Context:
• The Delhi government plans to conduct cloud seeding operations to combat rising air pollution levels in the National Capital Region (NCR).
• The initiative, supported by IIT Kanpur, marks India’s latest experiment in artificial rainfall as an emergency measure to mitigate post-Diwali smog and seasonal farm-fire pollution.
Key Highlights:
- Cloud Seeding Initiative in Delhi
- The Delhi government is considering cloud seeding on Tuesday (November 12, 2025), depending on favourable weather conditions.
- The exercise was postponed on Monday due to ministerial engagements in Chhath Puja celebrations and weather instability.
- The first trial was conducted on October 23, 2025, in collaboration with IIT Kanpur, marking a major step in urban pollution management through atmospheric intervention.
- Pollution Scenario in Delhi-NCR
- On Monday, Delhi’s Air Quality Index (AQI) stood at 301 (very poor category), slightly improving from 315 the previous day.
- The contribution of farm fires to PM2.5 concentration is forecasted to rise to 5.87% by Wednesday, up from 1.86% on Monday.
- Persistent smog episodes post-Diwali, combined with crop residue burning in neighbouring states, continue to worsen Delhi’s air quality and visibility.
- Implementation and Challenges
- The Indian Institute of Tropical Meteorology (IITM) and IIT Kanpur are jointly guiding the operational and meteorological parameters for the project.
- Cloud seeding operations depend heavily on cloud moisture content, wind velocity, and humidity, which have been inconsistent this season.
- The Delhi government aims to assess whether artificial rainfall can reduce particulate concentration and improve atmospheric cleansing during pollution peaks.
Relevant Scientific / Technical Concepts:
- Cloud Seeding:
- Definition: A weather modification technique that enhances precipitation by dispersing substances such as silver iodide, potassium iodide, or sodium chloride into clouds.
- Working Principle: These particles act as cloud condensation nuclei (CCN), promoting droplet coalescence and increasing the likelihood of rainfall.
- Methods Used:
- Aerial Seeding: Chemicals dispersed from aircraft into cloud formations.
- Ground-Based Generators: Release of seeding material from the ground into convective air currents.
- Air Quality Indicators:
- AQI (Air Quality Index): Categorizes air quality into bands (Good, Satisfactory, Moderate, Poor, Very Poor, Severe).
- PM2.5: Fine particulate matter with diameter ≤ 2.5 micrometers; penetrates deep into lungs, causing cardiovascular and respiratory issues.
- Decision Support System (DSS): Developed by IITM Pune, it models pollution sources (e.g., farm fires, vehicular emissions) to forecast air quality.
Relevant Prelims Points:
- Silver Iodide is the most commonly used cloud seeding agent worldwide.
- National Clean Air Programme (NCAP): India’s national strategy launched in 2019 to reduce PM concentrations by 40% by 2026.
- Commission for Air Quality Management (CAQM): Apex body managing Delhi-NCR’s air pollution response.
Relevant Mains Points:
- Significance:
- Immediate relief measure for air pollution management in urban areas.
- Can aid in dust suppression and smog reduction during peak pollution episodes.
- Demonstrates India’s move towards climate-tech interventions for environmental resilience.
- Challenges:
- Weather dependency: Success rates remain uncertain in dry or low-humidity conditions.
- Cost-effectiveness: Cloud seeding operations are expensive with short-term results.
- Environmental Concerns: Long-term ecological impacts of silver iodide not fully established.
- Way Forward:
- Integrate cloud seeding with sustainable mitigation strategies, including crop residue management, emission controls, and green infrastructure.
- Strengthen predictive meteorology systems for optimized cloud seeding timing.
- Enhance public transparency through real-time pollution and intervention data sharing.
Possible Mains Question:
“Evaluate the effectiveness and limitations of cloud seeding as a tool for combating urban air pollution in India.”