The intense heatwave experienced by most of South and Southeast Asia this year was made 30 times more likely due to human-caused climate change, according to the World Weather Attribution group, an international coalition of leading climate scientists.

In April, countries including Bangladesh, India, Laos and Thailand experienced record-breaking heatwaves, with temperatures soaring as high as 45°C in Thailand and 42°C in Laos.

The World Weather Attribution’s latest report revealed that in both the South Asian and Southeast Asian regions, temperatures were at least two degrees Celsius hotter than they would have been without climate change.

“Global temperatures will continue to increase and events like this will become more frequent and severe…until overall greenhouse gases emissions are halted,” the scientists said in a statement.

The researchers analysed weather data and computer model simulations, following peer-reviewed methods, to compare today’s climate, after about 1.2°C of global warming since the late 1800s, with the climate of the past. The analysis looked at the average maximum temperature and maximum heat index for four consecutive days in April across two regions, one covering south and east India and Bangladesh, and a second one including all of Thailand and Laos.

The heat index is a measure that combines temperature and humidity and reflects more accurately the impacts of heatwaves on the human body.

“In Bangladesh and India, events like the recent humid heatwave used to occur less than once a century on average [but] they can now be expected around once in five years now,” the scientists said. If global temperatures rise by two degrees, such events could occur annually, they said.

Meanwhile, the recent humid heatwave in Laos and Thailand “would have been nearly impossible without the influence of climate change”, said the coalition of scientists.

“It is still a very unusual event that can only be expected around once in 200 years, even with the influence of human-caused climate change. But if temperature rise reaches 2 degrees, it will become much more common, occurring about once in 20 years.”

The heat has already caused widespread hospitalisations, damaged roads, sparked fires and led to school closures but the full human cost of the extreme weather event is still unknown.

Read the full article about heatwaves in Asia by Samantha Ho at Eco-Business.