What is cloud seeding and how can it help clean Delhi’s toxic air? Explained

The national capital Delhi may soon receive artificial rainfall for the first time after Diwali, in an effort to reduce its dangerous pollution.

The IIT Kanpur-led trial in the Burari region earlier this week has paved the way for a possible full-scale cloud seeding effort on October 29, provided weather conditions remain favourable.

Let us understand what cloud seeding is and what impact it can have on Delhi’s pollution.

what is cloud seeding

Cloud seeding is a form of weather modification that encourages precipitation by spreading substances such as silver iodide or sodium chloride or liquid propane into clouds.

These compounds act as nuclei that attract tiny water droplets, helping them merge and fall as rain.

This method has been used for decades in areas suffering from water scarcity. This is often done using aircraft or ground-based generators.

How can it help Delhi’s pollution?

Delhi’s air quality regularly falls into the “severe” category after Diwali due to existing pollution caused by emissions from firecrackers and weather conditions.

Read more: Delhi’s cloud seeding on October 29 can serve as model for Lucknow, Mumbai, Patna, Ghaziabad: IIT Kanpur professor

Professor Manindra Aggarwal, a scientist at IIT Kanpur who is leading the cloud observing experiment in Delhi, says that if there is enough moisture in the Delhi sky on the day of the operation, artificial rain can significantly reduce the levels of particulate matter.

“Even a single effective spell of rain can bring down PM2.5 and PM10 levels significantly for several days,” he told News18, adding that a successful effort could bring down the air quality index (AQI) levels below 100, bringing the capital’s air into the “good” or “moderate” categories.

Drawbacks of Cloud Seeding

However, the cloud seeding process is not a permanent solution to air pollution. This is only a temporary mitigation device.

“Cloud seeding cannot replace long-term measures like clean energy transition, stubble management or public transport improvements,” Professor Aggarwal said.

He described it as an “emergency response tool, not a permanent cure” that provides short-term relief rather than addressing the root causes of pollution.

If the efforts prove effective and the mission is successful, a similar experiment can be considered for other polluted cities like Mumbai, Lucknow, Patna and Ghaziabad, the professor said.

Now, with coordination between the India Meteorological Department (IMD), Indian Institute of Science (IISc), Delhi government and IIT Kanpur, the final decision depends on favorable and suitable conditions to witness artificial rain for the first time in Delhi on October 29.