Why in News :
- Delhi will trial cloud seeding (artificial rain) from July 4–11, 2025 to combat severe air pollution, especially PM2.5 and PM10 levels.
- The project is a collaboration between IIT Kanpur, IMD Pune, and the Delhi Government.
- Estimated Cost: ₹3.21 crore for five sorties.
What is Cloud Seeding?
A weather modification technique used to induce or enhance precipitation. Introduces “seeding agents” (e.g., silver iodide, dry ice, NaCl) into clouds to stimulate rainfall.
How It Works
- Clouds contain small water droplets or ice crystals that do not always precipitate.
- Seeding agents act as condensation nuclei, encouraging droplets to grow larger.
- Larger droplets fall as artificial rain.
Methods of Cloud Seeding
- Aircraft-based seeding (as used in Delhi trial)
Ground-based generators
- Rocket/artillery launch systems (used in limited international cases)
Expected Impact on Air Pollution
Rain from cloud seeding can:
- Wash out particulate matter (PM2.5, PM10).
- Remove gaseous pollutants (e.g., NOₓ, SO₂, ammonia).
- Temporarily clear smog and settle atmospheric dust.
Limitation: Pollution source remains unaffected (vehicles, industry).
Duration: Air quality improves for hours to a few days only.
Risks: Runoff pollution may affect soil and water bodies.
| Comparative Experience China: Used during the 2008 Olympics for smog control. UAE, India (past attempts): Used to boost rainfall and reduce pollution during winters. Limitations noted: Inconsistency, weather dependency, cost–benefit debates. |
Significance
- Innovation in urban air pollution mitigation.
- May supplement GRAP (Graded Response Action Plan) measures.
- Could pioneer regional geoengineering methods for climate-stressed cities.
Challenges
- Atmospheric dependency: Needs specific cloud conditions.
- High cost vs. limited effect.
- Data limitations on long-term impact and public health outcomes.
- Inter-agency coordination (IIT, IMD, DGCA, MoEFCC) required.
Way Forward
- Evaluate this trial’s results through independent scientific analysis.
- Integrate with long-term pollution control measures (vehicle emissions, biomass burning).
- Build transparent protocols and ethical frameworks for artificial weather interventions.
- Strengthen air quality monitoring before and after cloud seeding.
| UPSC Relevance GS1 – Geography: Weather modification, precipitation processes GS3 – Environment: Air pollution mitigation, sustainable technology GS2 – Governance: Centre–State coordination, environmental health Mains Practice Questions Q. What is cloud seeding? Can it be a viable solution to urban air pollution in India? Discuss its merits, limitations, and ethical implications. (GS3 – Environment) |