Analysis estimates that the early summer heatwave of 2025 brought about 2,305 excess deaths due to the higher than normal temperatures
Research has shown that the frequency and intensity of extreme heat events is increasing in Western European and in the last two decades it has emerged as the fastest-warming region. This century, Europe has seen thousands of excess heat-related deaths with the summer of 2022 standing out with more than 60,000 deaths as a result of extreme heat. An impact study found that more than 50% of these excess deaths could be attributed to human-induced climate change. In the following summer in 2023, even though the heat was less intense, a total of over 47,000 heat-related deaths were recorded.
By 2050, By 2050, a substantial share of Europe’s population is expected to be exposed to extreme heat. Under a 2°C global warming scenario, approximately 163 millionEuropeans could face unprecedented summer temperatures, nearly twice the number currently affected.
Now an analysis by the Grantham Institute at Imperial College, London on the early summer heatwave of 2025 in Europe indicates that 2,305 excess deaths are estimated to have occurred due to the high temperatures, with 65% of these attributed to human-induced climate change. This means that the number of expected excess deaths has been approximately tripled by human-caused climate change. More than 80% of the estimated excess deaths due to heat are expected in people older than 65 years.
It should be remembered that at the time of the analysis, the actual number of observed deaths during the analysis period was not yet available and therefore the reported values should be considered as estimates of estimates of attributable mortality rather than observed outcomes.
Observational data was analyzed to assess changes in heatwave intensity in 12 major European cities, to determine the impact of climate change. The cities include London, Paris, Frankfurt, Budapest, Zagreb, Athens, Rome, Milan, Sassari, Barcelona, Madrid, and Lisbon. These were chosen as significant urban centres, distributed across diverse European subregions, and where heat health warnings have been issued.
Two cities stand out with Milan estimated to be the hardest hit in absolute terms, with approximately 317 of the 499 heat-related deaths attributable to climate change. Madrid is estimated to be the hardest hit in relative terms, with more than 90% of the estimated excess heat-related deaths to be attributable to climate change.
