Two billion people face exposure to ‘dangerous heat’ by 2100, study finds

23rd May 2023


Shutterstock 2180966313

Related Topics

Author

Chris Seekings

The number of people exposed to dangerously hot temperatures will increase from around 60 million today to two billion by 2100 under current climate policies, a new study has found.

This would represent 22% of the projected end-of-century population living with "dangerous" average temperatures of 29°C or higher.

However, limiting global warming to 1.5°C above pre-industrial levels, rather than a projected 2.7°C, would leave just 5% of the population exposed – saving a sixth of humanity from the extreme temperatures.

The study, led by researchers at the University of Exeter’s Global Systems Institute, highlights the “huge potential” for decisive climate policy to limit the human costs and inequities of climate change.

In “worst-case scenarios” of 3.6°C or even 4.4°C of global warming, it suggests that half of the world’s population could be exposed to dangerous heat.

“The costs of global warming are often expressed in financial terms, but our study highlights the phenomenal human cost of failing to tackle the climate emergency,” said professor Tim Lenton, director of the Global Systems Institute.

“For every 0.1°C of warming above present levels, about 140 million more people will be exposed to dangerous heat. This reveals both the scale of the problem and the importance of decisive action to reduce carbon emissions.

“Limiting global warming to 1.5°C rather than 2.7°C would mean five times fewer people in 2100 being exposed to dangerous heat.”

Human population density has historically peaked in places with an average temperature of about 13°C, with mortality increasing below and above this threshold, according to the study.

Assuming a future population of 9.5 billion people, it suggests that India would have the greatest number of people exposed to dangerous temperatures under 2.7°C of global warming – with more than 600 million.

However, under 1.5°C of global warming, this figure would be about 90 million.

Nigeria would have the second-largest heat-exposed population under 2.7°C of global warming, on more than 300 million, but less than 40 million under 1.5°C of warming.

The research team – which included the Potsdam Institute for Climate Impact Research, the International Institute for Applied Systems Analysis, and the Universities of Washington, North Carolina State, Aarhus and Wageningen – stress that the worst impacts can be avoided by rapid action to cut greenhouse gas emissions.

Speaking about the conception of the study, professor Marten Scheffer, of Wageningen University, said: “We were triggered by the fact that the economic costs of carbon emissions hardly reflect the impact on human wellbeing.

“Our calculations now help bridging this gap, and should stimulate asking new, unorthodox questions about justice.”

Image credit: Shutterstock

Subscribe

Subscribe to IEMA's newsletters to receive timely articles, expert opinions, event announcements, and much more, directly in your inbox.


Transform articles

Facing the climate emergency challenge in local government

It’s well recognised that the public sector has the opportunity to work towards a national net-zero landscape that goes well beyond improving on its own performance; it can also influence through procurement and can direct through policy.

19th March 2024

Read more

The UK government’s carbon capture, usage and storage (CCUS) strategy is based on optimistic techno-economic assumptions that are now outdated, Carbon Tracker has warned.

13th March 2024

Read more

The UK’s new biodiversity net gain (BNG) requirements could create 15,000 hectares of woodlands, heath, grasslands, and wetlands and absorb 650,000 tonnes of carbon each year.

13th March 2024

Read more

The UK government’s latest Public Attitudes Tracker has found broad support for efforts to tackle climate change, although there are significant concerns that bills will rise.

13th March 2024

Read more

Multinational corporations are undermining their net-zero commitments with excessive air travel and no plans to reduce ‘the low hanging fruit’ of carbon footprints, a study by Transport & Environment has found.

13th March 2024

Read more

The UK government’s climate adaptation plans are ‘inadequate’ and falling ‘far short’ of what is required, the Climate Change Committee (CCC) has warned today.

13th March 2024

Read more

Large businesses across the world are avoiding climate action due to fear they will be called out for getting their work wrong, according to a new Carbon Trust report.

29th February 2024

Read more

A thought-provoking discussion on how storytelling can change the world took place in Central London last night, alongside an exclusive sneak preview of an upcoming IEMA film series.

29th February 2024

Read more

Media enquires

Looking for an expert to speak at an event or comment on an item in the news?

Find an expert

IEMA Cookie Notice

Clicking the ‘Accept all’ button means you are accepting analytics and third-party cookies. Our website uses necessary cookies which are required in order to make our website work. In addition to these, we use analytics and third-party cookies to optimise site functionality and give you the best possible experience. To control which cookies are set, click ‘Settings’. To learn more about cookies, how we use them on our website and how to change your cookie settings please view our cookie policy.

Manage cookie settings

Our use of cookies

You can learn more detailed information in our cookie policy.

Some cookies are essential, but non-essential cookies help us to improve the experience on our site by providing insights into how the site is being used. To maintain privacy management, this relies on cookie identifiers. Resetting or deleting your browser cookies will reset these preferences.

Essential cookies

These are cookies that are required for the operation of our website. They include, for example, cookies that enable you to log into secure areas of our website.

Analytics cookies

These cookies allow us to recognise and count the number of visitors to our website and to see how visitors move around our website when they are using it. This helps us to improve the way our website works.

Advertising cookies

These cookies allow us to tailor advertising to you based on your interests. If you do not accept these cookies, you will still see adverts, but these will be more generic.

Save and close