In July 1980, an extreme heat wave hit the southern United States and raised thermometers to 38.4 degrees. In November 1985, an infernal heat episode left Brazil with a record temperature of 36.5 degrees. In April 1998, Southeast Asia suffered an unprecedented heat wave episode and, at the time, the recorded 32.8 degrees seemed an extreme impossible to overcome. All these records that, in their day, stood out as records will take less and less time to become obsolete because, as the scientific community has been warning for decades, the advance of the climate crisis and global warming is laying the ground for heat waves are becoming more intense and frequent.
As pointed out a new analysis published this Wednesday in the journal ‘Science Advances’, in recent decades the planet has experienced a boom in extreme heat waves. But while some of these episodes have grabbed headlines and filled rivers of ink, others have gone totally unnoticed. Especially in the case of weather extremes that have taken place in the global south and in disadvantaged regions of the globe. “In this places, an extreme in temperature can have more damaging effects because he can increase mortality rates“, says Vikki Thompson, author of the study and scientist at the Cabot Institute of the University of Bristol, in the United Kingdom.
You don’t have to go far back in time to see the effects of an extreme heat wave in a country plagued by poverty and social inequalities. India and Pakistan have been experiencing an extreme heat wave for a week now, with temperatures above 40 degrees and highs close to 50. It is estimated that more than a billion inhabitants Some of these regions are especially vulnerable to these temperature extremes. Today, the vast majority of heat stroke deaths recorded during this episode coincide with the poorest rural areas of the country. In the last 50 yearsAccording to a recent analysis, extreme heat has left more than 17,000 dead in India. The majority, in poor regions and in people exposed to the elements.
The extreme heat waves not only are they increasing but, as the records corroborate, they are expanding into territories that (until now) had barely suffered this type of extreme episode. The clearest example, experts explain, is the heat wave that last summer struck the United States and Canada. The episode, which left highs close to 50 degrees and hundreds of deaths in just one week, “it would have been virtually impossible without the impact of the climate crisis“. “If humans had not influenced the climate, and triggered global warming, this heat wave would have been 150 times less likely“, then concluded an analysis carried out by the University of Oxford.
The severity of heat waves, the experts put forward, does not depend so much on the temperatures that are reached but on how much the temperatures rise with respect to normal values. In it canada casefor example, the heat wave raised temperatures more than 10 degrees from the mean values in a country that, until now, I was not used to it to these types of weather extremes. The same thing that happened last June in Helsinki, when the thermometers reached 31.7 degrees and thus registered the highest temperature ever detected in the city.
More intense and frequent heat waves
The advance of the climate crisis, experts warn, will cause increasingly intense and frequent heat waves. According to the latest report of the Intergovernmental Panel on Climate Change (IPCC), until the last century these extreme events occurred once every ten years. Now, the chances have been multiplied by four. And if global thermometers exceed four degrees on average, it will be up to 9.4 times more likely of an extreme heat event.