India, Pakistan must brace for even worse heatwaves

The devastating heatwave that gripped India and Pakistan over the last two months is unprecedented, but worse—perhaps far worse—is on the horizon as climate change continues apace, top climate scientists told AFP.

Extreme heat across much of India and neighbouring Pakistan in March and April exposed more than a billion people to scorching temperatures well above 40˚C (104˚F). The hottest part of the year is yet to come.

Heatwave mortality in India has increased by more than 60% since 1980.

Air quality has deteriorated, and large swathes of land are at risk of extreme fire danger. Power blackouts last week as electricity demand hit record levels served as a warning of what might happen if temperatures were to climb even higher.

Scientists at Imperial College London’s Grantham Institute led by Friederike Otto, a pioneer in the field of attribution science, are crunching the numbers.

“How much more likely and intense this particular heatwave has become is something we’re still working on,” she told AFP. “But there is no doubt that climate change is a huge game changer when it comes to extreme heat,” she added. “What we see right now will be normal, if not cool, in a 2˚C to 3˚C world.”

Earth’s surface, on average, is 1.1˚C above preindustrial levels. National carbon cutting pledges under the Paris Agreement, if fulfilled, would still see the world warm 2.8˚C.

“Before human activities increased global temperatures, we would have seen the heat that hit India around once in 50 years,” said Marian Zachariah, a researcher at Imperial College London. “But now we can expect such high temperatures about once ever four years.” Continued global warming, in other words, guarantees greater heat extremes in the coming decades.

“The rise in heatwaves, floods, cyclones and droughts that we have seen in this region so far are in response to just 1˚C” Roxy Mathew Koll, a climate scientist at Indian Institute of Tropical Meteorology, told AFP. “It is difficult for me to even imagine the impacts when the increase in global temperatures are doubled.”

Annual time series of average April maximum temperature are shown below over all of India, NW and central India –