Artificial Rain in Delhi

Syllabus: GS3/ Environment

In News

• Delhi is set to launch its first-ever cloud seeding trial to combat its persistent air pollution through artificial rain. The initiative is coordinated by IIT Kanpur and IMD Pune.

What is Artificial Rain?

• Artificial rain refers to inducing precipitation by injecting certain chemicals into clouds to accelerate the process of raindrop formation.
• Cloud seeding involves dispersing substances like:
  • Silver iodide (AgI)
  • Potassium iodide
  • Sodium chloride
  • Dry ice (CO₂)
• These act as condensation nuclei, attracting water droplets, which then combine to form rain.
• Conditions Required: Potential rain-bearing clouds, sufficient humidity and atmospheric instability & Favorable wind and temperature conditions.

Advantages of Cloud Seeding

• Air Pollution Mitigation: In cities like Delhi, artificial rain can wash down particulate matter and other pollutants, providing temporary relief from severe air pollution. 
• Drought Mitigation and Water Resource Augmentation: States like Maharashtra and Karnataka have used cloud seeding to combat water shortages (e.g., “Project Meghdoot” and “Varshadhari”).
• Forest Fire Control: By increasing moisture levels, cloud seeding can potentially reduce the risk and intensity of wildfires.
• Science-backed Intervention: Several countries like China, Thailand, UAE, and USA (Texas, Nevada) use cloud seeding for weather control, drought mitigation, and even clearing skies during major events (e.g., 2008 Beijing Olympics).

Concerns & Criticism

• Environmental Damage: Runoff from cloud-seeded rains can contaminate lakes, rivers, and groundwater.
• Temporary Solution to a Structural Problem: Core issues like stubble burning, vehicular emissions, and urban planning remain unaddressed.
• Ethical and Legal Issues: The ability to manipulate weather raises complex ethical questions about human intervention in natural processes & its implications.
• Health and Ecosystem Risks: Long-term chemical accumulation in soil may affect plant growth, reduce soil fertility, and enter the food chain.

Way Ahead

• Use Artificial Rain as a Last Resort: Should be opted only when AQI breaches dangerous levels.
• Robust Scientific Backing: Need for real-time satellite data, Doppler radars, and meteorological modelling.
• Invest in Permanent Air Quality Solutions: Electric vehicle (EV) push, Green infrastructure (urban forests, vertical gardens) & crop residue management (e.g., PUSA bio-decomposer).

Source: TOI