The influence of anthropogenic emissions on air quality in Beijing-Tianjin-Hebei of China around 2050 under the future climate scenario

The Beijing-Tianjin-Hebei (BTH) region of China is one of the most frequently referenced areas with PM2.5 air pollution and various control measures; hence, it is critical to project the future air quality on this region under different emission scenarios. In this study, using a global climate model, regional meteorological model, emission process model and air quality model, a future air quality research modeling system is designed and utilized to explore the air quality conditions over the BTH region in 2050. Two sensitivity experiments with different in-tensity emission inventories were set to quantify the influence of anthropogenic emissions on the future air quality in the BTH region under the identical representative concentration pathway (RCP) scenarios of RCP4.5, which is provided by the famous climate model Geophysical Fluid Dynamics Laboratory Earth System Model with the Generalized Ocean Layer Dynamics component (GFDL-ESM2G). The results show that the annual PM2.5 concentration over BTH under the EIT1 (Emissions for Interim Target-1) scenario is 32.7 mu g/m3, less than 35 mu g/ m3, approximately half of the value under the baseline emission scenario, and reaches the Interim Target-1 by the World Health Organization (WHO), which is also the national air quality standard for annual PM2.5 concen-trations in China. The frequency of nonpolluted projects can reach 95%, and the frequency of heavily polluted projects is well under 1% under the EIT1 emission scenario. These results indicate that emission reduction is significantly required to achieve the new Chinese PM2.5 target.