A new assessment warns that if the Earth’s average temperature exceeds the pre-industrial average by 2 degrees, then in extreme heat events, a wide range of areas may become too hot to survive without artificial cooling.
The paper found that in a humid heat wave, even healthy people aged 18 to 60 are so hot that keeping a safe core body temperature will be about three to six percent, the size of the United States. It will threaten areas over 60 years old (more vulnerable) and will increase to about 35% of the planet.
The paper was just published in the Journal Nature Comments on Earth and Environment.
Last year was the first calendar year, with global average temperatures above 1.5 degrees above the pre-industrial average. At the current warming rate, it can reach 2 degrees by the middle or later stage of the 21st century.
“There are also likely to be a hitherto hot threshold for older people in the hottest areas of the planet so far,” said Tom Matthews, lead author of King’s College London. “In this case,” , even in the shadows, long-term exposure outside can be subjected to strong breezes and good condition of moisture, which is also expected to cause fatal heat.”
Based on previous work, this article asks “What if?” “What if we underestimate the heat and wetterness of the worst future events?” Radley Horton, professor of Columbia Climate School and co-author of the paper )explain.
Horton co-authored a 2017 paper that predicts that a fatal combination of heat and humidity may begin to appear later in the century, and then a 2020 study showed that they were already in a short time. Appeared,
To evaluate, the team combines scientific discoveries to link physical climate science to the risk of thermal mortality. The analysis examines what they call a “free” threshold, the threshold beyond which the threshold rises uncontrollably, and a “adverse” threshold, where the core temperature increases to 42 C in six hours.
Between 1994 and 2023, the unpaid threshold, temperature and humidity combination made the body uncoordinated, violating about 2% of the global land area for adults under the age of 60. More than 20% of the land surface crosses this threshold for older people. Although the unpaid thresholds for all age groups have been passed, so far the indivisible thresholds have been used only for older people.
If the levels are 4 to 5 degrees higher than before industry, in extreme cases, older people may experience uncompensated calories on about 60% of the land. At this warming level, the indivisible heat will also begin to become a threat to young people in the hottest subtropical areas.
Some regions are more likely to cross the small number of indispensable and unrelaxable thresholds, while sub-Saharan Africa and South Asia have the largest number of people.
“As more planets experience outdoor conditions too hot, it is crucial for our physiology that people can reliably enter cooler environments to avoid heating,” Matthews said.
There have been more than 260,000 heat-related deaths in the deadliest heat incidents since 2000. The deadliest incidents in the 21st century collectively resulted in nearly 200,000 deaths, including about 72,000 in Europe in 2003, another 62,000 in Europe in 2022, and the Russian heat wave in 2010, with about 56,000 deaths.
The study also involved researchers at the University of California Stanford, NASA Goddard Space Studies, and Boston University.
Adapted from a press release from King’s College London.
