Unleashing the Power of the Skies: Will the Marvels of Cloud Seeding finally save Delhi from its alarming AQI?

New Delhi topped a real-time list on November 3, 2023, of the world's most polluted cities, which put India's capital's AQI at 611 in the 'hazardous' category. The AQI of Delhi severely rose to around 300 on the festival of lights, Diwali, or should we call it the festival of pollution?

Under these appalling circumstances, revolutionising rainfall and unleashing the science behind cloud seeding is our last resort. However, cloud seeding is not a cheap undertaking, especially for a large metropolis like Delhi. Delhi will have to bear a huge expenditure of Rs 1 lakh per square km, summing up to Rs 13 crore. Allocation of this money should not be a difficult job for a 3.65 trillion economy if the anticipated outcome is achieved.

The real issue at hand for Delhi is not the cost but rather the appropriate course of action for advancing cloud seeding technology. While cloud seeding has been experimented with for decades, its effectiveness can vary depending on atmospheric conditions and other factors. Many countries have taken a dig at it and have been quite successful in this endeavour.

China has been experimenting with cutting-edge technologies in an attempt to use cloud seeding to enhance rainfall on the largest freshwater reserve in Asia—the Tibetan Plateau. The system involved installing more than 500 fuel-burning chambers on the mountains. The chambers burned solid fuel to produce silver iodide, a cloud-seeding agent with a crystalline structure much like ice. Situated atop precipitous mountain peaks, the chambers overlook the South Asian monsoon's damp winds. Rain and snow are created when wind hits the mountain because it creates an upward draft and lifts the particles into the clouds.

This experiment was repeated in China in 2008, during the Olympics, to prevent rain over Beijing's open-air, 91,000-seat Olympic stadium, and several times in Russian to prevent rain on public holidays and to bring down fires in Siberia. This time the cloud seeding was not done by fuel-burning chambers but by employing aircraft and a network of artillery and rocket launch sites, wherein the engineers deployed silver iodide and dry ice into approaching clouds, allowing their rain to be dispersed.

Several instances of this have been encountered in the United Arab Emirates as well to tackle water scarcity challenges within the country. The meteorological department of the UAE adopted a different strategy altogether. Instead of relying on chemicals, they used electrical charges. These electrical charges forced water droplets to combine into larger ones, allowing the water droplets to hit the ground instead of evaporating. A fleet of drones, not conventional aircraft, delivers the electrical charges to excite the water molecules present in the cloud cover. In 2014, the UAE sent a total of 187 missions into the sky to seed the cloud, 214 missions in 2017, 184 in 2018, and 247 in 2019. It can be said that the drowning-powered clouds in the UAE have actually proven to be the silver lining for their future.

Now the real answer that awaits everybody is: out of all the feasible approaches, what will Delhi adopt as its future course of action? In my opinion, hygroscopic cloud seeding is the most probable solution as suggested by the Indian Institute of Technology, Kanpur. This is the most likely solution because the Indian government has already tested it in Solapur, Maharashtra, resulting in 18 percent more rainfall than usual, as reported in a study published in the Bulletin of the American Meteorological Society (BAMS). The experiment is done in warm clouds with a cloud base height greater than zero degrees Celsius. Calcium chloride particles were released at the convective cloud base to trigger rainfall, much like what happened in China (during the Olympics) and Russia.

In the quest for cleaner air, cloud seeding emerges as a promising but challenging solution for Delhi. The experience of nations like China, Russia, and the UAE showcases the potential benefits, but the road ahead for Delhi is very complex. The promise of healthier skies in Delhi still hangs in balance. The journey towards cloud seeding may be demanding, but the stakes are very high—a breathable future for the city, which is in dire need of transformation. As decisions are made for the capital city, the skies over it may one day see a silver lining, heralding a new era against pollution.

References

• Artificial rain & cloud seeding in Delhi won’t work, ‘as ineffective as the smog tower’, say experts. (2023, November 18). Moneycontrol. https://www.moneycontrol.com/news/environment/artificial-rain-cloud-seeding-in-delhi-wont-work-as-ineffective-as-the-smog-tower-say-experts-11764291.html

• Dixit, P. (2023, November 17). What is artificial rain? Here's how cloud seeding fared in UAE, China, Russia. Business Today. https://www.businesstoday.in/technology/news/story/what-is-artificial-rain-heres-how-cloud-seeding-fared-in-uae-china-russia-406046-2023-11-17

• Dockrill, P. (2018, April 26). China's 'Sky River' Will Be The Biggest Artificial Rain Experiment Ever : ScienceAlert. ScienceAlert. https://www.sciencealert.com/how-china-s-sky-river-will-be-the-biggest-artificial-rain-experiment-ever-cloud-seeding

• Ganndhiok, J. (2023, November 19). Clouds over Delhi government’s plan to induce rain amid air pollution. Hindustan Times. https://www.hindustantimes.com/cities/delhi-news/clouds-over-delhi-govt-plan-to-induce-rain-101700416986444.html

• The Hindu Bureau. (2023, November 3). Delhi air pollution: What you need to know right now? The Hindu. https://www.thehindu.com/news/cities/Delhi/delhi-air-pollution-what-you-need-to-know-right-now/article67492521.ece