We tell you why heat waves come earlier, are longer and more intense

We tell you why heat waves come earlier, are longer and more intense

Heat waves – like the one currently suffocating much of Europe – are starting earlier, lasting longer and becoming more intense as a result of climate change, warns an expert in the UN.

“It’s only going to get more intense and more frequent”John Nairn, senior adviser on extreme heat at the Geneva-based World Meteorological Organization (WMO), told AFP.

Consequences of global warming

The heat dome that has covered a large part of the Old Continent for nearly a week, the forest fires raging in Greece, Canada and Hawaii and the summer temperatures in South America yet in the middle of winter, are not An illusion.

Longer and more frequent heat waves are the “consequence of global warming that we see appearing most rapidly in weather systems”underlined the researcher, who insists on the fact that the scientists had warned. “People are much too serene”, he laments. “Science warned you this was coming. And it’s not going to stop there”he warns.

Increasingly dangerous heat waves

John Nairn calls for being more “smart” in the face of heat. In particular, he recommends that we focus our attention on the fact that nighttime temperature minima continue to rise, while it is the daytime heat records that make the headlines.

Recurring high nighttime temperatures are particularly dangerous to human health, as the body is then unable to recover from the heat it experiences during the day. Higher nighttime temperatures also mean that energy built up during the day has nowhere to escape, pushing temperatures even higher the next day.

We therefore arrive at “longer periods of higher temperatures”says the scientist, explaining that “It’s cumulative… So heat waves become much more dangerous.”

And as the climate continues to change, the situation is likely to get worse, according to John Nairn. He is particularly concerned about the situation in the tropics and subtropics, taking as an example the record heat recorded in South America in recent weeks, with temperatures of up to 40°C in the middle of what is supposed to be their winter. . “It’s just not normal”he insists.

“We need to stop burning fossil fuels”

In the future, he predicts that “we’re going to see a lot more heat waves over a much longer period of the year.” In tropical and subtropical regions, “unfortunately, everything indicates that severe and extreme heat waves are likely to occur at any time (of the year) before the end of the century”.

In other latitudes, less sunshine means that heat waves are not expected all year round, but the researcher points out that, there too, we will see more “periods abnormally hot for the season”, even in winter.

When asked what can be done, John Nairn believes that “we all have the ability to reverse the trend”. “We have to electrify everything (…) and stop burning fossil fuels. It’s not more complicated than that”, he throws.