Last month’s extreme heat in India driven by climate change: study

In India, several northern and eastern cities recorded maximum temperatures above 44°C on April 18. Dhaka recorded 40.6°C on April 15, the hottest day in Bangladesh in the last few decades. Thailand recorded its highest- ever temperature of 45.4°C on April 15 in the city of Tak. The Sainyabuli province in Laos reported 42.9°C on April 19, all-time high temperature recorded in the country so far. Vientiane recorded 41.4°C on April 15, the hottest day ever for the Laos capital.

“These extreme temperatures, combined with humidity, caused a sudden increase in heat stroke cases, roads melting and a strong surge in electricity demand in all four countries. As many as 13 casualties and about 50-60 hospitalisations due to heat stroke were reported in Navi Mumbai, Maharashtra, on April 16 alone, while other sources mention 650 hospitalisations. Casualties have been reported in Thailand also. The true cost to human lives will only be known only later,” the report said.

“In West Bengal, Tripura and Odisha, schools closed three weeks earlier than planned due to the heatwave. In addition, a large number of forest fires occurred during the same time in India, Thailand and Laos,’’says the report.

As part of the study, scientists from India, Thailand, France, Australia, Denmark, Germany, Kenya, the Netherlands, the US and the United Kingdom collaborated to assess to what extent human-induced climate change altered the likelihood and intensity of the extreme heat in these four countries.

The estimated heat index values exceeded the threshold (41°C), considered as dangerous, over the large parts of the South Asian regions studied. In a few areas, it neared the range of “extremely dangerous” values (above 54°C) under which maintaining body temperature is difficult.

“Until overall greenhouse gas emissions are halted, global temperatures will continue to increase and events like this will become more frequent and severe,” the report said. The analysis also found that such events in India and Bangladesh, previously once-a-century, can now be expected around once in every five years because of human-caused climate change.

“Although we have recognised heatwaves as one of the deadliest disasters, particularly in countries like India, Bangladesh and Thailand, there is a lack of knowledge with respect to who is vulnerable, loss and damage estimation, household coping mechanisms, and the most effective heat action plans. Except for the human casualties, other economic and non-economic loss and damage indicators are not documented. This creates a dearth in assessing the extent of risk, who is vulnerable, and also operationalising any adaptation planning,’’ said Chandra Sekhar Bahinipati of IIT, Tirupati.