die offs , with large segments of ecosystems collapsing in waves. This has already started in coral reefs, scientists say, and could start in tropical forests by the 2040s.

Keeping global warming under 2 degrees Celsius, or 3.6 degrees Fahrenheit, the upper limit outlined by the Paris Agreement, would reduce the number of species exposed to dangerous climate change by 60 percent, the study found.

Despite these grim predictions, climate change isn’t yet the biggest driver of biodiversity loss. On land, the largest factor is the ways in which people have reshaped the terrain itself, creating farms and ranches, towns and cities, roads and mines from what was once habitat for myriad species. At sea, the main cause of biodiversity loss is overfishing. Also at play: pollution, introduced species that outcompete native ones, and hunting. A sobering report in 2019 by the leading international authority on biodiversity found that around a million species were at risk of extinction, many within decades.

While climate change will increasingly drive species loss, that’s not the only way in which the two are interlinked. Last year the same biodiversity panel joined with its climate change counterpart to issue a paper declaring that neither crisis could be addressed effectively on its own. For example, intact ecosystems like peatlands and forests both nurture biodiversity and sequester carbon; destroy them, and they turn into emitters of greenhouse gasses as well as lost habitat.

What to do? The science is clear that the world must transition away from fossil fuels far more quickly than is happening. Deforestation must stop . Consuming less meat and dairy would free up farmland for restoration , providing habitat for species and stashing away carbon. Ultimately, many experts say, we need a transformation from an extraction-based economy to a circular one. Like nature’s cycle, our waste — old clothes, old smartphones, old furniture — must be designed to provide the building blocks of what comes next.

Countries around the world are working on a new United Nations biodiversity agreement , which is expected to be approved later this year. One sticking point: How much money wealthy countries are willing to give poorer ones to protect intact natural areas, since wealthy countries have already largely exploited theirs.

Advertisement

What’s the status of U.S. climate legislation and emissions?

Where is the trimmed back version of climate legislation at? Joe Manchin reportedly said he would support such a bill. What do you know about the bill and will it pass with just Democrats? — Richard Buttny, Virgil, N.Y.

What is the current stated U.S. goal regarding reducing greenhouse gases and climate change, and how likely is it that we will achieve that goal? What do we need to do today to make progress toward achieving that goal? — Kathy Gray, Oak Ridge, Tenn.

By Lisa Friedman

Richard, as to the last part of your question, honestly, at this point your guess is as good as ours.

But here is what we know so far. Senator Joe Manchin III, Democrat of West Virginia, the most powerful man in Congress because his support in an evenly divided Senate is key, effectively killed President Biden’s Build Back Better climate and social spending legislation when he ended months of negotiations last year, saying he could not support the package .

A few weeks ago amid talks of revived discussions, Mr. Manchin was blunt. “There is no Build Back Better legislation,” he told reporters. Mr. Manchin also has not committed to passing a smaller version of the original $1 trillion spending plan. He has, however, voiced support for an “all of the above” energy package that increases oil and gas development.

Democrats hope that billions of dollars in tax incentives for wind, solar, geothermal and electric vehicle charging stations can also make its way into such a package. But relations between the White House and Mr. Manchin are rocky and it is unclear whether such a bill could pass before lawmakers leave town for an August recess.

To your emissions question, Kathy, Mr. Biden has pledged to cut United States emissions 50 to 52 percent below 2005 levels by 2030 . Energy experts say it is a challenging but realistic goal, and critical for helping the world avert the worst impacts of climate change.

It’s not going to be easy. So far there are few regulations and even fewer laws that can help achieve that target. Mr. Biden’s centerpiece legislation, the Build Back Better Act, includes $550 billion in clean energy tax incentives that researchers said could get the country about halfway to its goal. But, as noted, that bill is stalled in the Senate . Even if it manages to win approval this year, the administration will still have to enact regulations on things like power plants and automobile emissions to meet the target.

Will our drinking water be safe?

A lot of coverage on climate change deals with rising sea levels and extreme weather — droughts, floods, etc. My question is more about how climate change will affect drinking water and access to safe clean water. Are we in danger within our current lifetime to see an impact to safe water within the U.S. due to climate change? — Jessica, Silver Spring, Md.

By Christopher Flavelle

Climate change threatens Americans’ access to clean drinking water in a number of ways. The most obvious is drought: Rising temperatures are reducing the snowpack that supplies drinking water for much of the West.

But drought is far from the only climate-related threat to America’s water. Along the coast, cities like Miami that draw drinking water from underground aquifers have to worry about rising seas pushing saltwater into those aquifers , a process called saltwater intrusion. And rising seas also push up groundwater levels, which can cause septic systems to stop working, pushing unfiltered human waste into that groundwater.

Even in cities far from the coast, worsening floods are overwhelming aging sewer systems , causing untreated storm water and sewage to reach rivers and streams more frequently . And some 2,500 chemical sites are in areas at risk of flooding, which could cause those chemicals to leach into the groundwater.

In some cases, protecting drinking water from the effects of climate change is possible, so long as governments can find enough money to upgrade infrastructure — building new systems to contain storm water, for example, or better protect chemicals from being released during a flood.

Far harder will be finding new supplies of water to make up for what’s lost as temperatures rise. Some communities are responding by pumping more water from the ground. But if those aquifers are depleted faster than rainwater can replenish them, they will eventually run dry, a concern with the Ogallala Aquifer that supports much of the High Plains.

Even with significant reductions in water use, climate change could reduce the number of people that some regions can support, and leave more areas dependent on importing water.

Can you solve drought by piping water across the country?

Why don’t we create a national acequia system to capture excess rain falling primarily in the Eastern United States and pipeline it to the drought in the West? — Carol P. Chamberland, Albuquerque, N.M

The idea of taking water from one community and giving it to another has some basis in American history. In 1913, Los Angeles opened an aqueduct to carry water from Owens Valley, 230 miles north of the city, to sustain its growth.

But the project, in addition to costing some $23 million at the time, greatly upset Owens Valley residents, who so resented losing their water that they took to dynamiting the aqueduct. Repeatedly .

Today, there are some enormous water projects in the United States, though building a pipeline that spanned a significant stretch of the country would be astronomically more difficult. The distance between Albuquerque, for example, and the Mississippi River — perhaps the closest hypothetical starting point for such a pipeline — is about 1,000 miles, crossing at least three states along the way. Moving that water all the way to Los Angeles would mean piping it at least 1,800 miles across five states.

So the engineering and permitting challenges alone would be daunting. And that’s assuming the local and state governments that would have to give up their water would be willing to do so.

China dealt with similar challenges to build a colossal network of waterways that is transferring water from the country’s humid south to its dry north. But of course, China’s system of government makes engineering feats of that scale somewhat more feasible to pull off.

For the United States, it would be easier to just build a series of desalination plants along the West coast, according to Greg Pierce, director of the Human Right to Water Solutions Lab at the University of California, Los Angeles. And before turning to desalination, which is itself energy-intensive and thus expensive, communities in the West should work harder at other steps, such as water conservation and recycling, he said.

“It’s not worth it,” Dr. Pierce said of the pipeline idea. “You’d have to exhaust eight other options first.”

Is the weather becoming more extreme than scientists predicted?

How can we have faith in climate modeling when extreme events are much worse than predicted? Given “unexpected” extreme events like the 2021 Pacific Northwest heat wave and extreme heat in Antarctica that appear to shock scientists, it’s difficult for me to trust the I.P.C.C.’s framing that we haven’t run out of time. — Kevin, Herndon, Va.

By Raymond Zhong

Climate scientists have said for a long time that global warming is causing the intensity and frequency of many types of extreme weather to increase. And that’s exactly what has been happening. But global climate models aren’t really designed to simulate extreme events in individual regions. The factors that shape individual heat waves, for instance, are very local. Large-scale computer models simply can’t handle that level of detail quite yet.

That said, sometimes there are events that seem so anomalous that they make scientists wonder if they reflect something totally new and unforeseen, a gap in our understanding of the climate. Some researchers put the 2021 Pacific Northwest heat wave in that category, and are working to figure out whether they need to re-evaluate some of their assumptions.

For its part, the I.P.C.C. has hardly failed to acknowledge what’s happening with extreme weather. But its mandate is to assess the whole range of climate research, which might make it lean toward the middle of the road in its summaries. A decade ago, when a group of researchers looked back at the panel’s assessments from the early 2000s, they found that it generally underestimated the actual changes in sea level rise, increases in surface temperatures, intensity of rainfall and more. They blamed the instinct of scientists to avoid making conclusions that seem “excessively dramatic,” perhaps out of fear of being called alarmist.

The panel’s latest report, from April , concluded that we haven’t run out of time to slow global warming, but only if nations and societies make some huge changes right away. That’s a big if.

How can I hear from climate scientists themselves?

Why are climate change scientists faceless, aloof, terrible communicators and absent from social media? — A reader in Dallas

Climate science may not yet have its Bill Nye or its Neil deGrasse Tyson, but plenty of climate scientists are passionate about communicating their work to the public. Lots of them are on Twitter. Here’s a (very small) cross-section of people to follow, in alphabetical order:

Alaa Al Khourdajie : Senior scientist in London with the Intergovernmental Panel on Climate Change, the body of experts convened by the United Nations that puts out regular, authoritative surveys of climate research. Tweets on climate change economics and climate diplomacy.

Andrew Dessler : Professor of atmospheric sciences at Texas A&M University. Elucidator of energy and renewables, climate models and Texas.

Zeke Hausfather : Climate research lead at the payment processing company Stripe and scientist at Berkeley Earth, a nonprofit research group. A seemingly tireless chronicler, charter and commentator on all things climate.

David Ho : Climate scientist at the University of Hawaii at Manoa and École Normale Supérieure in Paris. Talks oceans and carbon dioxide removal, with wry observations on transit, cycling and life in France, too.

Twila Moon : Deputy lead scientist at the National Snow and Ice Data Center in Boulder, Colo. Covers glaciers, polar regions and giant ice sheets, and why we should all care about what happens to them.

Maisa Rojas : Climatologist at the University of Chile and Chile’s current environment minister. Follow along for slices of life at the intersection of science and government policy.

Sonia I. Seneviratne : Professor of land-climate dynamics at ETH Zurich in Switzerland. Tweets on extreme weather, greenhouse gas emissions and European energy policy.

Chandni Singh : Researcher on climate adaptation at the Indian Institute for Human Settlements in Bangalore. Posts about how countries and communities are coping with climate change, in both helpful ways and not so helpful ones.

Kim Wood : Geoscientist and meteorologist at Mississippi State University. A fount of neat weather maps and snarky GIFs.

What kind of trees are best to plant for the planet?

The world is trying to reforest the planet by planting nonnative trees like eucalyptus. Is this another disastrous plan? Shouldn’t they be planting native trees? — Katy Green, Nashville

Ecologists would say planting native trees is the best choice. We recently published an article on this very topic , examining how tree planting can resurrect or devastate ecosystems, depending on what species are planted and where.

To be sure, people need wood and other tree products for all kinds of reasons, and sometimes nonnative species make sense. But even when the professed goal is to help nature, the commercial benefits of certain trees, like Australian eucalyptus in Africa and South America or North American Sitka spruce in Europe, often win out.

A new standard is in development that would score tree planting projects on how well they’re doing with regard to biodiversity, with the aim of helping those with poor scores to improve.

The same ecological benefit of planting native species also holds true for people’s yards. Doug Tallamy, a professor of entomology at the University of Delaware, worked with the National Wildlife Federation to develop this tool to help people find native trees, shrubs and flowers that support the most caterpillars, which in turn feed baby birds .

Can we engineer solutions to atmospheric warming?

Why are we not investing in scalable solutions that can remove carbon or reduce solar radiation? — Hayes Morehouse, Hayward, Calif.

By Henry Fountain

As a group, these types of solutions are referred to as geoengineering, or intentional manipulation of the climate. Geoengineering generally falls into two categories: removing some of the carbon dioxide already in the atmosphere so Earth traps less heat, known as direct air capture, or reducing how much sunlight reaches Earth’s surface so that there is less heat to begin with, usually called solar radiation management.

There are a few companies developing direct air capture machines, and some have deployed them on a small scale. According to the International Energy Agency, these projects capture a total of about 10 thousand tons of CO2 a year, a tiny fraction of the roughly 35 billion tons of annual energy-related emissions. Removing enough CO2 to have a climate impact would take a long time and require many thousands of machines, all of which would need energy to operate.

The captured gas would also have to be securely stored to keep it from re-entering the atmosphere. Those hurdles make direct air capture a long shot, especially since, for now at least, there are few financial incentives to overcome them. No one wants to pay to remove carbon dioxide from the air and bury it underground.

Solar radiation management is a different story. The basics of how to do it are known: inject some kind of chemical (perhaps sulfur dioxide) into the upper atmosphere, where it would reflect more of the sun’s rays. Relatively speaking, it wouldn’t be all that expensive (a fleet of high-flying planes would probably suffice) although once started it would have to continue indefinitely.

The major hurdle to developing the technology has been grave concern among many scientists, policymakers and others about unintended consequences that might result, and about the lack of a structure to govern its deployment. To date, there have been almost no real-world studies of the technology .

How do we know how warm the planet was in the 1800s?

One key finding of climate science is that global temperatures have increased by 2 degrees Fahrenheit since the late 1800s. How can we possibly have reliable measures of global temperatures from back then, keeping in mind that oceans cover about 70 percent of the globe and that a large majority of land has never been populated by humans to any significant degree? — Robert, Madison, Wis.

The mercury thermometer was invented in the early 1700s, and by the mid- to late 19th century, local temperatures were being monitored continuously in many locations, predominantly in the United States, Europe and the British colonies. By 1900, there were hundreds of recording stations worldwide, but over half of the Southern Hemisphere still wasn’t covered. And the techniques could be primitive. To measure temperatures at the sea’s surface, for instance, the most common method before about 1940 was to toss a bucket overboard a ship, haul it back up with a rope and read the temperature of the water inside.

To turn these spotty local measurements into estimates of average temperatures globally, across both land and ocean, climate scientists have had to perform some highly delicate analysis . They’ve used statistical models to fill in the gaps in direct readings. They’ve taken into account when weather stations changed locations or were situated close to cities that were hot for reasons unrelated to larger temperature trends.

They have also used some clever techniques to try to correct for antiquated equipment and methods. Those bucket readings , for example, might be inaccurate because the water in the bucket cooled down as it was pulled aboard. So scientists have scoured various nations’ maritime archives to determine what materials their sailors’ buckets were made of — tin, wood, canvas, rubber — during different periods in history and adjusted the way they incorporate those temperature recordings into their computations.

Such analysis is fiendishly tricky. The numbers that emerge are uncertain estimates, not gospel truth. Scientists are working constantly to refine them. Today’s global temperature measurements are based on a much broader and more quality-controlled set of readings, including from ships and buoys in the oceans.

But having a historical baseline, even an imperfect one, is important. As Roy L. Jenne, a researcher at the National Center for Atmospheric Research, wrote in a 1975 report on the institution’s collections of climate data: “Although they are not perfect, if they are used wisely they can help us find answers to a number of problems.”

Does producing batteries for electric cars damage the environment more than gas vehicles do?

Is the environmental damage collecting metals/producing batteries for electric cars more dangerous to the environment than gas powered vehicles? — Sandy Rogers, San Antonio, Texas

By Hiroko Tabuchi

There’s no question that mining the metals and minerals used in electric car batteries comes with sizable costs that are not just environmental but also human.

Much of the world’s cobalt, for example, is mined in the Democratic Republic of Congo , where corruption and worker exploitation has been widespread. Extracting the metals from their ores also requires a process called smelting, which can emit sulfur oxide and other harmful air pollution.

Beyond the minerals required for batteries, electric grids still need to become much cleaner before electric vehicles are emissions free.

Most electric vehicles sold today already produce significantly fewer planet-warming emissions than most cars fueled with gasoline, but a lot still depends on how much coal is being burned to generate the electricity they use.

Still, consider that batteries and other clean technology require relatively tiny amounts of these critical minerals, and that’s only to manufacture them. Once a battery is in use, there are no further minerals necessary to sustain it. That’s a very different picture from oil and gas, which must constantly be drilled from the ground, transported via pipelines and tankers, refined and combusted in our gasoline cars to keep those cars moving, said Jim Krane, a researcher at Rice University’s Baker Institute for Public Policy in Houston. In terms of environmental and other impacts, he said, “There’s just no comparison.”

How close are alternatives to fuel-powered aircraft?

As E. V.s are to gas-powered cars, are there greener alternatives to fuel-powered planes that are close to commercialization? — Rashmi Sarnaik, Boston

There are alternatives to fossil-fuel-powered aircraft in development, but whether they are close to commercialization depends on how you define “close.” It’s probably fair to say that the day when a significant amount of air travel is on low- or zero-emissions planes is still far-off.

There has been some work on using hydrogen , including burning it in modified jet engines. Airbus and the engine manufacturer CFM International expect to begin flight testing a hydrogen-fueled engine by the middle of the decade.

As with cars, though, most of the focus in aviation has been on electric power and batteries. The main problem with batteries is how little energy they supply relative to their weight. In cars that’s less of an obstacle (they don’t have to get off the ground, after all) but in aviation, batteries severely limit the size of the plane and how far it can fly.

One of the biggest battery-powered planes to fly so far was a modified Cessna Grand Caravan, test-flown by two companies, Magnix and Aerotec. Turboprop Grand Caravans can carry 10 or more people up to 1,200 miles. The companies said theirs could fly four or five people 100 miles or less.

The limitations of batteries, at least for now, have led some companies to work on other designs. Some use fuel cells, which work like batteries but can continuously supply electricity using hydrogen or other fuel. Others use hybrid systems — like hybrid cars, combining batteries and fossil-fuel-powered engines. In one approach, the engines provide some power and also keep the batteries charged. In another, the engines are used in takeoff and descent, when more power is needed, and the batteries for cruising, which requires less power. That keeps the number of batteries, and the weight, down.

Can countries meet the goals they set in the Paris agreement?

What countries, if any, have a realistic chance of meeting their Paris agreement pledges? — Michael Svetly, Philadelphia

According to Climate Action Tracker , a research group that analyzes climate goals and policies, very few. Ahead of United Nations talks in Glasgow last year, the organization found most major emitters of carbon dioxide, including the United States and China, are falling short of their pledge to stabilize global warming around 1.5 degrees Celsius, or 2.7 degrees Fahrenheit.

A few are doing better than most, including Costa Rica and the United Kingdom. Just one country was on track to meet its promises: Gambia, a small West African nation that has been bolstering its renewable energy use.

What will happen to N.Y.C.?

How is N.Y.C. planning for relocation or redevelopment, or both, of its many low-lying neighborhoods as floodwaters become too high to levee? — A reader in North Bergen, N.J.

New York City has yet to announce plans to fully relocate entire neighborhoods threatened by climate change, with all the steps that would entail: determining which homes to buy, getting agreement from homeowners, finding a new patch of land for the community, building new infrastructure, securing funding and so on.

Relocation projects on that scale, often described as “managed retreat,” remain extremely rare in the United States. What projects have been attempted so far have mostly been in rural areas or small towns , and their success has been mixed.

And the idea of pulling back from the water, while never easy, is especially fraught in New York City, which has some of the highest real estate values in the country. Those high values have been used to justify fantastically expensive projects to protect low-lying land in the city, rather than abandon it — like a $10 billion berm along the South Street Seaport , or a $119 billion sea wall in New York Harbor .

Perhaps unsurprisingly, then, the city’s most recent Comprehensive Waterfront Plan , issued in December, makes no mention of managed retreat. But the plan does include what it calls “housing mobility” — policies aimed at helping individual households move to safer areas, for example by giving people money to buy a new home on higher ground, as well as paying for moving and other costs. The city also says it is limiting the density of new development in high-risk areas.

Robert Freudenberg, a vice president of the Regional Plan Association, a nonprofit planning group in New York, New Jersey and Connecticut, gave city officials credit for beginning to talk about the idea that some areas can’t be protected forever.

“It’s an extremely challenging topic,” Mr. Freudenberg said. But as flooding gets worse, he added, “we can’t not talk about it.”

As oceans rise, will the Great Lakes, too?

The oceans are predicted to rise and affect coastal areas and cities, however, does this rise also affect the coastal areas of the Great Lakes, as the lakes are connected to the Atlantic Ocean via the St. Lawrence River and one would have to assume they would eventually be impacted? — Terri Messinides, Madison, Wis.

The Great Lakes are not directly threatened by rising oceans because of their elevation: The lowest of them, Lake Ontario, is about 240 feet above sea level. The St. Lawrence River carries water from the lakes to the Atlantic Ocean, but because of the elevation change, rising waters in the Atlantic can’t travel in the other direction.

That said, climate change is causing increasingly frequent and intense storms in the Great Lakes region, and the effects, including higher water levels and more flooding, are in many respects the same as those caused by rising seas. It’s just a different manifestation of climate change.

When it comes to precipitation, the past five years, from April 2017 through March 2022, the last month for which complete data is available, have been the second-wettest on record for the Great Lakes Basin, according to records kept by the National Oceanic and Atmospheric Administration . The water has risen accordingly. In 2019, water levels in the lakes hit 100-year highs , causing severe flooding and shoreline erosion.

At the same time, higher temperatures increase the rate of evaporation, which can lead to abnormally low water levels. People who live around the Great Lakes can expect to see both extremes — high water driven by severe rainfall, and low water driven by evaporation — happen more often as the climate continues to warm.

What is the environmental cost of cryptocurrency?

Can you tell us about the damage being done to our environment by crypto mining? I’ve heard the mining companies are trying to switch to renewable energy, yet at the same time reopening old coal power plants to provide the huge amounts of electricity they need. — Barry Engelman, Santa Monica, Calif.

Cryptomining, the enigmatic way in which virtual cryptocurrencies like Bitcoin are created (and which is also behind technology like NFTs ), requires a whole lot of computing power, is highly energy-intensive and generates outsize emissions. We delved into that process, and its environmental impact in this article — but suffice to say the problem isn’t going away soon.

The way Bitcoin is set up, using a process called “proof of work,” means that as interest in cryptocurrencies grows and more people start mining, more energy is required to mine a single Bitcoin. Researchers at Cambridge University estimate that mining Bitcoin uses more electricity than midsize countries like Norway. In New York, an influx of Bitcoin miners has led to the reopening of mothballed power plants.

But you might wonder about the traditional financial system: doesn’t that use energy, too? Yes, of course. But Bitcoin, for all its hype, still makes up just a few percent of all the world’s money or its transactions. So even though one industry study estimated that Bitcoin consumes about a 10th of the energy required by the traditional banking system, that still means Bitcoin’s energy use is outsize.

To address its high emissions footprint, cryptomining has increasingly tapped into renewable forms of energy, like hydroelectric power. But figuring out exactly just how much renewable energy Bitcoin miners use can be tricky. For one, we don’t exactly know where many of these miners are. We do know a lot of crypto miners used to be in China, where they had access to large amounts of hydro power. But now that they’ve largely been kicked out, cryptomining’s global climate impact has likely gotten worse .

In the United States, cryptominers have started to tap an unconventional new energy source: drilled gas, collected at oil and gas wells. The miners argue that this gas would otherwise have been flared or vented into the atmosphere, so no excess emissions are created. The reality is not that clear cut: If the presence of those cryptominers disincentivizes oil and gas companies from piping away that gas to be used elsewhere, any savings effect is blunted.

Other efforts are afoot to make cryptomining less damaging for the environment, including an alternative way of cryptomining involving a process called “proof of stake,” that doesn’t require miners to use as much energy. But unless Bitcoin, the most popular cryptocurrency, switches over, that’s going to do little to dent miners’ energy use.

How much do volcanoes contribute to global warming?

What does the data look like for greenhouse gas emissions in the last 200 years if volcanic activity was subtracted out? — Haley Rowlands, Boston

Volcanic activity generates 130 million to 440 million tons of carbon dioxide per year, according to the United States Geological Survey . Human activity generates about 35 billion tons of carbon dioxide per year — 80 times as much as the high-end estimate for volcanic activity, and 270 times as much as the low-end estimate. And that’s carbon dioxide. Human activity also emits other greenhouse gases, like methane, in far greater quantities than volcanoes.

The largest volcanic eruption in the past century was the 1991 eruption of Mount Pinatubo in the Philippines; if an explosion that size happened every day, NASA has calculated , it would still release only half as much carbon dioxide as daily human activity does. The annual emissions from cement production alone, one small component of planet-warming human activity, are greater than the annual emissions from every volcano in the world.

There is also no evidence that volcanic activity has increased over the past 200 years. While there have been more documented eruptions, researchers at the Smithsonian Institution’s Global Volcanism Program found that this was attributable not to an actual trend, but rather to “increases in populations living near volcanoes to observe eruptions and improvements in communication technologies to report those eruptions.”

All told, volcanic activity accounts for less than 1 percent of greenhouse gas emissions, which is not enough to contribute in any meaningful way to the increase we’ve seen over the past 200 years. The Intergovernmental Panel on Climate Change found in 2013 (see Page 56 of its report ) that the climatic effects of volcanic activity were “inconsequential” over the scale of a century.

Do carbon dioxide concentrations vary around the globe?

Why is the concentration of carbon dioxide in the atmosphere at Mauna Loa Observatory in Hawaii used as the global reference? It’s only one point on Earth. Do concentrations vary between different parts of the world? — Evan, Boston

At any given moment, levels of carbon dioxide in the air vary from place to place, depending on the amount of vegetation and human activity nearby. Which is why, as a location to monitor the average state of the atmosphere, at least over a large part of the Northern Hemisphere, a barren volcano in the middle of the Pacific has much to offer. It’s high above the ground and far enough from major sources of industrial pollution but still relatively accessible to researchers.

Today, the National Oceanic and Atmospheric Administration studies global carbon dioxide levels by looking at readings from Mauna Loa Observatory and a variety of other sources. These include observatories in Alaska, American Samoa and the South Pole, tall towers across the United States, and samples collected by balloons, aircraft and volunteers around the world. ( Here’s a map of all those sites.)

NOAA also checks its measurements at Mauna Loa against others from the same location, including ones taken independently, using different methods, by the Scripps Institution of Oceanography . On average, the difference in their monthly estimates is tiny.

Could a ‘new ice age’ offset global warming?

Will increases in global temperature associated with climate change be mitigated by the coming of a new “ice age?” — Suzanne Smythe, Essex, Conn.

In a “mini ice age,” if it occurred, average worldwide temperatures would drop, thus offsetting the warming that has been caused by emissions of greenhouse gases from the burning of fossil fuels in the last century and a half.

It’s a nice thought: a natural phenomenon comes to our rescue. But it’s not happening, nor is it expected to.

The idea is linked to the natural variability in the amount of the sun’s energy that reaches Earth. The sun goes through regular cycles, lasting about 11 years, when activity swings from a minimum to a maximum. But there are also longer periods of reduced activity, called grand solar minimums. The last one began in the mid-17th century and lasted seven decades.

There is some debate among scientists whether we are entering a new grand minimum . But even if we are, and even if it lasted for a century, the reduction in the sun’s output would not have a significant effect on temperatures. NASA scientists, among others, have calculated that any cooling effect would be overwhelmed by the warming effect of all the greenhouse gases we have pumped, and continue to pump, into the atmosphere.

Essay Service Examples Environment Global Warming

Cause and Effect Essay on Global Warming

Table of contents

Global warming essay 1 (100 words), global warming essay 2 (150 words), introduction, the problem of global warming, global warming essay 3 (200 words), what is global warming, reasons for global warming, global warming essay 4 (500 words), what are the causes of global warming, how can you reduce global warming, global warming essay 5 (600 words), what are the global warming factors, how can global warming be stopped, how can global warming be lowered, global warming essay 6 (2500 words), causes of global warming, effects of global warming on human health, dengue fever, asthma, dysentery, ebola, lyme, sleeping sickness and intestinal parasites, other effects on health, opposing opinions, solutions to global warming.

• Proper editing and formatting
• Free revision, title page, and bibliography
• Flexible prices and money-back guarantee

• Transition to Renewable Energy: Shifting from fossil fuels to clean and renewable energy sources, such as solar, wind, and hydropower, can significantly reduce greenhouse gas emissions. Encouraging the adoption of renewable energy through government policies and incentives, as well as supporting research and development in this field, is crucial.
• Energy Efficiency: Improving energy efficiency in homes, industries, and transportation can lower energy consumption and, consequently, greenhouse gas emissions. This can be achieved through measures such as using energy-efficient appliances, properly insulating buildings, promoting public transportation, and adopting fuel-efficient vehicles.
• Sustainable Land Use and Forest Conservation: Protecting and restoring forests is essential in combating global warming. Trees absorb CO2 and release oxygen, acting as natural carbon sinks. Reducing deforestation and implementing sustainable land use practices, such as afforestation and reforestation, can help mitigate the impacts of climate change.
• Waste Reduction and Recycling: The improper disposal of waste, particularly organic waste in landfills, leads to the release of methane, a potent greenhouse gas. Encouraging waste reduction, recycling, and composting can significantly reduce methane emissions and contribute to combating global warming.
• Climate-Friendly Agriculture: Implementing sustainable agricultural practices, such as precision farming, agroforestry, and organic farming, can minimize greenhouse gas emissions from the agricultural sector. These practices also help improve soil health, water conservation, and biodiversity.
• Education and Awareness: Raising awareness about the causes and consequences of global warming is crucial. Education empowers individuals to make informed choices, adopt sustainable practices, and demand policy changes that prioritize climate action. Governments, educational institutions, and civil society organizations should collaborate to promote climate literacy at all levels.
• Greenhouse Gas Emissions: The primary factor driving global warming is the excessive release of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) into the atmosphere. These gases trap heat from the sun, resulting in a gradual rise in Earth's temperature.
• Deforestation: The rampant destruction of forests contributes significantly to global warming. Trees act as carbon sinks, absorbing CO2 from the atmosphere. However, deforestation disrupts this balance, releasing stored carbon back into the atmosphere and reducing the planet's capacity to absorb greenhouse gases.
• Industrial Activities: The burning of fossil fuels, including coal, oil, and natural gas, for energy production and transportation is a major source of greenhouse gas emissions. The combustion process releases vast amounts of CO2, exacerbating the greenhouse effect and intensifying global warming.
• Transition to Renewable Energy Sources: Shifting away from fossil fuels and investing in renewable energy technologies is crucial in combating global warming. Governments and businesses must prioritize the development and adoption of clean energy alternatives such as solar, wind, and hydroelectric power. Incentives and subsidies can encourage the rapid transition to sustainable energy systems.
• Energy Efficiency and Conservation: Reducing energy consumption through improved efficiency and conservation measures can play a significant role in curbing global warming. Promoting energy-efficient appliances, implementing building codes that encourage energy conservation, and raising awareness about responsible energy usage are effective strategies to minimize greenhouse gas emissions.
• Reforestation and Forest Conservation: Protecting existing forests and undertaking large-scale reforestation efforts are vital to combat global warming. Trees absorb CO2 and release oxygen, acting as natural carbon sinks. Governments should implement policies that discourage deforestation and promote sustainable land management practices. Additionally, afforestation programs can help restore degraded ecosystems and enhance carbon sequestration.
• Sustainable Agriculture Practices: The agricultural sector is a significant contributor to global warming through practices such as excessive fertilizer use and livestock methane emissions. Implementing sustainable farming techniques, such as precision agriculture and organic farming, can reduce greenhouse gas emissions and promote soil health. Additionally, promoting plant-based diets can help reduce methane emissions from livestock.
• Transportation Reforms: The transportation sector is a major source of greenhouse gas emissions. Encouraging the adoption of electric vehicles, improving public transportation infrastructure, and promoting alternative modes of transportation like cycling and walking can significantly reduce carbon emissions. Governments should also invest in the development of sustainable fuels and promote fuel efficiency standards.
• International Cooperation: Global warming is a global challenge that requires collective action. Governments, international organizations, and civil society must collaborate to establish binding agreements and frameworks to reduce greenhouse gas emissions. Initiatives such as the Paris Agreement serve as crucial platforms for international cooperation, aiming to limit global temperature rise and foster resilience to climate change.

Frequently Asked Questions

How to prevent global warming?

To prevent global warming, we must reduce greenhouse gas emissions by transitioning to renewable energy sources, such as solar and wind power. Additionally, we should promote energy efficiency, conserve resources, protect forests, and adopt sustainable practices in agriculture and transportation. Global cooperation and individual actions are crucial in mitigating climate change.

Our writers will provide you with an essay sample written from scratch: any topic, any deadline, any instructions.

Cite this paper

Related essay topics.

Get your paper done in as fast as 3 hours, 24/7.

Related articles

Most popular essays

• Global Warming
• Macroeconomics

The Paris Accord, which is a worldwide agreement among nations, is intended to counter the effects...

• Climate Change

Global teenage climate activists and over 4 million people around the globe went on a strike last...

In the words of Stephen Hawking, the universe was formed as the result of a “happy accident”. Life...

• Carbon Dioxide

Climate change isn’t just bad for the planet’s health, it's bad for people’s too. Since many...

• Transportation

Most of the world's airports were designed before when the global temperature was not as high as...

Global warming is highly controversial issue in this global world where each country facing...

'Global warming isn’t a prediction. It is happening', by James Hansen. Based on this quote, global...

There are multiple climate change indicators that we can easily associate global warming with,...

• Greenhouse Gas

The modern world faced the problem of global warming which is considered to be the growth of...

Join our 150k of happy users

• Get original paper written according to your instructions
• Save time for what matters most

Fair Use Policy

EduBirdie considers academic integrity to be the essential part of the learning process and does not support any violation of the academic standards. Should you have any questions regarding our Fair Use Policy or become aware of any violations, please do not hesitate to contact us via [email protected].

We are here 24/7 to write your paper in as fast as 3 hours.

Provide your email, and we'll send you this sample!

By providing your email, you agree to our Terms & Conditions and Privacy Policy .

Say goodbye to copy-pasting!

Get custom-crafted papers for you.

Enter your email, and we'll promptly send you the full essay. No need to copy piece by piece. It's in your inbox!

• Biology Article
• Essay on Global Warming

Essay On Global Warming

Essay on global warming is an important topic for students to understand. The essay brings to light the plight of the environment and the repercussion of anthropogenic activities. Continue reading to discover tips and tricks for writing an engaging and interesting essay on global warming.

Essay On Global Warming in 300 Words

Global warming is a phenomenon where the earth’s average temperature rises due to increased amounts of greenhouse gases. Greenhouse gases such as carbon dioxide, methane and ozone trap the incoming radiation from the sun. This effect creates a natural “blanket”, which prevents the heat from escaping back into the atmosphere. This effect is called the greenhouse effect.

Contrary to popular belief, greenhouse gases are not inherently bad. In fact, the greenhouse effect is quite important for life on earth. Without this effect, the sun’s radiation would be reflected back into the atmosphere, freezing the surface and making life impossible. However, when greenhouse gases in excess amounts get trapped, serious repercussions begin to appear. The polar ice caps begin to melt, leading to a rise in sea levels. Furthermore, the greenhouse effect is accelerated when polar ice caps and sea ice melts. This is due to the fact the ice reflects 50% to 70% of the sun’s rays back into space, but without ice, the solar radiation gets absorbed. Seawater reflects only 6% of the sun’s radiation back into space. What’s more frightening is the fact that the poles contain large amounts of carbon dioxide trapped within the ice. If this ice melts, it will significantly contribute to global warming. 

A related scenario when this phenomenon goes out of control is the runaway-greenhouse effect. This scenario is essentially similar to an apocalypse, but it is all too real. Though this has never happened in the earth’s entire history, it is speculated to have occurred on Venus. Millions of years ago, Venus was thought to have an atmosphere similar to that of the earth. But due to the runaway greenhouse effect, surface temperatures around the planet began rising. 

If this occurs on the earth, the runaway greenhouse effect will lead to many unpleasant scenarios – temperatures will rise hot enough for oceans to evaporate. Once the oceans evaporate, the rocks will start to sublimate under heat. In order to prevent such a scenario, proper measures have to be taken to stop climate change.

More to Read: Learn How Greenhouse Effect works

Tips To Writing the Perfect Essay

Consider adopting the following strategies when writing an essay. These are proven methods of securing more marks in an exam or assignment.

• Begin the essay with an introductory paragraph detailing the history or origin of the given topic.
• Try to reduce the use of jargons. Use sparingly if the topic requires it.
• Ensure that the content is presented in bulleted points wherever appropriate.
• Insert and highlight factual data, such as dates, names and places.
• Remember to break up the content into smaller paragraphs. 100-120 words per paragraph should suffice.
• Always conclude the essay with a closing paragraph.

Explore more essays on biology or other related fields at BYJU’S.

Leave a Comment Cancel reply

Your Mobile number and Email id will not be published. Required fields are marked *

Request OTP on Voice Call

Post My Comment

Very helpful Byju’s

this app is very useful

Sample essay on global warming

Very nice and helpful⭐️

Amazing essay

This essay is very helpful to every student Thank you Byjus! 😊😊😊

This one is so helpful and easy to understand. Thank you, Byju’s!

Register with BYJU'S & Download Free PDFs

Register with byju's & watch live videos.

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
• Open access
• Published: 13 August 2024

Reducing climate change impacts from the global food system through diet shifts

• Yanxian Li   ORCID: orcid.org/0000-0002-1947-7541 1 ,
• Pan He   ORCID: orcid.org/0000-0003-1088-6290 2 , 3 ,
• Yuli Shan   ORCID: orcid.org/0000-0002-5215-8657 4 ,
• Ye Hang   ORCID: orcid.org/0000-0002-1368-905X 4 ,
• Shuai Shao   ORCID: orcid.org/0000-0002-9525-6310 6 ,
• Franco Ruzzenenti 1 &
• Klaus Hubacek   ORCID: orcid.org/0000-0003-2561-6090 1  

Nature Climate Change ( 2024 ) Cite this article

2744 Accesses

154 Altmetric

Metrics details

• Climate-change impacts
• Climate-change mitigation

How much and what we eat and where it is produced can create huge differences in GHG emissions. On the basis of detailed household-expenditure data, we evaluate the unequal distribution of dietary emissions from 140 food products in 139 countries or areas and further model changes in emissions of global diet shifts. Within countries, consumer groups with higher expenditures generally cause more dietary emissions due to higher red meat and dairy intake. Such inequality is more pronounced in low-income countries. The present global annual dietary emissions would fall by 17% with the worldwide adoption of the EAT-Lancet planetary health diet, primarily attributed to shifts from red meat to legumes and nuts as principal protein sources. More than half (56.9%) of the global population, which is presently overconsuming, would save 32.4% of global emissions through diet shifts, offsetting the 15.4% increase in global emissions from presently underconsuming populations moving towards healthier diets.

Similar content being viewed by others

Simple dietary substitutions can reduce carbon footprints and improve dietary quality across diverse segments of the US population

The ongoing nutrition transition thwarts long-term targets for food security, public health and environmental protection

Adoption of the ‘planetary health diet’ has different impacts on countries’ greenhouse gas emissions

Food choices impact both our health and the environment 1 , 2 . The food system is responsible for about one-third of global anthropogenic GHG emissions 3 , 4 and climate goals become unattainable without efforts to reduce food-related emissions 5 , 6 . However, not everyone contributes the same way to food-related emissions because of disparities in lifestyle, food preferences and affordability within and across countries 7 , 8 , 9 . High levels of food consumption (especially animal-based diets), one of the leading causes of obesity and non-communicable diseases 10 , 11 , lead to substantial emissions 9 , 12 . Simultaneously, >800 million people still suffer from hunger and almost 3.1 billion people cannot afford a healthy diet 13 . Ending hunger and malnutrition while feeding the growing population by extending food production will further exacerbate climate change 14 , 15 . Given the notable increase in emissions driven by food consumption despite efficiency gains 16 , changing consumer lifestyles and choices are needed to mitigate climate change 17 .

Research shows that widespread shifts towards healthier diets, aligned with the sustainable development goals (SDGs) of the United Nations 18 , offer solutions to this complex problem by eradicating hunger (SDG 2), ensuring health (SDG 3) and mitigating emissions (SDG 13) 19 , 20 , 21 , 22 . Numerous dietary options have been proposed as guidelines for diet shifts 1 , 23 , 24 . The planetary health diet 12 , proposed by the EAT-Lancet Commission, stands out as a prominent option. It aims to improve health while limiting the impacts of the food system within planetary boundaries by providing reference intake levels for different food categories 9 , 25 . It is flexibly compatible with diversities and preferences of regional and local diets 12 . Previous research has estimated changes in country-specific environmental impacts, including GHG emissions 26 , 27 , 28 and water consumption 25 , resulting from adopting the planetary health diet. However, there is limited evidence on how different population groups will contribute differently in this process 7 .

Food consumption and associated emissions differ as a result of disparities in consumer choices guided by social and cultural preferences, wealth and income 29 . Quantifying food-related emissions along the entire supply chain for different products and population groups provides information for emission mitigation through changing consumer choices 17 . With the improved availability of household consumption data, recent studies have revealed inequality in energy consumption 30 , 31 and carbon emissions 17 , 32 , 33 , 34 . Although there are several studies on income- or expenditure-specific food-related emissions within individual countries based on survey-based data 35 , 36 , 37 , 38 , previous studies have not assessed global food-related emissions with a detailed breakdown into specific products and population groups. Furthermore, reducing the overconsumption of wealthy or otherwise overconsuming groups can increase the availability of resources for reducing hunger and malnutrition 7 . However, it remains unclear how emissions from different population groups would change in response to global diet shifts.

To fill these gaps, this study evaluates GHG emissions (CO 2 , CH 4 and N 2 O) throughout the global food supply chains (including agricultural land use and land-use change, agricultural production and beyond-farm processes) 16 induced by diets, termed ‘dietary emissions’, in 2019 and the potential emission changes of global diet shifts. Food loss and waste during household consumption 25 , 39 , 40 have been subtracted from the national food supply to obtain dietary intake. We quantify dietary emissions of 140 products 16 (classified into 13 food categories 12 ) on the basis of the global consumption-based emissions inventory of detailed food products 16 . By linking detailed food intake amounts to the food consumption patterns of 201 global expenditure groups (grouped according to the per capita total expenditure of each group) from the household-expenditure dataset 41 based on the World Bank Global Consumption Database (WBGCD) 42 , we analyse the unequal distribution of dietary emissions in 139 countries or areas, covering 95% of the global population. Despite limitations, the total expenditure of consumers, which effectively reflects patterns in household income, consumption and asset accumulation, is a useful approximation to represent levels of income and wealth 31 , 43 . Additionally, we build a scenario of shifting from diets in 2019 to the global planetary health diet to estimate emission changes ( Methods ). This study investigates differences in dietary emissions among regions, countries and population groups, identifying areas where efforts are needed to mitigate emissions during the global transition towards a healthier and more planet-friendly diet.

Present dietary emissions across countries

In this study, dietary emissions account for emissions along the entire global food production supply chains, which are allocated to final consumers of diets. We use the term ‘GHG footprints’ to specifically refer to the dietary emissions of an individual over 1 year 17 , 34 . The total dietary emissions and country-average per capita GHG footprints show different distributions across countries in 2019 (Fig. 1a ; for detailed food categories see Supplementary Figs. 1 – 9 ). The present total global dietary emissions reach 11.4 GtCO 2 e (95% confidence interval 8.2–14.7 Gt) (details of uncertainty ranges in Supplementary Tables 1 and 2 ). China (contributing 13.5% of emissions) and India (8.9%), the world’s most populous countries (Supplementary Table 3 ), are the largest contributors to global dietary emissions. Alongside Indonesia, Brazil, the United States, the Democratic Republic of Congo, Pakistan, Russia, Japan and Mexico, the top ten contributors represent 57.3% of global dietary emissions but with very unequal per capita emissions within and between countries. We find the highest country-average per capita footprints in Bolivia, with 6.1 tCO 2 e, followed by Luxembourg, Slovakia, Mongolia, the Netherlands and Namibia, with >5.0 tCO 2 e (Supplementary Discussion 2.1 ). Haiti (0.36 tCO 2 e) and Yemen (0.38 tCO 2 e) have the lowest country-average footprints, followed by Burundi, Ghana and Togo. Insufficient food intake of residents due to limited food affordability 44 , 45 is the root cause of low footprints in these low- and lower-middle-income countries 46 .

a , Total and per capita dietary emissions for 139 countries/areas. b , Regional dietary emissions from different food categories and populations. The bar chart (left primary axis) shows the regional emission amounts and the line chart (right secondary axis) shows the number of regional populations. Columns are ordered by the descending per capita GDP of regions (Supplementary Tables 5 and 6 ). USA, United States; AUS, Australia; WE, Western Europe; CAN, Canada; JPN, Japan; RUS, Russia; ROEA, Rest of East Asia; EE, East Europe; CHN, China; ROO, Rest of Oceania; NENA, Near East and North Africa; BRA, Brazil; ROLAC, Rest of Latin America and the Caribbean; ROSEA, Rest of Southeast Asia; IDN, Indonesia; IND, India; ROSA, Rest of South Asia; and SSA, Sub-Saharan Africa. Details for the division and scope of regions are shown in Supplementary Fig. 10 and Supplementary Tables 7 and 8 . Country classification by income levels is based on the World Bank 46 . Credit: World Countries basemap, Esri ( https://hub.arcgis.com/datasets/esri::world-countries/about ).

Source data

While animal-based (52%) and plant-based (48%) products contribute nearly equally to global dietary emissions 4 , 16 , the latter accounts for 87% of calories in global diets (Supplementary Table 4 ). The three main sources of emissions, namely red meat (beef, lamb and pork) (5% of calories), grains (51%) and dairy products (5%), contribute to 29%, 21% and 19% of global emissions, respectively. The substantial emissions from red meat and dairy products are attributed to their considerably higher emissions per unit of calories compared to other categories (Supplementary Table 4 ).

To highlight emission differences at a regional level, we further group the country-level results into 18 regions according to geographical locations and development levels (Fig. 1b and Supplementary Fig. 10 ). In most regions, animal-based products contribute fewer calories (less than a quarter) (Supplementary Data 21 ) but yield more emissions than plant-based products, especially in Australia (84% from animal-based products), the United States (71%) and the region Rest of East Asia (71%) where residents excessively consume both red meat and dairy products. However, the consumption of plant-based products in Indonesia (83% of total calories), Rest of Southeast Asia (92%) and Sub-Saharan Africa (77%) accounts for the most emissions, at 92%, 73% and 64%, respectively. Southeast Asia including Indonesia has a high-emission proportion from grains (42%) due to the prevalent meals dominated by rice. The typical food basket in Sub-Saharan Africa is broadly made up of grains, tubers, legumes and nuts 25 , 47 , representing over half of the regional emissions.

Unequal distribution of dietary emissions within countries

We find substantial differences in per capita GHG footprints within countries and regions. To clearly present the distribution of footprints within each country and region, individuals are sorted in ascending order of their total expenditure levels and then sequentially allocated to ten expenditure deciles with equal population size (Supplementary Fig. 11 and Fig. 2a ). As expenditures increase, individuals tend to have higher levels of footprints, with the largest increase attributed to red meat and dairy products. Richer populations usually have higher per capita footprints related to animal-based products than the poorer in most regions (Fig. 2b ). However, there are differences in per capita footprints within expenditure deciles. For example, even in high-income countries such as Australia and Japan, the dietary intake of red meat for some people in the poorest deciles falls below the recommended levels (Supplementary Data 15 ). Rest of East Asia is one exception, with the poorest decile having high footprints due to a substantial intake of red meat, as seen in Mongolia where beef and mutton are the most common dish 48 .

a , GHG footprints from all types of food categories. The size of the bubble refers to the average total expenditure represented by the decile. b , GHG footprints from different food categories. The colours of bubbles in a and b indicate expenditure deciles ranging from the poorest in blue to the wealthiest in red and are comparable only within each region.

Footprints related to plant-based products in specific regions show a different trend from animal-based products as expenditures increase. The middle expenditure groups are responsible for the highest footprints associated with grains in Sub-Saharan Africa and Southeast Asia and the highest footprints of tubers, vegetables and fruits (mainly starchy tropical fruits 49 ) in the Rest of Oceania. These locally produced, high-carbohydrate products are traditional staple foods. In poor countries, agricultural policy primarily targets improving the productivity of staple food, with little investment in the market and facilities for nutrient-rich products 50 , 51 . Consequently, the need for dietary diversity for middle- and low-income people is not adequately addressed 50 , leading to increased consumption of these lower-cost products. However, wealthier consumers can afford more expensive products, such as red meat, reducing their reliance on these staple products.

We use the GHG footprint Gini (GF-Gini) coefficient, calculated on the basis of data from 201 expenditure groups, to measure the dietary emission inequality within a country (Fig. 3 ), with 0 indicating perfect equality and 1 indicating perfect inequality. The inequality of dietary emissions tends to decline with the increase of the per capita GDP of a country, especially for animal-based products. We find the highest inequality of dietary emissions of food products generally in low-income countries, most of which are located in Sub-Saharan Africa. In Sub-Saharan Africa, the highest spending 10% of the population contributes 40% of the regional emissions from red meat, 39% from poultry and 35% from dairy products. In contrast, high-income countries generally have relatively low inequality with high levels of emissions despite country-to-country variations. The GF-Gini coefficients for all types of products of most Western European countries are <0.20 (Supplementary Tables 9 and 10 ), which is lower than for other high-income countries such as the United States, Australia, Canada and Japan.

a – j , The x axis represents the country-average per capita GDP, and the y axis represents the national GF-Gini coefficients of all types of ( a ) and different ( b – j ) food categories. b , Beef, lamb and pork. c , Dairy products. d , Poultry, eggs and fish. e , Grains. f , Tubers and starchy vegetables. g , Vegetables and fruits. h , Legumes and nuts. i , Added fats. j , All sugars. Logarithmic regression (red solid line) and locally weighted regression analysis (blue dotted line) are used to determine the relationship between the national GF-Gini coefficient (dependent variable) and the country-average per capita GDP (independent variable). The coefficients of determination ( R 2 ) and the exact P values from the two-sided Student’s t -test for the logarithmic regression are indicated in each subgraph. The error bands (grey shaded areas) represent 95% confidence intervals around the fitted logarithmic regression lines. Blue, orange and green dots represent all types of products, animal-based products and plant-based products, respectively.

Dietary emission shares across consumer groups

There are notable differences in dietary emission shares associated with food categories across expenditure deciles between regions (Fig. 4 ). In high-income countries, expenditure groups have relatively similar patterns of dietary emissions, with large shares of red meat and dairy products contributing the largest amount of emissions. Even poor consumer groups in high-income countries tend to be more likely to be able to afford animal-based products as a result of relatively lower prices for dairy products, eggs, white meat and processed red meat. This contrasts with the high prices of animal-based products due to supply constraints in most low- and lower-middle-income countries 52 , 53 . Except in high-income countries, starchy staple foods (including grains and tubers), with low prices but high-carbohydrate content 44 , 54 , constitute a large proportion of dietary emissions because of the high level of consumption, especially in Southeast Asia and Sub-Saharan Africa. As individuals’ expenditures increase in these countries, emission shares from starchy staple foods in total emissions decrease substantially. These changes demonstrate that as the affordability of food increases, populations tend to adopt instead more diverse diets composed of fewer starchy staple foods and more meat, dairy products, vegetables and fruits. This trend generally aligns with Bennett’s Law 25 , 55 , 56 . For example, research shows that with rapid economic growth, China’s urban or high-income groups increase their intake of non-starchy foods to fulfil their requirements of dietary diversity 35 , while poorer groups, often engaging in strenuous physical jobs, predominantly consume inexpensive starchy staple foods. One exception is Rest of Oceania, where poorer groups have higher percentages of emissions from not only tubers but also vegetables and fruits. Owing to relatively low expenditure on food, poor populations in this island region usually choose locally cultivated tubers and fruits (such as cassava, taro and bananas) 57 , 58 with high intensities of land-use emissions 59 .

The numbers at the bottom of each bar represent the expenditure levels of regional expenditure deciles, ranging from the poorest (1) to the wealthiest (10). Food categories are shown in the colour legend. a , United States. b , Australia. c , Western Europe. d , Canada. e , Japan. f , Russia. g , Rest of East Asia. h , Eastern Europe. i , China. j , Rest of Oceania. k , NENA. l , Brazil. m , ROLAC. n , Rest of Southeast Asia. o , Indonesia. p , India. q , Rest of South Asia. r , Sub-Saharan Africa.

Emission changes from adopting the planetary health diet

To estimate the emission changes from a global diet shift, we build a hypothetical scenario by assuming that everyone in all countries adopts the planetary health diet ( Methods ). Results indicate that the global dietary emissions would decrease by 17% (1.94 (1.51–2.39) GtCO 2 e) compared with the 2019 level (details of the uncertainty ranges can be found in Supplementary Tables 11 and 12 ). The presently overconsuming groups (56.9% of the global population) would save 32.4% of global emissions through diet shifts, more than offsetting the 15.4% increase in global emissions from the presently underconsuming groups (43.1% of the global population) as a result of adopting healthier diets (Supplementary Table 13 ). National dietary emissions in 100 countries would decline by 2.88 GtCO 2 e, whereas the other 39 countries (mainly low- and lower-middle-income countries 46 in Sub-Saharan Africa and South Asia) would have an increase in emissions by 938 MtCO 2 e (Fig. 5a ; for detailed food categories see Supplementary Figs. 12 – 20 ).

a , Volume changes and percentage changes of national emissions for 139 countries/areas. b , Regional emission changes from different food categories. Abbreviations of 18 regions and the source of the base map are listed in Fig. 1 caption.

Countries would be affected differently regarding emission changes by adopting the planetary health diet, reflected in the percentage change in national emissions (Fig. 5a ). Uzbekistan (−74%), Australia (−70%), Qatar (−67%), Turkey (−65%) and Tajikistan (−64%) would see the largest percentage decrease. In comparison, most of the countries with an estimated considerable percentage increase are located in Sub-Saharan Africa and the Middle East, with the largest percentage increase from Iraq (+155%). Notably, with the increase in per capita GDP, the percentage change in overall dietary emissions of countries shows a shift from a positive to a negative trend, primarily led by changes in animal-based emissions (Supplementary Fig. 21 ).

Global emission reduction would be dominantly driven by red meat and grains (Fig. 5b ). The reduction in meat, eggs and fish would lead to 2.04 GtCO 2 e of emission reduction, of which 94% is driven by the decrease in red meat. China (22%), the United States (15%) and Brazil (14%) would be the largest contributors to emission reduction associated with a decrease in red meat consumption. A decline in grains would result in 914 MtCO 2 e of emission reduction, of which 56% would happen in Asia. A further 240 and 89 MtCO 2 e reduction in emissions would come from reduced sugars and tubers, respectively. However, increased proteins (legumes and nuts and dairy products), added fats and vegetables and fruits would partly offset the above-reduced emissions by 41%. Intake of legumes and nuts would increase in all regions, leading to a further 757 MtCO 2 e of emissions, whereas most of the emission increase related to added fats (largely vegetable oils) (279 Mt) and dairy products (143 Mt) would take place in Sub-Saharan Africa, China and other Asian countries. Global dietary emissions associated with vegetables and fruits would increase by 163 Mt, despite declines in China and Rest of Oceania.

The decline in per capita GHG footprints would be achieved primarily in wealthy consumer groups in high- and upper-middle-income countries, while increased footprints would occur mainly in poor groups in most countries (Fig. 6a ). Results show that the shifts of chief protein sources from animal-based to plant-based proteins according to the planetary health diet 12 would contribute the most to changes in footprints globally (Fig. 6b ). For example, in Australia, Brazil, Canada and the United States where diets are dominated by red meat and dairy products, the top and upper-middle expenditure groups would have notable reductions in footprints. However, most populations in South and Southeast Asia and Sub-Saharan Africa would have a considerable increase in footprints because of the present low levels of red meat intake. Meanwhile, the present intake of plant-based proteins in all countries is below the recommended level 25 . Footprints related to legumes and nuts would increase for most expenditure groups in all regions to meet nutrient demands. This increase is particularly substantial in Rest of Oceania, Brazil, Indonesia and Sub-Saharan Africa, where most of the consumed legumes and nuts are domestically produced with high land-use emission intensities 59 , 60 , assuming the present production and trade patterns remain unchanged.

a , Changes in GHG footprints from all types of food categories. The size of the bubble refers to the average total expenditure represented by the decile. b , Changes in GHG footprints from different food categories. The colours of bubbles in a and b indicate expenditure deciles ranging from the poorest in blue to the wealthiest in red and are comparable only within each region.

Discussion and conclusions

This study uncovers the extent of inequality of dietary emissions within countries based on detailed expenditure data 17 , 34 and underlines the dependence of dietary emissions on expenditure and income levels. Emissions aggregated at expenditure deciles may lose some fine-grained information from the 201 expenditure groups. For example, people from the lowest expenditure groups in affluent countries may experience malnutrition or even hunger, which is not adequately captured at a decile level. Nevertheless, the GF-Gini coefficient calculated from 201 groups provides an accurate reflection of emission inequality. Results show that affluent countries consume high-emission diets but show relatively lower levels of inequality, whereas many poor countries tend to have diets with lower emissions but higher levels of inequality.

The objective of the diet shift scenario is to assess the potential implications of emission mitigation of the food system resulting from changing consumer choices. Widespread diet shifts offer dual benefits by moving 43.1% of the global population out of underconsumption and mitigating 17% of global dietary emissions. The simulated changes in the volume of global emissions under the planetary health diet approximate the findings by ref. 26 (Supplementary Discussion 1 ). However, worldwide diet shifts require tailored policies targeted at regions, countries, expenditure groups and products instead of ‘one-size-fits-all’ policies.

We find that, compared to plant-based products, animal-based products, particularly red meat and dairy products, exhibit greater potential for reducing both emission volumes and emission disparities among different expenditure groups. Priorities lie in reducing the overconsumption of specific emission-intensive products in affluent countries (particularly the high-expenditure groups), such as beef in Australia and the United States, to achieve health 9 , 12 and climate benefits 25 , 26 , 28 . Incentives, such as implementing subsidies or taxation on environmental externalities through food or carbon pricing 61 , ecolabelling 62 and expanding the availability of less emission-intensive products (for instance, menu design for diverse vegetarian foods 63 ), can encourage consumers to make dietary changes. Moreover, a well-designed (primarily urban) food environment can reshape residents’ dietary patterns 35 and the parallel development of urban planning and infrastructure can alleviate the time and financial burdens of shifts to healthier diets 64 . However, in countries such as Mongolia, where diets heavily rely on red meat and dairy products because of their traditional nomadic lifestyle and limited accessibility of diverse foods, especially in rural areas 48 , diet shifts may not be feasible but there is a need to improve national nutritional education 48 .

Low-income countries face more severe challenges in reaching healthier diets. On the one hand, diet shifts require increased food consumption in these countries. For example, in Sub-Saharan Africa, the planetary health diet requires a 3.4-fold increase in dairy consumption for the entire population and a 69-fold increase for the poorest decile (Supplementary Fig. 22 ). However, Sub-Saharan Africa and South and Southeast Asia, which have experienced stagnating agriculture production efficiency for decades 8 , cannot produce domestically nor afford to import the food required for diet shifts 65 . It is crucial to enhance the production efficiency of feed and food crops through various measures such as crop and soil management techniques 8 , 66 and the introduction of high-yielding crop varieties and hybrids 67 , 68 . Moreover, increasing the proportions of nutrient-rich products in food imports 65 and reducing restrictive trade policies which tend to raise food prices 25 , 69 help to address this challenge. On the other hand, poor populations often opt for lower-cost, calorie-dense but less nutritionally beneficial foods. High cost and low affordability remain the largest barriers for these individuals to select healthier diets 44 , 54 , 70 , 71 . Others 44 found that >1.58 billion low-income populations worldwide cannot afford the cost of the planetary health diet. Therefore, policy efforts (for instance, pricing interventions 72 , technical assistance to reduce food production costs 73 and so on) should focus on making food more affordable and accessible, especially for lower expenditure groups 37 , 74 . However, studies indicate that lower food prices may decrease the income of agricultural households 75 , 76 , widen wealth gaps between individuals employed in food- and non-food sectors, especially in low-income agrarian countries and exacerbate rural poverty 1 , 77 . In this sense, policies aimed at promoting diet shifts should be deliberately and cautiously designed with vulnerable groups in mind to reduce inequality 37 , 61 .

Lastly, altered food demand due to diet shifts can induce notable structural adjustments within the global agri-food system. Although this study does not assess the feasibility of countries supplying sufficient food if the planetary health diet was adopted, results indicate that the composition of global food production would change considerably to adapt to the substantial changes in demand 8 , 25 , 77 . The diet shifts would necessitate the global supply (in calorie content) of red meat decrease by 81%, all sugars by 72%, tubers by 76% and grains by 50%, while that of legumes and nuts increase by 438%, added fats by 62% and vegetables and fruits by 28% (Supplementary Data 16 ). Research 77 , 78 confirms that changed food demand could cause fluctuating prices of agricultural products and land in global markets, triggering spillover effects between different food categories or to other non-food sectors (for example, stimulating biofuel production) and partly offsetting the benefits of diet shifts. Therefore, policy-making should focus on alleviating these effects. Incentives such as increased subsidies or tax breaks can generate new economic opportunities and motivations for industries that need to scale up production to meet the heightened demand for products (for example, plant-based proteins). By contrast, for emission-intensive food industries that need to downsize, measures such as gradual crop substitution 25 , 79 could be adopted to optimize production and reduce the costs of production transformations while safeguarding the interests of producers.

In this study, we first assess the GHG emissions from diets comprising 140 products 16 (Supplementary Table 14 ) in 139 countries or areas (we collectively use the term ‘country’ because most of them are individual countries) (Supplementary Data 1 ) in 2019 based on the global consumption-based emission inventory of detailed food products from ref. 16 . The inventory 16 provides data (in mass units) of GHG emissions (including CO 2 , CH 4 and N 2 O) generated during supply chain processes, including agricultural land use and land-use change (LULUC), agricultural activities and beyond-farm processes (excluding emissions from household and end of life) 4 . All emissions are allocated to final consumers of food products. The year 2019 (the latest year before the COVID-19 pandemic) is selected as a baseline year, which can reflect the level of present dietary intake without the interference of the pandemic 80 , 81 . Subsequently, dietary emissions from different expenditure groups are quantified by matching diets with the household-expenditure dataset 42 to reflect the differences and potential inequality of dietary emissions. Finally, to measure the magnitude of the emission impact of the global diet shift, we model the transition from diets in 2019 to the widespread adoption of the planetary health diet. The research framework of this study is shown in Supplementary Fig. 23 .

The following data sources are mainly used in this study. The consumption-based food emissions inventory 16 is based on data derived from the FAOSTAT 82 , comprising national emission accounts of supply chain processes and data on food trade and production. Data on food loss and waste throughout the global supply chain and at the household level as well as food supply data, all used for linking emissions with diets, are obtained from FAOSTAT 83 and previous research 25 , 39 . The household-expenditure data 41 are built on the basis of the WBGCD 42 and further refined and supplemented by consumer expenditure surveys from high-income countries 17 , 41 to bridge the dietary emissions with different expenditure groups. Detailed data sources used for calculation are provided in Supplementary Table 15 . Data processing, assumptions and uncertainties for all calculations are also given.

Dietary energy intake and emissions

Accounting of food consumption and supply chain emissions.

The estimation of the present dietary emissions and the emission changes for adopting the EAT-Lancet planetary health diet 12 is based on the accounting framework designed by ref. 16 . They assess global GHG emissions induced by the consumption of food products in 181 countries based on the physical trade flow approach 84 , 85 . Consumption-based GHG emissions along global supply chains, including local production and international trade, are calculated as follows 16 , 84 :

where E i,r refers to the consumption-based GHG emission of product i in country r . G i / P i represents the vector of direct emission intensity of product i from entire food supply chain processes, of which G i denotes total emissions generated from entire supply chain process of product i , P i is the production vector of product i . \({(I-{A}^{i})}^{-1}\) is the trade structure of product i , of which A i is the matrix of export shares and I is the identity matrix with the same dimension as matrix A i . DMI i refers to the vector of direct material input of product i and DMC i,r is the vector of domestic material consumption of product i in country r with values set to zero for other countries. The DMI of a country is defined as the total inputs of products and the DMC is defined as the amount of products consumed domestically. DMI equals DMC plus exports of products (or production plus imports). F i refers to the vector of total (or consumption-based) emission intensity of product i from food supply chain processes, that is, total emissions induced by per unit of domestic consumption of product i . All variables in equation ( 1 ) are in units of mass (metric tonnes).

Feed products are excluded from diets because emissions from feed crops have been allocated to livestock products that consume feed during production 16 . Food loss and waste (FLW) along supply chains and households are subtracted to quantify the net intake amount of food products from the household stage.

Dietary calorie conversions

We use the annual per capita food supply (FS) quantity of 140 food products from the supply utilization accounts of FAOSTAT 83 and population from the United Nations 86 to calculate the total supply amount of product i in country r (FS i,r , in the unit of mass):

where \({{\rm{FS}}}_{{\rm{per}}}^{i}\) denotes the per capita supply of product i per year and p r refers to the population in country r .

To be consistently matched with the DMC , the FS values should be limited within the coverage of the DMC and values that exceed this range are removed. At the same time, to aggregate food products into food categories and compare their nutritional contents with the reference level from the planetary health diet, we convert the quantity of food consumption or supply into calorie content using product-specific nutritive factors (calories per unit weight of product) 87 , 88 from FAO (Supplementary Table 14 ).

Subtracting food loss and waste at the household level

The food supply derived from FAOSTAT datasets does not exclude FLW that happens during household consumption 25 . FLW before dietary intake can be divided into two parts: the FLW during supply chain processes (including agricultural production, postharvest handling and storage, processing and packaging and distribution) as well as the FLW during the food preparation and supply for household consumption 39 , 40 . The food supply value provided by FAOSTAT only excludes FLW during supply chain processes. Therefore, we exclude household FLW using the method by ref. 25 to calculate the annual dietary intake for each product as follows:

where DI i,r and \({{\rm{DI}}}_{{\rm{per}}}^{i,r}\) refer to the national and per capita caloric intake amount of product i in country r each year, respectively. \({{\rm{FS}}}_{{\rm{energy}}}^{i,r}\) and \({{\rm{FS}}}_{{\rm{energy}\_per}}^{i,r}\) are the national and per capita supply quantity (in calorie content) of product i annually, respectively. Parameter \({f}_{{\rm{FLW}}}^{\;i,r}\) is the FLW factor in the household consumption stage 39 of food product i in country r . Others 39 provide regional FLW factors, expressed as the weight percentage of food that is lost or wasted at different stages of food production and consumption, for different food categories. As a result, household food waste is subtracted from the FS to obtain the dietary intake amount of each product. Detailed household FLW factors are shown in Supplementary Table 16 .

Quantifying dietary GHG emissions

Our equation ( 1 ) can be transformed into the following equation to calculate the total emission intensity of food calorie consumption:

where \({F}_{{\rm{energy}}}^{\,i,r}\) represents total emissions per unit of calorie content of product i in country r , \({{\rm{DMC}}}_{{\rm{energy}}}^{i,r}\) refers to total calorie content of product i consumed domestically in country r . Then, emissions from the dietary intake (without FLW) of product i in country r ( \({E}_{{\rm{intake}}}^{\,i,r}\) ) are calculated as follows:

Classification of food categories

The EAT-Lancet Commission report provides coverage of different food categories in the planetary health diet and their recommended caloric intake levels at 2,500 kcal for adults each day 12 (Supplementary Table 17 ). In this study, we classify 140 products into 13 aggregated food categories according to the planetary health diet 12 , including grains, tubers or starchy vegetables, vegetables, fruits, dairy products, red meat (beef, lamb and pork), chicken and other poultry, eggs, fish, legumes, nuts, added fats (both unsaturated and saturated oils) and all sugars. On the basis of the data availability of the FAOSTAT 4 , 82 , the food products in this study include both primary and processed products (primary and secondary food processing) which can be classified into specific food categories 16 . Ultraprocessed products that combine ingredients from several food categories, such as ice creams made from both dairy and sugar, are not considered. Detailed coverages of each food category and their mapping relationship with specific products are shown in Supplementary Table 18 .

Matching diets with the household-expenditure dataset

We explore the dietary emissions from consumers with different expenditure levels (defined as expenditure groups) using the household-expenditure dataset 41 for the year 2011. The dataset, containing 116 countries and almost 90% of the global population (Supplementary Table 19 ), is primarily based on the household survey microdata from the WBGCD 42 , supplemented by consumer expenditure surveys of national statistical offices from high-income countries such as the United States and European countries 17 , 41 . For every country in the dataset, 201 expenditure groups (grouped according to the per capita total expenditure of each group) and the corresponding population share are listed. The annual per capita expenditure of people in different expenditure groups ranges from <US$50 to ~US$1 million per year (expressed in 2011 Purchasing Power Parities, PPP) 31 , 34 . For each expenditure group, the expenditure for 33 different sectors of goods and services (including 11 food items) and the corresponding expenditure share in national consumption of each sector are provided 31 , 34 , 41 . For some affluent (or poor) countries that do not have a sufficient representative number of people at the bottom (or top) end of the expenditure spectrum, the population in the corresponding expenditure groups is empty. Expenditure shares of 11 food items are matched with the 140 products in this study (Supplementary Table 20 ). We calculate the dietary intake of different food products for each expenditure group in each country by multiplying the food expenditure share of groups with the total dietary intake amounts of food products of each country.

This study assumes that the amount of food consumption is proportionate to food expenditures and the purchasing price for the same product is unchanged across 201 groups ignoring higher prices for high-quality or luxury food items within the same food category. Although the assumption of an unchanged purchasing price is an unsolved limitation shared by similar studies using monetary expenditure data 31 , 34 , 41 , household expenditures on food can still effectively highlight the differences in food consumption and emissions across consumer groups with different affordability of, and spending on, food. We also assume that the proportion of food sources from local production and trade for the same food category remains constant across the 201 groups. In other words, the magnitude of dietary emissions is solely determined by the size and pattern of food expenditure of each group and the associated supply chains for each food consumption item.

For countries that are major food consumers (and emitters) but without data in WBGCD, expenditure shares from countries with similar development levels and eating habits and neighbouring geographical locations are used to calculate the distribution of their food expenditure. We finally select 201 expenditure groups in 139 countries/areas, covering 95% of the global population in 2019 (Supplementary Table 3 and Supplementary Data 3 ). Details for dealing with missing data are provided in Supplementary Table 7 . Countries or areas are then classified into 18 regions for comparison according to geographical locations (Supplementary Table 8 ). The WBGCD expenditure data from the year 2011 are adjusted to PPP in 2019 to represent the expenditure level of populations in figures. Results of emissions from 13 types of food categories of 201 expenditure groups at the national and regional levels are shown in Supplementary Data 8 , 10 and 11 .

Analysis of GF-Gini coefficients

Calculation of gf-gini coefficients.

This study uses the GF-Gini coefficient 33 , 89 , which is based on the well-known Gini coefficient 90 , to measure the inequality of GHG footprints from 201 expenditure groups within countries, regions and globally. The GF-Gini coefficient ranges from 0 to 1, indicating the emission distribution across expenditure groups changes from perfect equality to perfect inequality. The GF-Gini coefficient of each food category is calculated as 33 :

where Gini j indicate the GF-Gini coefficient of food category j (including product i , i  = 1, 2, 3, …, n ). Expenditure groups and their population are reordered in ascending order of per capita GHG footprint of food category j and m refers to the reordered number of groups ( m  = 1, 2, 3, …, 201). \({D}_{m}^{j}\) and \({Y}_{m}^{j}\) represent the proportions of population and GHG footprints (of food category j ) for each expenditure group, respectively. \({T}_{m}^{j}\) is the cumulative proportion of GHG footprints of each expenditure group. The results of national, regional and global GF-Gini coefficients are shown in Supplementary Tables 9 and 10 .

Regression analysis

We use the regression approach to examine the relationship between the national GF-Gini coefficients and the per capita GDP 91 , 92 of 139 countries/areas. The GF-Gini coefficient of each country is regarded as the dependent variable ( y ) and the national per capita GDP acts as the independent variable ( x ). Initially, locally weighted regression is applied to illustrate the trend lines within the scatterplot. Subsequently, we test different regression methods for validation based on the general trend. Ultimately, we found that logarithmic regression is the most fitting for dietary emissions of most food categories, particularly in the case of animal-based products. Thus, the logarithmic regression is applied.

Scenario of the planetary health diet

Scenario setting and assumptions.

To estimate the emission changes resulting from the transition from the 2019 diet to the global planetary health diet, we build a hypothetical scenario by assuming that individuals belonging to 201 different expenditure groups in all countries will all reach the reference intake level of 13 types of food categories 12 . First, we assume that the proportion of food sources from local production and trade in each country is unchanged, that is, emission changes from dietary shifts would be calculated on the basis of emissions from local production and imports accounting for emissions along global food supply chains, similar to studies by refs. 25 , 26 . At the same time, emission changes induced by decreased food consumption in countries following the planetary health diet, such as carbon uptake from agriculture abandonment 59 or emission increase from non-food biomass production in saved agricultural land 77 , are not considered in this study. Second, we assume that agricultural and food-related production technology, trade patterns and emission intensities of food supply chain processes remain unchanged during the diet transition. Third, fluctuations in food prices induced by altered food demand or the affordability of the planetary health diet for different consumer groups are not considered in this study.

Diet gaps for different food categories

The diet gap (DG) reflects gaps between present dietary intake and the planetary health diet 12 , 25 , as follows:

where \({{\rm{DG}}}_{{\rm{per}}}^{j,r}\) is defined as the percentage ratio of the present per capita caloric intake of food category j in country r each year ( \({{\rm{DI}}}_{{\rm{per}}}^{\,j,r}\) ) to the annual reference level ( \({{\rm{DI}}}_{{\rm{EAT}}\_{\rm{per}}}^{i}\) ). \({{\rm{DI}}}_{{\rm{EAT}\_day\_per}}^{\,j}\) is the recommended per capita caloric intake of food category j each day 12 (Supplementary Table 17 ). We assume a uniform annual calorie reference level for each food category across all populations in all countries. We allow flexibility in local diets by keeping the composition of each food category unchanged, requiring only that the calorie content reaches the reference level. According to the definition, present food intake is considered insufficient compared with reference levels when DG is <100%, while it is deemed excessive and should be reduced when DG is >100%. Daily per capita caloric intake of food categories from 201 expenditure groups of countries or regions are shown in Supplementary Data 12 and 13 . We calculate the DG for food categories of 201 expenditure groups at national and regional levels (Supplementary Data 14 and 15 ).

According to equation ( 1 ), the total emissions per unit of calorie content of food category j in country r ( \({F}_{{\rm{energy}}}^{\;j,r}\) ) can be calculated as:

where E j,r refers to the national emissions due to consumption of food category j in country r . Thus, emission changes for adopting the planetary health diet are calculated as follows:

where \(\Delta {E}_{{\rm{intake}}}^{\;j,r}\) represents the national emission changes of food category j in country r , \({E}_{{\rm{intake}}}^{\;j,r}\) is the national emissions from intake of food category j in country r . Changes in dietary emissions of food categories from 201 groups are shown in Supplementary Data 9 . The number of people with increased/decreased emissions from 201 groups is shown in Supplementary Data 19 .

Uncertainty analysis

We assess the uncertainty range of dietary emissions from different food products using a Monte Carlo approach, which simulates the uncertainties caused by activity data, emission factors and parameters in each emission process 16 , 59 , 93 . More details can be found in Supplementary Methods 1 .

Limitations

This study has the following limitations regarding data analysis and scenario setting.

In terms of data analysis, this study is limited by the data availability. First, we use regional household food loss and waste factors of aggregated food categories without more detailed product division at the national level because of a lack of data. There might also be differences between calculated and actual food intake amounts that are unable to be removed, such as animal bones or fruit skins 25 . Second, we use the consumer household-expenditure dataset based on WBGCD for the year 2011, which provides the most precise and detailed differentiation of consumer groups and their consumption patterns within countries so far. We assume that the shares in food expenditure and population for each expenditure group are the same as in 2011. Third, we assume that the composition of different products aggregated in one category consumed by expenditure groups is the same as the national consumption composition and there is no difference in the price of food products purchased by people from different expenditure groups. In addition, data for some populous high- or upper-middle-income countries are missing from the household-expenditure dataset. However, the countries are the world’s major food consumers and emitters, their emission changes due to diet shifts are important for the global food system. We use the expenditure shares of similar countries in the household-expenditure dataset to allocate the distributions of food expenditure in these countries.

In terms of scenario setting, we focus on the impact induced by changes in consumer choices without changing the proportion of food supply sources (domestic production and imports). We do not consider altering the proportions of supply sources and associated emissions in this study. However, future studies may explore the impacts of the production side and supply chains for diet shifts. Moreover, as we focus on the present emission inequality and mitigation potentials within the food system, we assume that the income and expenditure levels of expenditure groups remain unchanged. However, a shift in food supply may affect household income and subsequently alter the household food budgets, especially for populations employed in, or countries reliant on, food-related sectors. Additionally, as a result of data and model limitations, this study does not consider price fluctuations induced by food demand and subsequent changes in household affordability or spillover effects (between food categories or to non-food sectors). Future studies may combine assessment models incorporating elasticities to project the long-term feasibilities and consequences of diet shifts.

Reporting summary

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

Data availability

Data for LULUC, agricultural and beyond-farm emissions and data for physical food consumption are curated by the FAO and can be freely obtained from FAOSTAT 82 , available from ref. 16 . Data of food loss and waste rate are retrieved from FAOSTAT 82 and ref. 25 . The global household-expenditure data are obtained from the World Bank 42 and refs. 17 , 41 . Population data used in this study are obtained from World Population Prospects of the United Nations 86 . Data on per capita GDP in countries can be collected from the World Bank 91 and the International Monetary Fund 92 . Supplementary datasets are also available on Zenodo ( https://doi.org/10.5281/zenodo.11934909 ) 94 . Source data are provided with this paper.

Code availability

Data collection is performed in MATLAB and Microsoft Excel. Code developed for data processing in MATLAB and R in this study is available from Zenodo ( https://doi.org/10.5281/zenodo.11880402 ) 95 .

Springmann, M., Godfray, H. C. J., Rayner, M. & Scarborough, P. Analysis and valuation of the health and climate change cobenefits of dietary change. Proc. Natl Acad. Sci. USA 113 , 4146–4151 (2016).

Article   CAS   Google Scholar  

Kesse-Guyot, E. et al. Sustainability analysis of French dietary guidelines using multiple criteria. Nat. Sustain. 3 , 377–385 (2020).

Article   Google Scholar  

Crippa, M. et al. Food systems are responsible for a third of global anthropogenic GHG emissions. Nat. Food 2 , 198–209 (2021).

Tubiello, F. N. et al. Pre-and post-production processes increasingly dominate greenhouse gas emissions from agri-food systems. Earth Syst. Sci. Data 14 , 1795–1809 (2022).

Clark, M. A. et al. Global food system emissions could preclude achieving the 1.5 °C and 2 °C climate change targets. Science 370 , 705–708 (2020).

Ivanovich, C. C., Sun, T., Gordon, D. R. & Ocko, I. B. Future warming from global food consumption. Nat. Clim. Change 13 , 297–302 (2023).

Béné, C. et al. Five priorities to operationalize the EAT-Lancet Commission report. Nat. Food 1 , 457–459 (2020).

Navarre, N., Schrama, M., de Vos, C. & Mogollón, J. M. Interventions for sourcing EAT-Lancet diets within national agricultural areas: a global analysis. One Earth 6 , 31–40 (2023).

Laine, J. E. et al. Co-benefits from sustainable dietary shifts for population and environmental health: an assessment from a large European cohort study. Lancet Planet. Health 5 , e786–e796 (2021).

Craig, W. J. Health effects of vegan diets. Am. J. Clin. Nutr. 89 , S1627–S1633 (2009).

Afshin, A. et al. Health effects of dietary risks in 195 countries, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet 393 , 1958–1972 (2019).

Willett, W. et al. Food in the Anthropocene: the EAT-Lancet Commission on healthy diets from sustainable food systems. Lancet 393 , 447–492 (2019).

The State of Food Security and Nutrition in the World 2022: Repurposing Food and Agricultural Policies to Make Healthy Diets More Affordable (FAO, 2022); https://www.fao.org/documents/card/en/c/cc0639en

Bajželj, B. et al. Importance of food-demand management for climate mitigation. Nat. Clim. Change 4 , 924–929 (2014).

Springmann, M. et al. Options for keeping the food system within environmental limits. Nature 562 , 519–525 (2018).

Li, Y. et al. Changes in global food consumption increase GHG emissions despite efficiency gains along global supply chains. Nat. Food 4 , 483–495 (2023).

Hubacek, K., Baiocchi, G., Feng, K. & Patwardhan, A. Poverty eradication in a carbon constrained world. Nat. Commun. 8 , 912 (2017).

Sustainable Development Goals: 17 Goals to Transform Our World (United Nations, 2017); https://www.un.org/sustainabledevelopment/sustainable-development-goals/

Humpenöder, F. et al. Projected environmental benefits of replacing beef with microbial protein. Nature 605 , 90–96 (2022).

Hasegawa, T., Havlík, P., Frank, S., Palazzo, A. & Valin, H. Tackling food consumption inequality to fight hunger without pressuring the environment. Nat. Sustain. 2 , 826–833 (2019).

Kim, B. F. et al. Country-specific dietary shifts to mitigate climate and water crises. Glob. Environ. Change 62 , 101926 (2020).

Denton, F. et al. in Climate Change 2022: Mitigation of Climate Change (eds Shukla, P. R. et al.) 1727–1790 (Cambridge Univ. Press, 2022).

Tilman, D. & Clark, M. Global diets link environmental sustainability and human health. Nature 515 , 518–522 (2014).

Springmann, M. et al. Health and nutritional aspects of sustainable diet strategies and their association with environmental impacts: a global modelling analysis with country-level detail. Lancet Planet. Health 2 , e451–e461 (2018).

Tuninetti, M., Ridolfi, L. & Laio, F. Compliance with EAT-Lancet dietary guidelines would reduce global water footprint but increase it for 40% of the world population. Nat. Food 3 , 143–151 (2022).

Semba, R. D. et al. Adoption of the ‘planetary health diet’ has different impacts on countries’ greenhouse gas emissions. Nat. Food 1 , 481–484 (2020).

Guo, Y. et al. Environmental and human health trade-offs in potential Chinese dietary shifts. One Earth 5 , 268–282 (2022).

Sun, Z. et al. Dietary change in high-income nations alone can lead to substantial double climate dividend. Nat. Food 3 , 29–37 (2022).

Mbow, C. et al. in Climate Change and Land (eds Shukla, P. R. et al.) Ch. 5 (IPCC, 2019); https://www.ipcc.ch/site/assets/uploads/sites/4/2022/11/SRCCL_Chapter_5.pdf

Millward-Hopkins, J. & Oswald, Y. Reducing global inequality to secure human wellbeing and climate safety: a modelling study. Lancet Planet. Health 7 , e147–e154 (2023).

Guan, Y. et al. Burden of the global energy price crisis on households. Nat. Energy 8 , 304–316 (2023).

Hubacek, K. et al. Global carbon inequality. Energy Ecol. Environ. 2 , 361–369 (2017).

Mi, Z. et al. Economic development and converging household carbon footprints in China. Nat. Sustain. 3 , 529–537 (2020).

Bruckner, B., Hubacek, K., Shan, Y., Zhong, H. & Feng, K. Impacts of poverty alleviation on national and global carbon emissions. Nat. Sustain. 5 , 311–320 (2022).

He, P., Baiocchi, G., Hubacek, K., Feng, K. & Yu, Y. The environmental impacts of rapidly changing diets and their nutritional quality in China. Nat. Sustain. 1 , 122–127 (2018).

Rao, N. D. et al. Healthy, affordable and climate-friendly diets in India. Glob. Environ. Change 49 , 154–165 (2018).

He, P., Feng, K., Baiocchi, G., Sun, L. & Hubacek, K. Shifts towards healthy diets in the US can reduce environmental impacts but would be unaffordable for poorer minorities. Nat. Food 2 , 664–672 (2021).

Reynolds, C. J., Horgan, G. W., Whybrow, S. & Macdiarmid, J. I. Healthy and sustainable diets that meet greenhouse gas emission reduction targets and are affordable for different income groups in the UK. Public Health Nutr. 22 , 1503–1517 (2019).

Gustavsson, J., Cederberg, C., Sonesson, U., Van Otterdijk, R. & Meybeck, A. Global Food Losses and Food Waste-Extent, Causes and Prevention (FAO, 2011); https://www.fao.org/3/mb060e/mb060e00.htm

Kummu, M. et al. Lost food, wasted resources: global food supply chain losses and their impacts on freshwater, cropland and fertiliser use. Sci. Total Environ. 438 , 477–489 (2012).

Zhong, H., Feng, K., Sun, L., Cheng, L. & Hubacek, K. Household carbon and energy inequality in Latin American and Caribbean countries. J. Environ. Manag. 273 , 110979 (2020).

Global Consumption Database (World Bank, 2022); https://datatopics.worldbank.org/consumption/

Wier, M., Birr-Pedersen, K., Jacobsen, H. K. & Klok, J. Are CO 2 taxes regressive? Evidence from the Danish experience. Ecol. Econ. 52 , 239–251 (2005).

Hirvonen, K., Bai, Y., Headey, D. & Masters, W. A. Affordability of the EAT-Lancet reference diet: a global analysis. Lancet Glob. Health 8 , e59–e66 (2020).

The State of Food Security and Nutrition in the World 2023 (FAO, 2023); https://doi.org/10.4060/cc3017en

World Bank Country and Lending Groups (World Bank, 2021); https://datahelpdesk.worldbank.org/knowledgebase/articles/906519-world-bank-country-and-lending-groups

Okou, C., Spray, J. A. & Unsal, M. F. D. Staple Food Prices in Sub-Saharan Africa: An Empirical Assessment (International Monetary Fund, 2022); https://www.imf.org/en/Publications/WP/Issues/2022/07/08/Staple-Food-Prices-in-Sub-Saharan-Africa-An-Empirical-Assessment-520567

Delgermaa, D., Yamaguchi, M., Nomura, M. & Nishi, N. Assessment of Mongolian dietary intake for planetary and human health. PLoS Glob. Public Health 3 , e0001229 (2023).

Burkhart, S., Underhill, S. & Raneri, J. Realizing the potential of neglected and underutilized bananas in improving diets for nutrition and health outcomes in the Pacific Islands. Front. Sustain. Food Syst. 6 , 805776 (2022).

Pingali, P. Agricultural policy and nutrition outcomes—getting beyond the preoccupation with staple grains. Food Secur. 7 , 583–591 (2015).

Sibhatu, K. T. & Qaim, M. Rural food security, subsistence agriculture and seasonality. PloS ONE 12 , e0186406 (2017).

Headey, D. D. & Alderman, H. H. The relative caloric prices of healthy and unhealthy foods differ systematically across income levels and continents. J. Nutr. 149 , 2020–2033 (2019).

Bai, Y., Alemu, R., Block, S. A., Headey, D. & Masters, W. A. Cost and affordability of nutritious diets at retail prices: evidence from 177 countries. Food Policy 99 , 101983 (2021).

Batis, C. et al. Adoption of healthy and sustainable diets in Mexico does not imply higher expenditure on food. Nat. Food 2 , 792–801 (2021).

Bennett, M. K. International contrasts in food consumption. Geogr. Rev. 31 , 365–376 (1941).

D’Odorico, P. et al. The global food–energy–water nexus. Rev. Geophys. 56 , 456–531 (2018).

Traditional Pacific Island Crops (Univ. Hawaii, 2024); https://guides.library.manoa.hawaii.edu/paccrops

Fiji—Agricultural Commodities (International Trade Administration, 2022); https://www.trade.gov/country-commercial-guides/fiji-agricultural-commodities

Hong, C. et al. Global and regional drivers of land-use emissions in 1961–2017. Nature 589 , 554–561 (2021).

Hong, C. et al. Land-use emissions embodied in international trade. Science 376 , 597–603 (2022).

Darmon, N., Lacroix, A., Muller, L. & Ruffieux, B. Food price policies improve diet quality while increasing socioeconomic inequalities in nutrition. Int. J. Behav. Nutr. Phys. Act. 11 , 66 (2014).

Poore, J. & Nemecek, T. Reducing food’s environmental impacts through producers and consumers. Science 360 , 987–992 (2018).

Bacon, L. & Krpan, D. (Not) Eating for the environment: the impact of restaurant menu design on vegetarian food choice. Appetite 125 , 190–200 (2018).

Swinburn, B. A. et al. The global syndemic of obesity, undernutrition and climate change: the Lancet Commission report. Lancet 393 , 791–846 (2019).

Geyik, O., Hadjikakou, M., Karapinar, B. & Bryan, B. A. Does global food trade close the dietary nutrient gap for the world’s poorest nations? Glob. Food Secur. 28 , 100490 (2021).

Pradhan, P., Fischer, G., Van Velthuizen, H., Reusser, D. E. & Kropp, J. P. Closing yield gaps: how sustainable can we be. PloS ONE 10 , e0129487 (2015).

Sánchez, P. A. Tripling crop yields in tropical Africa. Nat. Geosci. 3 , 299–300 (2010).

Huang, J., Pray, C. & Rozelle, S. Enhancing the crops to feed the poor. Nature 418 , 678–684 (2002).

The State of Food Security and Nutrition in the World 2020. Transforming Food Systems for Affordable Healthy Diets (FAO, 2020); https://www.fao.org/documents/card/en?details=ca9692en

Allcott, H. et al. Food deserts and the causes of nutritional inequality. Q. J. Econ. 134 , 1793–1844 (2019).

Springmann, M., Clark, M. A., Rayner, M., Scarborough, P. & Webb, P. The global and regional costs of healthy and sustainable dietary patterns: a modelling study. Lancet Planet. Health 5 , e797–e807 (2021).

Darmon, N. & Drewnowski, A. Contribution of food prices and diet cost to socioeconomic disparities in diet quality and health: a systematic review and analysis. Nutr. Rev. 73 , 643–660 (2015).

Baylis, K., Peplow, S., Rausser, G. & Simon, L. Agri-environmental policies in the EU and United States: a comparison. Ecol. Econ. 65 , 753–764 (2008).

Swinnen, J. The right price of food. Dev. Policy Rev. 29 , 667–688 (2011).

Headey, D. D. Food prices and poverty. World Bank Econ. Rev. 32 , 676–691 (2018).

Google Scholar  

Headey, D. & Hirvonen, K. Higher food prices can reduce poverty and stimulate growth in food production. Nat. Food 4 , 699–706 (2023).

Gatto, A., Kuiper, M. & van Meijl, H. Economic, social and environmental spillovers decrease the benefits of a global dietary shift. Nat. Food 4 , 496–507 (2023).

Puma, M. J., Bose, S., Chon, S. Y. & Cook, B. I. Assessing the evolving fragility of the global food system. Environ. Res. Lett. 10 , 024007 (2015).

Davis, K. F. et al. Alternative cereals can improve water use and nutrient supply in India. Sci. Adv. 4 , eaao1108 (2018).

Le Quéré, C. et al. Temporary reduction in daily global CO 2 emissions during the COVID-19 forced confinement. Nat. Clim. Change 10 , 647–653 (2020).

Shan, Y. et al. Impacts of COVID-19 and fiscal stimuli on global emissions and the Paris Agreement. Nat. Clim. Change 11 , 200–206 (2021).

FAOSTAT Database (FAO, 2022); https://www.fao.org/faostat/en/

Supply Utilization Accounts, Food Blances, FAOSTAT Online Database (FAO, 2022); https://www.fao.org/faostat/en/#data/SCL

Kastner, T., Kastner, M. & Nonhebel, S. Tracing distant environmental impacts of agricultural products from a consumer perspective. Ecol. Econ. 70 , 1032–1040 (2011).

Kastner, T., Erb, K.-H. & Haberl, H. Rapid growth in agricultural trade: effects on global area efficiency and the role of management. Environ. Res. Lett. 9 , 034015 (2014).

World Population Prospects 2022 (United Nations, 2022); https://population.un.org/wpp/Download/Standard/Population/

Food Balance Sheets—A Handbook (FAO, 2001); https://www.fao.org/3/x9892e/X9892e05.htm#P8217_125315

Nutritive Factors (FAO, 2023); https://www.fao.org/economic/the-statistics-division-ess/publications-studies/publications/nutritive-factors/en/

Wiedenhofer, D. et al. Unequal household carbon footprints in China. Nat. Clim. Change 7 , 75–80 (2017).

Gini, C. Measurement of inequality of incomes. Econ. J. 31 , 124–125 (1921).

The World Bank Data: GDP per Capita (Current US$) (World Bank, 2023); https://data.worldbank.org/indicator/NY.GDP.PCAP.PP.CD

Datasets, World Economic Outlook (April 2023): GDP per Capita, Current Prices (IMF, 2023); https://www.imf.org/external/datamapper/NGDPDPC@WEO/OEMDC/ADVEC/WEOWORLD

Xu, X. et al. Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods. Nat. Food 2 , 724–732 (2021).

Li, Y. et al. Supplementary Datasets for ‘Reducing climate change impacts from the global food system through diet shifts’. Zenodo https://doi.org/10.5281/zenodo.11934909 (2024).

Li, Y. et al. Code for ‘Reducing climate change impacts from the global food system through diet shifts’. Zenodo https://doi.org/10.5281/zenodo.11880402 (2024).

Download references

Acknowledgements

This study was supported by the National Natural Science Foundation of China (grant nos 72243004, 32101315, 71904098). Y.S. and S.S. acknowledge support from the National Natural Science Foundation of China (grant no. 72243004). Yu Li acknowledges support from the National Natural Science Foundation of China (grant no. 32101315). P.H. acknowledges support from the National Natural Science Foundation of China under a Young Scholar Programme Grant (grant no. 71904098). Yanxian Li and Y.H. acknowledge the funding support by the China Scholarship Council PhD programme. We thank Y. Zhou for supporting visualization and J. Yan for assisting in writing and revising. For the purpose of open access, a CC BY public copyright license is applied to any author accepted manuscript arising from this submission.

Author information

Authors and affiliations.

Integrated Research on Energy, Environment and Society (IREES), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen, the Netherlands

Yanxian Li, Franco Ruzzenenti & Klaus Hubacek

School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK

Department of Earth System Science, Tsinghua University, Beijing, China

School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK

Yuli Shan & Ye Hang

School of Public Administration, Chongqing Technology and Business University, Chongqing, China

School of Business, East China University of Science and Technology, Shanghai, China

You can also search for this author in PubMed   Google Scholar

Contributions

Yanxian Li, Y.S. and K.H. designed the research. Yanxian Li performed the analysis with support from P.H., Yu Li, Y.H. and S.S. on analytical approaches and visualization. Yanxian Li led the writing with efforts from P.H., Y.S., F.R. and K.H. Y.S. and K.H. supervised and coordinated the overall research. All co-authors reviewed and commented on the manuscript.

Corresponding authors

Correspondence to Yuli Shan or Klaus Hubacek .

Ethics declarations

Competing interests.

The authors declare no competing interests.

Peer review

Peer review information.

Nature Climate Change thanks Catharina Latka and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

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

Supplementary information

Supplementary information.

Supplementary Methods, Discussion, Figs. 1–23, Tables 1–24 and references.

Reporting Summary

Supplementary data.

Detailed data for calculated results in this study.

Source Data Fig. 1

Source data for creating Fig. 1.

Source Data Fig. 2

Source data for creating Fig. 2.

Source Data Fig. 3

Source data for creating Fig. 3.

Source Data Fig. 4

Source data for creating Fig. 4.

Source data Fig. 5

Source data for creating Fig. 5.

Source Data Fig. 6

Source data for creating Fig. 6.

Rights and permissions

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

Reprints and permissions

About this article

Cite this article.

Li, Y., He, P., Shan, Y. et al. Reducing climate change impacts from the global food system through diet shifts. Nat. Clim. Chang. (2024). https://doi.org/10.1038/s41558-024-02084-1

Download citation

Received : 07 November 2023

Accepted : 05 July 2024

Published : 13 August 2024

DOI : https://doi.org/10.1038/s41558-024-02084-1

Share this article

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

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

Provided by the Springer Nature SharedIt content-sharing initiative

Quick links

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

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

Climate Change: Evidence and Causes: Update 2020 (2020)

Chapter: conclusion, c onclusion.

This document explains that there are well-understood physical mechanisms by which changes in the amounts of greenhouse gases cause climate changes. It discusses the evidence that the concentrations of these gases in the atmosphere have increased and are still increasing rapidly, that climate change is occurring, and that most of the recent change is almost certainly due to emissions of greenhouse gases caused by human activities. Further climate change is inevitable; if emissions of greenhouse gases continue unabated, future changes will substantially exceed those that have occurred so far. There remains a range of estimates of the magnitude and regional expression of future change, but increases in the extremes of climate that can adversely affect natural ecosystems and human activities and infrastructure are expected.

Citizens and governments can choose among several options (or a mixture of those options) in response to this information: they can change their pattern of energy production and usage in order to limit emissions of greenhouse gases and hence the magnitude of climate changes; they can wait for changes to occur and accept the losses, damage, and suffering that arise; they can adapt to actual and expected changes as much as possible; or they can seek as yet unproven “geoengineering” solutions to counteract some of the climate changes that would otherwise occur. Each of these options has risks, attractions and costs, and what is actually done may be a mixture of these different options. Different nations and communities will vary in their vulnerability and their capacity to adapt. There is an important debate to be had about choices among these options, to decide what is best for each group or nation, and most importantly for the global population as a whole. The options have to be discussed at a global scale because in many cases those communities that are most vulnerable control few of the emissions, either past or future. Our description of the science of climate change, with both its facts and its uncertainties, is offered as a basis to inform that policy debate.

A CKNOWLEDGEMENTS

The following individuals served as the primary writing team for the 2014 and 2020 editions of this document:

• Eric Wolff FRS, (UK lead), University of Cambridge
• Inez Fung (NAS, US lead), University of California, Berkeley
• Brian Hoskins FRS, Grantham Institute for Climate Change
• John F.B. Mitchell FRS, UK Met Office
• Tim Palmer FRS, University of Oxford
• Benjamin Santer (NAS), Lawrence Livermore National Laboratory
• John Shepherd FRS, University of Southampton
• Keith Shine FRS, University of Reading.
• Susan Solomon (NAS), Massachusetts Institute of Technology
• Kevin Trenberth, National Center for Atmospheric Research
• John Walsh, University of Alaska, Fairbanks
• Don Wuebbles, University of Illinois

Staff support for the 2020 revision was provided by Richard Walker, Amanda Purcell, Nancy Huddleston, and Michael Hudson. We offer special thanks to Rebecca Lindsey and NOAA Climate.gov for providing data and figure updates.

The following individuals served as reviewers of the 2014 document in accordance with procedures approved by the Royal Society and the National Academy of Sciences:

• Richard Alley (NAS), Department of Geosciences, Pennsylvania State University
• Alec Broers FRS, Former President of the Royal Academy of Engineering
• Harry Elderfield FRS, Department of Earth Sciences, University of Cambridge
• Joanna Haigh FRS, Professor of Atmospheric Physics, Imperial College London
• Isaac Held (NAS), NOAA Geophysical Fluid Dynamics Laboratory
• John Kutzbach (NAS), Center for Climatic Research, University of Wisconsin
• Jerry Meehl, Senior Scientist, National Center for Atmospheric Research
• John Pendry FRS, Imperial College London
• John Pyle FRS, Department of Chemistry, University of Cambridge
• Gavin Schmidt, NASA Goddard Space Flight Center
• Emily Shuckburgh, British Antarctic Survey
• Gabrielle Walker, Journalist
• Andrew Watson FRS, University of East Anglia

The Support for the 2014 Edition was provided by NAS Endowment Funds. We offer sincere thanks to the Ralph J. and Carol M. Cicerone Endowment for NAS Missions for supporting the production of this 2020 Edition.

F OR FURTHER READING

For more detailed discussion of the topics addressed in this document (including references to the underlying original research), see:

• Intergovernmental Panel on Climate Change (IPCC), 2019: Special Report on the Ocean and Cryosphere in a Changing Climate [ https://www.ipcc.ch/srocc ]
• National Academies of Sciences, Engineering, and Medicine (NASEM), 2019: Negative Emissions Technologies and Reliable Sequestration: A Research Agenda [ https://www.nap.edu/catalog/25259 ]
• Royal Society, 2018: Greenhouse gas removal [ https://raeng.org.uk/greenhousegasremoval ]
• U.S. Global Change Research Program (USGCRP), 2018: Fourth National Climate Assessment Volume II: Impacts, Risks, and Adaptation in the United States [ https://nca2018.globalchange.gov ]
• IPCC, 2018: Global Warming of 1.5°C [ https://www.ipcc.ch/sr15 ]
• USGCRP, 2017: Fourth National Climate Assessment Volume I: Climate Science Special Reports [ https://science2017.globalchange.gov ]
• NASEM, 2016: Attribution of Extreme Weather Events in the Context of Climate Change [ https://www.nap.edu/catalog/21852 ]
• IPCC, 2013: Fifth Assessment Report (AR5) Working Group 1. Climate Change 2013: The Physical Science Basis [ https://www.ipcc.ch/report/ar5/wg1 ]
• NRC, 2013: Abrupt Impacts of Climate Change: Anticipating Surprises [ https://www.nap.edu/catalog/18373 ]
• NRC, 2011: Climate Stabilization Targets: Emissions, Concentrations, and Impacts Over Decades to Millennia [ https://www.nap.edu/catalog/12877 ]
• Royal Society 2010: Climate Change: A Summary of the Science [ https://royalsociety.org/topics-policy/publications/2010/climate-change-summary-science ]
• NRC, 2010: America’s Climate Choices: Advancing the Science of Climate Change [ https://www.nap.edu/catalog/12782 ]

Much of the original data underlying the scientific findings discussed here are available at:

• https://data.ucar.edu/
• https://climatedataguide.ucar.edu
• https://iridl.ldeo.columbia.edu
• https://ess-dive.lbl.gov/
• https://www.ncdc.noaa.gov/
• https://www.esrl.noaa.gov/gmd/ccgg/trends/
• http://scrippsco2.ucsd.edu
• http://hahana.soest.hawaii.edu/hot/

Climate change is one of the defining issues of our time. It is now more certain than ever, based on many lines of evidence, that humans are changing Earth's climate. The Royal Society and the US National Academy of Sciences, with their similar missions to promote the use of science to benefit society and to inform critical policy debates, produced the original Climate Change: Evidence and Causes in 2014. It was written and reviewed by a UK-US team of leading climate scientists. This new edition, prepared by the same author team, has been updated with the most recent climate data and scientific analyses, all of which reinforce our understanding of human-caused climate change.

Scientific information is a vital component for society to make informed decisions about how to reduce the magnitude of climate change and how to adapt to its impacts. This booklet serves as a key reference document for decision makers, policy makers, educators, and others seeking authoritative answers about the current state of climate-change science.

READ FREE ONLINE

Welcome to OpenBook!

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

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

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

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

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

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

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

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

View our suggested citation for this chapter.

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

Get Email Updates

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