Cloud seeding: Pune-IITM scientists say a misguided fix for Delhi’s pollution crisis

To address Delhi’s air pollution crisis, Environment Minister Gopal Rai has suggested that the Delhi government is looking into other options like artificial rain, which can lead to settling airborne pollutants and improve visibility. However, according to scientists, in the recent air pollution in Delhi, the absence of clouds have posed a significant challenge for artificial rain efforts.

“Cloud seeding requires the presence of clouds, and without them, the process is simply not possible. Moreover, not all clouds are suitable for cloud seeding, as specific types and conditions are necessary to generate artificial rain effectively,” Dr Ghude said.

Over the past five years, data showed that during peak pollution episodes in Delhi and the surrounding areas, clouds are rarely present. Without clouds, cloud seeding becomes ineffective, raising questions about its feasibility in such conditions.

“Cloud seeding requires the presence of moisture-laden clouds. Delhi’s winters are typically dry with minimal cloud cover, making seeding ineffective. The success of cloud seeding is not guaranteed, as it heavily depends on pre-existing weather conditions and precise execution,” the scientist said.

According to the expert, during winter, Delhi often experiences temperature inversions, trapping pollutants near the surface. “These stable atmospheric conditions do not favor the development of clouds that could be seeded. The scale of Delhi’s pollution problem is vast, requiring massive, continuous rain over a large area to have a measurable impact,” he added.

Even if a few isolated clouds could be seeded—an unlikely scenario—it would not result in heavy or widespread rainfall. According to Dr Ghude, the effort required to generate sustained rainfall for effective pollution control is neither practical nor feasible.

Winter pollution in Delhi is primarily caused by fine particulate matter (PM2.5 and PM10) from vehicular emissions, stubble burning, and industrial activity. “Rain can temporarily wash away pollutants but doesn’t address the source of emissions. Rain might clean the air momentarily, but pollution levels can quickly rebound as emissions persist,” Dr Ghude said.