Heat in S. Asia could exceed survivable levels by 2100: study
South Asia, home to one- fifth of the world’s population, could see humid heat rise to unsurvivable levels by the century’s end if nothing is done to halt global warming, researchers said Wednesday.
The study in the journal Science Advances warned of “summer heat waves with levels of heat and humidity that exceed what humans can survive without protection.”
The research is based on two climate models. One is a “business- as- usual” scenario in which little is done to contain climate change.
The second is aimed at lim- iting temperature rise to well below two degrees Celsius, as pledged by more than 190 nations under the 2015 Paris climate accord.
The study is the first of its kind to look not just at temperatures, but at the forecast of “wet- bulb temperature,” which combines temperature, humidity and the human body’s ability to cool down in response.
The survivability threshold is considered to be 35 C, or 95 degrees Fahrenheit.
Under a business- as- usual scenario, “wet- bulb temperatures are projected to approach the survivability threshold over most of South Asia, and exceed it at a few locations, by the end of the century,” said the report.
About 30 percent of the population in the region would be exposed to these harmful temperatures, up from zero percent at present, said the report.
The densely populated farming regions of South Asia could fare the worst, because workers are exposed to heat with little opportunity for escape into airconditioned environments.
“Deadly heat waves could begin within as little as a few decades to strike regions of India, Pakistan, and Bangladesh, including the fertile Indus and Ganges river basins that produce much of the region’s food supply,” said the report.
India is home to 1.25 billion people, while another 350 million live in Bangladesh and Pakistan.
Already in 2015, the fifthdeadliest heat wave in modern history swept over large parts of India and Pakistan, killing some 3,500 people.