World Alert | Record Heat in Pakistan and India | Monday, May 23, 2022
Climate change boosted odds of record heat in Pakistan and India
The punishing heat experienced by India and Pakistan in March and April was the most intense, widespread and persistent in the region’s history. A study released Monday finds that human-caused climate change made this historic event at least 30 times more probable. It determined that climate change elevated temperatures by about 1.8 degrees Fahrenheit (1 degree Celsius).
“What was particularly exceptional and particularly unusual was how early it started,” said Friederike Otto, co-author of the study in a news conference on Monday.
India experienced its highest March temperatures in 122 years, and Pakistan and northwest and central India endured their hottest April. Numerous all-time and monthly temperature records were broken across both countries. Over the two months, extreme heat affected nearly 70 percent of India and 30 percent of Pakistan.
This heat event “was highly, highly unlikely” in a world without climate change, said Arpita Mondal, a co-author and professor at the Indian Institute of Technology Mumbai.
The heat took an enormous toll on people throughout the region. Workers were no longer able to work full days outside, straining their livelihoods and the economy. Key farming areas in India are expected to see a 10 to 35 percent decrease of crop yields due to the heat wave, driving local market prices to rise and reducing global wheat supplies when supplies are already stressed due to Russia’s invasion in Ukraine. Hundreds of forest fires also burned across India. In Pakistan, snowmelt caused a glacial lake to flood and wipe out an important bridge.
Across the two countries, at least 90 deaths have been tied to the heat.
The analysis was conducted by the World Weather Attribution group, which uses computer modeling to investigate the links between ongoing weather events and climate change. The team ran simulations using 20 different models with and without the effects of human-induced climate change to determine the effect of rising temperatures on the magnitude of the heat. The results, which are not yet peer-reviewed, come from well-established methodologies that have been used in past analyses, including the 2021 Pacific Northwest heat wave.
Otto said the study’s estimate of climate change’s effect is conservative due to data constraints and that rising temperatures probably increased the likelihood of the event “higher than 30 times.”
The study was released just five days after a similar analysis from the UK Met Office. It found that the likelihood of a record warm April and May in northwest India and Pakistan has become about 100 times more likely due to climate change. Otto said the UK Met Office’s estimation, which was based off one model, is well within the uncertainty of their study.
“Both show that climate change is a real game changer when it comes to these kind of heat waves,” said Otto. “The main message to take away here [is] that adaptation to heat has been the absolute essential thing to do in life in every part of the world, really, but especially also in this part of the world.”
The World Weather Attribution study also examined how likely a similar heat wave to this year’s would occur in an even warmer world. The team found such a heat wave would become 2 to 20 times more likely if the planet reaches 3.6 degrees (2 degrees Celsius) above preindustrial levels.
India has already warmed around 1.8 degrees (1 degree Celsius) since the preindustrial era. Pakistan has warmed 2.2 degrees (1.2 degrees Celsius).
The study adds to a growing number of research that underlines how climate change is increasing extreme weather events across the world. According to the latest U.N. climate report released last year, evidence shows that heat waves have increased across almost all land areas due to climate change.
“We have studied many heat waves and in all cases but one climate change was clearly assessed as the main driver of the change in the likelihood,” said Robert Vautard, director of the Institut Pierre-Simon Laplace in Paris and co-author of several studies with the World Weather Attribution group.
Northern India and Pakistan face another round of heat later this week. After some relatively cool weather the next several days, temperatures are forecast to rise several degrees above average Friday into the weekend.