According to a new analysis by the World Weather Attribution Network (WWA), hundreds of millions of people in India and Pakistan are groaning under the leaden heat. Climate change has increased the likelihood of a heat wave that hit the region nearly 30 times.
In India, temperatures in March were three to eight degrees above average for weeks. Mercury rose to 44 degrees Celsius, in Pakistan as much as 49 degrees. The heat wave was accompanied by an exceptional drought, which has claimed at least 90 lives so far, and led to energy shortages and crop failures.
Relatively young attribution research investigates the contribution of climate change to specific extreme weather events. Scientists do this by using climate models to look at how likely an extreme phenomenon is in a world without a warm climate.
People in the area can now expect such a scorching heat once every 100 years, when it is usually only once every 3,000 years. The analysis also shows that the temperature during the heat wave was approximately one degree higher than in the pre-industrial climate.
The future does not look so rosy. So far, the climate has warmed by 1.2 degrees compared to the pre-industrial era. If we manage to limit warming to two degrees Celsius, as agreed in the Paris climate agreement, the probability of a similar heat wave will be two to twenty times more than it is today, and it will be half to one and a half degrees warmer.
“We are used to higher temperatures in India and Pakistan,” said Krishna Ashutaraw (Indian Institute of Technology Delhi), who was involved in carrying out the study. But this heat wave started exceptionally early and lasted for a very long time. People have had no cooling for weeks.” Heat waves in the area particularly affect millions of people who work outdoors, such as farmers, construction workers and street vendors.
“Heat waves are among the deadliest weather phenomena, and they will increase dramatically in an increasingly warming world,” said WWA researcher Frederick Otto (Imperial College London). “As long as we continue to emit greenhouse gases, these disasters will become fewer and less extraordinary.”
