Summer heat killed more than 50,000 in Europe's cities, two-thirds linked to climate change: study

Extreme heat this summer caused more than 50,000 deaths in European urban areas, and about two-thirds of them can be attributed to human-caused climate change, according to a new study by researchers at Imperial College London and the London School of Hygiene and Tropical Medicine (LSHTM).

The analysis, accepted for publication in the journal Nature Health, covered 854 urban areas in the 27 EU countries, the UK, Norway and Switzerland between June 1 and August 31. These areas account for roughly 40 per cent of the population of those countries.

Worst toll since 2000

The researchers said the estimated toll is the highest since 2000, nearly double the roughly 29,000 heat deaths estimated for 2022 and about 28,000 for 2003. Around a third of the deaths happened between June 17 and July 1, when daily average temperatures ran more than 5 degrees Celsius above the 1991 to 2020 average.

Southern and western Europe saw the highest temperatures and death rates, though northern countries that usually have mild summers were also hit hard. In the UK, the study estimated about 4,500 heat-related deaths across 135 urban areas. Older adults were the most affected group.

How the estimate was made

The team compared daily temperatures under today's climate, about 1.4 degrees Celsius warmer than pre-industrial times, with a modelled world without human-driven warming, and combined both with established links between temperature and deaths. The figures are modelled estimates rather than counts of death certificates citing heat, but the authors said similar methods have previously matched numbers later published by national health agencies.

LSHTM researcher Pierre Masselot said it is becoming clear that cities are "poorly adapted to rising heat". A companion study by the same group estimated more than 430,000 heat deaths across the same cities from 2000 to 2025, with the share linked to climate change rising over time.

Why it matters for India

Indian cities face longer and more intense heatwaves each year. The European findings underline the value of heat action plans, early warnings and cooling measures for the elderly and outdoor workers, areas several Indian states have begun to strengthen.