Quantifying effects of Indian aerosol emissions on regional aerosol abundances, energy balance, and health impacts, using a novel national emission inventory

After years of rapid growth, India has become a hotspot for emissions of aerosols and their precursors, recently surpassing China in terms of magnitude of SO₂ emissions. The resulting high air pollution levels influence climate through interactions with solar radiation, clouds, and the hydrological cycle, and pose one of the greatest environmental threats to public health. Model estimates of these impacts are influenced by the substantial spread that exists between current emission inventories, in terms of both trend and magnitude. Activity and fuel data is heterogeneous and can be challenging to compile, and many emission sources are highly region specific. Hence, inventories need to be based on up-to-date national statistics and detailed sectoral information.

Here we use one such inventory for Indian anthropogenic emissions, the recently developed, bottom up SNEII (Sabe National Emission Inventory for India) dataset to simulate and evaluate regional air pollution levels for 2018. SNEII includes a more detailed spatial allocation of point sources of emissions and sectoral disaggregation than many global inventories. The results are compared to estimates using the Community Emission Data System (CEDS) emissions, version 2021, also placing them in the context of the trend over the past decades. For most species, SNEII estimates higher emissions, and we explore the resulting impact of these differences on simulated aerosol abundances, as well as implications for radiative forcing and premature mortality. Finally, we quantify the sectoral contribution to air pollution with a finer breakdown than previously provided, including sectors unique for Indian/South Asian region.