50,391 deaths recorded in Europe's record heat as fossil fuels drive majority of toll

50,391 people died across 854 European cities during the extreme heat waves of June, July, and August this year, according to a new study set to appear in Nature Health.

The research team estimated that 32,619 of those deaths were directly caused by the added warmth from burning coal, oil, and gas. This figure represents nearly two-thirds of the total mortality linked to the record-breaking temperatures.

The death toll stands 71 percent higher than the 29,480 deaths recorded in 2022, the previous deadliest summer on record for the region. The authors noted that the current figures are likely an underestimate because they exclude a deadly heat wave in May and cover only 854 cities. These urban centers hold approximately 40 percent of Europe's total population.

Italy, France, Spain, and Germany recorded the highest death tolls. Garyfallos Konstantinoudis, a biostatistician at Imperial College London and co-author of the study, stated that about one-third of the deaths occurred between June 17 and July 1. During that period, temperatures ran 5.3 C above normal.

The impact was not limited to the elderly. While more than half of the victims were aged 85 or older, the heat claimed the lives of more than 800 people between the ages of 20 and 44.

Clair Barnes, the lead author and a climate scientist at Imperial College London, explained that some cities experienced temperatures 12 C above normal. She observed that infrastructure in Western and Northern Europe is not designed to handle the current temperatures driven by human-caused warming. Barnes added that Europe is the fastest-warming continent and is now 2.5 C hotter than in pre-industrial times.

To isolate the effect of climate change, the researchers used computer simulations to model a world without anthropogenic warming. They compared these simulations to actual death counts to determine the gap attributable to global warming. Barnes said the share of heat deaths linked to warming has increased from roughly 45 percent in the early 2000s to 65 percent today.

The study relied on statistical modelling to account for age groups and each city's optimal temperature, the point at which the fewest deaths occur. This method was necessary because heat deaths are often underreported on death certificates. The team validated their model against government estimates, which largely aligned. For example, the model calculated 2,700 excess deaths for the May and June heat waves in Britain, while the UK's health statistics agency reported 2,800.

Dr. Howard Frumkin, a former director of the National Center for Environmental Health in the U.S. who was not involved in the study, noted that summers are getting hotter while attribution tools are becoming more accurate. He said these trends together produce higher and more reliable counts. Outside experts, including Dr. Courtney Howard of the Canadian Medical Association, emphasized the need for investment in early-warning systems and equitable access to low-carbon cooling alongside emissions cuts.