Study: 50,000 summer heat deaths

A new study estimates that extreme heat killed 50,391 people across Europe this summer. Researchers determined that 32,619 of those deaths resulted directly from temperatures elevated by the burning of coal, oil, and gas. The findings are scheduled for publication in an upcoming issue of Nature Health.

The research team modeled heat-related mortality in 854 European cities during heat waves in June, July, and August. They calculated that the total death toll is 71 percent higher than the previous record set in 2022, which accounted for 29,480 deaths. The authors note that the current figures likely represent a lower bound, as the analysis excludes a deadly heat wave in May and covers only cities that house about 40 percent of the continent's population.

Italy, France, Spain, and Germany recorded the highest number of fatalities. 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 degrees Celsius above normal. More than half of the victims were aged 85 or older, but the heat also 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, observed that some cities experienced temperatures 12 degrees Celsius above normal. She explained that much of the infrastructure in Western and Northern Europe was not designed to handle the temperatures caused by human-caused warming. Barnes added that Europe is the fastest-warming continent and is now 2.5 degrees Celsius hotter than in pre-industrial times. She said this extra warming can tip temperatures from uncomfortable to dangerous and potentially deadly.

To isolate the impact of climate change, the team ran computer simulations of a world without such warming and compared the results to actual deaths. The difference represents the effect of global warming. Barnes noted that the share of heat deaths attributable to warming has risen from about 45 percent in the early 2000s to 65 percent today. The researchers used statistical modeling to account for age and each city's optimal temperature, checking results against government estimates that mostly matched.

For the heat waves in Britain during May and June, the model produced 2,700 excess deaths, while the United Kingdom's health statistics agency reported 2,800. Several outside experts described the methods as state-of-the-art. Howard Frumkin, former director of the National Center for Environmental Health in the U.S., said summers are getting hotter while attribution tools are becoming more accurate. He stated that these trends produce higher and more reliable counts.

Experts emphasized that adaptation must proceed alongside emissions cuts. Courtney Howard, president-elect of the Canadian Medical Association, called for investment in early-warning systems, equitable access to low-carbon cooling, and neighborhood buddy systems for those at highest risk. Jonathan Patz of the University of Wisconsin-Madison said society cannot keep mopping up the mess on the floor without thinking about turning the faucet off. He stressed the need to address fossil fuel burning.