Temperatures over 50°C in Death Valley in the USAhistorical record 45.3°C in Catalonia, temperature over 43°C in Phoenix, Arizona for 24 days: without Climate Change, such heatwaves would be “almost impossible” in Europe and the United Statesshows a study of the network World Weather Attribution (WWA).

This scientific network that evaluates the relationship between extreme weather events and climate deregulation estimates that this deregulation has made heat waves “at least 50 times more likely”.

THE Climate changecaused by man-made emissions of greenhouse gases, “has made heatwaves hotter and more frequent,” points it out WWA.

“Recent heat waves are no longer phenomena of an exceptional nature” and those to come “they will be more intense and more frequentif emissions are not reduced quickly,” the researchers conclude.

Because if natural phenomena such as anticyclones and El Nino may contribute to the genesis of heat waves, “increasing global temperatures due to fossil fuel burning is the main reason why heat waves are so severe”, highlights the WWA network.

2.5°C warmer

To reach these conclusions, the authors of the studysix Dutch, British and one American scientist, were based on historical meteorological data and climate models to make the comparison between today’s climate and a 1.2 degree temperature increase from what it once was.

The scientists looked mainly at the periods when the heat was most dangerousthat is, from July 12 to 18 in southern Europe, from July 1 to 18 in the western United States, Texas, northern Mexico, and from July 5 to 18 in central and eastern China.

They remind that global warming is exacerbating the intensity of temperatures: with her, heatwaves in Europe are 2.5 °C warmerheatwaves in North America by 2°C and in China by 1°C, according to the study of WWA.

July 2023 is expected to be the warmest July on record”According to NASA and the European Observatory Copernicus.

“In the past, such events would have been unnatural. But in today’s climate, they can now reproduce almost every 15 years in North America, every 10 years in southern Europe and every 5 years in China,” explains Mariam Zachariah, a scientist at Imperial College London who took part in the study.

The scientific study is not surprising

These heat wavesthey will become even more frequent and reproduce every two or three years“, if the warming reaches +2°C, “an event that can happen in thirty years, unless all the countries that have signed the Paris Agreement fully respect their commitments and quickly reduce their emissions”, he added.

These early summer conditions may become the norm and even be considered coolif we don’t achieve carbon neutrality,” says British climatologist Friederike Otto.

In her opinion, “The results of this study are not surprising (…) From a scientific point of view, it is boring for it does nothing but confirm what we have predicted. But what we did not anticipate is the extent to which we are vulnerable to the effects of Climate Change. Because it kills people.”

However, “these heat waves are not evidence of ‘accelerating warming’ or ‘climate collapse’. We still have time to turn the situation around”the scientist believes.

“It is urgent that we stop burning fossil fuels and work to reduce our vulnerabilities. If we don’t, tens of thousands of people will continue to die,” says Friederike Otto, calling it “absolutely necessary” to adopt international legislation to phase out minerals at the 128th UN Climate Conference (COP) in November in Dubai.