Scientists say crushing temperatures that blanketed Europe last summer may have led to more than 61,000 heat-related deaths, highlighting the need for governments to address the health impacts of global warming.
In their study, published Monday in the journal Nature Medicine, researchers examined official mortality figures from 35 European countries and found a marked increase in deaths between late May and early September last year compared with the average recorded over a 30-year period.
The increase in heat-related deaths was higher among older people, women and in Mediterranean countries, they found. But the data also indicated that measures taken in France since a deadly heat wave two decades ago may have helped prevent deaths there last year.
"In the pattern of summer mean temperatures in Europe during the summer of 2022, we don't see borders," said co-author Joan Ballester of the Barcelona Institute for Global Health. The highest temperatures were recorded across a swath of southwestern Europe, from Spain to France and Italy.
"But when we look at the heat-related mortality, we start to see borders," Ballester told The Associated Press. While France had 73 heat-related deaths per million inhabitants last summer, Spain's rate was 237 and Italy's was 295, the study found.
"Possibly France drew lessons from the experience of 2003," he said.
France's warning system includes public announcements with advice on how to stay cool and encouraging people to drink water and avoid alcohol.
Not all of the heat-related deaths calculated across Europe last summer were linked to climate change. Some would have occurred even if summer temperatures had stayed in line with the long-term average. But there is no doubt that the intense heat in 2022 — which saw numerous European records tumble — led to higher mortality rates, as other studies on heat deaths have also shown.
The authors calculated that there were over 25,000 more heat-related deaths last summer than the average from 2015 to 2021.
Without appropriate prevention measures, "we would expect a heat-related mortality burden of 68,116 deaths on average every summer by the year 2030," the authors said. They forecast that figure would rise to over 94,000 by 2040 and more than 120,000 by mid-century.
Governments in Spain and Germany recently announced new measures to address the effects of hot weather on their populations. In Switzerland, a group of seniors is citing the danger posed to older women by intense heat in a court case seeking to force the government to take tougher climate action.
One difficulty for researchers is that heat-related deaths are often happening in people with pre-existing conditions, such as cardiovascular disease, said Matthias an der Heiden of Germany's Robert Koch Institute, who was not involved in the study.
In such cases, the heat is not the underlying cause of death and therefore not recorded in the cause of deaths statistics. This can cloak the significant impact that heat has on vulnerable people, with up to 30% more deaths in certain age groups during periods of hot weather.
"The problem is going to get more acute due to climate change and medical systems need to adjust to that," he said.
An der Heiden also noted that the Nature study estimated almost double the number of heat deaths in Germany last year than his institute. While the discrepancy can be explained by the different threshold values for heat used, it indicates the need for a more detailed description of heat-related mortality that distinguishes between moderate and intensive heat, he said.
According to co-author Ballester, the impact of heat depends greatly on the overall health of the population, particularly with regard to heart and lung disease.
Other measures, already being implemented in countries such as France, include raising awareness about the dangers of high temperatures and identifying individuals who need special attention during heat waves, he said.
"These are cheap, cost-effective measures," said Ballester.
He dismissed the suggestion that rising temperatures around the globe could, on balance, be beneficial due to fewer deaths during the winter months, noting the manifold risks posed to human civilization by rapid climatic change.
"In my opinion and the opinion of all the climate scientists, the less the climate is modified, the better," said Ballester. "That's why it's so important that we start, as soon as possible, mitigating climate change and reducing vulnerability."