Changes of anthropogenic carbon emissions and air pollutants during the COVID-19 epidemic in China

Abstract

We quantify the changes of anthropogenic carbon emissions and major air pollutants during the COVID-19 epidemic in China by analyzing data from economic sectors,1 580 surface monitoring sites,and 6 satellite retrievals.Compared to the first quarter of 2019,national carbon emissions decreased by 9.8% in 2020 with the maximum reduction of 43.4% in transportation sector.Compared to the average of February-March in 2019,surface ozone concentrations increased by 1.9 nL/L(5%) during the epidemic on the country level,with major reductions in North China Plain but enhancements in the Southeast.Surface PM2.5 concentrations decreased by 12.6 μg·m-3(24.9%) with the maximum reduction in Yangtze River Delta(YRD).For NO2, both the surface concentrations and tropospheric column density showed consistent reductions of 20%-30% in Beijing-Tianjin-Hebei,Pearl River Delta,and YRD.Surface CO concentrations declined by 17% while tropospheric column CO increased by 2.5%,likely because the transportation of air pollutants from biomass burning outside China enhances CO density at high levels in southern China.Aerosol optical depth significantly decreased in the middle and eastern China,leading to an increased surface shortwave radiation by 11.6 W·m-2(9.6%).