The footprint of human-induced climate change on heat-related deaths in the summer of 2022 in Switzerland

Abstract

As in most countries in Europe, the 2022 summer in Switzerland was exceptionally hot, only comparable to the infamous 2003 summer, and particularly devastating in terms of excess health burden. Here we combine methods in climate epidemiology and attribution to quantify the mortality associated with heat and the contribution of human-induced climate change in the 2022 summer in Switzerland. We estimate 623 deaths [95% empirical confidence interval (95% eCI): 151 - 1,068] due to heat between June-August 2022, corresponding to 3.5% of all-cause mortality. More importantly, we find that 60% of this burden (370 deaths [95% eCI: 133-644]) could have been avoided in absence of human-induced climate change. Older women were affected the most, as well as populations in western and southern Switzerland and more urbanized areas. Our findings demonstrate that human-induced climate change was a relevant driver of the exceptional excess health burden observed in Switzerland.