Study: this summer's heat killed an estimated 50,000 people in European cities, two-thirds of them due to climate change

Record heat in Europe this summer was linked to an estimated 50,391 deaths in 854 cities, and 32,619 of them — almost two-thirds — would not have happened without human-caused climate change, according to a study by researchers at Imperial College London reported by AP and The BMJ. AP says the study is due in an upcoming issue of Nature Health.

Key figures

• The toll is about 71% higher than the previous deadliest summer in the same researchers’ series, 2022 (29,480 deaths).
• About a third of the deaths fell in the intense heatwave of 17 June – 1 July, when temperatures were 5.3 °C above normal, co-author Garyfallos Konstantinoudis told AP.
• More than half of those who died were 85 or older, but more than 800 were aged 20–44. Italy, France, Spain and Germany had the highest tolls.
• The share of heat deaths attributable to warming has risen from about 45% in the early 2000s to about 65% now, lead author Clair Barnes said.

How it was calculated — and limitations

This is a modelling study, not a count of death certificates: heat deaths are often not recorded as such. The team estimated excess deaths from city-specific temperature–mortality relationships by age, then compared the real summer with simulations of a world without climate change. The cities cover only about 40% of Europe’s population and the analysis leaves out a deadly heatwave in May, so the authors call the figures underestimates. As a check, their method gave about 2,700 excess deaths for British heatwaves in May–June, close to the UK statistics agency’s 2,800, AP reported.

Experts quoted by AP called for heat early-warning systems, access to low-carbon cooling and checks on vulnerable neighbours, alongside cutting fossil-fuel use.