Imperial College study links 50,391 European summer deaths to climate change

More than 50,000 people died across Europe this summer due to extreme heat, with human-caused climate change responsible for the majority of those deaths.

A new study published in Nature Health analyzed heat-related mortality in 854 European cities during June, July, and August. Researchers calculated that 50,391 individuals died because of warmer temperatures. Of that total, 32,619 deaths were attributed to the additional heat generated by burning coal, oil, and gas. This toll is 71 percent higher than the 29,480 deaths recorded during the previous deadliest summer in 2022.

The figures represent a minimum estimate because they exclude a deadly heat wave in May and cover only the 854 cities, which house about 40 percent of the continent's 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, noted that about one-third of the deaths occurred between June 17 and July 1, when temperatures averaged 5.3 degrees Celsius above normal. More than half of the victims were 85 years or older, but the heat also claimed more than 800 lives among people aged 20 to 44.

Clair Barnes, the lead author and a climate scientist at Imperial College London, stated that some cities experienced temperatures 12 degrees Celsius above normal. She explained that infrastructure in Western and Northern Europe was not designed for these conditions. Barnes added that Europe is the fastest-warming continent and is now 2.5 degrees Celsius hotter than pre-industrial levels. This extra warming can shift temperatures from uncomfortable to potentially deadly.

To determine the climate change contribution, the team compared this summer's actual deaths against computer simulations of a world without global warming. The difference represents the effect of climate change. Barnes said the share of heat deaths attributable to warming has risen from about 45 percent in the early 2000s to 65 percent now. Because heat deaths are often underreported, the researchers used statistical models that account for age and each city's optimal temperature. They validated the results against government estimates, which largely matched. For example, the model predicted 2,700 excess deaths during the May and June heat waves in Britain, while the UK health statistics agency reported 2,800.

Outside experts reviewed the methods and described them as state-of-the-art. Dr. Howard Frumkin, a former director of the National Center for Environmental Health in the United States, said the combination of hotter summers and improved attribution tools is producing higher and more reliable counts. Other experts emphasized the need for adaptation alongside emission cuts. Dr. Courtney Howard, president-elect of the Canadian Medical Association, called for investment in early-warning systems and equitable access to low-carbon cooling. Dr. Jonathan Patz of the University of Wisconsin-Madison stressed the need to address fossil fuel burning to stop the problem at the source.