Differentiated regional impacts of future meteorological changes and anthropogenic emission control on PM2.5 concentrations in China

Despite great progress in past decades, mitigating ambient fine particulate matter (PM_2.5) pollution remains a long-term task for China in protecting human health. Effective strategies must account for the impacts of future meteorological changes and anthropogenic emission variations, which vary substantially across regions and climate change scenarios. In this study, we assessed meteorological conditions, anthropogenic emissions, and PM_2.5 concentrations in 2060 in key regions in mainland China under various climate change scenarios by coupling an integrated assessment model and a regional meteorology/air quality dynamic downscaling simulation system. The results show that surface temperature and humidity are projected to increase across mainland China under all scenarios (SSP126, SSP245, SSP370, SSP585), while other meteorological factors vary by region and scenario. In the Jing-Jin-Ji and Fenwei Plain, meteorological changes are expected to worsen air pollution, leading to PM_2.5 increases of over 3.5 and 1.5 μg/m³, respectively. Conversely, meteorological changes are likely to reduce PM_2.5 in the Yangtze River Delta, Pearl River Delta, and Sichuan Basin in most scenarios. The analysis of anthropogenic emission variations demonstrates that large anthropogenic emissions reductions will significantly decrease PM_2.5 concentrations in all key regions, but the extent of reductions varies due to regional differences in emission sources. Among key regions, the Pearl River Delta usually exhibits the smallest proportional reductions in emissions and the least decline in PM_2.5 concentration across various scenarios. The differentiated regional impact of meteorological changes and anthropogenic emission control on future PM_2.5 concentrations in China highlights the necessity of region-specific policies to mitigate future PM_2.5 pollution.