- Why in news
- On 5 February 2026, the Minister of State for Earth Sciences told the Rajya Sabha that Delhi's cloud seeding is a trial run by the Delhi government with IIT Kanpur. The Ministry of Earth Sciences is not part of it.
- What it is
- Cloud seeding is a weather modification method. Particles are released into suitable clouds to help form raindrops or ice crystals and so increase rain. It needs existing clouds with enough moisture. In Delhi it is being tested as a possible emergency tool against smog.
- Purpose and stage
- It is at trial stage. It is meant as an emergency option during episodic high-pollution events, and only when suitable cloud cover is present.
- AIRWISE
- AIRWISE is an air-quality warning and decision support framework for emissions. IITM Pune developed it with IMD. It covers monitoring, emissions inventories, source apportionment and prediction.
Don’t confuse with Cloud seeding vs artificial rain as pollution cure: Cloud seeding can only work where suitable clouds already exist. It does not create clouds, and rain only briefly washes out pollutants. It does not cut emissions.
Don’t confuse with IITM vs IMD: IITM, Pune is a research institute under MoES. IMD is the weather forecasting agency. AIRWISE was developed by IITM with IMD.
Science and technology: 57 Prelims questions since 2013; most test the concept behind the news, not the news itself. In Mains, 12 news-triggered questions.
Why it matters
- It adds a possible emergency tool for severe smog episodes in Delhi NCR.
- Trial results can show whether cloud seeding is workable and cost-effective.
Problems
- It works only when suitable clouds are present, and winter smog days often lack them.
- Rain gives only temporary relief and does not address emission sources. Effects and costs are still uncertain.
Way forward
- Judge the trial on evidence, then decide whether to scale it.
- Keep source-based controls such as GRAP and emission cuts as the main response.
Put in your answer
AIRWISE framework: Example of a science-based air-quality system that combines forecasting, source apportionment and emissions inventories.
CAIPEEX: IITM's earlier research on rain enhancement in the rain shadow region, 2017-2019, offers an Indian evidence base.
- 2015Mains GS1 · Q15Why is Delhi's air pollution more serious than Mumbai's and Kolkata's?
- 2021Mains GS3 · Q7Revised WHO air quality guidelines and changes needed in India's National Clean Air Programme.
- 2019Prelims Q25Context of cirrus thinning and stratospheric sulphate injection, including artificial rains option.
- 2025Prelims Q85Which chemicals are used in artificial rainfall to reduce air pollution?
UPSC’s own questions that come close to this issue, from our Prelims and Mains banks.
No practice question for this one; the card may still help an answer. Why: Lasting pollution-mitigation topic, still at trial stage and with few firm facts for a statement.
Worth revising until Prelims 2027: most news questions come within two years of the event.