Extreme rainfall made 10 percent heavier by human-caused climate change triggered landslides that killed hundreds, according to a new study.
A sudden burst of rainfall on July 30 caused a cascade of landslides that buried hundreds of people in the mountainous Kerala region of southern India.
That downpour was 10 percent heavier because of human-caused climate change, according to a study by World Weather Attribution, a group of scientists who quantify how climate change can influence extreme weather. Nearly six inches, or 150 millimeters, of rain fell on soils already highly saturated from two months of monsoon and marked the third highest single-day rain event on record for India.
“The devastation in northern Kerala is concerning not only because of the difficult humanitarian situation faced by thousands today, but also because this disaster occurred in a continually warming world,” said Maja Vahlberg, a climate risk consultant at the Red Cross Red Crescent Climate Centre. “The increase in climate-change-driven rainfall found in this study is likely to increase the number of landslides that could be triggered in the future.”
In a state that is highly prone to landslides, the Wayanad district is considered the riskiest part. As of Tuesday, at least 231 people had died and 100 remained missing.
The Kerala landslides were the second extreme landslide event in July, following one in Ethiopia that killed 257 people. July was the second-worst month on record, after July 2019, with 95 landslide events that caused 1,167 fatalities, according to data maintained by Dave Petley, the vice-chancellor of the University of Hull. Together, they caused roughly one-third of the more than 3,600 deaths resulting from some 429 fatal landslides recorded this year, Dr. Petley said in an email.
Already, 2024 is an outlier, Dr. Petley posted to The Landslide Blog on Tuesday. He wrote that he could “only speculate on the likely underlying reasons for this very high incidence of fatal landslides,” but “the most likely cause continues to be the exceptionally high global surface temperatures, and the resultant increase in high intensity rainfall events.”