Improving air quality management through forecasts: From Science to Policy to Action

Air quality management in urban environments is a critical challenge, especially in rapidly developing regions. Forecasting plays an important role by enabling concerned agencies to anticipate and mitigate air pollution risk. Cities like Beijing have used forecast-based alert systems to inform and enact emergency measures during high pollution episodes. Public and private sectors in India have also taken initiatives to provide air quality forecasts. Some of these initiatives also forecast source contributions of major pollutants like PM2.5. India’s flagship initiative on air quality improvement, the National Clean Air Programme (NCAP), has also realised the criticality of utilising forecasts to drive emergency clean air action. The NCAP aims to extend the reach of forecasting to 131 non-attainment cities. The NCAP also envisions formulating Graded Response Action Plans (GRAP) to deal with high pollution phases in these cities. All the 131 non-attainment cities have developed GRAPs, with most of them based on measured concentrations rather than forecasts. Delhi is the first Indian city to revise its GRAP and make it forecast-based, enabling pre-emptive actions against pollution. We examine the efficacy of such proactive measures in Delhi, evaluating the impact of forecast-based GRAP on the city's air quality using quasi-experimental methods. Furthermore, we explore global best practices in employing forecasts for air quality management, providing insights into how cities can effectively adopt and leverage these forecasting tools. By showcasing both Indian and global examples, the analysis underscores the transformative potential of air quality forecasts in shaping policy and driving actionable responses to improve urban air quality.