A Fifth of the World Could Live With Dangerous Heat by 2100, New Study Warns

Most people live in a place with a mean annual temperature of 55 to 80 degrees Fahrenheit. But billions of people could see that figure jump to 84 degrees or higher, research says.

Share this article

A man dumps water on his head from a Municipal Water Tanker to cool himself outside a slum cluster on a hot summer day in New Delhi, India on May 23, 2023. Credit: Kabir Jhangiani/NurPhoto via Getty Images
A man dumps water on his head from a Municipal Water Tanker to cool himself outside a slum cluster on a hot summer day in New Delhi, India on May 23, 2023. Credit: Kabir Jhangiani/NurPhoto via Getty Images

Share this article

One in five people could live in dangerously hot conditions by the end of the century if global warming continues at its current pace, even if nations uphold their pledges under the Paris Agreement, scientists warned in a new peer-reviewed study. It’s the latest research published in recent days that points to the stark human and societal costs of the accelerating climate crisis as global carbon emissions continue to rise to unprecedented levels.

The study, published Monday in the journal Nature Sustainability, estimates that some 2 billion people would see a mean annual temperature of 84 degrees Fahrenheit or higher, starting in as early as 2070, when Earth’s population is expected to reach at least 9.5 billion. Most people live in a “human climate niche” that ranges between a mean annual temperature of 55 degrees and 80 degrees, the researchers said, so that many people experiencing a major uptick in regional heat would be unprecedented.

Such a temperature threshold, where 84 degrees or higher becomes the middle ground for the year, can also be very dangerous for anyone without air conditioning or other means to cool off, the study’s authors also noted. According to their estimate, some of the nations that will be hardest hit by the heat are also home to some of the world’s poorest communities, where air conditioning typically isn’t an option.

Of the estimated 2 billion people that could be forced out of their climate niche and into dangerous extreme heat, the study found, 600 million will be in India, 300 million in Nigeria and 100 million in Indonesia.

“Those people who are affected are the poorer people on the planet,” Tim Lenton, director of the Global Systems Institute at Exeter and the study’s lead author, told Forbes. “At higher temperatures, life becomes unbearable, affecting water, agriculture and food. You can’t barricade yourself from climate change. There is an undeniable interconnection amongst nations.”

Among the study’s most pertinent findings is the drastic difference it would make for the world to limit average warming to just 1.5 degrees Celsius above pre-industrial levels—the most ambitious target of the Paris Agreement. Scientists estimate that under the global climate treaty’s current pledges, the world is still on track to warm by roughly 2.7 degrees Celsius by 2100. But if emissions were significantly slashed to limit average warming to 1.5 degrees, Monday’s study said, just 400 million people would be pushed outside their climate niche instead of 2 billion.

Monday’s study also comes on the heels of a major report released last week by the United Nations’ weather agency, which warned that heat will likely soar to record levels in many parts of the world over the next five years. Global warming, combined with a climate pattern known as El Niño, will largely drive that heat, the report’s authors said, with the next five years almost certainly set to be the warmest five-year period ever recorded.

“This will have far-reaching repercussions for health, food security, water management and the environment,” Petteri Taalas, the World Meteorological Organization’s secretary general, told the New York Times. “We need to be prepared.”

It’s not just extreme heat that climate scientists have warned about in recent days.

On Monday, the World Meteorological Organization released another report, which found that the economic damage of natural disasters continues to rise, even as improvements in early warning systems have helped reduce the loss of life. In that report, the U.N. body tallied nearly 12,000 extreme weather, climate and water-related events globally between 1970 and 2021 that have killed more than 2 million people and caused $4.3 trillion worth of economic damage.

And climate change is already affecting all parts of the world, not just the poorer regions. About $1.7 trillion of that financial damage took place in the United States alone.

The new studies and reports, in many ways, are pointing to a reality with which many people are already familiar. This week, swathes of India are baking under extreme heat, with some places reaching temperatures as high as 113 degrees Fahrenheit on Monday. Over the weekend, raging wildfires in Canada continued to send smoke south into the U.S., prompting officials in Colorado and Montana to issue air quality alerts. And last week, heavy rainfall inundated 43 towns in Italy, causing landslides and flash floods that killed 14 people and destroyed hundreds of roads.

More Top Climate News

States Reach Breakthrough Deal to Protect Drought-Stricken Colorado River: Arizona, California and Nevada on Monday proposed a plan to significantly reduce their water use from the drought-stricken Colorado River over the next three years, Suman Naishadham and Ken Ritter report for the Associated Press. Though temporary, the deal is a potential breakthrough in a year-long stalemate that pitted Western states against one another. It would conserve an additional 3 million acre-feet of water through 2026, when current guidelines for how the river is shared expire.

Climate Protesters Dragged from Shell Shareholder Meeting as They Rush Stage: Climate change protesters were dragged away by security Tuesday as they tried to storm the stage at Shell’s shareholder meeting, the Associated Press reports. The incident, one of several high-profile disruptions in recent weeks, comes as activist investors pressure banks and oil majors to adopt shareholder resolutions that more intentionally address how energy companies and their financiers will move away from fossil fuels and toward clean energy.

New York City Is Sinking Due to Weight of Its Skyscrapers, New Research Finds: A new study found that New York City is sinking under its own sheer weight, increasing the risk of flooding as climate change simultaneously drives sea level rise, Oliver Milman reports for the Guardian. The city’s buildings, including iconic skyscrapers like the Empire State Building, weigh roughly 1.68 trillion pounds altogether, the research found, and all that weight is compressing the region’s clay-rich soil and causing it to subside approximately 1-2 millimeters a year on average.

Today’s Indicator

44

That’s how many hours of sleep humans are losing every year on average as climate change drives warmer nighttime temperatures, according to a new study. Sleep loss was especially prominent in lower-income and elderly communities, it found.

Hi, and thanks for reading Inside Climate News. We hope you liked this article. While you were here, you may have noticed something that sets us apart from many other news outlets: our news is free to read.

That’s because Inside Climate News is a 501c3 nonprofit organization. We do not charge a subscription fee, lock our news behind a paywall, or clutter our website with ads. Instead, we give our news freely to you and to anyone who wants to learn about what’s happening to the climate.

We also share our news freely with scores of other media organizations around the country that can’t afford environmental journalism. We’ve built bureaus from coast to coast to get quality news to everyone who needs it. We collaborate, partner, and share.

Since day one, reader donations have funded every aspect of what we do. We opened our doors in 2007, and just six years later, earned a Pulitzer Prize for National Reporting. Now we run the oldest and largest dedicated climate newsroom in the country. We hold polluters accountable, expose environmental injustice, debunk misinformation, and inspire action.

It’s all possible because of readers like you. Today we’re asking you to invest in this work, our newsroom, and our continued growth. Help us keep reporting on the biggest crisis facing our planet and reach even more readers in more places. With your support, we can tell stories like the one you just read – stories that change hearts and minds and have seminal and enduring impact. Because of you, they’ll remain free for everyone, everywhere.

Please chip in now with whatever amount you can afford. It takes just a moment to give, and every gift makes a difference.

Thank you,

Share this article