India’s attempt to tackle New Delhi’s toxic air by using cloud seeding appears to have produced disappointing results, with scientists and activists questioning whether the costly experiment was worth it. Cloud seeding — a process in which aircraft spray particles such as silver iodide or salt into clouds to induce rainfall is intended to help wash pollutants out of the atmosphere. Authorities in Delhi, in collaboration with the Indian Institute of Technology (IIT) Kanpur, began the trials last week using a Cessna aircraft over parts of the capital. However, officials said the initial tests yielded minimal rainfall due to limited cloud cover. “This will never do the job it’s an illusion,” said environmental activist Bhavreen Kandhari. “We can only control air pollution by addressing its sources, not by chasing clouds.” Local media reported that the government has spent around $364,000 on the project so far. Each winter, a thick blanket of smog envelops Delhi and its 30 million residents, as cold air traps emissions from vehicle exhaust, factory smoke, and crop burning in nearby states. Despite various government efforts including vehicle restrictions, anti-smog towers, and mist-spraying trucks Delhi consistently ranks among the world’s most polluted capitals. Following the latest cloud seeding attempt, levels of PM2.5 the fine particles linked to heart and lung disease reached 323 micrograms per cubic meter, over 20 times the World Health Organization’s safe daily limit. A study published in The Lancet Planetary Health last year estimated that 3.8 million deaths in India between 2009 and 2019 were associated with air pollution exposure. Questions also remain about the environmental impact of cloud seeding chemicals. The U.S. Environmental Protection Agency (EPA) says limited research suggests silver iodide poses little risk to human health or the environment, but acknowledges that the long-term effects of widespread use remain unclear. Research process Environmental activists say even if cloud seeding produces rain, the benefits are short-lived. Climate scientist Daniele Visioni at Cornell University said it was unclear how efficient it was in heavy polluted conditions. “It can’t create rain where there is no moisture in the air, but it just ‘forces’ some of the water to condense in one location rather than another,” he told AFP. “There is only one thing that can sensibly reduce pollution: avoiding the burning of fossil fuels.” Virendra Sachdeva, from Delhi’s ruling Bharatiya Janata Party (BJP), said it was too early to dismiss the cloud seeding experiment as a “scientific failure”. “It is a part of the research process, and success is not always achieved in the first attempt,” he told reporters. However, two atmospheric scientists at IIT Delhi called the cloud seeding plan “another gimmick”. “It is a textbook case of science misapplied and ethics ignored,” Shahzad Gani and Krishna Achutarao wrote in The Hindu newspaper. Mohan George, from the Delhi-based Centre for Science and Environment, said artificial rain was not the answer. “The levels of pollution will come back almost immediately as rain stops,” the scientist told AFP. When it does work, it will increase precipitation in one area — while potentially decreasing it for another. Costly spectacle Cloud seeding, first developed in the 1940s, has been used in various countries to induce rain, clear fog, and reduce drought, but with mixed results. China used it during the 2008 Beijing Olympics in an attempt to control the weather. Gani and Achutarao said Delhi’s pollution causes — unchecked emissions and seasonal crop burning — are well known. So too are the solutions cleaner fuel, better waste management and stricter enforcement of rules. “Instead of reinforcing these priorities, parts of the scientific ecosystem researchers, advisors, and institutions — are lending credibility to a costly spectacle that will do little to address the sources of the crisis,” they said.
India’s Cloud Seeding Trials Criticized as ‘Costly Spectacle’
