Climate Change Exposes 1 Billion More People to Extreme Heat Stress Each Year
Updated
Updated · abcnews.com · Jun 22
Climate Change Exposes 1 Billion More People to Extreme Heat Stress Each Year
3 articles · Updated · abcnews.com · Jun 22
Summary
A Nature Climate Change study found 22% of the global population now faces at least one day of extreme heat stress each year, up from 16% in the 1970s—about 1 billion additional people.
Researchers traced the rise to climate change after analyzing global heat-stress data from 1950 to 2024 using the Universal Thermal Climate Index, which captures temperature, humidity, wind, solar radiation and human response.
The burden is worsening both day and night: the 10 warmest nights each year have warmed faster than the 10 warmest days, and subtropical regions now see up to 50 extra days annually of strong to extreme heat stress.
Extreme heat stress now occurs 2.5 times more often in Europe and South America and twice as often in North America, underscoring growing health risks because high overnight temperatures leave less time for the body to recover.
The authors said heat-health action plans, early-warning systems, urban cooling measures and wider use of heat-stress metrics will be needed as heat becomes more frequent, severe and prolonged worldwide.
With nights warming faster than days, is the deadliest heat threat now the one that happens after sunset?
New models show heat is deadlier than we thought. Are we severely undercounting historical climate change victims?
As cities deploy cooling solutions, how can we ensure the most vulnerable communities are not left behind in the heat?
Escalating "Feels-Like Temperatures": The Human and Societal Toll of the Global Heat Crisis
Overview
The world is facing an intensifying global heat crisis, with heat stress rising significantly and posing immediate threats to human health and society. Since the 1970s, 'feels-like temperatures'—which combine heat and humidity—have consistently increased on the hottest days and nights. High humidity makes these conditions especially dangerous by preventing sweat from evaporating, the body's main way to cool down. As a result, humid heat waves are much more deadly than dry ones, and people struggle to recover, especially at night. Recent tragic events, such as the deaths of children during France's intense heat waves, highlight the urgent need for action.