Cloud-seeding an impractical measure to reduce Delhi smog, say experts

New Delhi: People in Delhi are presently grappling with the heavy smog that has taken over the city post Diwali celebrations.

The national capital's pollution levels were already bordering on hazardous before Diwali and after the festival, the air quality took on that very standard.

Residents have since been complaining of respiratory issues like asthma, bronchitis, difficulty in breathing and other allergies.

The pressure on the government is definitely mounting and because the matter requires desperate measures, Delhi CM Arvind Kejriwal suggested cloud seeding.

On Monday, Delhi environment minister Imran Hussain urged Union environment minister Anil Madhav Dave to "bring artificial rain technology like other countries do," as per a report in the Economic Times.

However, cloud seeding may not be the proper solution for the kind of weather conditions Delhi is currently facing.

"You need more moisture to do cloud seeding. I think it's an impractical idea because cloud seeding may not be possible in such a large area. The smog may return in a day or two because emissions will continue. Plus, there will be additional emissions from the aircraft used," said professor Manju Mohan of Centre for Atmospheric Sciences, IIT Delhi, told the Economic Times.

Indian Institute of Tropical Meteorology, Pune, has a cloud seeding and weather modification programme, and scientists from there have been testing physical problem of aerosol particles all over Delhi. "Moisture can be a tricky issue in Delhi. The relative humidity should be between 80% and 90%, but that alone is not enough. We need to understand what the pollution particles in Delhi are like. What are their chemical and physical properties? These particles may not be able to form rain drops like clouds do," said a scientist.

He added that even if pollutants are washed out, relief would be short-term as emission would continue. The nature of pollutants would also determine the environmental impact of rains that wash down these. "Acid rain is not common any more, but we need to study what are these pollutants," he added, The Economic Times further reported.

Furthermore, the total cost of a single cloud-seeding exercise could range between Rs 10 crore and Rs 12 crore, including the cost of the aircraft, radar technology and other equipment.