Exclusive: Why Rekha Gupta pressed ahead with cloud seeding despite Centre’s 2024 caution

New Delhi: A day after two cloud seeding trials did not lead to artificial rain in the city, the Delhi government paused the exercise on Wednesday citing low moisture. 

This was followed by a political row around a record accessed by NewsDrum that shows the Union Environment Ministry had, in late 2024, conveyed expert opinion that winter cloud seeding over Delhi is generally unsuitable.

The ministry’s reply to the Rajya Sabha in December 2024 summarised inputs from the India Meteorological Department, the Commission for Air Quality Management and the Central Pollution Control Board. 

The experts said winter clouds over Delhi are mostly Western Disturbance systems that either produce natural rain on their own or sit too high, typically above 5-6 km, for seeding aircraft to be effective. 

They also said the required cloud microphysics are largely absent in Delhi’s cold and dry months, and that a dry layer below the cloud base can evaporate precipitation before it reaches the ground. 

The note further flagged uncertainty about effectiveness and possible side effects of seeding chemicals.

According to the same record, this view was shared formally with the Delhi government through a D.O. letter dated October 30, 2024. 

The Delhi Pollution Control Committee was separately asked on September 23, 2024 to submit a detailed, specific proposal for evaluation. 

CAQM also convened a stakeholder meeting on November 27, 2024 to explore feasibility, while Delhi wrote multiple times between August and November 2024 seeking discussions on cloud seeding as an emergency winter measure.

The emergence of this paper trail has sharpened questions on how a trial flight was carried out this year despite the Centre’s own expert caution last winter. 

Opposition leaders cited the 2024 record and alleged that the exercise was driven by publicity rather than outcomes, pointing also to NewsDrum’s earlier analysis on gaps between official claims and ground-level solutions in Delhi’s air management. 

They argued that public money should not have gone to an experiment with a low likelihood of success in winter conditions.

The Delhi government rejected that charge. A senior official told NewsDrum that the administration “looked at it practically, tried, and stopped the trial after failure”, adding that trying and failing is preferable to “fooling the public”, like Arvind Kejriwal did for several years. 

Sources also argued that no special permission was required for a limited trial run, and that a field test was the logical next step after years of debate on artificial rain.

IIT-Kanpur, which executed Tuesday’s sorties, said the flights did not bring rain but provided “key insights”. 

The institute said instruments recorded a measurable 6 to 10 per cent reduction in PM2.5 and PM10 in the target area despite limited moisture. 

Director Manindra Agrawal said the objective was to validate protocols, instruments and cloud microphysics in Delhi’s winter setting, and that multiple data points across several trials are needed before judging efficacy.

On costs, IIT-Kanpur said the operation over roughly 300 square kilometres cost about Rs 60 lakh, about Rs 20,000 per square kilometre. 

A 1,000 square kilometre run would be around Rs 2 crore. If conducted through an entire winter assuming favourable clouds once in 10 days, the expense would be in the range of Rs 25-30 crore. 

Agrawal argued that this outlay is small compared to the sums already spent on pollution control in Delhi.

Environment Minister Manjinder Singh Sirsa called Tuesday’s attempt “successful” in reaching the trial stage and said nine to ten sorties are planned to identify the moisture threshold at which seeding can induce rain. 

He said the next flight depends entirely on weather and will go ahead only if cloud and moisture parameters are suitable.

The Aam Aadmi Party questioned why a trial was flown when central agencies had already indicated that Delhi’s winter conditions are not conducive. 

The party said no rainfall was recorded anywhere in the city and alleged that the exercise was optics-led. It also asked why public funds were spent when the 2024 record warned that the preconditions for effective seeding are rarely met in winter.

For now, the government has paused the exercise for want of moisture. Officials said they would await a fresh weather call before attempting another run. 

Meanwhile, Delhi’s air quality index stood at 279 (“poor”) on Wednesday, down from 294 a day earlier and 301 on Monday, keeping the focus on measures that work in winter-grade conditions.