The role of China's urban green space in synergistically mitigating PM2.5-attributed health impact and climate change

Abstract

Urban green space (UGS) serves to mitigate ambient pollutant concentrations through adsorption and dispersion effects while providing carbon sequestration via photosynthesis, contributing synergistically to urban climate and air quality improvement. This study quantifies this synergistic role by evaluating the UGS-attributed reduction in PM_2.5-related health impacts, the UGS-produced carbon sequestration, and the socioeconomic value of these co-benefits, using Chinese cities as a case study. From 2008 to 2022, UGS collectively prevented an estimated 179.34 thousand PM_2.5-related premature deaths and sequestered 349.81 million tCO₂e, corresponding to socioeconomic values of 694.69 and 314.94 billion CNY, respectively. Driven by urbanization and the expansion of UGS in China, UGS-attributed health benefits and carbon sequestration have shown steady growth over the past 15 years. Furthermore, this study evaluates the UGS investment-benefit ratio, environmental Gini coefficient, and offsetting rate (relative to city-level PM_2.5-related health impacts and CO₂ emissions), revealing inequalities in UGS-related environmental investment, benefits, and responsibilities across cities. The identification of associated socioeconomic factors indicated that urbanization progress exerted a complex influence on the capacity of UGS to deliver environmental health and climate co-benefits. As an integral component of urban green infrastructure and a product of urbanization, the UGS helps offset negative environmental impacts arising from urban development and construction to a certain extent. A comprehensive and system-wide evaluation of UGS-derived co-benefits can inform UGS spatial planning and support green urbanization, Beautiful China development, and achieving Sustainable Development Goal 11.