Cloud seeding SOS measure, not harmful to humans, environment: IIT Kanpur director

IIT-Kanpur Director Manindra Aggarwal has clarified this cloud seeding There is an “SOS measure” to combat excessive pollution, and this technique is not harmful to humans or the environment, as it uses only small amounts of chemicals to induce rain.

In an interview with PTI, Aggarwal, whose team led the recent cloud-seeding trials in Delhi, said that although both efforts did not produce artificial rain, they provided valuable data and scientific insights for future operations.

“This helps us understand the relationship between the amount of seed material used, the moisture content of clouds and their impact on ground level. This will help us improve future operations,” he said.

Aggarwal said the exercise was stopped due to low moisture content in the clouds, making the conditions unsuitable for effective seeding.

“We need at least 30% to 50% cloud moisture. Since that was not available, we decided to wait until the situation improves,” he said. The trials will resume when favorable weather arrives, he said.

Allaying fears about environmental or health hazards, Aggarwal said the mixture sprayed into the clouds consists mainly of common salt and a small amount of silver iodide.

“We use less than a kilogram of silver iodide per 100 square kilometers – less than 10 grams per square kilometre. This is too little to have any harmful effects on humans, animals or vegetation,” he said.

Aggarwal admitted that cloud seeding cannot be a permanent solution to air pollution.

“This is an SOS measure, which 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,” Agarwal said.

Environmentalists have expressed concern about the potential accumulation of silver iodide in soil and water, which could affect crops, aquatic life, and drinking water quality.

Aggarwal said the concentrations used were negligible and did not pose an ecological risk.

Highlighting the innovation behind the effort, Aggarwal said the technology including flares and seeding material has been developed indigenously at IIT-Kanpur, marking a ‘Make in India’ milestone.

He said that the institute had earlier conducted successful trials in Kanpur in 2017-18, but this is the first such experiment in the Delhi-NCR region.

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.

Also read: Delhi’s cloud-seeding trial fails to produce artificial rain; here’s why