Extreme heat and humidity are increasing across the globe, threatening millions of lives and economies in places where it could become fatal to work outdoors, scientists said on Friday.
Parts of Australia, India, Bangladesh, the Gulf, China, Mexico and the United States have experienced hundreds of previously rare incidents of extreme heat and humidity since 1979, said the study in the journal Science Advances.
These punishing conditions have lasted only one to two hours but climate change is likely to prolong them to about six hours at a time by 2060 and expand the affected areas, lead author Colin Raymond told the Thomson Reuters Foundation.
“That’s kind of a conservative estimate but that’s still earlier than anyone else had projected,” said Raymond, who did the research as a PhD student at Columbia University and now works for NASA.
Moist, humid conditions make it harder for people to sweat away excess heat, leading to health risks including heat stroke, which can kill or disable victims who go untreated, according to the US Centers for Disease Control and Prevention (CDC).
Many scientists are examining the potential increase in extreme heat and its impact on economies and health, with mental health problems set to soar as people have trouble sleeping and working.
A climate change activist in a hammock occupying Oxford Circus in the busy shopping district of central London on April 18, 2019 on the fourth day of an environmental protest by the Extinction Rebellion group. (AFP)
Limiting warming to 1.5C above pre-industrial times is the most ambitious goal of the 2015 Paris Agreement on climate change and world temperatures have already risen by 1.2C.
A separate paper published this week by the Netherland’s Wageningen University warned of “near-unlivable” heat of above 29 degrees Celsius (84.2°F) for a third of humanity by 2070.
In the Columbia University-led study, data from nearly 8,000 weather stations showed readings approaching or exceeding 30C have doubled since 1979, and two - in the Gulf and Pakistan’s Indus River Valley - reported values above 35C.