Impact of Climate Change on Aerosol Concentrations in Eastern China Based on Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) Datasets

Changes in surface layer aerosol concentrations induced by climate change are important for understanding regional air quality. In this study, the impact of climate change on surface-layer aerosol concentrations over East Asia were investigated using multi-model results from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) under the RCP8.5 scenario during 2000-2100. With anthropogenic emissions of aerosols and aerosol precursors kept at year 2000 levels, the annual mean concentrations of surface-layer sulfate, organic carbon, and black carbon over northern China (31°N-45°N, 105°E-122°E) were simulated to increase by 28%, 21%, and 9%, respectively, owing to climate change over 2000-2100. Compared to that in 2000, annual mean surface-layer nitrate concentration in 2100 over eastern China was simulated to decrease by 30% by climate change alone. The climate-induced changes in fine particulate matter (PM_2.5) concentrations were simulated to have large seasonal variation. Due to significant decreases in nitrate concentrations in the winter, wintertime PM_2.5 concentrations over eastern China were simulated to decrease by 15% over 2000-2100. Furthermore, the changes in summertime PM_2.5 concentrations during 2000-2100 were found to have different patterns in northern and southern China; PM_2.5 concentrations in northern China would increase by 16%, while those in southern China would decrease by 9%.