Small Increase in Mean Temperatures Linked to Big Jump in Deadly Heat Waves

A temperature increase of just 0.5 degrees C — 0.9 F — is enough to have more than doubled the probability of deadly heatwaves in India over the last 50 years, according to research published in the journal Science AdvancesThat raises worrying implications for many other countries that could experience mean temperature rises of up to 9 F by century’s end, the study’s authors say.

“In addition to India, populations in other developing countries in low- to mid-latitude regions are especially hard hit by these extreme heat events,” notes lead author Omid Mazdiyasni of the University of California at Irvine. Added Amir AghaKouchak, a UC Irvine climatologist and a co-author of the report, ”The general public may think that a 1 or 2 degree (C) temperature rise is not that significant, but our results show that even small changes can result in more heat waves and more death.”

Standardized number of heat wave days, summer mean temperatures, and heat-related mortality in India.

Standardized number of heat wave days, summer mean temperatures, and heat-related mortality in India. STUDY AUTHORS

Heatwave deaths almost doubled in India in recent years, from 1,300 in 2010 to 2,500 in 2015, according to the Hindustan Times. And India saw its most intense heat wave on record in 2016, according to Climate Central.

The Associated Press reports that the vast majority of Indian cities and states are not prepared to handle more heat. Many of the country’s more than 1 billion people lack access to electricity and reliable sources of clean water, which are particularly important to protecting those most vulnerable to heat-related illness — the very young, the elderly, and those with underlying medical conditions.

 “This study effectively demonstrates that much of India resides on a knife’s edge in terms of potential increases in heat wave deaths,” adds climate scientist Radley Horton of Columbia University.