Heat caused over 47,000 deaths in Europe in 2023, notably among women, as climate change is causing the hottest days in northwest Europe to warm at double the rate of average summer days.
However, the research, published on the hottest day of the year so far in the UK, also concluded that heat related mortality would have been 80% higher in absence of measures taken in recent years, from early warning of heatwaves to public health campaigns.
Elisa Gallo of the Barcelona Institute for Global Health (ISGlobal) and colleagues used mortality records of 96 million deaths from the European Statistical Office (Eurostat) to estimate the heat-related mortality burden in 2023 across 35 European countries.
Their study, published on Monday 12 August in Nature Medicine, suggests that at least 47,312 heat-related deaths may have occurred between May 29 and October 1 last year, which is the second-highest mortality burden since 2015, surpassed only by 2022, the highest heat deaths of the past decade.
Although the study underlines the importance of adapting to heatwaves, Dr Gallo stressed ‘the need to tackle the root of the problem by addressing emissions of greenhouse gases…every gram of CO2 released into the atmosphere pushes us towards the limits of what we can realistically adapt to.’
‘We need to work harder and faster on reducing greenhouse gas emissions,’ said Dr Gallo, which is the subject of Energy Revolution: The Adani Green Energy Gallery in the Science Museum.
The Barcelona team estimates that last year the largest number of heat-related deaths occurred in southern Europe, including Greece (393 deaths per million), Bulgaria (229 deaths per million), Italy (209 deaths per million), Spain (175 deaths per million), Cyprus (167 deaths per million) and Portugal (136 deaths per million), mostly as a result of two heatwaves in mid-July and late August.
While the overall mortality was almost 13,000 in Italy, it was around 2,000 in the UK last year.
The team also modelled what the impact of heat-related mortality in 2023 could have been without present-century climate-adaptation measures, such as improvements in healthcare, social protection and lifestyle, progress in occupational health, air conditioning and insulation, preparedness efforts, increased awareness of risks, and more effective communications and early warning.
Their analysis suggests that, without measures that have cut the vulnerability of populations in recent years, heat-related mortality in 2023 could have been 80% higher in the general population, and in people 80 years of age and older, it could have more than doubled. ‘There have been societal adaptation processes to high temperatures during the present century, which have dramatically reduced the heat-related vulnerability and mortality burden of recent summers, especially among the elderly,’ said Dr Gallo.
In line with previous studies, the data also show a higher vulnerability of women. Specifically, after accounting for the population, the heat related mortality rate was 55% higher in women than in men.
The authors of the study caution that these numbers may underestimate the actual number of heat related deaths due to the lack of daily, uniform mortality records and estimate that the likely toll in 2023 could have actually been of the order of 58,000 deaths in the 35 countries studied.
They also point out that Europe is warming at a rate twice as fast as the global average, due to climate change. ‘There is an urgent need to implement strategies aimed at further reducing the mortality burden of the coming warmer summers, together with more comprehensive monitoring of the impacts of climate change on vulnerable populations’ added Joan Ballester Claramunt, an author of the study.
The study has been carried out as part of the EARLY-ADAPT project, funded by the European Research Council, and aimed at studying how populations are adapting to the health challenges triggered by climate change.