Improvements in life expectancy mask rising trends in heat-related excess mortality attributable to climate change

submitted by dumnezero to europe 21 points | 0 comments https://www.nature.com/articles/s41467-025-66681-0

Abstract: Previous attribution studies of heat-related excess mortality have given limited attention to temporal trends in vulnerability and their non-climatic drivers. Here, we address this gap by combining counterfactual temperature data derived from multidecadal reanalysis series with time-varying warm-season temperature-mortality associations for the 15 most populous cities in Germany over 1993-2022. We find that declining vulnerability, associated with improvements in life expectancy, has led to decreasing trends in heat-related excess mortality in most cities despite summer warming. In contrast, if life expectancies had not improved, climate change would have induced increasing trends in the heat-related death burden. The growing anthropogenic fingerprint also emerges in the relative proportion of heat-related excess mortality attributable to climate change, which increased by 5.6% per decade (95% confidence interval: 2.6%, 8.6%), averaging 53.6 % (49.8%, 58.9%) across the study period. Our results underline the importance of accounting for evolving vulnerability when attributing human health outcomes to climate change.

Conclusion paragraph:

our study suggests that declining risks of heat-related mortality in the 15 most populous cities of Germany, associated with improvements in life expectancies, have so far overcompensated the increased heat exposure due to climate change. As a result, temporal trends in heat-related excess mortality were negative from 1993 to 2022. However, given the intense regional warming expected under current greenhouse gas emission trajectories, the trend may flip sign in the coming years. Strong efforts in adaptation, such as through heat-health action plans, urban greening, and the expansion of residential air conditioning, might lower the heat vulnerability of the population to keep up with the pace of increasing temperatures, which ultimately will depend on the stringency of mitigation undertaken.