
A severe heatwave that swept across parts of Western Europe between June 23 and July 2 has likely caused around 2,300 heat-related deaths in 12 major cities, according to a new study published on Wednesday. Researchers estimate that roughly 1,500 of these deaths can be directly attributed to human-caused climate change.
The analysis, conducted by a consortium of over a dozen scientists from research institutions in the UK, Netherlands, Denmark, and Switzerland, examined mortality rates during the 10-day period in cities including Barcelona, Madrid, London, and Milan—home to a combined population of more than 30 million people.
Temperatures soared above 40°C (104°F) in parts of Spain, and wildfires broke out in several areas of France, prompting health alerts and emergency responses across the continent.
Climate Change Intensified the Heat
According to the study, climate change increased heatwave temperatures by up to 4°C (7.2°F), significantly worsening the health impacts of the already extreme weather.
“Climate change has made it significantly hotter than it would have been, which in turn makes it a lot more dangerous,” said Ben Clarke, a climate researcher at Imperial College London.
Hidden Toll of Extreme Heat
Researchers used epidemiological models and historical mortality data to estimate the excess deaths caused by the heatwave. The fatalities include not only deaths from direct heat exposure, but also cases where extreme temperatures worsened underlying health conditions.
Experts have referred to heatwaves as “silent killers” because their deadly impact often goes unnoticed in real-time, particularly among vulnerable populations such as the elderly and those with pre-existing medical conditions.
As Europe continues to experience more frequent and intense heatwaves, scientists and public health officials are calling for urgent adaptation measures and greater climate resilience planning to prevent further loss of life.