A substantial reduction of total and group-specific population risk to compound heat and drought events in China through achieving carbon neutrality

Compound climate extremes, such as compound heat and drought events (CHDEs), in combination with population growth and aging, pose a growing risk to the socioeconomic system. However, the potential risks of frequent and intense CHDEs under climate change on group-specific populations and the advantages of achieving carbon neutrality in reducing CHDE damage have not been extensively explored. Our research quantified total and group-specific population exposure to CHDEs in four future scenarios in China and examined the benefits of carbon neutrality. Results show total population exposure to CHDEs will increase significantly in all scenarios, reaching a maximum of 540.55±125.52×10 8 person-days in 2081–2100 under shared socioeconomic pathways (SSP) 3-7.0, 3.93±0.91 times that of the base period (1995–2014). Exposure in southeastern China, particularly in Shandong, Hebei, Henan, and Jiangsu, is much higher than in inland northwestern China. The increase in exposure for the elderly is higher than that of children and working-age population, with the maximum value reaching 175.84±33.71×10 8 person-days, 9.57±1.83 times compared to the base period. Achieving carbon neutrality under SSP1-2.6 is projected to significantly reduce total population exposure by 72–84% in the late 21st century (2081–2100) than other scenarios in the same period. The reduction rate for the elderly ranges from 41% to 61%, which is less substantial than for children or working-age population. The effect of climate change is the primary factor in reducing exposure to the total population, children, and working-age population, while its interactive effect with population is the dominant contributor (53–56%) for the elderly. Thus, efforts to achieve carbon neutrality are urgently needed in China to reduce the number and inequality of the population exposed to CHDEs. Special attention should be paid to the elderly, who are particularly vulnerable and disproportionately affected by CHDEs. • Population exposure in China will increase 3.93±0.91-fold under SSP3-7.0. • Exposure rise for the elderly is higher than for children and working-age adults. • Achieving carbon neutrality may notably reduce population exposure by 72–84%.