Climate change’s fingerprints on ever hotter heatwaves

Matthieu Sorel, a climatologist at Meteo-France, said that climate change was already influencing the frequency and severity of heatwaves.

“We’re on the way to hotter and hotter summers, where 35 degrees Celsius becomes the norm and 40 degrees Celsius will be reached regularly,” he said.


The heatwaves of the future depend largely on how rapidly the global economy can decarbonise.

The UN’s climate science panel has calculated that 14 per cent of humanity will be hit with dangerous heat every five years on average with 1.5 degrees Celsius of warming, compared with 37 per cent at 2 degrees Celsius.

“In all of places in the world where we have data there is an increase in mortality risk when we are exposed to high temperatures,” said Eunice Lo, a climate scientist at the University of Bristol’s Cabot Institute for the Environment.

It’s not only the most vulnerable people who are at risk of health impacts from heat, it’s even the fit and healthy people who will be at risk.”

There is a real risk in future of so-called “wet bulb” temperatures – where heat combines with humidity to create conditions where the human body cannot cool itself via perspiration – breaching lethal levels in many parts of the world.

As well as the imminent threat to human health, heatwaves compound drought and make larger areas vulnerable to wild fires, such as those now raging across parts of France, Portugal, Spain, Greece and Morocco.

They also menace the food supply.

India, the world’s second-largest wheat producer, chose to ban grain exports after the heatwave impacted harvests, worsening a shortage in some countries prompted by Russia’s invasion of key exporter Ukraine.