Comparing the Radiative Forcings of the Anthropogenic Aerosol Emissions From Chile and Mexico

There has been growing interest in the potential of short‐lived climate forcer (SLCF) mitigation to reduce near‐term global warming. Black carbon (BC), organic carbon (OC), and sulfur dioxide (SO 2 ) are SLCFs which change the Earth's radiative balance directly by affecting radiation, and indirectly by altering cloud properties. We used the ECHAM‐HAMMOZ aerosol‐climate model to study the radiative forcings due to mitigating the anthropogenic emissions of BC, OC, and SO 2 from Chile and Mexico. Limiting our analysis to areas where these emissions had notable effects on both aerosol and clouds, we found that the total radiative forcings of anthropogenic aerosol emissions are different for Chile and Mexico. This was explained by differences in aerosol emissions, orography, and meteorology in these two countries. Especially the radiative forcing for Chilean emissions was influenced by the persistent stratocumulus cloud deck west of Chile. To reduce the uncertainty of our radiative forcing calculations, we nudged the wind and surface pressure toward pre‐generated fields. As nudging affects the calculated effective radiative forcing (ERF), we here used the identifier ERF NDG . Our results indicate that the removal of OC and SO 2 emissions caused a positive ERF NDG while the removal of BC emissions caused a positive ERF NDG for Chile, but a negative ERF NDG for Mexico. When accounting for co‐emission of other aerosol compounds, reducing BC emissions led to positive ERF NDG in both countries. Compared to China, the removal of anthropogenic SO 2 emissions in Chile and Mexico caused a much larger global average ERF NDG per emitted unit mass of SO 2 .