The summer of 2022 was the hottest on record in Europe. It was also particularly deadly since more than 60,000 deaths are attributable to this heat, according to a study published Monday which calls for redoubled efforts to cope with the heat waves to come.
Against the backdrop of global warming, the European continent experienced an intense series of heat waves last year that broke temperature records, resulting in drought and forest fires.
Eurostat, the statistical office of the European Union, had already reported an unusually high excess mortality, but the share of mortality attributable to heat had not been quantified until now.
It is now done: scientists from the French National Institute of Health (Inserm) and the Barcelona Institute for Global Health (ISGlobal) have obtained temperature and mortality data for the period 2015 -2022 in 823 regions of 35 European countries, i.e. a total population of more than 543 million people.
These data were used to estimate epidemiological models to predict temperature-attributable mortality for each region and each week of the summer period.
In total, their analysis, published in the review NatureMedicineestimates that between May 30 and September 4, 2022, there would have been 61,672 heat-attributable deaths in Europe.
“Protecting people”
During this period, a more particularly intense heat wave occurred between July 18 and 24, with a total of 11,637 deaths.
“It’s a very high number of deaths,” comments Hicham Achebak, researcher at Inserm and co-author of the study. “We knew the effects of heat on mortality with the precedent of 2003, but with this analysis, we see that there is still a lot of work to be done to protect populations”.
The excess mortality in the summer of 2003, during which Europe experienced one of the greatest heat waves in its history, had exceeded the figure of 70,000 deaths in Europe. However, it is difficult to make a comparison, as the methodologies vary between these estimates.
For the summer of 2022, if we break down by country, France recorded the highest increase in temperature compared to seasonal averages, with 2.43ºC above the average values for the period 1991-2020, followed by Switzerland (2.30 ºC), Italy (2.28 ºC), Hungary (2.13 ºC) and Spain (2.11 ºC).”
But in absolute terms, the country with the highest death toll was Italy, with 18,010 fatalities, followed by Spain (11,324) and Germany (8,173). France arrives in 4e position, with 4,807 deaths.
The French public health agency had estimated the number of excess deaths recorded in the summer of 2022 in the country at 3,000, for the three heat peaks alone last summer.
80 years and over
The study published in NatureMedicine specifies that the vast majority of deaths are concentrated among people aged 80 and over.
Another lesson: heat-attributable mortality was 63% higher among women than among men. This greater vulnerability is observed especially among those over 80, with a mortality rate 27% higher than that of men.
Europe is the continent experiencing the greatest warming, up to 1°C more than the global average. In this context, the estimates made by the research teams suggest that in the absence of an effective response, the continent will face an average of more than 68,000 excess deaths each summer by 2030 and more than 94,000 by 2040.
“These predictions are based on the current level of vulnerability and future temperatures,” says Hicham Achebak. “If we take very effective measures, the vulnerability can be reduced,” he added.
“This study proves that heat prevention strategies need to be reassessed, taking particular account of gender and age,” reacted Chloe Brimicombe, climate researcher at the University of Graz, Austria, in a note from the UK Science Media Center.
It illustrates “an urgent need to protect the most vulnerable populations”, also underlined Raquel Nunes, professor at the University of Warwick, in England.