Impacts of Suppressing Excessive Light Rain on Aerosol Radiative Effects and Health Risks

Abstract

Aerosols modulate Earth's energy balance both directly and indirectly. Directly they scatter or absorb solar radiation, and indirectly they alter cloud micro-and macro-physical properties by serving as cloud ice and condensation nuclei (Boucher et al., 2013;Y. Wang et al., 2014). The effective radiative forcing (ERF, defined as Earth's energy imbalance to a radiative perturbation) (Forster et al., 2016;Myhre et al., 2013) from aerosol-radiation-interaction (ERFari) and aerosol-cloud interaction (ERFaci) due to changes in aerosol concentrations in the industrial era (present-day, PD) relative to preindustrial (PI) levels has been quantified by global climate models (GCMs). In the fifth phase of the Coupled Model Intercomparison Project (CMIP5), the total (shortwave + longwave) ERF due to anthropogenic aerosols (ERFari + aci) was estimated to be −1.17 ± 0.30 W/m 2 , with ERFari of −0.25 ± 0.22 W/m 2 and ERFaci of −0.92 ± 0.34 W/m 2 , respectively (Zelinka et al., 2014). Its updated value from CMIP6 models is −1.04 ± 0.20 W/m 2 , with −0.23 ± 0.19 W/m 2 from ERFari and −0.81 ± 0.30 W/m 2 from ERFaci (Smith et al., 2020). Observationally, Chung et al. (2005) estimated ERFari to be −0.35 W m −2 with a range of −0.6 to −0.1 W m −2 from satellite and ground-based observations. Using satellite-based estimation, Jia