What is Cloud seeding? Does it really help control pollution?

Every winter Delhi-NCR wakes up to grey smog. People cough, eyes and noses struggle with irritation, schools close, and in the middle of all this, one idea that people believe is to make it rain. Well, artificial rain or cloud seeding sounds like a fix, but is it actually a fix or a temporary solution?What is cloud seeding?Cloud seeding is a way of helping clouds produce rain artificially. Small particles are released into a cloud from an aircraft. The common ones are silver iodide, potassium iodide, and dry ice. Water droplets in the cloud stick to these particles and grow heavier. Fall as rain. One important thing to understand: cloud seeding cannot make clouds. It can only help a cloud that already has moisture. No cloud, no rain.Delhis first tryOn October 28, 2025, IIT Kanpur and the Delhi government carried out the cloud seeding trial over Delhi to reduce pollution. A small aircraft flew over areas like Burari, North Karol Bagh, and Mayur Vihar. Fired 14 flares. The mixture had 20 percent silver iodide with the rest made of rock salt and common salt. The clouds had about 15 to 20 percent moisture, which was too low.

The Indian Meteorological Department had also warned beforehand that conditions were not right. IIT Kanpurs report said trace rain of 0.1 mm in Noida and 0.2 mm in Greater Noida was seen,. That is too small for weather stations to even record. The days attempt was put on hold for the same reason.

Did it reduce pollution?The report noted that PM2.5 levels dropped in some areas like Mayur Vihar, Karol Bagh and Burari after the attempts. It was not clear if cloud seeding caused that. Past studies in India including the CAIPEEX program running since 2009 have not found proof that it works every time. Results also depend heavily on the weather. Even when rain does come, it only washes out pollution for a while. Once the rain stops and the sources keep releasing smoke, the air can turn bad again.What the experts sayThe honest answer came from the IIT Kanpur director himself Manindra Agrawal. He called cloud seeding an "SOS measure" meant for emergencies when pollution is very high and the right clouds are present. In his words, it is not a fix. The real solution, he said, is to control the sources of pollution.What actually worksDelhis smog comes from vehicle exhaust, construction dust, industry, and stubble burning. Rain cannot fix these. Cutting the sources can transport, control dust, regulate industry, and helping farmers manage crop waste.