The Indian capital, New Delhi, is preparing a new weapon in the fight against deadly air pollution: cloud seeding. The experiment, which could take place as early as next week, would involve introducing chemicals like silver iodide into cloudy skies to create rain and, it is hoped, remove fine particles that hover above. above one of the greatest cities in the world.
The need is desperate. Delhi has already tried traffic restriction measures, multi-million dollar air filtration towers and the use of fleets of water spray trucks to dissolve particles in the air, but to no avail.
The use of cloud seeding, if it comes to fruition, would be controversial. “It’s not a good use of resources at all because it’s not a solution, it’s like a temporary relief,” says Avikal Somvanshi, a researcher at the Center for Science and Environment in New Delhi. Environmentalists and scientists worry that much of the government’s response focuses on mitigating pollution rather than trying to cut off its source. “There’s just no political intent to solve this problem, it’s one of the biggest problems,” says Bhavreen Kandhari, an activist and co-founder of Warrior Moms, a network of mothers demanding clean air.
The air is so bad that schools in and around Delhi have announced closures and offices are allowing employees to work from home. The government has advised children, the elderly and people with chronic illnesses to stay indoors as much as possible. Diesel trucks, except those carrying essential goods, are no longer allowed to operate in the city. Bouts of rain last week cleared the air, but the respite was short-lived as air quality deteriorated further, helped by firecrackers set off this weekend to celebrate Diwali, the Hindu festival lights.
Now, authorities in Delhi are seeking permission from Indian federal agencies to try cloud seeding. The technique involves flying a plane to spray clouds with salts like silver or potassium iodide or solid carbon dioxide, also known as dry ice, to cause precipitation. The chemical molecules attach to moisture already present in the clouds to form larger droplets which then fall as rain. China has used artificial rain to combat air pollution in the past, but for cloud seeding to work properly, there needs to be significant cloud cover with reasonable moisture content, which is generally lacking. to Delhi during winter. If weather conditions are favorable, scientists leading the project at the Indian Institute of Technology Kanpur plan to carry out cloud seeding around November 20.
Until then, at least, Delhi will remain shrouded in a thick gray haze, which has become a toxic winter ritual. Smog, a dangerous cocktail of particulate matter and harmful gases, results from a series of unfortunate events that occur at the start of winter.