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More than 99.9% of studies agree: Humans caused climate change

By krishna ramanujan.

More than 99.9% of peer-reviewed scientific papers agree that climate change is mainly caused by humans, according to a new survey of 88,125 climate-related studies.

The research updates a similar 2013 paper revealing that 97% of studies published between 1991 and 2012 supported the idea that human activities are altering Earth’s climate. The current survey examines the literature published from 2012 to November 2020 to explore whether the consensus has changed.

“We are virtually certain that the consensus is well over 99% now and that it’s pretty much case closed for any meaningful public conversation about the reality of human-caused climate change,” said Mark Lynas, a visiting fellow at the Alliance for Science and the paper’s first author.

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“It's critical to acknowledge the principal role of greenhouse gas emissions so that we can rapidly mobilize new solutions, since we are already witnessing in real time the devastating impacts of climate related disasters on businesses, people and the economy,” said Benjamin Houlton, the Ronald P. Lynch Dean of the College of Agriculture and Life Sciences and a co-author of the study, “ Greater than 99% Consensus on Human Caused Climate Change in the Peer-Reviewed Scientific Literature ,” which published Oct. 19 in the journal Environmental Research Letters.

In spite of such results, public opinion polls as well as opinions of politicians and public representatives point to false beliefs and claims that a significant debate still exists among scientists over the true cause of climate change. In 2016, the Pew Research Center found that only 27% of U.S. adults believe that “almost all” scientists agreed that climate change is due to human activity, according to the paper. A 2021 Gallup poll pointed to a deepening partisan divide in American politics on whether Earth’s rising observed temperatures since the Industrial Revolution were primarily caused by humans.

“To understand where a consensus exists, you have to be able to quantify it,” Lynas said. “That means surveying the literature in a coherent and non-arbitrary way in order to avoid trading cherry-picked papers, which is often how these arguments are carried out in the public sphere.”

 In the study, the researchers began by examining a random sample of 3,000 studies from the dataset of 88,125 English-language climate papers published between 2012 and 2020. They found only found four out of the 3,000 papers were skeptical of human-caused climate change. “We knew that [climate skeptical papers] were vanishingly small in terms of their occurrence, but we thought there still must be more in the 88,000,” Lynas said.

Co-author Simon Perry, a United Kingdom-based software engineer and volunteer at the Alliance for Science, created an algorithm that searched out keywords from papers the team knew were skeptical, such as “solar,” “cosmic rays” and “natural cycles.” The algorithm was applied to all 88,000-plus papers, and the program ordered them so the skeptical ones came higher in the order. They found many of these dissenting papers near the top, as expected, with diminishing returns further down the list. Overall, the search yielded 28 papers that were implicitly or explicitly skeptical, all published in minor journals.

If the 97% result from the 2013 study still left some doubt on scientific consensus on the human influence on climate, the current findings go even further to allay any uncertainty, Lynas said. “This pretty much should be the last word,” he said.

Support for the Alliance for Science is provided by the Bill and Melinda Gates Foundation.

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Scientific Consensus: Earth's Climate Is Warming

Temperature data from four international science institutions. All show rapid warming in the past few decades and that the last decade has been the hottest on record.

Temperature data showing rapid warming in the past few decades, the latest data going up to 2022. According to NASA, 2016 and 2020 are tied for the warmest year since 1880, continuing a long-term trend of rising global temperatures. On top of that, the nine most recent years have been the hottest. Credit: NASA's Goddard Institute for Space Studies

It’s important to remember that scientists always focus on the evidence, not on opinions. Scientific evidence continues to show that human activities ( primarily the human burning of fossil fuels ) have warmed Earth’s surface and its ocean basins, which in turn have continued to impact Earth’s climate . This is based on over a century of scientific evidence forming the structural backbone of today's civilization.

NASA Global Climate Change presents the state of scientific knowledge about climate change while highlighting the role NASA plays in better understanding our home planet. This effort includes citing multiple peer-reviewed studies from research groups across the world, 1 illustrating the accuracy and consensus of research results (in this case, the scientific consensus on climate change) consistent with NASA’s scientific research portfolio.

With that said, multiple studies published in peer-reviewed scientific journals 1 show that climate-warming trends over the past century are extremely likely due to human activities. In addition, most of the leading scientific organizations worldwide have issued public statements endorsing this position. The following is a partial list of these organizations, along with links to their published statements and a selection of related resources.


Statement on climate change from 18 scientific associations.

"Observations throughout the world make it clear that climate change is occurring, and rigorous scientific research demonstrates that the greenhouse gases emitted by human activities are the primary driver." (2009) 2

AAAS emblem

"Based on well-established evidence, about 97% of climate scientists have concluded that human-caused climate change is happening." (2014) 3

ACS emblem

"The Earth’s climate is changing in response to increasing concentrations of greenhouse gases (GHGs) and particulate matter in the atmosphere, largely as the result of human activities." (2016-2019) 4

AGU emblem

"Based on extensive scientific evidence, it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. There is no alterative explanation supported by convincing evidence." (2019) 5

AMA emblem

"Our AMA ... supports the findings of the Intergovernmental Panel on Climate Change’s fourth assessment report and concurs with the scientific consensus that the Earth is undergoing adverse global climate change and that anthropogenic contributions are significant." (2019) 6

AMS emblem

"Research has found a human influence on the climate of the past several decades ... The IPCC (2013), USGCRP (2017), and USGCRP (2018) indicate that it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-twentieth century." (2019) 7

APS emblem

"Earth's changing climate is a critical issue and poses the risk of significant environmental, social and economic disruptions around the globe. While natural sources of climate variability are significant, multiple lines of evidence indicate that human influences have had an increasingly dominant effect on global climate warming observed since the mid-twentieth century." (2015) 8

GSA emblem

"The Geological Society of America (GSA) concurs with assessments by the National Academies of Science (2005), the National Research Council (2011), the Intergovernmental Panel on Climate Change (IPCC, 2013) and the U.S. Global Change Research Program (Melillo et al., 2014) that global climate has warmed in response to increasing concentrations of carbon dioxide (CO2) and other greenhouse gases ... Human activities (mainly greenhouse-gas emissions) are the dominant cause of the rapid warming since the middle 1900s (IPCC, 2013)." (2015) 9


International academies: joint statement.

"Climate change is real. There will always be uncertainty in understanding a system as complex as the world’s climate. However there is now strong evidence that significant global warming is occurring. The evidence comes from direct measurements of rising surface air temperatures and subsurface ocean temperatures and from phenomena such as increases in average global sea levels, retreating glaciers, and changes to many physical and biological systems. It is likely that most of the warming in recent decades can be attributed to human activities (IPCC 2001)." (2005, 11 international science academies) 10

UNSAS emblem

"Scientists have known for some time, from multiple lines of evidence, that humans are changing Earth’s climate, primarily through greenhouse gas emissions." 11


USGCRP emblem

"Earth’s climate is now changing faster than at any point in the history of modern civilization, primarily as a result of human activities." (2018, 13 U.S. government departments and agencies) 12


IPCC emblem

“It is unequivocal that the increase of CO 2 , methane, and nitrous oxide in the atmosphere over the industrial era is the result of human activities and that human influence is the principal driver of many changes observed across the atmosphere, ocean, cryosphere, and biosphere. “Since systematic scientific assessments began in the 1970s, the influence of human activity on the warming of the climate system has evolved from theory to established fact.” 13-17


List of worldwide scientific organizations.

The following page lists the nearly 200 worldwide scientific organizations that hold the position that climate change has been caused by human action.

U.S. Agencies

The following page contains information on what federal agencies are doing to adapt to climate change.

Technically, a “consensus” is a general agreement of opinion, but the scientific method steers us away from this to an objective framework. In science, facts or observations are explained by a hypothesis (a statement of a possible explanation for some natural phenomenon), which can then be tested and retested until it is refuted (or disproved).

As scientists gather more observations, they will build off one explanation and add details to complete the picture. Eventually, a group of hypotheses might be integrated and generalized into a scientific theory, a scientifically acceptable general principle or body of principles offered to explain phenomena.


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Worst- and Best-Case Scenarios for Warming Less Likely, Groundbreaking Study Finds

The research narrows the range for how much Earth’s average temperature may rise if CO 2 levels are doubled

Worst- and Best-Case Scenarios for Warming Less Likely, Groundbreaking Study Finds

How much warming will greenhouse gas emissions cause in the coming years? It’s one of the most fundamental questions about climate change—and also one of the trickiest to answer.

Now, a  major study  claims to have narrowed down the range of possible estimates.

It presents both good and bad news. The worst-case climate scenarios may be somewhat less likely than previous studies suggested. But the best-case climate scenarios—those assuming the least amount of warming—are almost certainly not going to happen.

It’s “the most important climate science paper that’s come out in several years,” according to climate scientist Andrew Dessler of Texas A&M University, who was not involved with the study.

The effort also illuminates some of the challenges of a decadeslong scientific quest to predict the strength of future climate change.

At the heart of the new study is a concept known as “climate sensitivity”—how sensitive the Earth is to greenhouse gas emissions and how much it’s likely to warm in response. In studies, scientists often focus on the amount of warming that might be expected if carbon dioxide concentrations doubled their preindustrial levels.

It’s a hypothetical scenario, but one that’s not impossible.

Prior to the industrial era—around 150 years ago—global CO 2 concentrations hovered around 280 parts per million in the atmosphere. Doubling that amount would put the total at 560 ppm.

Today, CO 2 levels have climbed above 400 ppm.

The metric has existed for decades now. In 1979, a groundbreaking  report  led by Massachusetts Institute of Technology scientist Jule Charney—dubbed the “Charney Report”—suggested the planet’s climate sensitivity probably fell within a range of 1.5 to 4.5 degrees Celsius for a doubling of CO 2 .

In the years since, that range hasn’t changed much. Most studies have found that the amount of warming to be expected after a doubling of CO 2 probably falls within those boundaries.

The most recent assessment report from the United Nations’ Intergovernmental Panel on Climate Change, published in 2014, suggested there was about a 66% chance—a “likely” probability, in other words—that the climate sensitivity range falls between 1.5 and 4.5 C. That’s anywhere from 2.7 to 8.1 degrees Fahrenheit.

Many of the difficulties narrowing the range have stemmed from the sheer complexity of the question.

In a simple sense, greenhouse gases in the atmosphere warm the Earth by trapping heat from the sun that would otherwise be radiated back out into space. But there are other factors that can affect the total amount of warming the planet experiences over time.

These include physical changes in the air that makes up the atmosphere, the amount of water vapor in the atmosphere, and the melting of snow and ice on the Earth’s surface, which can speed up the rate of climate change as they disappear.

Then there’s the question of cloud feedbacks, often cited by scientists as one of the biggest uncertainties about future climate change. Warming in the atmosphere can change the size, density and lifespan of clouds. And clouds, in turn, are capable of either worsening or lessening global warming, depending on their characteristics.

Over the years, though, scientists have dramatically improved their understanding of the Earth’s climate response.

“Behind the scenes, underneath the hood, our understanding of a lot of the processes was much better,” Dessler told E&E News. “And so I think that even though the range hadn’t changed, that masked a real tremendous improvement in our understanding.”

Narrowing the range

The new study narrows the range at both ends, particularly the lower end. It finds there’s a 66% chance that the sensitivity range falls between 2.6 and 3.9 C of warming (4.9 to 7 F).

Several factors made the revised estimates possible.

Perhaps most importantly, the new study investigates multiple lines of evidence when it comes to climate sensitivity. It uses global climate models, which simulate large-scale processes across the whole world. It also uses detailed, process-based models, which can simulate fine-scale events related to the formation of clouds.

It also examines the Earth’s response to recent greenhouse gas emissions, since the onset of the industrial era. And it even uses ancient ice and sediment samples to look back at the Earth’s long-term climate history and evaluate how the planet changed in the past.

It’s a departure from many other recent sensitivity studies, according to Mark Zelinka, an atmospheric scientist at Lawrence Livermore National Laboratory and one of the study’s co-authors.

Most papers have focused on individual categories of evidence—for instance, only looking at the Earth’s ancient climate, or only investigating cloud feedbacks.

In an email to E&E News, Zelinka noted that “the various lines of evidence related to climate sensitivity have never really been systematically brought together and analyzed in concert.”

That’s critical for a question with so many different factors playing a role, and so many possible ways of investigating them.

This approach has allowed the authors to reduce their uncertainties about the new estimates, Dessler noted.

“What they’ve done here, effectively, is a meta-analysis of all the previous studies,” he said. “And then they use a statistical framework to try to take everything that people have published on this and everything we know and try to ask the question: What range of climate sensitivity is consistent with all of the evidence that’s out there?”

And since the new report relies on so many previous studies of climate sensitivity, it’s benefited from years of advancements in scientists’ understanding of the Earth’s climate system.

Clouds, in particular, are helping to close the gaps.

“The primary reason for difficulty in narrowing the range over the years is that we do not know well enough how clouds will respond to warming,” said Zelinka. “We have made a lot of progress on this recently, and this has contributed to narrowing the range.”

The new report devotes a large chunk of its analysis exclusively to clouds. It examines the growing body of science on how different types of clouds respond to climate change, and how changes in these clouds may affect future climate change.

The mounting evidence suggests that clouds are unlikely to mitigate climate change on a global scale, the report concludes. On the contrary, they’re more likely to make it worse.

With a new, more confident sensitivity estimate in hand, the report begs the question: What does this mean for future climate policy?

On the one hand, the study strikes a blow to a favorite argument used by climate deniers: The uncertainty about climate sensitivity suggests future warming might not actually be that severe.

The new report strongly suggests that the best-case sensitivity scenarios—those at the lower end of the old ranges—are probably not in the cards.

Still, the revised range doesn’t change much when it comes to the international climate goals outlined by the Paris Agreement. Nations worldwide are striving to keep global temperatures within 2 C of their preindustrial levels.

To reach that target, world leaders would have to ensure global CO 2 concentrations never double at all.

“It’s not clear to me how much we would gain from further decreases in the uncertainty” of this metric, Dessler said. “What this has done, in my opinion, is it’s really moved the game away from these questions about the physics of the climate system into questions about how are humans going to react to climate change.”

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at .


Chelsea Harvey is a reporter with E&E News .

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U.S. Climate Resilience Toolkit

Communities, businesses, and individuals are taking action to document their vulnerabilities and build resilience to climate-related impacts. Click dots on the map to preview case studies, or browse stories below the map. Use the drop-down menus above to find stories of interest. To expand your results, click the Clear Filters link.

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Discover the case studies from the Global Synthesis Report on Climate Action by Sector 2022

Discover in this article the 15 case studies available, to be found in the 2022 global synthesis report by sector 2022..

The Climate Chance Observatory offers 15 new case studies in its latest Global Synthesis Report, covering the 5 major emission sectors analyzed in the 2022 edition: energy, transport, building, waste and land use.

The goal? Highlight remarkable initiatives at the level of countries, regions or cities, which make it possible to identify the most effective tools to move towards a low-carbon society.

Some case studies are based on contributions from experts and specialized organizations.

Georgia :  Gender-sensitive energy cooperatives in Georgian rural areas , in partnership with WECF 

Mali :  Access to “clean” energy thanks to decentralised solar mini-grids 

Cambodia : A sustainable wood fuel value chain to combat deforestation , in partnership with GERES 


Buenos Aires :  Leveraging environmental and climate data to promote soft mobility , in partnership with UCLG 

Spain, Barcelona :  Sant Antoni, the green street inspiring the city , in partnership with Construction 21 

Zimbabwe :  Promoting access to sustainable and electric mobility in rural areas to empower women , in partnership with Movin’On Lab Africa

Austria, Vienna :  Phasing out fossil fuels in heating to decarbonise buildings , in partnership with EnergyCities 

Indonesia : Betting on reflective roofs to avoid air conditioning

France, Angers :  EnergieSprong, an industrialized zero-energy renovation project, a lever for mass uptake , in partnership with Green Flex 

Alsace : Towards a made in Europe production of low-carbon lithium with the EuGeLi project  

Kamikatsu :  A social project beyond the zero waste objective

São Paulo : A circular food system to reduce organic waste 

Yaeda Valley : By protecting their land and wildlife, local populations obtain income through the carbon compensation mechanism

Sundarbans : Banking on mangroves for land, life and livelihood 

Durban : Agroecology in the service of the fight against food inequalities

global climate change case study

Newsroom Post

Climate change widespread, rapid, and intensifying – ipcc.

GENEVA, Aug 9 – Scientists are observing changes in the Earth’s climate in every region and across the whole climate system, according to the latest Intergovernmental Panel on Climate Change (IPCC) Report, released today. Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion—such as continued sea level rise—are irreversible over hundreds to thousands of years.

However, strong and sustained reductions in emissions of carbon dioxide (CO 2 ) and other greenhouse gases would limit climate change. While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize, according to the IPCC Working Group I report, Climate Change 2021: the Physical Science Basis , approved on Friday by 195 member governments of the IPCC, through a virtual approval session that was held over two weeks starting on July 26.

The Working Group I report is the first instalment of the IPCC’s Sixth Assessment Report (AR6), which will be completed in 2022.

“This report reflects extraordinary efforts under exceptional circumstances,” said Hoesung Lee, Chair of the IPCC. “The innovations in this report, and advances in climate science that it reflects, provide an invaluable input into climate negotiations and decision-making.”

Faster warming

The report provides new estimates of the chances of crossing the global warming level of 1.5°C in the next decades, and finds that unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach.

The report shows that emissions of greenhouse gases from human activities are responsible for approximately 1.1°C of warming since 1850-1900, and finds that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming. This assessment is based on improved observational datasets to assess historical warming, as well progress in scientific understanding of the response of the climate system to human-caused greenhouse gas emissions.

“This report is a reality check,” said IPCC Working Group I Co-Chair Valérie Masson-Delmotte. “We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done, and how we can prepare.”

Every region facing increasing changes

Many characteristics of climate change directly depend on the level of global warming, but what people experience is often very different to the global average. For example, warming over land is larger than the global average, and it is more than twice as high in the Arctic.

“Climate change is already affecting every region on Earth, in multiple ways. The changes we experience will increase with additional warming,” said IPCC Working Group I Co-Chair Panmao Zhai.

The report projects that in the coming decades climate changes will increase in all regions. For 1.5°C of global warming, there will be increasing heat waves, longer warm seasons and shorter cold seasons. At 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health, the report shows.

But it is not just about temperature. Climate change is bringing multiple different changes in different regions – which will all increase with further warming. These include changes to wetness and dryness, to winds, snow and ice, coastal areas and oceans. For example:

For the first time, the Sixth Assessment Report provides a more detailed regional assessment of climate change, including a focus on useful information that can inform risk assessment, adaptation, and other decision-making, and a new framework that helps translate physical changes in the climate – heat, cold, rain, drought, snow, wind, coastal flooding and more – into what they mean for society and ecosystems.

This regional information can be explored in detail in the newly developed Interactive Atlas as well as regional fact sheets, the technical summary, and underlying report.

Human influence on the past and future climate

“It has been clear for decades that the Earth’s climate is changing, and the role of human influence on the climate system is undisputed,” said Masson-Delmotte. Yet the new report also reflects major advances in the science of attribution – understanding the role of climate change in intensifying specific weather and climate events such as extreme heat waves and heavy rainfall events.

The report also shows that human actions still have the potential to determine the future course of climate. The evidence is clear that carbon dioxide (CO 2 ) is the main driver of climate change, even as other greenhouse gases and air pollutants also affect the climate.

“Stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net zero CO 2 emissions. Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate,” said Zhai.

For more information contact:

IPCC Press Office [email protected] , +41 22 730 8120

Katherine Leitzell [email protected]

Nada Caud (French) [email protected]

Notes for Editors

Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change

The Working Group I report addresses the most updated physical understanding of the climate system and climate change, bringing together the latest advances in climate science, and combining multiple lines of evidence from paleoclimate, observations, process understanding, global and regional climate simulations. It shows how and why climate has changed to date, and the improved understanding of human influence on a wider range of climate characteristics, including extreme events. There will be a greater focus on regional information that can be used for climate risk assessments.

The Summary for Policymakers of the Working Group I contribution to the Sixth Assessment Report (AR6) as well as additional materials and information are available at

Note : Originally scheduled for release in April 2021, the report was delayed for several months by the COVID-19 pandemic, as work in the scientific community including the IPCC shifted online. This is first time that the IPCC has conducted a virtual approval session for one of its reports.

AR6 Working Group I in numbers

234 authors from 66 countries

Over 14,000 cited references

A total of 78,007 expert and government review comments

(First Order Draft 23,462; Second Order Draft 51,387; Final Government Distribution: 3,158)

More information about the Sixth Assessment Report can be found here .

About the IPCC

The Intergovernmental Panel on Climate Change (IPCC) is the UN body for assessing the science related to climate change. It was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988 to provide political leaders with periodic scientific assessments concerning climate change, its implications and risks, as well as to put forward adaptation and mitigation strategies. In the same year the UN General Assembly endorsed the action by the WMO and UNEP in jointly establishing the IPCC. It has 195 member states.

Thousands of people from all over the world contribute to the work of the IPCC. For the assessment reports, IPCC scientists volunteer their time to assess the thousands of scientific papers published each year to provide a comprehensive summary of what is known about the drivers of climate change, its impacts and future risks, and how adaptation and mitigation can reduce those risks.

The IPCC has three working groups: Working Group I , dealing with the physical science basis of climate change; Working Group II , dealing with impacts, adaptation and vulnerability; and Working Group III , dealing with the mitigation of climate change. It also has a Task Force on National Greenhouse Gas Inventories that develops methodologies for measuring emissions and removals. As part of the IPCC, a Task Group on Data Support for Climate Change Assessments (TG-Data) provides guidance to the Data Distribution Centre (DDC) on curation, traceability, stability, availability and transparency of data and scenarios related to the reports of the IPCC.

IPCC assessments provide governments, at all levels, with scientific information that they can use to develop climate policies. IPCC assessments are a key input into the international negotiations to tackle climate change. IPCC reports are drafted and reviewed in several stages, thus guaranteeing objectivity and transparency. An IPCC assessment report consists of the contributions of the three working groups and a Synthesis Report. The Synthesis Report integrates the findings of the three working group reports and of any special reports prepared in that assessment cycle.

About the Sixth Assessment Cycle

At its 41st Session in February 2015, the IPCC decided to produce a Sixth Assessment Report (AR6). At its 42nd Session in October 2015 it elected a new Bureau that would oversee the work on this report and the Special Reports to be produced in the assessment cycle.

Global Warming of 1.5°C , an IPCC special report on the impacts of global warming of 1.5 degrees Celsius above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty was launched in October 2018.

Climate Change and Land , an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems was launched in August 2019, and the Special Report on the Ocean and Cryosphere in a Changing Climate was released in September 2019.

In May 2019 the IPCC released the 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories , an update to the methodology used by governments to estimate their greenhouse gas emissions and removals.

The other two Working Group contributions to the AR6 will be finalized in 2022 and the AR6 Synthesis Report will be completed in the second half of 2022.

For more information go to

The website includes outreach materials including videos about the IPCC and video recordings from outreach events conducted as webinars or live-streamed events.

Most videos published by the IPCC can be found on our YouTube and Vimeo channels.

Call for case studies on climate change and health

The year 2021 is due to be a crucial year for international climate action, with far-reaching consequences for the long-term health and resilience of communities and societies. In recovering from the global shock caused by COVID-19 - and the resulting damage to livelihoods, health, and sustainable development – governments are increasingly urged to prioritise a healthy and sustainable recovery of their economies that takes into account the broader social and environmental determinants of health.

In May 2020, millions of health professionals called for a healthy recovery , and WHO released its  Manifesto for a green, healthy recovery from COVID-19 , laying out 6 prescriptions and over 70 actionables for more sustainable and healthy societies post-COVID.

In 2021, WHO and the global health community will continue to drive the conversation on recovery and resilience by envisioning how a healthy, equitable recovery from COVID-19 can advance the rapid decarbonization of the world economy. To further this goal, WHO will be collecting case studies on health and climate change, to be highlighted in upcoming events and initiatives throughout the year, including at the COP26 climate conference.

What kind of case studies are we looking for?

We are looking for short, real-life stories about an initiative, project or advocacy campaign that showcase some of the great work that is already being implemented to reduce the impact of climate change on human health, and to help communities and societies recover from COVID-19 and transition to a healthy, climate-resilient and climate-just future. Sharing experiences of less successful case studies and lessons learned is also welcome. 

What should a climate & health case study look like?

How to submit a case study?

The case studies can be submitted via this online form or in text format (1200 words max) , following the guiding questions , by email to [email protected] . The guiding questions are meant to help you structure your case study and help ensure all relevant information is present, but are not mandatory. Complementing the case studies with visual materials, such as photos from the field, would be most welcome.

Interested organizations and individuals are also encouraged to showcase their projects by submitting a short 1-2 minute video with footage and testimonials from the field, by email to [email protected] . These recordings could be used to create an advocacy video “The healthy, equitable and climate resilient future we want” that will be projected at the 2021 Global Conference on Health and Climate Change at the margin of COP26.

The deadline for submitting the case studies is August 31 st .

How will the case studies be used?

A selection of case studies will be presented at the upcoming Regional consultations on Climate Change and Health prepared by the World Health Organization (WHO) and the Global Climate and Health Alliance (GCHA) in April-May 2021.

Case studies will also be featured in the COP26 Special Report "The Health Argument for Climate Action", to be published in November 2021, and will be featured on the WHO website and on a forthcoming WHO/WMO Online Portal on Climate Change and Health*.

*Selected submissions will be further co-developed into case studies in collaboration with the WHO climate change team. Case studies aim to highlight the scope and diversity of ongoing global efforts on climate change and health, but do not necessarily imply endorsement from WHO.

Regional Consultations on Climate Change and Health

2021 Global Conference on Health and Climate Change

COP26 Case Studies on Climate Change and Health

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Global Climate Change

The global climate has changed significantly in the recent past. The change recorded revolves around the heating of the earth or increased planet’s temperature.

Many assumptions have been made regarding the causes of earth’s changes in temperature; with some quarters blaming human beings as the main cause of variance in the planet’s temperature. However, other quarters refute the assertion that men are behind the global climate change through refuting the points advanced by those proposing human beings as the main cause of the changes in global climate. For instance, those proposing the analyzed process is man-made have advanced that the increase in greenhouse gases and water vapors in the atmosphere are the main pointers people to be the cause of global climate change. In addition, the use of aerosols and domestication of animals has been blamed as contributing to earth’s climate modification. On the other hand, those opposing the aforementioned assumptions indicate that a green house gas such as carbon dioxide is not a pollutant as it plants utilize it for growth. Moreover, the opponents have refuted the idea that climate change is a global phenomenon.

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They note that climate change is regional, and it has been established to modify rapidly from the past, which explains why it will still keep changing in the future. Considering the above-indicated points, it can be deducted the researched process is man-made because of the human activities that have been mentioned. Thus, this essay explores why the global climate change is man-made. The global climate change occurs because of the activities that humans do. According to Archer (2011), man-made climate change are resulted of the increased greenhouse gases emission into the atmosphere.

This happens mainly through two major activities, which include manufacturing in the factories and agricultural activities. Notably, the two pointed processes of producing enhance the greenhouse effect. This has a profound impact on earth because the greenhouse gases such as carbondioxide, water vapor and other gases in the atmosphere are not impervious to the sun. They allow the sun’s penetration into the atmosphere, which absorbs the planet’s heat that could be otherwise absorbed into outer space. Booth, Hammond, Lamond, & Proverbs (2012) assert that there would be no adverse climatic changes if the greenhouse gases were not emitted in large quantities into the earth’s atmosphere. Alternatively, it should be considered that, in limited quantities, the greenhouse gases in the earth’s atmosphere are more acceptable than a total lack of those; therefore this can also lead to lower of the atmosphere, which would make the planet uninhabitable.

Thus, more specifically, transport and agricultural activities are hugely blamed for the rising in such gases in the atmosphere. Humans eep advancing their transport from time to time: and the pollutant emissions have filled the surrounding our planet gaseous envelope with an emancipation of the road and air transport. These systems emit carbon into the atmosphere. Other greenhouse gases that contribute to global climate change include nitrous oxide, methane, hydroluorocarbons, sulphur hexafluoride and perfluorocarbons. Oxlade (2006) affirms these are entirely artificial gases, which prove that human beings are the main causes of the global climate change.

It is essential to note that power stations, which burn coal, are the main contributors of these greenhouse gases. Other causes of global warming include land use and livestock. These are human activitities and they contribute to climate modification in various ways. A case study by Shipley (2011) affirms that anthropogenic emmissions increased in the atmosphere between 1750-2007. The cause of growth of the harmful CO2 emmisions was the burning of fossil fuels, which is a human activity.

In addition, these greenhouse gases rose in the atmosphere due to the change in the use of land. Deforestation ranks top among the changes in land use by humans. This contributes to the global warming because of the reduction in the amount of carbon dioxide that the trees in the deforested areas could have absorbed. Hense the quantity of greenhouse causing gases in such areas doubles. It is also essential to note that deforestation goes hand in hand with burning of biomass, which also leads to the aforementioned process. These changes in land use are significantly human motivated; thus, are a weighty contribution to the global climatic changes.

Houghton (2004) has also been keen on the causes of climatic changes in around the globe, and he has noted that human domestication process is also a major contributor to global warming. This is effected by the increase in the number of livestock that humans have domesticated with time. According to Houghton (2004), livestock occupy almost 71 percent of the land that is utilized for agricultural purposes. Besides, Booth, Hammond, Lamond, & Proverbs (2012) point out that human liverstock activities contribute to emission of 9 percent carbon dioxide into the atmosphere, 37 percent of methane and 63 percent of nitrous oxide, which results because of fertilizer use.One more man-made cause of global climate change is blamed on the use of aerosols. Their use by human consequences to suspension of droplets or particles in the atmosphere and this leads to the cooling effect because it requires the burning of biomass, which begins with deforestation.

The use of aerosols also impacts on industrial pollution, especially while the production of soot, ammonium, airborne sulfates and nitrates. Lastly, the caused by desertification dust either contributes to global climatic changes. However, it also necessary to explore the ppoints advanced by opponents of global waming been a result of humans. Firstly, Houghton (2004) indicates that opponents believe carbon dioxide is not a contributor to changes in the global climate. This abounds from the fact that carbon plays a significant role in the atmosphere and has been in existence in the history of the earth. Since this chemical element has existed in more and few quantities, this proves the viewpoint that it plays a minimal role in altering the earth as plants also utilize it in their development.

Another position advanced by opponents is that climate change does not occur drastically. They are of the opinion that it takes a long time to change, and the fact humans are blamed for accelerating the change process is not genuine. In addition, the opponents of people been the cause of the climatic modification assert that the process cannot be claimed to be global. In their standpoint, climate change to be a regional affair and not a global one. This abounds from the fact that regional climate changes have been recorded to be changing adversely from the past, and it is a phenomenon that will continue in the future.

The opponents assert that humans will have to adapt to the changes as they unfold and they should not expect only warmer conditions that favor them. Despite the above allegations by opponents, they indicate that individuals should be cautious to engage in the destruction of the ennvironment, and try their best to preserve it for the next genrations. Nevertheless, the opponents statements do not hold much water as that of proponents regarding humans as the main cause of global climatic changes (Houghton, 2004). It should be noted that those supporting the notion that global climatic changes are initiated by men have produced solid evidence to back their claims.In conclusion, global climate transformations have baffled many people, whereas they have resulted to environments that humans and other animals cannot thrive in comfortably as they initially did. Thus, this has motivated many researchers into the causes of global climate changes, and various opinions have abounded.

Mostly, the analyzed phenomena have been blamed on human acivities. Some of man-made contribution to changes in global climatic conditions include desertification, livestock keeping, industries, transport and the use of aerosols. However, not everyone consented to the fact the global climatic change is entirely a man-made problem. Thus, opponents indicate that climatic modifications have been exhibited since time immemorial and this mostly occurs regionally as opposed to globally. Opponents also advance that greenhouse gas such as carbon dioxide is not as dangerous as it is implicated. This is because there earth has comprised of the gas from ancient times, and that plants also use it for their development, which renounces the claim that the gas is a major contributor to greenhouse effect, and global warming, as well.

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Climate change - case studies

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Setting an ambitious target in the utilities sector.


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Climate Risk-based Decision Analysis (CRIDA)

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global climate change case study


Through the AGWA network , an international community of practice for the application of bottom-up approaches to plan under deep uncertainty has steadily grown. This growth is indicative of the need for systematic guidance to develop long term planning under uncertainty and to come up with robust or resilience adaptation projects.

Several initiatives show the progressive uptake of CRIDA in decision-making processes. The UN Economic Commission for Europe highlights the use of CRIDA as part of their program of work for 2020-2022 to build capacity to increase resilience to climate change. The World Bank has institutionalized the application of the Decision Tree, to evaluate the resilience of their infrastructure investments, and what changes might be recommended. The Millennium Challenge Corporation successfully applied CRIDA to design robustness into a Lusaka water treatment plant in Zambia. A highly collaborative CRIDA approach was also used in the city of Udon Thani, Thailand for an investment strategy to enhance resilience to urban floods and droughts. The city is currently in the design and construction ($25 million) of a first phase, based on a recommendation from a CRIDA study, that integrates urban storm water storage and diversion with recreation at the downtown.Through continuous training and outreach, UNESCO-IHP is developing a global CRIDA community of practice. Translations of the CRIDA book in different languages also supports this effort.  

In the U.S., the California Department of Water Resources (DWR) conducted a CRIDA study of the State Water Project (SWP) which delivers approximately 4.2 million acre-feet of water per year to more than 27 million Californian and over 750,000 acres of farmland. This study is published in the California Fourth Climate Change Assessment. A second pilot, supported during initial stages by the Institute for Water Resources, adopted the CRIDA approach to enhance flood and drought resilience in the Tuolumne River basin. This pilot established CRIDA’s capacity to support multi-objective decisions in large water resource systems with diverse federal, state and local interests. The DWR recently convened a conference highlighting this work, which focused on better integrating CRIDA style approaches and tools into the state’s long term water resource plans. CRIDA provided DWR a pragmatic framework to implement the California State Executive Order N-10-19 to prepare “a water resilience portfolio that meets the needs of communities, economy, and environment through the 21st century.”

An extensive CRIDA study has also been implemented in the Chilean agriculture-intensive Limari Basin, identifying adaptation options in a region heavily impacted by the recent mega-drought (2010-2020), as well as projected to become drier under climate change scenarios.

Colombo, Sri Lanka. Yasas Upeakshika Amilakumari Bandara. 2018. Collaborative Risk-Informed Decision Analysis for Climate Change Adaptation at Municipal Water Supply of Colombo, Sri Lanka. Asian Institute of Technology, master’s thesis.

Bangkok, Thailand. “Collaborative Risk Informed Decision Analysis (CRIDA): An Evaluation of Critical Thresholds for Bangkok Water Supply Utility. Ms. Rachel Koh, Asian Institute of Technology. Supervisor: Prof Mukand Singh Babel.

Philippines . Gilroy, Kristin and Jeuken, Ad. 2018. Collaborative Risk Informed Decision Analysis: A water security case study in the Philippines. Climate Services 11: 62-71.

Udon Thani, Thailand. Mendoza et al., in prep. Reducing flood risk through green infrastructure in Udon Thani, Thailand.  A highly collaborative CRIDA approach was used in the city of Udon Thani, Thailand for an investment strategy to enhance resilience to urban floods and droughts. The city is currently in the design and construction ($25 million) of a first phase (recommended from the CRIDA study) that integrates urban storm water storage and diversion with recreation at the downtown.

Latin American and the Caribbean

Colombia. Gómez-Dueñas, Santiago, Kristin Gilroy, Berry Gersonius and Michael McClain. 2018. Decision Making under Future Climate Uncertainty: Analysis of the Hydropower Sector in the Magdalena River Basin, Colombia. Aqua-LAC 10(2): 81-92.

Chile. Verbist, K. M. J., H. Maureira, P. Rojas and S. Vicuna. In press. A Stress Test for Climate Change Impacts on Water Security: a CRIDA Case Study. Climate Risk Management Journal. Article reference: CRM_CLRM_2019_150.  

Verbist, K., Rojas, P. and H. Maureira. 2020. A Stress Test for Climate Change Impacts on Water Security - Case study from the Limarí Watershed in Chile . UNESCO, Paris, 45p.

Mexico. WWF-Mexico, AGWA, WWF, IHP, CAZALAC, CONAGUA, IDB. Eco-Engineering: “Examining Mexico’s Water Reserves Program as an Ecosystem-Based Adaptation Instrument” – “assess the role of water reserves in assisting natural and human systems as they adapt to climate change and to understand the role of water reserves as an adaptation tool for CONAGUA.” . CONAGUA is implementing in 300 basins.

Guayaquil, Ecuador . Ongoing Deltares study. “Guayaquil invests in flood resilience and climate adaptation… Guayaquil is among the most vulnerable coastal delta-cities in the world and prone to urban flooding by intensive rainfall and high sea levels. Together with the municipality of Guayaquil, Deltares is leading a consortium that will improve the city’s resilience to urban flooding resulting in an adaptation strategy for future climate change. The main output will be an investment strategy for flood risk adaptation for the Febres Cordero neighbourhood, which has about 400.000 inhabitants…“Project activities include a bottom-up vulnerability assessment, the identification and evaluation of potential actions, the development of an adaptation strategy as well as an analysis for opportunities for upscaling towards other neighbourhoods and delta cities. The participative planning approach will be based on CRIDA (Collaborative Risk Informed Decision Analysis)…The Guayaquil Partners for Water project will be one of the first applications of this integrated approach.”

Zambia - Iolanda – - “The intake structure at the Iolanda water treatment plant was rehabilitated under the Zambia compact. MCC’s pilot of the CRIDA approach examined investment decisions at Iolanda in light of uncertainties about future water availability.”

Tkach, M., J. Kucharski, J. Olszewski, R. Chaudhry, and G. Mendoza. In Press. A risk informed study to enhance water supply resilience of the Iolanda Water treatment plant in Zambia.

Sweden - Carstens, Christoffer, Karin Mossberg Sonnek, Riitta Räty, Per Wikman-Svahn, Annika Carlsson-Kanyama and Jonathan Metzger. 2019. Insights from Testing a Modified Dynamic Adaptive Policy Pathways Approach for Spatial Planning at the Municipal Level. Sustainability 2019, 11(2), 433; . Uses a simplified form of Dynamic Adaptive Policy Pathways (DAPP) or CRIDA, which they cite 15 times.

Lower Rhine River . Extensive simulations by Deltares of the “Waas” River, based on the lower Rhine. Appears throughout Deltares literature.

North America

Lake Ontario–St. Lawrence . The International Lake Ontario–St. Lawrence River Study (March 2006) and the International Upper Great Lakes Study (March 2012)—led the International Joint Commission (IJC) to advise the U.S. and Canadian governments about long-term management of the North American Great Lakes in light of transboundary stakeholders and complex climate impacts. This advice included decisions on improved regulation of lake outflows and on infrastructural investments as well as the adoption of an adaptive management strategy to address uncertain impacts and potential extreme water levels (International Joint Commission 2013)…Large uncertainties remained. Indeed, a variety of hydrological parameters had data errors larger than the potential climate change signals. A process of adaptive management was recommended to establish a structured, iterative process of evaluation with the aim of reducing uncertainty over time and, if necessary, adjusting earlier management decisions. Therefore, the Great Lakes Adaptive Management (GLAM) Committee was created…

California . In the U.S., the California Department of Water Resources (DWR) conducted a CRIDA study of the State Water Project (SWP) which delivers approximately 4.2 million acre-feet of water per year to more than 27 million Californian and over 750,000 acres of farmland. This study is published in the California Fourth Climate Change Assessment.

A second pilot, supported during initial stages by the Institute for Water Resources, adopted the CRIDA approach to enhance flood and drought resilience in the Tuolumne River basin. This pilot established CRIDA’s capacity to support multi-objective decisions in large water resource systems with diverse federal, state and local interests.

The DWR recently convened a conference highlighting this work, which focused on better integrating CRIDA style approaches and tools into the state’s long term water resource plans. CRIDA provided DWR a pragmatic framework to implement the California State Executive Order N-10-19 to prepare “a water resilience portfolio that meets the needs of communities, economy, and environment through the 21st century.”

global climate change case study

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Climate Change


What's Happening & Why


Thousands of studies conducted by researchers around the world have documented increases in temperature at Earth’s surface, as well as in the atmosphere and oceans. Many other aspects of global climate are changing as well.  Human activities, especially emissions of heat-trapping greenhouse gases from fossil fuel combustion, deforestation, and land-use change, are the primary driver of the climate changes observed in the industrial era.

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Water footprint sustainability as a tool to address climate change in the wine sector: a methodological approach applied to a portuguese case study.

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1. Introduction

2. experiments, 2.1. case studies, 2.2. methodology, 2.2.1. field experiments in the vineyard, 2.2.2. sector sustainability assessment and life cycle assessment approach, 3.1. water footprint in the vineyard.

3.2. Water Footprint in the Winery Stage

3.3. lca indicators and water footprint sustainability, 3.3.1. indicators for water scarcity assessment, 3.3.2. indicators for water footprint profile assessment, 4. discussion, 4.1. direct water footprint in the vineyard, 4.2. direct water footprint in the winery, 4.3. water footprint sustainability assessment, 4.4. strategies to mitigate water footprint, 5. conclusions, author contributions, acknowledgments, conflicts of interest.

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Saraiva, A.; Presumido, P.; Silvestre, J.; Feliciano, M.; Rodrigues, G.; Silva, P.O.e.; Damásio, M.; Ribeiro, A.; Ramôa, S.; Ferreira, L.; Gonçalves, A.; Ferreira, A.; Grifo, A.; Paulo, A.; Ribeiro, A.C.; Oliveira, A.; Dias, I.; Mira, H.; Amaral, A.; Mamede, H.; Oliveira, M. Water Footprint Sustainability as a Tool to Address Climate Change in the Wine Sector: A Methodological Approach Applied to a Portuguese Case Study. Atmosphere 2020 , 11 , 934.

Saraiva A, Presumido P, Silvestre J, Feliciano M, Rodrigues G, Silva POe, Damásio M, Ribeiro A, Ramôa S, Ferreira L, Gonçalves A, Ferreira A, Grifo A, Paulo A, Ribeiro AC, Oliveira A, Dias I, Mira H, Amaral A, Mamede H, Oliveira M. Water Footprint Sustainability as a Tool to Address Climate Change in the Wine Sector: A Methodological Approach Applied to a Portuguese Case Study. Atmosphere . 2020; 11(9):934.

Saraiva, Artur, Pedro Presumido, José Silvestre, Manuel Feliciano, Gonçalo Rodrigues, Pedro Oliveira e Silva, Miguel Damásio, António Ribeiro, Sofia Ramôa, Luís Ferreira, Artur Gonçalves, Albertina Ferreira, Anabela Grifo, Ana Paulo, António Castro Ribeiro, Adelaide Oliveira, Igor Dias, Helena Mira, Anabela Amaral, Henrique Mamede, and Margarida Oliveira. 2020. "Water Footprint Sustainability as a Tool to Address Climate Change in the Wine Sector: A Methodological Approach Applied to a Portuguese Case Study" Atmosphere 11, no. 9: 934.

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Inferring future changes in gene flow under climate change in riverscapes: a pilot case study in fluvial sculpin

Landscape Ecology ( 2023 ) Cite this article

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Global climate change poses a significant threat to the habitat connectivity of cold-water-adapted organisms, leading to species extinctions. If gene flow can be modeled by landscape variables, changes in connectivity among populations could be predicted. However, in dendritic and heterogeneous stream ecosystems, few studies have estimated the changes in gene flow from genetic data, in part due to the difficulty in applying landscape genetics methods and accessing water temperature information.

Inferring the determinants and future changes of the gene flow in the cold-water adapted fluvial sculpin Cottus nozawae using a recently developed model-based riverscape genetics technique and a hydrological model for estimating water temperature.

The strength of gene flow on each stream section was modeled by watershed-wide riverscape variables and genome-wide SNP data for C. nozawae in the upper reaches of the Sorachi River, Hokkaido, Japan. Future changes in gene flow were inferred by this model and hydrologically estimated water temperatures under the high greenhouse gas concentration scenario (IPCC RCP8.5).

Stream order, water temperature, slope, and distance were selected as riverscape variables affecting the strength of gene flow in each stream section. In particular, the trend of greater gene flow in sections with higher stream order and lower temperature fluctuations or summer water temperatures was pronounced. The map from the model showed that gene flow is overall prevented in small tributaries in the southern area, where spring-fed environments are less prevalent. Estimating future changes, gene flow was predicted to decrease dramatically at the end of the twenty-first century.


Our results demonstrated that the connectivity of cold-water sculpin populations is expected to decline dramatically in a changing climate. Riverscape genetic modeling is useful for gaining information on population connectivity that does not fully coincide with habitat suitability.

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We thank Nobuo Ishiyama for his cooperation in validating the hydrological model. This study is partly supported by the research fund for the Ishikari and Tokachi Rivers provided by the Ministry of Land, Infrastructure, Transport and Tourism of Japan.

This study is partly supported by the research fund for the Ishikari and Tokachi Rivers provided by the Ministry of Land, Infrastructure, Transport and Tourism of Japan.

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Souta Nakajima

Present address: Water Environment Research Group, Public Works Research Institute, Minamihara 1-6, Tsukuba, Ibaraki, 305-8516, Japan

Authors and Affiliations

Graduate School of Agriculture, Hokkaido University, Kita-Ku N9W9, Sapporo, Hokkaido, 060-8589, Japan

Souta Nakajima & Futoshi Nakamura

Graduate School of Engineering, Muroran Institute of Technology, Mizumoto-Cho 27-1, Muroran, Hokkaido, 050-8585, Japan

Hiroaki Suzuki & Makoto Nakatsugawa

Research Institute of Energy, Environment and Geology, Hokkaido Research Organization, Kita-Ku N19W12, Sapporo, Hokkaido, 060-0819, Japan

Hiroaki Suzuki

Graduate School of Agricultural Science, Tohoku University, Yomogida 232-3, Naruko-Onsen, Osaki, Miyagi, 989-6711, Japan

Ayumi Matsuo, Shun K. Hirota & Yoshihisa Suyama

Present Address: Botanical Gardens, Osaka Metropolitan University, Kisaichi 2000, Katano, Osaka, 576-0004, Japan

Shun K. Hirota

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Conceptualization, S.N. and F.N.; Data curation, S.N. and S.K.H.; Formal analysis, S.N.; Funding acquisition; F.N.; Investigation, S.N., H.S., A.M., and S.K.H.; Methodology, S.N., H.S., M.N., and Y.S.; Project administration, F.N.; Resources, S.N., M.N., A.M., and Y.S.; Software, S.N. and H.S., A.M., and S.K.H.; Supervision, M.N., Y.S. and F.N.; Validation, S.N. and F.N.; Visualization, S.N.; Writing – original draft, S.N. and H.S.; Writing – review & editing, S.N., H.S., M.N., A.M., S.K.H., Y.S., and F.N.

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Nakajima, S., Suzuki, H., Nakatsugawa, M. et al. Inferring future changes in gene flow under climate change in riverscapes: a pilot case study in fluvial sculpin. Landsc Ecol (2023).

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Duke University Center for International and Global Studies

You are here, climate change and migration.

Piotr-Plewa-card_Climate Change and Migration_Duke Center for International and Global Studies

By Piotr Plewa  (Visiting Research Scholar, Duke University, DUCIGS fellow)

Today, one percent of the world is a barely livable hot zone. By 2070, this portion may increase to nineteen percent (NYT, 2020). The shrinking of livable habitat has made some people migrate and others adapt how they live and work.  According to World Bank’s most recent study on climate change and migration, Groundswell II, between 44 and 216 million people could migrate within their country of residence by 2050 (Clement et al. 2021).

Why do people migrate or adapt in place without migrating?

Climate has caused people to migrate or adapt in situ for hundreds of years. Even though climate change has accelerated in recent years, this does not mean that migration is inevitable (Ionesco and Chazanoel, n.d.). When migration happens, it is usually caused by a combination of factors, such as conflict and environmental change rather than environmental change alone. Migration is also more likely when there are no alternatives to leaving the usual place of residence (IDMC, 2021: 50).   Humans have suffered from both fast as well as slow occurring environmental processes.  Initially environmental migration has been associated with the fast processes, such as storms, floods or fires. Causing crises these processes attracted considerable attention.  It was not until recently that environmental migration became also associated with the slow processes, such as changing rainfall patterns, sea level rise, ocean acidification, water sanlinization or land erosion. These - less perceptible- events have become more frequent and intense (IPCC, 2014). They have affected people’s livelihoods and security (IDMC, 2021). 

Rising sea levels and saltwater intrusion damage coastal infrastructure and freshwater fish or crops. The degradation of coastal ecosystems also reduces protection against storms, tsunamis and other sudden-onset events, leaving people more exposed. As a result, they may move to a higher elevation or another area, including from a rural to an urban habitat.

However, due to financial and social cost associated with displacement , people are slow to abandon their usual place of residence, especially without any guarantees about livelihood and safety in the new destination. Farmers are most vulnerable to environmental change, but they are also most attached to land and livestock, which may not be easy to move. Elderly are generally less mobile and in in some societies, they are more attached to ancestral lands.  Natural, cultural and political barriers can make migration more difficult. Furthermore,they may lead to conflicts with the population whose land or other resources are being threatened by newcomers.  Migration policies, including internal ones, such as China’s registration system can render the move less likely even within the same country (Sherbinin in MPI, 2021c). Investments in disaster risk reduction, climate change adaptation and sustainable development can lower the likelihood of migration (IDMC, 2021a: 46).

Who are environmental migrants?

 According to International Organization of Migration (IOM, 2007: 33), environmental migrants are:

This definition recognizes that environmental migration can be forced or voluntary, temporary or permanent, within or across international borders. Furthermore, migration can result either from sudden-or slow - onset environmental processes.  In most cases, environmental migrants move in the context of a combination of environmental, economic, political and social factors and within national borders.

Due to the complex and multi-causal character of environmental migration, environmental migrants are not considered refugees under 1951 Refugee Convention.  There is a debate whether recognizing the term “environmental refugees” could undermine the protection of conventional refugees. While not as protected as refugees, environmental migrants are still protected by the Guiding Principles on Internal Displacement as well as by the international human rights law.

How many environmental migrants are there?

Even though climate change is considered an increasingly stronger driver of migration, the scale of displacement, especially associated with the slow-onset disasters and environmental change, is very difficult to monitor. Projections of environmentally-induced migration vary substantially, due to the different methodologies used and many uncertainties, such as the impact of environmental change and the ability or willingness of people to migrate.

One of the main challenges associated with monitoring displacement in the context of the slow-onset events is that such events do not become apparent until a crisis point has been reached (IDMC, 2021: 59).  Furthermore, according to Julia Blocher, intergovernmental organizations and governments may be cautious about citing estimated migration figures to avoid fueling anti-immigration narratives (Blocher in MPI 2021a).

According to Internal Displacement Monitoring Centre (IDMC), in 2020, disasters caused 30.7 million new displacements (IDMC, 2021). By comparison, conflict and violence caused 9.8 million new displacements that year.  The 2020 displacement figure is largely consistent with the trend for the 2011-2020 period. (IDMC, 2021: 6). 

East Asia and Pacific and South Asia experienced most new displacements in 2020. Fewer people were displaced in Americas Sub-Saharan Africa, Middle East and North Africa, Europe and Central Asia (figure 1) (IDMC, 2021:8).  The high impact on Eat and South Asia may be due to the region’s vulnerability to storms and floods (figure 2).

Figure 1: New displacements in the context of disasters, 2020. Source: Author, based on IDMC, 2021

In 2020, the vast majority of people were displaced in the context of tropical storms and floods (figure 2).  Wildfires, earthquakes and volcanic eruptions, landslides, extreme temperatures and droughts were less likely to cause displacement (IDMC, 2021: 10). 

Especially vulnerable to tropical storms and floods -China, the Philippines and Bangladesh- recorded more than four million new displacements each. Many of these displacements were pre-emptive evacuations (IDMC, 2021: 9). Afghanistan (16 %), India (13 %) and Pakistan (11%) accounted for most of the 7 million displacements as a result of disasters (IDMC, 2021: 12).

There is no reliable data on how long people remain displaced. However, there is a general agreement that most displaced do not return to their areas of origin. The displacement is more likely to become permanent when it occurred in the context of both conflict and climate change.  In some cases the same population can be displaced more than one time (IDMC, 2021: 6). 

Looking into the mid-term future, World Bank estimated that by 2050, without climate and development action, climate change could displace between 44 to 216 million people within the borders of their countries of residence, most in Sub-Saharan Africa, followed by South East Asia and the Pacific, South Asia, North Africa, Latin America and Eastern Europe and Central Asia (figure 3). The actual number of people moving would depend on the environmental change and governments’ action, including their ability to reduce global green house emissions (Clement et al., 2021).

Figure 3 Predicted maximum internal migration in the context of climate change (in millions), 2070. Source: Author, based on Clement et al. 2021

What could policymakers do?

Since the nexus of environmental change and displacement was not recognized until recently, many countries have yet to recognize it and take action.

  Migration and environmental policies have so far been developed separately, by the institutions in charge of respective matters. Joint collaboration on migration in the context of environmental change would allow to minimize the usual challenges associated with working in a silo. Multi-stakeholder collaboration would improve data availability, strengthen policy coherence and maximize funding.

The Global Compact on Migration (GCM) created an opportunity for more collaboration within and between countries. Among others, the GCM recommended that states cooperate to design of appropriate measures in the countries of origin to make migration a choice rather than a necessity, to improve disaster preparedness, disaster risk reduction and disaster response, and to facilitate population movements (IOM, 2021).

More countries recognize displacement associated with the fast rather than slow-onset effects of climate change.  Furthermore, more of the adopted policies aim to prevent displacement than mitigate its impacts or create durable solutions (IDMC, 2021: 53). 

Several countries, mostly small-island states suffering from slow-onset effects of climate change, such as Fiji, Vanuatu and Maldives, have adopted planned relocation.  However, relocation tends to be lengthy as it requires agreement of those to be relocated, finding a place to relocate and funds to implement it. Once in a new place, the relocated people need appropriate infrastructure and services including housing, employment, healthcare, and education. The relocated individuals may need access to training, loans as well as land and livestock.  Even though the lack of longitudinal data does not make it yet possible to determine the duration of displacement, it is expected people may remain living in displacement for years. Hence, policies aimed to accommodate those who moved in the context of environmental change should integrate them in the host community.

  Poor integration of displaced migrants poses a threat of anti immigrant tensions, particularly if the host community fears that migrants may add to the competition for scarce resources.  According to Julia Blocher, governments should be prepared to be criticized for doing too much for migrants as well as for not doing enough (MPI, 2021a).

Displacement, particularly large scale and long-term can be costly to the individuals being displaced and to the countries in which displacement takes place. IDMC estimated that displacement costs for the countries with smaller economies, such as Somalia, can amount to 20 percent of their GDP (IDMC, 2021). Funding for displacement should be annual and predictable. It should address the root causes of migration as well the effects of migration. It should come from multiple institutions as well as support the collaborative action of multiple institutions (IDCM, 2021: 54).   Strengthening of governance and administrative capacities of the countries benefitting from funding would allow to use the funds more effectively.

There are still many unknowns about migration in the context of climate change. Better data on displacement could help governments budget for displacement better.  For instance, if governments were able to better predict the profiles of those likely to be displaced, they could plan, for the provision of services specific to particular groups – e.g. education for children, vocational training for youth and health services for elderly. 

Clement, Viviane; Rigaud, Kanta Kumari; de Sherbinin, Alex; Jones, Bryan; Adamo, Susana; Schewe, Jacob; Sadiq, Nian; Shabahat, Elham. 2021. Groundswell Part 2: Acting on Internal Climate Migration . World Bank, Washington, DC.

IDMC (2021a), Global Report on Internal Migration 2021. Internal Displacement in a Changing Climate .  Internal Displacement Monitoring Centre.

Ionesco, D., Chazanoel, T. (n.d.), The Global Compact for Safe, Orderly and Regular Migration – Perspectives on Environmental Migration . International Organization for Migration.

IOM (2007), Discussion Note. Migration and the Environment . Ninety-fourth session. MC/INF/288.

IPCC (2014), Climate Change 2014. Synthesis Report . The Intergovernmental Panel on Climate Change.

MPI (2021a), One Billion Climate Migrants? Not So Fast . Migration Policy Institute.

MPI (2021b), Talking Money: Climate Finance and Migration . Migration Policy Institute.

MPI (2021c), Does Climate Change Cause Migration? It’s Complicated . Migration Policy Institute.

NYT (2020), The Great Climate Change Migration has Begun .  New York Times Magazine. July 23, 2020.

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Climate risk and response: Physical hazards and socioeconomic impacts

After more than 10,000 years of relative stability—the full span of human civilization—the Earth’s climate is changing. As average temperatures rise, climate science finds that acute hazards such as heat waves and floods grow in frequency and severity, and chronic hazards, such as drought and rising sea levels, intensify (Exhibit 1). In this report, we focus on understanding the nature and extent of physical risk from a changing climate over the next one to three decades, exploring physical risk as it is the basis of both transition and liability risks.

Our research methodology

In this report, we measure the impact of climate change by the extent to which it could affect human beings, human-made physical assets, and the natural world. While many scientists, including climate scientists, are employed at McKinsey & Company, we are not a climate modeling institution. Our focus in this report has been on translating the climate science data into an assessment of physical risk and its implications for stakeholders. Most of the climatological analysis performed for this report was done by Woods Hole Research Center (WHRC), and in other instances, we relied on publicly available climate science data, for example from institutions like the World Resources Institute. WHRC’s work draws on the most widely used and thoroughly peer-reviewed ensemble of climate models to estimate the probabilities of relevant climate events occurring. Here, we highlight key methodological choices:

Choice of climate scenario. We draw on climate model forecasts to showcase how the climate has changed and could continue to change, how a changing climate creates new risks and uncertainties, and what steps can be taken to best manage them. Four “Representative Concentration Pathways” (RCPs) act as standardized inputs to climate models. They outline different atmospheric greenhouse gas concentration trajectories between 2005 and 2100. During their inception, RCPs were designed to collectively sample the range of then-probable future emission pathways, ranging from lower (RCP 2.6) to higher (RCP 8.5) CO 2 concentrations. Each RCP was created by an independent modeling team and there is no consistent design of the socio-economic parameter assumptions used in the derivation of the RCPs. By 2100, the four RCPs lead to very different levels of warming, but the divergence is moderate out to 2050 and small to 2030. Since the research in this report is most concerned with understanding inherent physical risks, we have chosen to focus on the higher-emission scenario, i.e. RCP 8.5, because of the higher-emissions, lower-mitigation scenario it portrays, in order to assess physical risk in the absence of further decarbonization.

Case studies. In order to link physical climate risk to socioeconomic impact, we investigate nine specific cases where climate change extremes are measurable . These cover a range of sectors and geographies and provide the basis of a “micro-to-macro” approach that is a characteristic of MGI research. To inform our selection of cases, we considered over 30 potential combinations of climate hazards, sectors, and geographies based on a review of the literature and expert interviews on the potential direct impacts of physical climate hazards. We find these hazards affect five different key socioeconomic systems: livability and workability, food systems, physical assets, infrastructure services, and natural capital.

We ultimately chose nine cases to reflect these systems and based on their exposure to the extremes of climate change and their proximity today to key physiological, human-made, and ecological thresholds. As such, these cases represent leading-edge examples of climate change risk. They show that the direct risk from climate hazards is determined by the severity of the hazard and its likelihood, the exposure of various “stocks” of capital (people, physical capital, and natural capital) to these hazards, and the resilience of these stocks to the hazards (for example, the ability of physical assets to withstand flooding). Through our case studies, we also assess the knock-on effects that could occur, for example to downstream sectors or consumers. We primarily rely on past examples and empirical estimates for this assessment of knock-on effects, which is likely not exhaustive given the complexities associated with socioeconomic systems. Through this “micro” approach, we offer decision makers a methodology by which to assess direct physical climate risk, its characteristics, and its potential knock-on impacts.

Global geospatial analysis. In a separate analysis, we use geospatial data to provide a perspective on climate change across 105 countries over the next 30 years. This geospatial analysis relies on the same five-systems framework of direct impacts that we used for the case studies. For each of these systems, we identify a measure, or measures, of the impact of climate change, using indicators where possible as identified in our cases.

Similar to the approach discussed above for our cases, our analyses are conducted at a grid-cell level, overlaying data on a hazard (for example, floods of different depths, with their associated likelihoods), with exposure to that hazard (for example, capital stock exposed to flooding), and a damage function that assesses resilience (for example, what share of capital stock is damaged when exposed to floods of different depths). We then combine these grid-cell values to country and global numbers. While the goal of this analysis is to measure direct impact, due to data availability issues, we have used five measures of socioeconomic impact and one measure of climate hazards themselves—drought. Our set of 105 countries represents 90 percent of the world’s population and 90 percent of global GDP. While we seek to include a wide range of risks and as many countries as possible, there are some we could not cover due to data limitations (for example, the impact of forest fires and storm surges).

What this report does not do

Since the purpose of this report is to understand the physical risks and disruptive impacts of climate change, there are many areas which we do not address in this report:

We estimate inherent physical risk, absent adaptation and mitigation, to assess the magnitude of the challenge and highlight the case for action. Climate science makes extensive use of scenarios ranging from lower (Representative Concentration Pathway 2.6) to higher (RCP 8.5) CO 2 concentrations. We have chosen to focus on RCP 8.5, because the higher-emission scenario it portrays enables us to assess physical risk in the absence of further decarbonization. (For more details click on “Our research methodology”). In this report, we link climate models  with economic projections to examine nine cases that illustrate exposure to climate change extremes and proximity to physical thresholds. A separate geospatial assessment examines six indicators to assess potential socioeconomic impact in 105 countries. We also provide decision makers with a new framework and methodology to estimate risks in their own specific context.


Seven characteristics of physical climate risk stand out, climate change is already having substantial physical impacts in regions across the world, socioeconomic impacts will likely be nonlinear and have knock-on effects, global socioeconomic impacts could be substantial, countries with lower gdp per capita levels are generally more exposed, what can decision makers do.

We find that physical risk from a changing climate is already present and growing. Seven characteristics stand out. Physical climate risk is:

Increasing: In each of our nine cases, the level of physical climate risk increases by 2030 and further by 2050. Across our cases, we find increases in socioeconomic impact of between roughly two and 20 times by 2050 versus today’s levels. We also find physical climate risks are increasing across our global country analysis even as some countries find some benefits (such as expected increase in agricultural yields in countries such as Canada ).

Spatial: Climate hazards manifest locally. The direct impacts of physical climate risk thus need to be understood in the context of a geographically defined area. There are variations between countries and within countries.

Warming is “locked in” for the next decade because of physical inertia in the geophysical system.

Non-stationary: As the Earth continues to warm, physical climate risk is ever-changing or non-stationary. Further warming is “locked in” for the next decade because of physical inertia in the geophysical system. Climate science tells us that further warming and risk increase can only be stopped by achieving zero net greenhouse gas emissions. Furthermore, given the thermal inertia of the earth system, some amount of warming will also likely occur after net-zero emissions are reached.

Nonlinear:  Socioeconomic impacts are likely to propagate in a nonlinear way as hazards reach thresholds beyond which the affected physiological, human-made, or ecological systems work less well or break down and stop working altogether. This is because such systems have evolved or been optimized over time for historical climates (Exhibit 2).

Systemic: While the direct impact from climate change is local, it can have knock-on effects across regions and sectors, through interconnected socioeconomic and financial systems.

Regressive: The poorest communities and populations within each of our cases typically are the most vulnerable. Climate risk creates spatial inequality, as it may simultaneously benefit some regions while hurting others.

Under-prepared: While companies and communities have been adapting to reduce climate risk, the pace and scale of adaptation are likely to need to significantly increase to manage rising levels of physical climate risk. Adaptation is likely to entail rising costs and tough choices that may include whether to invest in hardening or relocate people and assets.

The planet’s temperature has risen by about 1.1 degrees Celsius on average since the 1880s. This has been confirmed by both satellite measurements and by the analysis of hundreds of thousands of independent weather station observations from across the globe. Scientists find that the rapid decline in the planet’s surface ice cover provides further evidence. This rate of warming is at least an order of magnitude faster than any found in the past 65 million years of paleoclimate records.

The average conceals more dramatic changes at the extremes. In statistical terms, distributions of temperature are shifting to the right (towards warmer temperatures) and broadening. That means the average day in many locations is now hotter (“shifting means”), and extremely hot days are becoming more likely (“fattening tails”). For example, the evolution of the distribution of observed average summer temperatures for each 100-by-100-kilometer square in the Northern Hemisphere shows that the mean summer temperature has increased over time (Exhibit 3). The share of the Northern Hemisphere (in square kilometers) that experiences an extremely hot summer—three-standard-deviation hotter average temperature in a given summer—has increased from zero to half a percent.

Averages also conceal wide spatial disparities. Over the same period that the Earth globally has warmed by 1.1 degrees, in southern parts of Africa and in the Arctic, average temperatures have risen by 0.2 and 0.5 degrees Celsius and by 4 to 4.3 degrees Celsius , respectively. In general, the land surface has warmed faster than the 1.1-degree global average, and the oceans, which have a higher heat capacity, have warmed less.

The affected regions will grow in number and size

Looking forward, climate science tells us that further warming is unavoidable over the next decade at least, and in all likelihood beyond. With increases in global average temperatures, climate models indicate a rise in climate hazards globally. These models find that further warming will continue to increase the frequency and/or severity of acute climate hazards and further intensify chronic hazards (Exhibit 4).

Climate change affects human life as well as the factors of production on which our economic activity is based. We measure the impact of climate change by the extent to which it could disrupt or destroy human life, as well as physical and natural capital.

Climate change is already having a measurable socioeconomic impact and we group these impacts in a five-systems framework. This impact framework is our best effort to capture the range of socioeconomic impacts from physical climate hazards and includes:

Related Reading:

Additional case studies on climate risk include: Reduced dividends on natural capital? Could climate become the weak link in your supply chain? Will infrastructure bend or break under climate stress? Can coastal cities turn the tide on climate risk? Will mortgages and markets stay afloat in Florida? Will the world's breadbaskets become less reliable? How will African farmers adjust to changing patterns of precipitation? A Mediterranean basin without a Mediterranean climate?

Would you like to learn more about our Sustainability Practice ?

The nine distinct cases of physical climate risk in various geographies and sectors that we examine, including direct impact and knock-on effects, as well as adaptation costs and strategies, help illustrate the specific socioeconomic impact of the different physical climate hazards on the examined human, physical, or natural system (Exhibit 5). Our cases cover each of the five systems across geographies and include multiple climate hazards, sometimes occurring at the same location. Overall, our cases highlight a wide range of vulnerabilities to the changing climate.

Specifically, we looked at the impact of climate change on livability and workability in India and the Mediterranean ; disruption of food systems through looking at global breadbaskets  and African agriculture ; physical asset destruction in residential real estate in Florida  and in supply chains for semiconductors and heavy rare earth metals ; disruption of five types of infrastructure services and, in particular, the threat of flooding to urban areas ; and destruction of natural capital  through impacts on glaciers, oceans, and forests.

Our case studies indicate that physical climate risk is growing, often in nonlinear ways. Physical climate impacts are spreading across regions, even as the hazards and their impacts grow more intense within regions. Most of the increase in direct impact from climate hazards to date has come from greater exposure to hazards rather than from increases in the mean and tail intensity of hazards. In the future, hazard intensification will likely assume a greater role. Key findings from our cases include:

Most of the increase in direct impact from climate hazards to date has come from greater exposure to hazards rather than from increases in the mean and tail intensity of hazards. In the future, hazard intensification will likely assume a greater role.

While our case studies illustrate the localized impacts of a changing climate, rising temperatures are a global trend and we assess how physical climate hazards could evolve in 105 countries.

In our assessment of inherent risk, we find that all 105 countries are expected to experience an increase in at least one major type of impact on their stock of human, physical, and natural capital by 2030. Intensifying climate hazards could put millions of lives at risk, as well as trillions of dollars of economic activity and physical capital, and the world’s stock of natural capital. The intensification of climate hazards across regions will bring areas hitherto unexposed to impacts into new risk territory. In particular:

Download Climate risk and response: Physical hazards and socioeconomic impacts , the full report on which this article is based (PDF–3.7MB).

While all countries are affected by climate change, we find that the poorest countries could be more exposed, as they often have climates closer to dangerous physical thresholds. They also rely more on outdoor work and natural capital and have less financial means to adapt quickly. The risk associated with the impact on workability from rising heat and humidity is one example of how poorer countries could be more vulnerable to climate hazards. When looking at the workability indicator (that is, the share of effective annual outdoor working hours lost to extreme heat and humidity), the top quartile of countries (based on GDP per capita) have an average increase in risk by 2050 of approximately 1 to 3 percentage points, whereas the bottom quartile faces an average increase in risk of about 5 to 10 percentage points. Lethal heat waves show less of a correlation with per capita GDP, but it is important to note that several of the most affected countries—Bangladesh, India, and Pakistan, to name a few—have relatively low per capita GDP levels.

As the Earth warms, the spatial extent and share of time spent in drought is expected to increase, rising to greater than 80 percent in parts of the world by 2050, notably the Mediterranean, southern Africa, and Central and South America. © National Geographic

In the face of these challenges, policy makers and business leaders will need to put in place the right tools, analytics, processes, and governance to properly assess climate risk, adapt to risk that is locked in, and decarbonize to reduce the further buildup of risk.

Much as thinking about information systems and cyber-risks has become integrated into corporate and public-sector decision making, climate change will also need to feature as a major factor in decisions. For companies, this will mean taking climate considerations into account when looking at capital allocation, development of products or services, and supply chain management, among others. For cities, a climate focus will become essential for urban planning decisions. Financial institutions could consider the risk in their portfolios. Developing a robust quantitative understanding is complex and will also require the use of new tools, metrics, and analytics. At the same time, opportunities from a changing climate will emerge and require consideration. These could arise from a change in the physical environment, such as new places for agricultural production, or for sectors like tourism, as well as through the use of new technologies and approaches to manage risk in a changing climate. One of the biggest challenges could stem from using the wrong models to quantify risk. These range from financial models used to make capital allocation decisions to engineering models used to design structures. For example, current models may not sufficiently take into account geospatial dimensions or assumptions could be based on historical precedent that no longer applies.

Societies have been adapting to the changing climate, but the pace and scale of adaptation will likely need to increase significantly. Key adaptation measures include protecting people and assets, building resilience, reducing exposure, and ensuring that appropriate financing and insurance are in place. Implementing adaptation measures could be challenging for many reasons. The economics of adaptation could worsen in some geographies over time, for example, those exposed to rising sea levels. Adaptation may face technical or other limits. In other instances, there could be hard trade-offs that need to be assessed, including who and what to protect and who and what to relocate.

While adaptation is now urgent and there are many adaptation opportunities, climate science shows us that the risk from further warming can only be stopped by achieving zero net greenhouse gas emissions. Decarbonization is not the focus of this research, however, decarbonization investments will need to be considered in parallel with adaptation investments, particularly in the transition to renewable energy. Stakeholders should consider assessing their decarbonization potential and opportunities from decarbonization.

Jonathan Woetzel is a director of the McKinsey Global Institute, where Mekala Krishnan is a senior fellow. Dickon Pinner is a senior partner in McKinsey’s San Francisco office. Hamid Samandari is a senior partner in the New York office. Hauke Engel is a partner in the Frankfurt office. Brodie Boland is an associate partner in the Washington office. Carter Powis is a consultant in the Toronto office.

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    Click on map to enlarge. Communities across the United States are anticipating, planning, and preparing for the impacts of climate change. Below are examples of municipal, state, or tribal communities that have taken action. Select from the options below to view cases according to the area of interest, geographic region, or level of government.

  19. Post‐migratory nonbreeding movements of birds: A review and case study

    2.6 Responses to global change. Given that resources and environmental conditions are common drivers of post-migratory nonbreeding movements, ongoing climate change, and landcover change could impact populations and movement patterns of species undertaking these movements.

  20. Climate Change

    Human-induced climate change is already affecting many weather and climate extremes in every region across the globe. Evidence of observed changes in extremes such as heatwaves, heavy...

  21. Climate Change

    This collection of activities, case studies, and interactive maps provides students with a holistic picture of the current state of the Amazon rain forest. Mapping Climate Change ... Climate change is a long-term shift in global or regional climate patterns. Often climate change refers specifically to the rise in global temperatures from the ...

  22. Water Footprint Sustainability as a Tool to Address Climate Change in

    A linear correlation between the carbon footprint and the indirect blue water footprint was also observed for both case studies. Climate change is expected to cause an earlier and prolonged water stress period, resulting in an increase of about 40% to 82% of blue WFP. ... G.V.; Alves, F. Impacts of climate change on wine production: A global ...

  23. Inferring future changes in gene flow under climate change in

    Context Global climate change poses a significant threat to the habitat connectivity of cold-water-adapted organisms, leading to species extinctions. If gene flow can be modeled by landscape variables, changes in connectivity among populations could be predicted. However, in dendritic and heterogeneous stream ecosystems, few studies have estimated the changes in gene flow from genetic data, in ...

  24. Climate Change and Migration

    According to World Bank's most recent study on climate change and migration, Groundswell II, between 44 and 216 million people could migrate within their country of residence by 2050 (Clement et al. 2021). Why do people migrate or adapt in place without migrating? Climate has caused people to migrate or adapt in situ for hundreds of years.

  25. Climate risk and response

    Case studies. In order to link physical climate risk to socioeconomic impact, we investigate nine specific cases where climate change extremes are measurable. These cover a range of sectors and geographies and provide the basis of a "micro-to-macro" approach that is a characteristic of MGI research.

  26. ERIC

    This collective case study examined how three educators (a high school social studies teacher, a university social studies teacher educator, and minister teaching an adult population) used a multimedia based curriculum guide, "Teaching the Levees", to teach about climate change to examine public priorities in relation to the environment.