Datanomics: Measuring India's cloud seeding scale and rainfall impact

On October 28, Delhi saw its first-ever cloud seeding trial, which will go on till October 30. While some states have previously used cloud seeding in water-stressed regions such as Marathwada in Maharashtra, this marks the first attempt in the country to use it as an anti-pollution measure. The capital has been battling severe post-monsoon smog episodes, with air quality frequently dipping into the “severe” category in recent years. Shikha Chaturvedi

   

Globally, cloud seeding has been used since the 1970s across more than 50 countries, primarily for drought control, agricultural enhancement, and water management. China remains the largest user, having carried out nearly 270,000 such operations by 2025, including a major 2014 campaign around Beijing to wash away smog before national sports events. A 2014 Beijing study found that a 1 mm increase in rainfall intensity reduced PM2.5 levels by 4-28 per cent, highlighting the potential of such interventions in improving air quality.

     

Maharashtra has been the most active state in using cloud seeding, followed by Andhra Pradesh and Karnataka. These efforts have primarily focused on rainfall augmentation during droughts. 

   

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Post-seeding observations show mixed results across states. Karnataka recorded the highest increase in rainfall at about 28 per cent, followed by Gujarat and Maharashtra. Tamil Nadu and Rajasthan saw relatively modest results. 

   

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Pollution levels were rising in Delhi in the run up to festivals. However, post Diwali emissions made it worse. Other factors such as stubble burning may have also played a role.