Study: More heat deaths due to climate change in Europe

According to a study, the extreme heat wave from late June to early July resulted in about three times as many deaths in Europe's major cities as would have been the case without the influence of climate change . According to the international research team from Imperial College London and the London School of Tropical Medicine, about one-third of the 2,300 deaths, or around 1,500, were directly attributable to climate change.

Scientists from Great Britain, Denmark, the Netherlands, and Switzerland analyzed developments in twelve major cities between June 23 and July 2. During this period, temperatures in many cities climbed to extremes, sometimes well over 40 degrees Celsius. According to the study, climate change increased daily maximum temperatures in cities by 1 to 4 degrees Celsius. Without this additional warming, only around 800 people would have died from heat-related effects.

For their analysis, the team compared real-world temperature data with model calculations that depict a scenario without human-caused climate change. They determined the expected number of heat-related deaths for both scenarios.

Older people particularly affected

According to the experts, vulnerable groups such as people with underlying health conditions were particularly affected by the recent heat wave. 88 percent of the estimated deaths occurred in the age group 65 and older, the team reports.

The twelve cities studied were affected by the consequences of the heat wave to varying degrees: Milan accounted for almost 320 of the additional deaths caused by climate change, Barcelona for 286, Paris for 235, and London for 171. In Frankfurt, the number is comparatively low, with 21 additional deaths.

Experts: "silent killer"

According to researchers, heatwaves cause significantly more deaths than other natural disasters. By comparison, 224 people died in the floods in the Spanish region of Valencia last year, and 243 people died in the 2021 flood disasters in northwestern Europe, including in the Ahr Valley.

"Heatwaves don't leave a trail of destruction like wildfires or storms," ​​explains co-author Ben Clarke of Imperial College London. "Their consequences are largely invisible, yet quietly devastating. A difference of just 2 to 3 degrees Celsius can mean the difference between life and death for thousands of people." The team therefore calls it a "silent killer."

Heat waves stronger and more frequent

According to data from the EU's Copernicus Climate Change Service, June 2025 was the hottest month on record in Western Europe. The average temperature was 20.49 degrees Celsius, exceeding the previous June record of 2003 (20.43 degrees Celsius). The Copernicus data series goes back to 1950, and in some cases even further.

"In a world that continues to warm, heatwaves will become more frequent, more intense, and affect more people," warns Samantha Burgess of the European Centre for Medium-Range Weather Forecasts (ECMWF). German cities in particular are ill-prepared for this, warns climate researcher Jochen Marotzke. He cites a lack of shading, too much glass, too few green spaces, and extensive sealing as reasons.

ch/pgr (KNA, dpa)