Europe's record summer heat killed over 50,000; study links two-thirds to climate change
Researchers say the toll is 71% higher than summer 2022's record and that the real figure is likely larger, since a May heat wave and most European cities were excluded.
At a glance
- A Nature Health study estimates 50,391 heat deaths in 854 European cities this summer.
- Researchers attribute 32,619 of those deaths to human-caused climate change.
- The toll is 71% higher than the previous deadliest summer, 29,480 deaths in 2022.
Record-breaking heat across Europe this summer killed 50,391 people in 854 cities, and researchers attribute 32,619 of those deaths — nearly two-thirds — to human-caused climate change, according to a study scheduled for an upcoming issue of Nature Health.
The toll is 71% higher than the previous deadliest summer counted by the same team, when 29,480 deaths were recorded in 2022. The authors say the true figure is higher still: their analysis leaves out a deadly May heat wave and covers only the 854 cities studied, home to roughly 40% of Europe's population.
A single heat wave's share
About one-third of the deaths occurred during an intense heat wave from June 17 to July 1, when temperatures ran 9.5 F (5.3 C) above normal, said co-author Garyfallos Konstantinoudis, a biostatistician at Imperial College London. Italy, France, Spain and Germany recorded the highest death tolls.
More than half of those who died were 85 or older, but the heat also killed more than 800 people aged 20 to 44, Konstantinoudis said. The team's earlier work found that Rome had the highest heat-death total of any European capital between 2000 and 2025.
Why the numbers are rising
Lead author Clair Barnes, a climate scientist at Imperial College London, said Europe is the fastest-warming continent and now runs 4.5 F (2.5 C) hotter than pre-industrial times. Some European cities saw temperatures 21.6 F (12 C) above normal this summer.
To separate ordinary summer heat from warming driven by burning coal, oil and gas, the researchers simulated a world without climate change and compared it with the deaths recorded this summer. Barnes said the share of heat deaths linked to global warming has grown from about 45% in the early 2000s to 65% today.
Konstantinoudis said heat deaths are often underreported and frequently missing from death certificates, so the team used statistical modelling to arrive at the 50,000 baseline estimate. Several outside experts agreed the methods are state-of-the-art.
Howard Frumkin, former director of the U.S. National Center for Environmental Health, who was not involved in the research, said hotter summers and improving attribution tools together are producing increasingly high and increasingly accurate counts of heat-related deaths.
Dr. Courtney Howard, president-elect of the Canadian Medical Association, said the response should include early-warning systems, equitable access to low-carbon cooling and neighbour check-ins for those most at risk, alongside rapid cuts to fossil fuel use.
Dr. Jonathan Patz of the University of Wisconsin-Madison, also not part of the study, said adaptation alone is not enough. He compared relying on cooling measures to mopping a floor without turning off the tap, arguing that prevention must address the burning of fossil fuels.
Source: NPR News.
Questions and answers
- How many people died from Europe's heat this summer?
- A study slated for Nature Health estimates 50,391 heat-related deaths across 854 European cities during June, July and August. The authors say the real figure is likely higher because a May heat wave and other cities were not counted.
- How much of the heat death toll is linked to climate change?
- Researchers attribute 32,619 of the deaths, nearly two-thirds, to extra heat caused by burning coal, oil and gas. They say that share has risen from about 45% in the early 2000s to 65% now.
- Which countries recorded the most heat deaths?
- Italy, France, Spain and Germany had the highest death tolls in the study. Among European capitals, Rome recorded the highest heat-death total from 2000 to 2025, according to the team's earlier research.
