Anthropogenic emissions over China have recently declined due to environmental actions. This work quantifies the sensitivity of sulfate aerosol (SO4) concentration in the upper troposphere and lower stratosphere (UTLS) to the reduction of SO2 emissions over China from 2010-2020 using an Earth system model (ESM) with two different aerosol representations. We find that a larger rate of SO2 emissions decline over from an updated Chinese emission inventory leads to improvement in modeled SO2 and SO4 concentrations when evaluated with airborne observations. The updated Chinese SO2 emissions reduce SO4 concentration by >20% at 200 hPa over the northern Pacific Ocean, and by >7% at 100 hPa throughout the global tropics. These SO4 reductions result in an estimated increase to global net radiative forcing of ~0.10-0.15 W m-2 by 2020, with local effects ~5-6 times greater over the North Pacific Ocean where the SO4 reductions are greatest.
Smith et al. (Tue,) studied this question.