Numerical study of the future PM concentration under climate change and best-health-effect (BHE) scenario.

The Beijing-Tianjin-Hebei (BTH) is one of the key areas with PM air pollution in China. Driven by the PM target accessibility of the Interim Target-1 (IT-1) by World Health Organization (WHO) and China's carbon neutrality, this study explored and quantified the contribution of climate change and anthropogenic emission to future PM in the region. The experiments considered future climate change scenarios RCP8.5, RCP4.5, and RCP2.6 with the baseline (Base) and reduced emission (EIT1) inventories in 2030, and RCP4.5 climate scenario with 3 emission inventories in 2050, the additional strong control emission scenario called Best-Health-Effect (BHE). Under various climate scenarios, the future air quality research modelling system projected annual PM concentrations nearing 35 μg/m in 2030. However, considering only the effect of emission reduction, the annual PM concentrations under EIT1 emission scenario is about 35% less than under Base scenario in different key years. The future PM concentrations are highly related to anthropogenic emission from human activities, while climate change by 2030 or 2050 has little impact on future air quality over the BTH region. The BHE emission reduction is significantly required for China to meet the new PM guideline value of WHO in the future.