Impacts of Aerosol Reduction in China on East Asian Summer Monsoon and Weather Extremes Following a Localized Carbon Neutral Emission Pathway

Abstract To achieve the goal of carbon neutrality, China is projected to significantly reduce anthropogenic aerosols in addition to greenhouse gases. Here, the future changes in East Asian summer monsoon (EASM) and weather extremes responding to the idealized local emission reductions of anthropogenic aerosols (AA) in China are investigated based on time‐slice simulations in an aerosol‐climate model together with a localized carbon neutral emission scenario, while greenhouse gases and other anthropogenic climate forcers are kept at the present‐day (2015) levels. The AA reduction in China leads to a positive change in June–July–August (JJA) mean effective radiative forcing over eastern China in 2030 and 2060s, along with a 0.2°C–0.4°C warming, respectively. It intensifies the temperature difference between land and ocean, and increases the precipitation over eastern China. Multiple EASM indices show that EASM intensity in JJA is estimated to be strengthened in the future, because of the AA decline in China. The AA emissions reduction toward carbon neutrality in China also presents a potential side effect of intensifying the summertime extreme temperatures and precipitation in China. This study reveals the important role of reductions of AA emissions in influencing EASM and weather extremes, which warrants careful assessment in the emission policymaking process prior to the implementation of mitigation strategies.