Picture this: It's another morning in Delhi, and millions of people wake up to check the air quality index on their phones before deciding whether their children should play outside. The numbers are grim, again. In a city where breathing clean air feels like a luxury, officials are now turning to something that sounds almost like science fiction: making rain from scratch.
Delhi is about to try something it's never done before—create artificial rain to wash the pollution out of its skies. The plan was supposed to kick off between July 4 and July 11 but with the monsoon already active, scientists had to push the experiment back to late August.
The idea behind cloud seeding is surprisingly simple, even if the execution isn't. Scientists take substances like silver iodide, iodized salt, or rock salt and scatter them into clouds heavy with moisture. These particles become tiny magnets for water droplets, encouraging them to clump together until they're heavy enough to fall as rain. Think of it as giving clouds a gentle nudge to do what they're already trying to do.
The project has serious backing—IIT Kanpur, the India Meteorological Department, and aviation authorities are all on board. While IIT Kanpur first suggested this back in 2018, it took years to overcome weather delays, funding headaches, and the usual bureaucratic maze. Now, with Rs 3.2 crore finally approved, Delhi's rain-making experiment is ready to take flight.
India isn't new to playing weather god, but Delhi's attempt is different. Maharashtra tried cloud seeding in 2019, and reported up to an 18% increase in rainfall from seeded clouds. Tamil Nadu and Karnataka have used it during droughts, while Rajasthan carried out similar efforts during dry spells in regions like Udaipur.
But here's what makes Delhi's plan stand out: it's not about growing crops or filling reservoirs. For the first time, cloud seeding is being used as an air purifier in one of the world's most densely packed cities. It's a bold move that's never been tested on this scale, in this kind of urban jungle.
The Reality Check
While the idea sounds promising, experts are urging caution. This isn't a magic wand that will instantly clear Delhi's air.
While the move signals a bold shift in how the city is tackling its pollution crisis, experts told BOOM it must be approached with caution.
Pradeep Kumar, air quality researcher at South Dakota State University, explains that cloud seeding might offer some relief if the stars align perfectly, but it's far from foolproof. The process needs very specific conditions—moisture-heavy nimbostratus clouds with at least 50% humidity at just the right altitude. "Even in ideal conditions, the success rate is only about 60–70%," he noted.
Here's the catch: pollution itself makes the job harder. All those particles in the air mess with the cloud's internal structure, making it tougher for natural rain to form in the first place.
Kumar breaks down what needs to happen for cloud seeding to work: "You need a strong upward current of air to carry seeding materials like silver iodide or salt into the active parts of the cloud." It's like trying to hit a moving target while blindfolded—you need perfect timing and precise aim. "If there is no upward current or the cloud is already full of ice, the chances of success are low."
Air quality researcher Polash Mukerjee puts it bluntly: "It's not a magic fix." Even in places where cloud seeding has shown some success - like a 10–15% increase in rainfall in parts of California, it only works when conditions are already favorable. "At best, it redistributes existing moisture rather than creating new rainfall," which means stealing rain from one area to give to another, potentially messing with weather patterns elsewhere.
Can Weather Modifications Go Wrong?
Mukerjee reminds us that tinkering with weather has a history of backfiring. He points to Project Cirrus from the mid-20th century, where scientists tried to steer a hurricane away from Florida but ended up pushing it toward Georgia instead, causing unexpected damage. "It's a reminder that tinkering with weather systems can have far-reaching and unintended consequences."
Both experts agree that artificial rain can temporarily reduce PM2.5 and PM10 levels by washing pollutants out of the air but the relief is short-lived. Once the rain stops, pollution levels typically bounce back unless the actual sources of pollution are addressed.
What Are The Environmental Risks?
There's another side to this story that often gets overlooked: what happens to the environment when we start regularly dumping chemicals into the sky?
Mukerjee warns that silver iodide, the go-to chemical for cloud seeding, doesn't just disappear after doing its job. "It's potentially toxic to aquatic life and may enter the food chain over time." Imagine the cumulative effect of repeated cloud seeding operations over months or years.
Kumar acknowledges the concern but notes that safer alternatives exist. Salt is typically used for warm cloud seeding and is less harmful. "Researchers are also exploring greener options like biological ice nucleators and electrostatic seeding." Still, he admits that silver iodide remains popular because "it's currently the most effective for cold cloud conditions."
What should Delhi weigh before using cloud seeding?
Before Delhi commits to making rain a regular part of its pollution strategy, experts say there are some hard questions to answer.
Mukerjee points out a fundamental problem: there isn't strong research backing the use of artificial rain specifically for reducing pollution. "Most of the existing research on dust suppression, such as studies in mining or road construction, shows that sprinkling water reduces particulate matter only for a short period, typically 60 to 75 minutes."
Instead of chasing temporary fixes, Mukerjee argues for tackling the root causes. This means identifying the biggest polluters — industries, vehicles, construction sites— and implementing systematic policies to reduce emissions at their source.
"We've seen short-term solutions backfire before," he warns, citing the example of using waste from the Ghaziabad landfill in road construction, which later broke down into microplastics, now another health hazard Delhi residents have to worry about.
Kumar echoes this caution, emphasising that cloud seeding could have ripple effects beyond Delhi's borders. "Cloud seeding could unintentionally alter rainfall patterns in neighbouring states," he points out, stressing the need for coordination between states.
Both experts agree: cloud seeding should be a band-aid, not a cure. "It cannot replace comprehensive emission control strategies," Kumar emphasises. Relying too heavily on artificial rain could create a dangerous illusion of progress while delaying more effective, long-term solutions.
For Delhi's millions of residents who deserve to breathe clean air, cloud seeding might offer occasional relief on particularly bad days. But it's an expensive, weather-dependent gamble that, at best, provides temporary respite from a problem that demands permanent solutions.
The real question isn't whether Delhi can make rain—it's whether the city is ready to make the hard choices needed to clean its air for good.