Increasingly lethal heat waves: the balance of the one that has invested Europe is clear. And the most extreme change more quickly.
The ten days of hellish heat that have invested Europe between the end of June and the beginning of July they caused the death of 1500 more peoplebetween 12 European cities, compared to the budget that would have caused a heat wave not aggravated by the global warming caused by man.
According to an analysis of the Imperial College London and the London School of Hygiene & Tropical Medicine, climate change have amplified the temperatures of 4 ° C e the deaths due to the excessive heat is tripled in the most vulnerable population.
A heat dome on Europe
The researchers focused on the 10 most critical days of the recent heat wave, those between June 23 and July 2, 2025, when A heat dome (“Heat Dome”)that is, a robust high pressure area positioned on central and western Europe has trapped the hot air in the lowest layers of the atmosphere and prevented the stirring with fresh air masses.
The phenomenon, made more and more frequent by climate change, caused heat waves that made the thermometer splashes at 35 ° C in London, at 40 ° C in Paris, forced Italy to emergency measures to protect the workers and triggered fires in several places in the Mediterranean.
Augmented lethality
Scientists of the World Weather Attribion Network, an academic collaboration that studies the immediate impact climate change on extreme weather events, to inform decision makers and the public debate on the effects of the climatic crisis, have tried to understand How lethal this wave of heat would have been, without global warming caused by man.
They estimated that in the 10 days considered, About 2300 people died from the heat wave in 12 cities of the continentAthens, Barcelona, Budapest, Frankfurt, London, Lisbon, Madrid, Milan, Paris, Rome, Sassari and Zagreb.
Based on analysis, 1500 of these deaths, i.e. 65%, are the result of the increase in temperatures Up to 4 ° C caused by climate change related to fossil fuels emissions. In other words, these 1500 people would not have died in the last wave of heat, if global warming had not made temperatures so extreme.
The heat is more lethal than floods
There would be the paw of climate change Behind 317 of the deaths attributed to excessive heat in Milan286 in Barcelona, 235 in Paris, 1712 in London, 164 in Rome, 108 in Madrid, 96 in Athens, 47 in Budapest, 31 in Zagreb, 21 in Frankfurt, 21 in Lisbon and 6 in Sassari.
This attribution so direct and concrete It makes the lethal effects of the climate that changes more tangible and clear, and shows that heat waves are an extreme climatic event even more dangerous than another consequence of climate change, that is, floods.
Those who invested Valencia in 2024 caused 224 deaths and those that took place in Northern Europe in 2021 caused 243 deaths.
88% of the deaths concerned people over 65, because The heat worsens existing diseases And it acts above all on the most vulnerable. Also for this reason, it is a silent killer, which often does not appear among the causes in death certificates.
The most extreme heat waves are the ones that worsen the most
In another study published on Nature Geosciencescientists from the University of California in Los Angeles and the Adolfo Ibañez University of Santiago del Chile concluded that are the most extreme heat waveslike those that last weeks, to become longer and frequent due to climate change.
The danger of heat waves is not gradually increasing, but is accelerating: “Each fraction of degree of heating will have a greater impact of the previous one” explains David Neelin, climatologist and author of the study. «This means that if the heating rate remains unchanged, Our adaptation must take place more and more quicklyespecially for the most extreme heat waves, which are changing more quickly ».
