Fast climate responses to emission reductions in aerosol and ozone precursors in China during 2013-2017

Abstract

China has been implementing a sequence of policies for clean air since the year 2013, and the aerosol pollution has been substantially improved, but ozone (O3)-related issues arose. Here, fast climate responses to emission reductions in aerosol and O3 precursors over China during 2013-2017 are investigated using the Community Earth System Model version 2 (CESM2). The overall decreases in aerosols produced an anomalous warming of 0.09 ± 0.10°C in eastern China (22-40 N, 110-122.5 E), which is further intensified by the increase in O3 in the lower troposphere, resulting in an enhanced warming of 0.16 ± 0.15 g C in eastern China. Reductions in industrial emissions contributed the most to the aerosol-induced warming, while emission reductions from residential sector induced a cooling effect due to a substantial decrease in light-absorbing black carbon aerosols. This implies that switching the residential sector to cleaner energy is more effective to achieve climate and health benefits in China.