Reduction of Global Sulfate Aerosol Concentration and Corresponding Radiative Effects From Recent Chinese SO2 Emission Reduction

Abstract Anthropogenic emissions over China have recently declined due to environmental actions. This work estimates the sensitivity of sulfate aerosol () concentration to the amount of emissions reduction over China from 2010 to 2020 using an Earth system model with two different aerosol representations. We find that a larger rate of emissions decline over 2010–2020 from an updated Chinese emission inventory leads to improvement in modeled and concentrations when evaluated with targeted airborne observations from the Asian summer monsoon region from the 2022 Asian summer monsoon Chemical and Climate Impact Project. Updated Chinese emissions reduce concentration by >20% at 200 hPa over the North Pacific, and by >7% at 100 hPa throughout the tropics. These reductions result in an increase to global net instantaneous radiative forcing of 0.10–0.15 W by 2020, with regional effects up to 6 times greater.