General
A day after failed attempts to induce rain artificially by chemically seeding clouds at several places in Delhi, the future of the BJP government’s big anti-pollution move remains at the mercy of the weather gods on Wednesday, October 29.
Delhi environment minister, Manjinder Singh Sirsa, said an attempt could be made after 4 pm, but the Indian Institute of Technology (IIT), Kanpur, the technical driver of the idea, was not so sure about exact timings.
In an official statement, IIT Kanpur said that the process is highly dependent on the right atmospheric conditions. But Sirsa said much the same thing but was more inclined towards repeating a pointed promise.
Also read | ‘If we fear failure…’: IIT Kanpur director on future of cloud seeding in Delhi
“While rainfall could not be triggered yesterday because moisture levels were around 15 to 20%, the trial delivered valuable insights,” the IIT said. Sirsa told news agency ANI, “According to the IMD (India Meteorological Department), there is an expectation that the moisture will increase after 4 pm this evening. As soon as the moisture report comes, the next trial will be started.”
He then said: “The aircraft is based in Meerut. As soon as information about higher moisture is received, cloud seeding will be performed — whether it’s 20% or 30%.”
The two cloud seeding attempts done on Tuesday cost approximately ₹1.28 crore.
Explaining why those attempts did not work, IIT Kanpur said it was because the moisture level in the clouds was not enough. The trial delivered valuable insights, though, it added.
It did lead to some tamp-down in pollutants. “Monitoring stations set up across Delhi captured real-time changes in particulate matter and moisture levels. The data shows a measurable reduction of 6 to 10 percent in PM2.5 and PM10 concentrations, indicating that even under limited moisture conditions, cloud seeding can contribute to improved air quality,” read the statement by IIT Kanpur.
But the air in the national capital remained under the “very poor” and “poor” categories in most places on Wednesday morning. As of 12 pm, the AQI in Anand Vihar was at 316 under the ‘very poor’ category, while at ITO it was at the 300 mark.
General Moisture level key to artificial rain
As for artificial rain, there is a percentage factor in likely success. “
“On Tuesday, our trial was conducted with 10-15% moisture. As per IMD, that’s the level as of now too,” minister MS Sirsa told ANI by noon on Wednesday.
He sought to explain: “See, this depends on how much water the clouds contain. If there is 10-15% humidity or moisture, the IIT believes that the chemical mixture they have created can perform.”
“At 50% moisture, rainfall does happen. But the IIT, which continues to research this, is attempting to induce rain even at low moisture levels. That’s why they attempted it at 10-15% moisture. Historically, rain has occurred at 50% moisture,” he added.
“The IIT’s current effort is to have different trials at different percentages of moisture, so that authentic data is obtained regarding the confirmed or definite probability of rain occurring at a given moisture level. Research is ongoing in this manner,” he further said.
He also addressed the criticism by BJP’s rival parties. “The opposition parties in Delhi, especially the Aam Aadmi Party, continuously criticise every move of the government. Be it (our work on cleaning the) Yamuna (for) Chhath Puja, or cloud seeding.”
General What happened on Tuesday, October 28?
A small, single-propeller aircraft was used by IIT Kanpur to crisscross overcast skies above northwest Delhi and other parts of the National Capital Region on Tuesday, firing silver iodide flares in two cloud seeding trials that failed to produce rain. .
AAP leader Saurabh Bharadwaj held a press conference questioning the government’s decision to conduct trials on a day when the IMD had anyway forecast rain. “Will Lord Indra come down to clarify whether it is artificial rain or natural rain?” he remarked.
The previous AAP government first floated the plan in the winter of 2023 but failed to execute it, citing unfavourable weather conditions. Last winter, too, the then AAP government proposed the programme but claimed it did not receive the BJP-led Centre’s backing for required flight and environmental permissions.
Under the BJP regime now, the Delhi cabinet approved the seeding project on May 7 with a total outlay of ₹3.21 crore for five trials, making each attempt cost roughly ₹64 lakh.
General What does science globally say?
Globally, cloud seeding has largely been seen as an ineffective weather modification technique except for in supercooled, high altitude applications to enhance mountain snowpack. Warm-season rainfall remains deeply contested with no scientific consensus yet of success.
Shahzad Gani, assistant professor at IIT Delhi’s Centre for Atmospheric Sciences, dismissed the trials as “futile attempts”, arguing that cloud seeding “cannot solve Delhi’s air pollution crisis”.
“Even setting aside the uncertainty around its effectiveness, it can only work when rain-bearing clouds already exist—and those conditions are extremely rare during the weeks when pollution is at its worst,” Gani said. “And even if some rain does fall, any improvement in air quality would be brief, because the sources of pollution continue.”