Deputy CM of Haryana Dushyant Chautala has urged PM Narendra Modi to implement cloud seeding plan in order to curb air pollution covering regions of Delhi and NCR. In his letter to Prime Minister, he wrote about IIT Kanpur project on cloud seeding technology which was non-functional due to unavailability of technical support and aircraft from the central government.
Let us understand what is cloud seeding.
It is a kind of weather modification technology that creates artificial rainfall. Cloud seeding only works when there are enough pre-existing clouds in the atmosphere and rain happens when moisture in the air reaches levels at which it can no longer be held. The technology aims to facilitate and accelerate that process by making available chemical ‘nuclei’ around which condensation can take place. The seeds used in the cloud seeding can be the iodides of silver or potassium, dry ice (solid carbon dioxide), or liquid propane and can be delivered by plane or simply by spraying from the ground.
The technology is evidently not new to India and it has been earlier attempted in states of Karnataka, Andhra Pradesh and Maharashtra to address drought.
Internationally, cloud seeding has been experimented Australia, America, Spain and France. However, in UAE, the technology led to creation of 52 storms in Abu Dhabi. Cloud seeding is a routine pattern in Russia and other cold countries where it is used to disperse fog at the airports.
Role of IIT Kanpur in Its Implementation
IIT Kanpur Scientist had developed a project to induce artificial rain through cloud seeding to clear smog in Delhi. The project was approved by the officials in the Environment Ministry. It demanded an aircraft of National Remote Sensing Agency — an ISRO-affiliated body — to fly into the clouds and create artificial rain while injecting silver iodide. This silver iodide would lead to formation of ice crystals, making the clouds denser and causing them to condense into rain and settle atmospheric dust and clearing the sky.
Last year the project got clearance from DGCA and Defense and Home Ministry but due to unavailability of aircraft it could not get implemented.
Is Cloud Seeding Technology Successful?
According to IMD, around 30 successful incidents of seeding have been recorded till last year. The Indian Institute of Tropical Meteorology which is based in Pune has been experimenting cloud seeding for many years now. The experiments have been carried out around Nagpur, Solapur, Hyderabad, Ahmedabad, Jodhpur, and recently Varanasi.
Depending on the local atmospheric conditions, moisture in air and cloud attributes, the success rate of cloud seeding technology is around 60-70 percent.