Anthropogenic activities change population heat exposure much more than natural factors and land use change: An analysis of 2020−2100 under SSP-RCP scenarios in Chinese cities

Global climate change, especially warming, has significant implications for human health. There are currently research gaps in the attribution of urban heat environment (UHE) changes and the exploration of heat exposure based on land use types. This study proposed a UHE change attribution algorithm based on land use types, separated contributions of natural factors (NAT), land use change (LUC), and other anthropogenic activities (OANT) in Chinese cities under Shared socioeconomic pathway-Representative concentration pathway (SSP-RCP) scenarios over different periods in the 21st century, further evaluated population heat exposure changes of the same three factors during extreme heat (i.e., maximum daily temperatures exceeding 35 °C). The average UHE changes were projected to be positive over each future period. Total OANT contribution would be slightly higher than that of NAT in the same period and scenario, while in most cases, contribution intensity of NAT would be greater than that of OANT. Total contribution and intensity of LUC would remain low. Population heat exposure changes of OANT would be 15.46 and 15.21 times higher than those of NAT and LUC, respectively. The outcomes of this study will help guide adaptation and mitigation of UHE changes under future scenarios and reduce negative impacts on human health.