Skip to Content
Climate change

Climate change-fueled heatwaves could kill millions

This summer’s record-setting heat spells portend a far deadlier future.
August 3, 2020
Photo by Ashkan Forouzani on Unsplash

Blistering heatwaves are breaking temperature records around the globe this year, from Iraq to the American Southwest. And it’s only going to get worse, as climate change accelerates.

By the end of this century, extreme heat spells could kill roughly as many people as all infectious diseases combined, including HIV, malaria and yellow fever, according to a new study.

The findings: Heatwaves will kill an additional 73 people per 100,000 by 2100, under a scenario in which nations continue to pump out high levels of greenhouse gas emissions (known as RCP8.5), according to research by the Climate Impact Lab, a group of climate economists and researchers at several US universities.

In some of the hottest and poorest parts of the world, like Bangladesh, Pakistan and Sudan, the mortality rate could reach or exceed 200 deaths per 100,000.

But … A growing number of climate researchers argue such a high-end scenario, though often used, is too pessimistic given flattening global emissions. Under a more optimistic scenario in which greenhouse gas pollution peaks around 2040 and begin falling thereafter, additional deaths would decline to 11 per 100,000. Depending on the population at that point, that could still be around a million extra fatalities.

Adapt: The 73 deaths projection takes into account investments into climate adaptions that richer nations are likely to make into things like air conditioning and urban cooling centers, based on historic patterns. If a country can afford it, adaptations are well worth the cost, cutting the death rate by 29% and shrinking the blow to domestic GDP. But many poor, hot nations, which will already suffer disproportionately from worsening heat waves, won’t have that luxury.

Methods: The researchers drew their conclusions by analyzing the historic links between temperature records and mortality data in dozens of nations, and projecting future deaths using highly regional climate projections.

Deep Dive

Climate change

These three charts show who is most to blame for climate change

Getting to the bottom of which countries have contributed most to climate change is complicated, but a few pieces of data can help.

Super-hot salt could be coming to a battery near you

New battery chemistries can help unlock more renewable energy for the grid.

Power beaming comes of age

How power beaming could change the way we power everything from satellites to mobile phones and reduce carbon emissions.

Inside Alphabet X’s new effort to combat climate change with seagrass

A previously unrevealed program would use cameras, computer vision, and machine learning to track the carbon stored in the biomass of the oceans.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.