Climate Change over East Asia in Decreasing Anthropogenic Aerosol

Abstract

　Aerosols directly and indirectly modify cloud properties and consequently have various effects on the climate. They possess significant potential to change circulation fields through changes in the radiation budget. We used earth system model simulations to estimate the effects of anthropogenic aerosols on the climate over East Asia in the future, where the emission of anthropogenic aerosols is expected to decrease owing to measures being taken to control air pollution. Anthropogenic aerosols have negative effects on surface temperature and precipitation and positive effects on cloud cover; these effects of aerosols become slightly weaker with decreasing anthropogenic aerosol emissions. Thus, a reduction in aerosols may weaken their cooling effect. Because of that, measures for the emission control of aerosols may promote global warming and precipitation over East Asia. In this study, the rate of change in temperature and that in precipitation caused by increasing of greenhouse gases is estimated to be 0.35 K/10-year and 0.69%/10-year, respectively, over East Asia. On the other hand, combining aerosol decreasing and the greenhouse gas effect just mentioned provides the increasing rate with 0.46 K/10-year in temperature and 2.6%/10-year in precipitation. The results suggest that decreasing of anthropogenic aerosols contributes to temperature rising and increased precipitation.