Explained: How successful is cloud seeding technology

News:Haryana Deputy Chief Minister has written to Prime Minister requesting him to undertake cloud seeding plan to combat air pollution engulfing Delhi and NCR.

Facts:

About Cloud Seeding:

• Cloud seeding is a kind of weather modification technology to create artificial rainfall.It works only when there is enough pre-existing clouds in the atmosphere. 
• Rain happens when moisture in the air reaches levels at which it can no longer be held and cloud seeding aims to facilitate and accelerate that process by making available chemical ‘nuclei’ around which the condensation can take place. 
• These seeds of rain can be the iodides of silver or potassium, dry ice (solid carbon dioxide) or liquid propane.The seeds can be delivered by plane or simply by spraying from the ground.

Where was Cloud Seeding tried earlier?

• Cloud seeding is not new to India and it has earlier been attempted in Karnataka, Andhra Pradesh and Maharashtra to address drought. 
• Similar experiments of cloud seeding had earlier been tried in Australia, America, Spain and France. 
• In United Arab Emirates,the cloud seeding technique led to creation of 52 storms in Abu Dhabi. 

Significance of Cloud Seeding:

• The Pune-based Indian Institute of Tropical Meteorology has been carrying out cloud seeding experiments for several years now. 
• The success rate of these experiments in inducing rains is about 60 to 70% depending on local atmospheric conditions, the amount of moisture in the air and cloud characteristics.