More than 50,000 people died from heat in European cities this summer, and roughly two-thirds of those deaths were attributable to human-caused climate change, researchers reported.
The team modeled heat-related mortality across 854 cities during repeated heat waves in June, July and August and estimated 50,391 deaths tied to higher temperatures. Of those, the authors said, 32,619 deaths were caused by the additional warming produced by the burning of coal, oil and natural gas. The results appear in an upcoming issue of Nature Health.
How the researchers reached their estimate
The study combined city-level temperature records, population data and statistical models of heat-related mortality to estimate deaths by age group across the sampled cities. The analysis examined the extra heat attributable to anthropogenic emissions and calculated how many more deaths occurred because of that added warming, the authors said.
- The study covers 854 cities, representing about 40% of Europe’s population.
- Researchers found 50,391 heat-related deaths across those cities in June, July and August.
- They attribute 32,619 of those deaths to the additional warming from fossil fuel combustion.
Lead author Clair Barnes, a climate scientist at Imperial College London, said the extreme temperatures tested infrastructure and social systems not designed for such heat in many parts of Western and Northern Europe.
“Much of Western and Northern Europe, our infrastructure is just not designed to cope with the sort of temperatures that we are seeing now because of the effects of human-caused warming,” Clair Barnes said.
Where and when the deadliest heat occurred
About one-third of the deaths occurred during a particularly intense period from June 17 to July 1, when temperatures reached about 5.3 C (9.5 F) above normal in parts of Europe, the paper said. During other episodes this summer, some cities recorded temperatures as much as 12 C (21.6 F) above typical values, the authors added.
Garyfallos Konstantinoudis, a biostatistician at Imperial College London and a co-author, noted that the study’s city sample and its time window mean the totals are underestimates. The authors did not include a deadly May heat wave in their analysis, and the 854 cities analyzed account for roughly 40% of Europe’s population, leaving many areas uncounted.
Context and limitations
The researchers compared this summer’s toll with their previously published estimate for the deadliest recent summer, 2022, when they found 29,480 heat-related deaths in the same set of cities. The 2026 figure is 71% higher than that earlier total. The paper, while attributing a portion of the deaths to human-caused warming, is careful to note the geographic and demographic limits of its sample and the modeling assumptions used to link temperature and mortality.
The findings add to a growing body of research tying extreme heat events to rising global temperatures and highlight differences in heat vulnerability across regions and age groups. The authors emphasize that adaptation and preparedness measures can reduce heat-related mortality but that their study focuses on attribution and mortality estimates rather than intervention outcomes.
