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

[Geoengineering News]

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2025GL118851

Authors: Warren P. Smith, Simone Tilmes, Benjamin Gaubert, Claire Granier, Yunqian Zhu, Oliver Eppers, Franziska Köllner, Philipp Brauner, Andrew Rollins, Eleanor Waxman, Gregory Schill, Colin Gurganus, L. Gregory Huey, David Tanner, Young-Ro Lee, Chelsea Bekemeier

04 February 2026

Abstract

Anthropogenic emissions over China have recently declined due to environmental actions. This work estimates the sensitivity of sulfate aerosol (SO4) concentration to the amount of SO2 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 SO2 emissions decline over 2010–2020 from an updated Chinese emission inventory leads to improvement in modeled SO2 and SO4 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 SO2 emissions reduce SO4 concentration by >20% at 200 hPa over the North Pacific, and by >7% at 100 hPa throughout the tropics. These SO4 reductions result in an increase to global net instantaneous radiative forcing of ∼0.10–0.15 W m−2 by 2020, with regional effects up to ∼6 times greater.

Source: AGU