European heatwave caused 2,300 deaths in 10 days: Study

Qatar Tribune

09-07-2025

Some 2,300 people are likely to have died of heat-related causes across 12 European cities during a severe heatwave that ended last week, with two-thirds of the deaths directly linked to climate change, according to a new study.
The analysis, published on Wednesday, focused on the 10-day period between June 23 and July 2, during which large parts of Western Europe were hit by extreme heat, with temperatures breaching 40 degrees Celsius (104 Fahrenheit) in Spain and wildfires breaking out in France.
It covered 12 cities with a combined population of more than 30 million, including Barcelona, Madrid, London and Milan, where the study said climate change had increased heatwave temperatures by up to 4C (39.2F).
Of the 2,300 people estimated to have died during this period, 1,500 deaths were linked to climate change, which made the heatwave more severe, said the study conducted by more than a dozen researchers from five European institutions in the United Kingdom, Netherlands, Denmark and Switzerland.
'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 researcher at Imperial College London, one of the institutions involved in the study.
The researchers used established epidemiological models and historical mortality data to estimate the death toll, which reflects deaths where heat was the underlying reason for mortality, including whether exposure exacerbated existing health conditions.
To assess what role climate change played, scientists compared how intense a heatwave would have been in a world that had not warmed due to burning masses of fossil fuels.
They concluded the heatwave 'would have been 2-4C (35.6-39.2F) cooler' without human-induced climate change in all but one of the 12 cities studied, noting that the added degrees greatly elevated the risk in these cities.
'What that does [the increased temperatures] is it brings certain groups of people into more dangerous territory,' said Clarke. 'For some people, it's still warm, fine weather. But for now, a huge sector of the population, it's more dangerous,' he told reporters.
Heatwaves are particularly dangerous for the elderly, the sick, young children, outdoor workers and anyone exposed to high temperatures for prolonged periods without relief.
The effect on health is compounded in cities, where heat is absorbed by paved surfaces and buildings, making urban areas much hotter than their surroundings.
The scientists said they used peer-reviewed methods to quickly produce the estimated death toll, because most heat-related deaths are not officially reported and some governments do not release this data. A more definitive death toll from the recent heatwave could take weeks to produce.
'An increase in heatwave temperature of just two or four degrees can mean the difference between life and death for thousands of people,' said Garyfallos Konstantinoudis, a lecturer at Imperial College London.
'This is why heatwaves are known as silent killers. Most heat-related deaths occur in homes and hospitals out of public view and are rarely reported,' he told reporters.