Ambient PM2.5 exposure and expected premature mortality to 2100 in India under climate change scenarios

Premature mortality from current ambient fine particulate (PM2.5) exposure in India is large, but the trend under climate change is unclear. Here we estimate ambient PM2.5 exposure up to 2100 by applying the relative changes in PM2.5 from baseline period (2001-2005) derived from Coupled Model Inter-comparison Project 5 (CMIP5) models to the satellite-derived baseline PM2.5. We then project the mortality burden using socioeconomic and demographic projections in the Shared Socioeconomic Pathway (SSP) scenarios. Ambient PM2.5 exposure is expected to peak in 2030 under the RCP4.5 and in 2040 under the RCP8.5 scenario. Premature mortality burden is expected to be 2.4-4 and 28.5-38.8% higher under RCP8.5 scenario relative to the RCP4.5 scenario in 2031-2040 and 2091-2100, respectively. Improved health conditions due to economic growth are expected to compensate for the impact of changes in population and age distribution, leading to a reduction in per capita health burden from PM2.5 for all scenarios except the combination of RCP8.5 exposure and SSP3.