The Asian Aerosol–Monsoon Climate System: A New Paradigm

The possible impact of anthropogenic aerosols on climate change of the Asian monsoon is well recognized, but not well understood. Unraveling the roles of greenhouse warming vs. aerosol on climate change in Asian monsoon regions is a major challenge. In this talk, I will show evidences that aerosol, like water vapor, clouds and precipitation is an intrinsic element of the Asian monsoon system. As such, aerosol impacts on climate change are not just due to increased anthropogenic emissions, but are strongly governed by feedback processes involving interactions of monsoon dynamics with radiation and cloud nucleation processes involving natural aerosol such as desert dust, black carbon from wildfires, as well as organic carbon from biogenic emissions. Better understanding of how ambient aerosols (natural and anthropogenic) interact with atmospheric dynamics and convection in affecting intrinsic monsoon processes, such as onset and breaks, floods and droughts, intraseasonal and interannual variability, and transport of chemical gases and aerosols will go a long way in providing better understanding of the roles of greenhouse warming, aerosols and other change agents in effecting climate change in Asian monsoon regions, as well as in informing societies and governments in formulating sound policies for mitigation and adaptation.