Future heat-related mortality in Europe driven by compound day-night heatwaves and demographic shifts
Xilin Wu, Jun Wang, Yong Ge, Shengjie Lai, Die Zhang, Zhoupeng Ren, Jianghao Wang
Abstract
Anthropogenic climate change is driving summer heat toward more humid conditions, accompanied by more frequent day-night compound heat extremes (high temperatures during both day and night). As the fast-warming and aging continent, Europe faces escalating heat-related health risks. Here, we projected future heat-related mortality in Europe using a distributed lag nonlinear model that incorporates humid heat and compound heat extremes, strengthened by a health risk-based definition of extreme heat and a scenario matrix integrating time-varying adaptation trajectories. Under 2010–2019 adaptation baselines, future heat-related mortality is projected to increase annually by 103.7-135.1 deaths per million people by 2100 across various population-climate scenarios for every degree of global warming, with Western and Eastern Europe suffering the most. If global warming exceeds 2 °C, climate change will dominate (84.0–96.8%) projected increase in heat-related mortality. Across all socioeconomic pathways, even a 50% reduction in heat-related relative risk through physiological adaptation will be insufficient to offset the climate change-driven escalation of future heat-related mortality. This study projects heat-related mortality in Europe across various adaptation scenarios by modelling humid and compound day-night heat, using a health-based heat definition. Without heat adaptation, mortality could rise by 103.7–135.1 deaths per million people per 1 °C of global warming.