Manipulated Clouds to Dispel Smog in India

Delhi air pollution

Indian scientists aim to artificially promote cloud formation for the first time to trigger heavy rainfall in parts of New Delhi. The experiment is designed to combat the smog that has been plaguing the city for over a week. New Delhi is considered the most air-polluted capital in the world.

Particulate matter pollution is particularly high there during the winter. One reason for winter smog is that farmers in the surrounding states burn crop residues, despite the ban, to quickly and inexpensively prepare for the next planting season. Additionally, emissions from vehicles, industry, and dust from construction sites and waste incineration contribute to the severe smog. Due to the intense smog, elementary school students in the city have already started their winter holidays instead of the planned January break; construction projects have been halted; and traffic restrictions are being considered.

What Makes Particulate Matter So Concerning?

The Swiss technology company IQAir, which monitors air quality worldwide, categorizes air pollution in Delhi as “dangerous,” the worst of six possible categories. The minuscule particulate matter can penetrate organs and is considered a contributor to heart and circulatory diseases, cancer, dementia, and other illnesses.

This is also a problem in Europe: According to the EU Environmental Agency, poor air quality is attributed to over 300,000 premature deaths annually in Europe.

Heavy rainfall could practically cleanse the air in Delhi. Additionally, the rain could prevent heavily polluted air from the surrounding regions from flowing towards the capital. According to Manindra Agrawal from the Indian Institute of Technology in Kanpur, the experiment’s best conditions will be around November 20 in Delhi.

Where Cloud Seeding Has Already Been Successful

The researchers plan to spray a salt mixture containing silver iodide for the experiment. This technique, known as “cloud seeding,” has been in use for decades. Dry ice or liquid nitrogen can also be suitable for this purpose. When introduced into the clouds, either by aircraft or ground-based methods, it causes cloud water to condense around the fine silver iodide droplets, forming drops that eventually lead to precipitation.

However, among experts, there is debate about the actual effectiveness of this method. The researcher in charge of the project, Agrawal, mentioned to Reuters, “We do not expect a large cloud covering all of Delhi, but several hundred square kilometers would be beneficial.” For reference, Delhi is approximately 1500 square kilometers in size and has around 20 million inhabitants. The estimated cost of the experiment is around 110,000 euros.

Cloud manipulation to induce rain has been attempted multiple times in various countries, including Mexico, the USA, China, Indonesia, and Malaysia. This would be the first such endeavor in India if the court approved it.