Heterogeneities in Regional Air Pollutant Emission Mitigation Across China During 2012–2020

Abstract

AbstractThe toughest‐ever clean air actions to date in China have helped to reduce national air pollutant emissions significantly in recent years. However, the heterogeneous mitigation paths and their determinated factors among regions were less concerned. To direct regional mitigation strategies more efficiently, we compiled a time‐series emission inventory of Chinese 30 provinces for SO2, NOx, primary PM2.5 and CO2 at detailed socioeconomic sectors, and then used spatial‐temporal index decomposition analysis to evaluate the driving forces for changes in regional pollutant emissions and emission intensities from 2012 to 2017 and from 2017 to 2020, separately. Our results showed that end‐of‐pipe control measures dominated the decreasing trend of China's pollutant emissions (38%–68% for SO2, NOx, and primary PM2.5), but their relative dominance diminished gradually, and the effects from energy policy emerged, even outweighing the former in southern areas during the second phase. Though driven by different factors, the chemistry, nonmetal, metal, energy and residential sectors dominated regional reduction trend and with varying degrees. Clean air action led to the convergence of regional emission intensity, while optimizing and upgrading industrial structure and improving energy efficiency is still necessary for further reduction in northern and western areas at present.