A Source Apportionment and Emission Scenario Assessment of PM2.5‐ and O3‐Related Health Impacts in G20 Countries

Abstract Exposure to air pollution is a leading risk factor for premature death globally; however, the complexity of its formation and the diversity of its sources can make it difficult to address. The Group of Twenty (G20) countries are a collection of the world's largest and most influential economies and are uniquely poised to take action to reduce the global health burden associated with air pollution. We present a framework capable of simultaneously identifying regional and sectoral sources of the health impacts associated with two air pollutants, fine particulate matter (PM2.5) and ozone (O3) in G20 countries; this framework is also used to assess the health impacts associated with emission reductions. This approach combines GEOS‐Chem adjoint sensitivities, satellite‐derived data, and a new framework designed to better characterize the non‐linear relationship between O3 exposures and nitrogen oxides emissions. From this approach, we estimate that a 50% reduction of land transportation emissions by 2040 would result in 251 thousand premature deaths avoided in G20 countries. These premature deaths would be attributable equally to reductions in PM2.5 and O3 exposure which make up 51% and 49% of the potential benefits, respectively. In our second application, we estimate that the energy generation related co‐benefits associated with G20 countries staying on pace with their net‐zero carbon dioxide targets would be 290 thousand premature deaths avoided in 2040; action by India (47%) would result in the most benefits of any country and a majority of these avoided deaths would be attributable to reductions in PM2.5 exposure (68%)