Climate change tripled heat-related deaths in early summer European heatwave

Summary

Human-caused climate change intensified the recent European heatwave and increased the number of heat deaths by about 1,500 in 12 European cities.

Focusing on ten days of heat from June 23 to July 2, the researchers estimated the death toll using peer-reviewed methods and found climate change nearly tripled the number of heat-related deaths, with fossil fuel use having increased heatwave temperatures up to 4°C across the cities.

They warn that heatwave temperatures will keep rising and future death tolls are likely to be higher, until the world largely stops burning oil, gas and coal and reaches net zero emissions. 

It is the first rapid study to estimate the number of deaths linked to climate change for a heatwave and was led by scientists at Imperial College London and the London School of Hygiene & Tropical Medicine.

Key points

• About 1,500 of the 2,300 estimated heat deaths, or 65%, are a result of climate change increasing the heat by 1-4°C, meaning the death toll was tripled due to the burning of fossil fuels.
• Climate change was behind 317 of the estimated excess heat deaths in Milan, 286 in Barcelona, 235 in Paris, 171 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 (a full breakdown of the results is given in the notes).
• This means the likely death toll of the climate change-driven heat in many European cities was higher than other recent disasters including the 2024 Valencia floods (224 deaths) and the 2021 floods in northwest Europe (243 deaths) 
• People aged 65 and over made up 88% of the deaths, highlighting how those with underlying health conditions are most at risk of premature death in heatwaves.