Projections of Heat-Related Mortality in Chinese Cities: The Roles of Climate Change, Urbanization, Socioeconomic Adaptation, and Landscape-Level Strategies.

BACKGROUND

Physiological heat strain induced by extreme temperatures in cities has led to significant heat-related deaths. Although socioeconomic adaptation is suggested to mitigate this issue, its effectiveness is limited. Conversely, there is a lack of comprehensive evaluation on the effectiveness of landscape-level strategies for mitigating heat-related deaths.

OBJECTIVES

We developed a comprehensive modeling framework to estimate the impacts of environmental stresses and mitigating strategies on heat-related deaths in China's cities from 2016 to 2055.

METHODS

The framework assesses future heat-related deaths through five experiments considering the influences of climate change, urbanization, socioeconomic adaptation, and landscape-level strategies. We used extrapolated region-specific exposure-response functions (ERF) and recent advancement of geo-statistics for public health to generate urban patch level ERF curves. We used these curves and temperature and population data to generate future heat-related deaths with a resolution and conducted 5,000 Monte Carlo simulations for uncertainty analysis.

RESULTS

Our analyses estimated that heat-related mortality will increase from deaths per million in 2016 to deaths per million in 2055 under SSP2-RCP4.5 (shared socioeconomic pathways-representative concentration pathways) scenario and from deaths per million to deaths per million under SSP5-RCP8.5 scenario, despite socioeconomic adaptation and landscape-level strategies. Socioeconomic adaptation (reducing deaths by ) and landscape-level strategies (reducing deaths by ) significantly mitigate heat-related deaths with varying effectiveness across different income levels. Specifically, in high-income cities with dense populations, landscape-level strategies are 2.2-4.3 times more effective than socioeconomic adaptation. Within these cities, implementing the same landscape-level strategies in the high-density urban centers led to an additional reduction up to in comparison with surrounding areas.

DISCUSSION

Our framework helps to systematically understand the effectiveness of landscape-level strategies in reducing heat-related mortality. Future sustainable city management should prioritize landscape-level strategies along with socioeconomic adaptation to support healthy and comfortable communities. https://doi.org/10.1289/EHP15010.