Comparison of Current and Future PM2.5 Air Quality in China Under CMIP6 and DPEC Emission Scenarios

Abstract

AbstractThe sixth Coupled Model Intercomparison Project (CMIP6) scenarios provide opportunities to explore global climate and pollution mitigation pathways with socioeconomic features, but they might be limited on regional‐scale projections due to inadequate consideration of local policies. Here, we simulated China's PM2.5 air quality with local policy‐based scenarios (Dynamic Projection for Emissions in China (DPEC)) and the CMIP6 scenarios. We found both emission inventories can reproduce China's base‐year PM2.5 and chemical aerosols while using DPEC emissions could better match in‐situ observations. In addition, DPEC mitigation scenarios can better capture China's PM2.5 decline during 2015–2019 (22% under SSP2‐45‐policy and 30% under SSP1‐26‐best) with observations (∼28%) than CMIP6 emissions. With the effects of current‐year bias and inadequate considerations of pollution control policies, PM2.5 projections in 2030 and 2050 with CMIP6 mitigation scenarios are 42%–48% (9–13 μg/m3) and 59%–73% (8–12 μg/m3) higher than projections with DEPC. Our study suggests the community should incorporate more region‐specific environmental policy in future scenario designs.