The dual impact of carbon neutrality and population aging on PM2.5-related mortality and economic burden in China

Abstract

Despite considerable regulatory interventions to mitigate air pollution, fine particulate matter (PM2.5) remains a critical health threat across China. Carbon neutrality strategies, though primarily aimed at mitigating climate change, may also yield substantial co-benefits for air quality and public health. However, the scale of these benefits may be undermined by rapid population aging. Here, we used a two-stage time-series analysis to quantify the exposure-response relationship between short-term PM2.5 exposure and mortality, using 50.9 million non-accidental deaths in mainland China. We then applied an air quality model to project future PM2.5 concentrations and estimate the associated disease burden under three carbon emissions scenarios. From 2013 to 2020, short-term PM2.5 exposure was attributable to 2.38% of all-cause mortality. By 2060, PM2.5 concentrations are projected to decline by 75.8%, 67.8%, and 40.1%, respectively, under three emission pathways: SSP119 (carbon neutrality), SSP126 (carbon peaking), and SSP245 (business as usual), compared with the baseline period. Consequently, excess mortality among individuals under 65 years of age is expected to decrease by 83.9%, 78.6%, and 60.1%, respectively. However, among adults aged 85 and over, PM2.5-attributable mortality is projected to increase by 15.6%, 53.5%, and 182.6%, respectively. By 2050, older adults are expected to account for more than 69% of PM2.5-related economic costs under the SSP119 scenario, reflecting the growing age-related burden in all scenarios. These findings underscore the health and financial benefits of achieving carbon neutrality and highlight the need to integrate demographic change into future climate and air quality policy frameworks.