Emission mitigation pathways to achieve PM2.5 interim target III of the world health organization in the Pearl River Delta in 2035

Abstract

By participating in the construction of China's Guangdong-Hong Kong-Macao Greater Bay Area (GBA) and as the core zone of the GBA, the region (PRD) aims to have the ambient air quality basically reaching the level of the world-class bay areas by 2035. In this study, we developed three scenario strategies (Moderate Scenario (SM), Intensified Scenario (SI) and Radical Scenario (SR)) for the PRD in 2035 taking the average annual PM2.5 concentrations in the PRD reaching the world health organization interim target 3 (WHO-III, 15 μg/m3) as the constraint standard. Under each scenario, we formulated the structural adjustment and end-of-pipe control measures to predict the development of industry, transportation and energy in the PRD in 2035. The results show that the total emissions of SO2, NOx, PM (Particulate Matters) and NMVOCs (Non-methane Volatile Organic Compounds) were 152, 511, 205 and 382kt in the SM scenario, respectively, and were 114, 436, 177 and 325kt in the SI scenario, respectively, while they are 77, 344, 143 and 269kt in the SR scenario, respectively. We also consider the emission reduction of pollutants outside the PRD. In this study, the SM, SI and SR scenarios were combined with different national scenario inventories (DPEC) in 2035 and the WRF-CMAQ model was used to simulate these scenarios. The simulation results show that annual average concentrations of PM2.5 in the PRD under the SM-DPEC1, SI-DPEC2 and SR-DPEC3 scenarios were expected to reach 15.1, 14.6 and 14.8 μg/m3, respectively, which just meet the WHO-III standard. In the process of achieving WHO-III target in the future, the government and policy makers can match the most suitable scenario in the study by referring to the actual decline of air pollutant emissions in the main contributing regions outside the PRD under each scenario, so as to obtain the best feasible control strategy in the PRD.