Delhi's cloud‑seeding trials produced little rain amid thin clouds and have been criticised as an expensive distraction. The roughly $364,000 experiment used silver iodide from aircraft but experts say seeding can only redistribute existing moisture and offers, at best, temporary relief. Environmental and health impacts of repeated chemical use remain uncertain, while researchers and campaigners emphasise that cutting emissions at source is the only durable solution.
Delhi's Cloud‑Seeding Trials Decried as a 'Costly Spectacle' That Won't Cure Winter Smog
Delhi's cloud‑seeding trials produced little rain amid thin clouds and have been criticised as an expensive distraction. The roughly $364,000 experiment used silver iodide from aircraft but experts say seeding can only redistribute existing moisture and offers, at best, temporary relief. Environmental and health impacts of repeated chemical use remain uncertain, while researchers and campaigners emphasise that cutting emissions at source is the only durable solution.
13:52, 02.11.2025Environment
Delhi's Cloud‑Seeding Trials Decried as a 'Costly Spectacle'
Officials in New Delhi launched cloud‑seeding trials last week using a Cessna aircraft and dispersing substances such as silver iodide and salt into clouds to try to wash particulate pollution from the air. Early sorties produced only minimal rain because cloud cover was thin, prompting scientists and activists to question both the effectiveness and the expense of the operation.
How cloud seeding is supposed to work
Cloud seeding aims to encourage water droplets to form around added particles so that rain falls and carries airborne pollutants to the ground. The technique has been used intermittently since the 1940s in efforts to induce rain, clear fog or relieve drought, but scientific results are mixed and outcomes depend heavily on existing moisture and atmospheric conditions.
What happened in Delhi
Delhi authorities, working with the Indian Institute of Technology (IIT) Kanpur, carried out tests over parts of the capital. Officials reported little rainfall from the initial flights, attributing the limited effect to thin clouds. Local media report the government has spent roughly $364,000 on the trials.
"This will never ever do the job, it's an illusion," said environmental campaigner Bhavreen Kandhari, arguing that only cutting emissions at source can reliably reduce pollution.
Experts voice doubts — and some caveats
Critics say that even when cloud seeding produces rain, benefits are temporary: pollution often rebounds once rain stops. Cornell climate scientist Daniele Visioni noted that seeding cannot create moisture out of thin air and mainly redistributes where condensation occurs.
Two atmospheric scientists at IIT Delhi, Shahzad Gani and Krishna Achutarao, described the exercise as "another gimmick," warning that it risks lending credibility to an expensive distraction from proven measures. Mohan George of the Centre for Science and Environment warned that increasing precipitation in one area could reduce it elsewhere.
Defenders of the experiment, including Virendra Sachdeva from Delhi's ruling party, said the tests are part of the research process and that one round is insufficient to judge success or failure.
Environmental and health questions
There are lingering uncertainties about the long‑term environmental and health impacts of repeated use of agents like silver iodide. The U.S. Environmental Protection Agency has said limited studies suggest silver iodide is unlikely to pose a major risk at typical application levels, but it also acknowledges that the effects of more widespread, long‑term use are not well understood.
Public health context underscores the urgency: a day after the most recent test, PM2.5 readings in Delhi hit 323 micrograms per cubic metre — more than 20 times the World Health Organization's recommended 24‑hour guideline — and a study in The Lancet Planetary Health estimated some 3.8 million deaths in India from air pollution between 2009 and 2019.
Bottom line
Experts and campaigners argue the proven path to durable air‑quality improvement is reducing emissions: cleaner fuels, better waste management, stricter enforcement, and cutting seasonal crop burning. While weather modification may have niche uses, many scientists warn it is unlikely to be a scalable solution to Delhi's systemic winter smog and caution against viewing it as a substitute for structural pollution controls.