Extreme heat waves are increasingly showing a tendency to stay longer in the places they hit, increasing their danger, according to a study released Friday, which is largely attributed to climate change.

Previous research has mainly dealt with the frequency and intensity of heat waves, but not many have studied how they move in space and time.

As heat waves, just like storms and other meteorological phenomena, are moved by the winds, Wei Zhang, one of the authors of the study, which was published yesterday on the website of the scientific journal Science Advances, explained to AFP.

Over the course of recent decades, heat waves have tended to “move slower and slower,” he explained. Element that means “how they can stay in an area for a longer time”, and this “has great consequences for its population”.

The researchers analyzed heat waves on a global scale between 1979 and 2020, using models based mainly on weather radar and satellite observations.

Their analysis showed that every decade, the speed of heat wave travel decreased by about 8 kilometers per day.

They also noticed that the average duration of heatwaves went from about 8 hours in the 1980s to 12 at the end of the period under study.

They also recorded that heat waves now reach much further than before and confirmed the increase in the frequency of these phenomena.

The researchers then looked at the role of climate change in these changes. For this purpose, they used climate models simulating two scenarios – with and without the emissions of gases that cause the greenhouse effect – and compared the results with the actual behavior of heat waves.

“It’s pretty clear to us that the dominant factor here to explain this trend is anthropogenic,” in other words, that it’s due to “greenhouse gases” that in turn are due to human activities, said Wei Zhang, of Utah State University.

He said he is particularly concerned about cities where heatwaves are settling in, as for example they may not have vegetation or cool spaces for their less privileged residents who lack air conditioning.

“Heat waves that travel farther and move more slowly will have more devastating consequences for nature and society in the future if greenhouse gas emissions continue to rise,” the research warns.