Projection of Future Air Quality in South Asia Using High Resolution

About one seventh of the world's population living in South Asia faces the risk of severe air pollution as anthropogenic emissions of air pollutants are increasing continuously due to the economic development and urbanization in the region. Recent studies show that air pollution in South Asia is already reducing the lifespan of about 660 million people by about 3 years and destroying enough food to feed about 94 million people. This problem may worsen in the future as anthropogenic emissions are expected to increase further due to economic growth in South Asia, and climate change is expected to lead to atmospheric conditions conducive for the production and accumulation of air pollutants. To learn how air quality will change in South Asia from present day conditions to the 2050 future time frame, we are conducting high resolution air quality simulations for the present day (1995-2005) and future (2046-2055) time periods over South Asia using the Nested Regional Climate Model coupled with Chemistry (NRCM-Chem). The model domain covers entire South Asia at a resolution of 60 km with a nested domain over the densely populated and polluted Indo-Gangetic Plain region at a resolution of 12 km. The model results are being evaluated with available in situ and satellite based observations and the evaluation results show that that NRCM-Chem model is able to capture several important features of the observed spatial and temporal distribution of key meteorological parameters and air pollutants. Preliminary analysis of model results show that annual average surface ozone and PM2.5 may increase by up to 15 ppbv and 25 µg m-3, respectively under RCP8.5 scenario with highest increase in the Indo-Gangetic Plain.