A recent study revealed that Delhi’s air pollution forecasting system accurately predicted days with “very poor and above” air quality over 80 percent of the time during the last two winters. Conducted by the Council on Energy, Environment and Water (CEEW), the study found that the city’s Air Quality Early Warning System (AQEWS) forecasted 83 out of 92 episodes classified as “very poor and above” (with an air quality index exceeding 300) in the winter of 2023-24, and 54 out of 58 such days in 2024-25.
The forecasting system has also shown improvements in predicting days of severe pollution (AQI above 400), accurately identifying one out of 15 such days in 2023-24 and increasing to five out of 14 in the following winter. Mohammad Rafiuddin, programme lead at CEEW, noted that the high accuracy of Delhi’s early warning systems is encouraging. He emphasized that updating emission inventories could enhance accuracy further, allowing for a better understanding of the pollutants affecting Delhi’s air quality. Rafiuddin also called for scaling up these systems in India with a focus on science, funding, and transparency to build public trust and ensure the effectiveness of Delhi’s Mitigation Plan 2025 is grounded in solid evidence.
Currently, eight Indian cities, including Ahmedabad, Pune, and Jaipur, employ an Air Quality Early Warning System, with more cities anticipated to adopt this under the National Clean Air Programme. Initiated in 2018 after numerous smog events and dust storms, Delhi’s AQEWS is managed by the Indian Institute of Tropical Meteorology (IITM) and the India Meteorological Department (IMD), offering pollution forecasts from three to ten days ahead. In 2021, IITM and IMD launched a Decision Support System (DSS) to identify pollution sources linked to forecasted levels. The CEEW study indicated that these tools already fulfill several global benchmarks for effective air quality systems; however, the DSS operates only in winter, which limits its practicality.
To enhance the system’s effectiveness, the study recommended year-round operation, including modeling scenarios like vehicle type restrictions and public transport expansion, along with establishing a national emission inventory that is updated every two to three years, ensuring public access to the information.