Distinct PM_2.5‐Related Near‐Term Climate Penalties Induced by Different Clean Air Measures in China

AbstractThe reductions in aerosols often exacerbate climate warming. It remains unclear how to effectively alleviate PM2.5 pollution while minimizing the penalty on climate warming. Here we identify the clean air measures in China that are associated with low aerosol climate penalty efficiency (ACPE), which is defined as aerosol radiative forcing per unit PM2.5 concentration reduction. The measures in transportation, residential combustion, and open burning sectors generally caused lower ACPE [0.07, 0.24, and 0.10 (W m−2)/(μg m−3)] than those from other sectors [0.34–0.46 (W m−2)/(μg m−3)]. This is ascribed to relatively small decreases in cloud concentration nuclei per unit PM2.5 reduction in these sectors, which is further attributed to either relatively low aerosol hygroscopicity or relatively small decrease in aerosol number. Most measures in the former three sectors have low ACPE of <0.15 [(W m−2)/(μg m−3)] and thus may be prioritized for synergistically controlling PM2.5 pollution and climate warming.