Comparing the radiative effects of the anthropogenic aerosol emissions
from Chile and Mexico
Abstract
There has been growing interest in the potential of short-lived climate
forcer (SLCF) mitigation to reduce near-term global warming. Black
carbon (BC) is a SLCF that is known to warm the climate by absorbing
insolation and to affect the radiative balance indirectly by altering
cloud properties. We used an aerosol-climate model to study the climatic
effects of the anthropogenic aerosol emissions of BC, organic carbon
(OC) and sulfur dioxide (SO2) 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 effects of
anthropogenic aerosol emissions are different for Chile and Mexico. This
was explained by differences in aerosol emission strengths, their
spatial distribution and differences in 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. The removal of OC and SO2 emissions caused a positive
effective radiative forcing (ERF), while the removal of BC emissions
caused a positive ERF for Chile, but a negative ERF for Mexico. When
accounting for co-emission of other aerosol compounds, reduction of BC
emission led to positive ERF in both countries. Compared to China, the
removal of all anthropogenic SO2 emissions in Chile and Mexico caused a
much larger global average ERF per emitted unit mass of SO2.