Scientists have estimated that more than 50,000 people died from heat-related causes across 854 European cities during the summer, with human-caused climate change contributing to thousands of those deaths.

The study estimated that 50,391 people died from high temperatures during June, July and August. Researchers attributed 32,619 of those deaths to additional heat linked to human activities, particularly the burning of fossil fuels.

According to the findings, the death toll was 71% higher than the previous summer record of 29,480 deaths in 2022. However, scientists warned that the figures may be higher because the research did not include a deadly heatwave in May. The study also covered only 854 cities, representing approximately 40% of Europe’s population.

One particularly intense heatwave between June 17 and July 1 accounted for about one-third of the estimated deaths. During that period, temperatures reached approximately 5.3 degrees Celsius above normal.

Scientists from Imperial College London said many European cities were struggling to cope with increasingly extreme temperatures. Some locations experienced temperatures as much as 12 degrees Celsius above normal, increasing the risk of dangerous heat exposure.

Older adults were among the most affected groups. More than half of the estimated deaths occurred among people aged 85 and older. However, younger adults were also affected, with more than 800 deaths recorded among people aged 20 to 44.

To determine the impact of climate change, scientists used computer simulations to compare actual summer temperatures with conditions in a modelled world without human-caused climate change. They used the differences to estimate how much additional warming contributed to heat-related deaths.

The researchers also found that the proportion of heat-related deaths attributed to global warming has increased from approximately 45% in the early 2000s to around 65% in recent years.

Experts say European cities need stronger heat-warning systems, better access to cooling and additional support for vulnerable residents. They also stressed the importance of reducing fossil fuel use to limit further warming.

Scientists noted that heat-related deaths are often under reported because extreme temperatures may not be listed directly on death certificates.