Cloud seeding can't be reliable strategy to tackle pollution in Delhi, says IIT study, Pg4.

Key Highlights:

• An IIT Delhi study concludes that cloud seeding is not a reliable strategy for managing winter air pollution in Delhi due to unsuitable climatological conditions.
• The study suggests cloud seeding should only be considered as a high-cost, short-term emergency measure.
• Delhi government conducted cloud seeding trials on October 28 using silver iodide and salt particles, but no rainfall was recorded in Delhi.
• The IIT-Delhi report emphasizes that sustained emission reduction is the most viable long-term solution to air pollution.

Detailed Insights:

• The IIT-Delhi report analyzed climatological data from 2011-2021, aerosol-cloud interaction assessments, and pollutant washout/recovery to assess cloud seeding viability.
• The study found a fundamental lack of sufficient moisture and saturation during peak pollution months (December-January) when intervention is most needed.
• Heavy natural rainfall effectively washes out PM2.5, PM10, and NOX, but air quality improvements are short-lived due to persistent emissions.
• The study raises concerns about the environmental and health impacts of seeding agents like silver iodide (AgI), high operational costs, and scientific uncertainties.
• Experts suggest that effective cloud seeding requires specific cloud conditions generally absent during Delhi’s cold and dry winter months.
• The report highlights the need for sustained reduction of emissions from vehicular traffic, industrial activities, construction dust, agricultural biomass burning, and residential heating.

Key Concepts Involved:

• Cloud Seeding: A weather modification technique that attempts to increase precipitation by dispersing substances into the air that serve as cloud condensation or ice nuclei.
• PM2.5 & PM10: Particulate matter with diameters of 2.5 micrometers or less and 10 micrometers or less, respectively, posing significant health risks when inhaled.
• Western Disturbances (WDs): Extratropical weather systems originating in the Mediterranean region that bring sudden winter rain and snow to the northwestern parts of the Indian subcontinent.