New Delhi: Delhi's winter atmosphere is climatologically unsuitable for consistent cloud seeding due to a fundamental lack of sufficient moisture and saturation, especially during December and January—the peak pollution months—according to a report by the Indian Institute of Technology (IIT) Delhi.

The report, prepared by IIT Delhi's Centre for Atmospheric Sciences based on climatological data from 2011 to 2021, follows two unsuccessful cloud-seeding trials conducted by the Delhi government in collaboration with IIT Kanpur at Burari, Karol Bagh, and Mayur Vihar.

“While cloud seeding is theoretically feasible under specific atmospheric conditions, during Delhi's winter, its practical utility as a consistent air-quality intervention is constrained. The required atmospheric conditions are rare and often coincide with natural rainfall, limiting its potential benefits,” the report stated.

Even when successful, induced rainfall would provide only temporary relief lasting one to three days before pollution levels rebound, it said. High operational costs, scientific uncertainties in aerosol-heavy environments, and lack of impact on emission sources make cloud seeding unsuitable as a primary pollution-control measure.

The report added that viable “windows of opportunity” for seeding—mainly during Western Disturbances—are extremely rare in Delhi's dry winter climate. It also noted operational challenges, as seedable cloud layers (2-5 km altitude) are often separated from dense aerosol layers below 2 km.

While glaciogenic seeding may work during existing rainy conditions, the study concludes that sustained emission reduction remains the only viable and long-term solution to Delhi's air pollution crisis.