IIT Kanpur director Manindra Agrawal (Image credits: Indian Institute of Technology Kanpur)
NEW DELHI: Cloud seeding is only a short-term emergency tool to combat severe pollution and poses no threat to humans or the environment, IIT-Kanpur director Manindra Agrawal clarified. He said the process uses only minute quantities of chemicals to induce rain and is safe for both people and nature.In an interview with PTI, Agrawal, whose team led the recent cloud-seeding trials in Delhi, explained that the technique is meant for emergency use and cannot be a long-term solution. “It is an SOS measure, something that can be used only when pollution levels are very high and suitable clouds are available. The real solution lies in reducing emissions and controlling pollution at the source,” he said.The Delhi government, in collaboration with IIT-Kanpur, conducted two cloud-seeding trials in Burari, north Karol Bagh, and Mayur Vihar on Tuesday, but there was no rain. Agrawal said that while the attempts did not produce artificial rainfall, they yielded important data for improving future operations.“It helps us understand the relationship between the amount of seeding material used, the moisture content of clouds, and their ground-level impact. This will help us fine-tune future operations,” he said.Agrawal noted that the exercise was paused due to unfavourable weather. “We need at least 30 to 50 per cent cloud moisture. Since that was not available, we decided to wait until conditions improve,” he said, adding that trials will resume once suitable conditions return.Addressing concerns about safety, Agrawal stressed that the mixture sprayed into clouds mainly contains common salt and a small amount of silver iodide. “We use less than one kilogram of silver iodide over 100 square kilometres — less than 10 grams per square kilometre. That’s too little to have any harmful effect on humans, animals or vegetation,” he said.Environmentalists have voiced fears about the possible buildup of silver iodide in soil and water, which could affect crops, aquatic life, and drinking water quality. However, Agrawal maintained that the concentrations used are negligible and pose no ecological risk.