Abstract/Summary

Improving air quality amid rapid industrialization and population growth is a huge challenge for India. To tackle this challenge, the Indian government implemented the National Clean Air Programme (NCAP) to reduce particulate matter (PM2.5 and PM10) pollution in hundreds of non-attainment cities that failed to meet the national ambient air quality standards. Here, we evaluate the efficacy of the NCAP, using data from the national air quality monitoring network combined with regional model simulations. Our results show an 8.8% per year decrease in annual PM2.5 pollution in the six non-attainment cities with continuous air pollution monitoring since 2017. Four out of the six cities had over 20% PM2.5 reduction in 2022 relative to 2017 and thus met the NCAP target. However, we identify that ~30% of the annual PM2.5 air quality improvements, and approximately half during winter when pollution is high, can be attributed to favorable meteorological conditions which are unlikely to persist as the climate warms. Meanwhile, annual PM2.5 levels in 44 out of 57 non-attainment cities with continuous monitors still failed to meet air quality standards in 2022. This work highlights the need for substantial additional mitigation measures beyond current NCAP policies to improve air quality in India.