Has cloud seeding worked to accelerate monsoons?

Fri, 2016-04-29 09:50 -- SCC India Staff

Cloud Seeding

Last year, the Maharashtra government shortlisted a private agency to provide cloud seeding with a view to generating artificial rainfall (from the August to October period). The state had allocated Rs 27 crore for the project.

However, this exercise and a similar one carried out carried out by Maharashtra in 2002 have failed to be successful. But, despite the ‘above-normal’ monsoon forecast, the state plans to undertake cloud seeding in parts of Maharashtra during the start of the current monsoon. This exercise will be concentrated over water supply schemes that provide water to Marathwada, a region that is reeling under drought due to the failure of the monsoon over the past couple of years.

Because the cloud seeding experiment was conducted from August to October last year, officials are of the opinion that the exercise failed because the monsoon was receding. There weren’t enough moisture-bearing clouds to generate artificial rainfall.

Another state to follow suit is Karnataka. Despite failing miserably in its earlier attempt, the state is going ahead with its plans for cloud seeding. Karnataka’s plans depend on the success of Maharashtra’s experiment.

The efficiency and efficacy of cloud seeding is yet to be proved. But like all scientific experiments, it takes time and patience to achieve the desired results. It was in the late 1940s that the General Electric Research Laboratory carried out the first experiments on cloud seeding. In India, the earliest experiments on cloud seeding were carried out over the Western Ghats with ground-based silver iodide generators. In 1952, cloud seeding was attempted in India with the use of salt and silver iodide into clouds through the use of hydrogen balloons released from the ground.

Indian experiments with cloud seeding have been successful in the past, especially those conducted by the Council for Scientific and Industrial Research which carried out long-term cloud seeding programmes over northern India, again using ground-based salt generators, during the period from 1957 to 1966. These experiments indicated that rainfall went up by 20 percent. Cloud seeding experiments over Baramati in Maharashtra during the period 1973-74, 1976, and 1979-86 were also successful, indicating an increase in rainfall of around 24 per cent.

That said, despite testing failures and partial success, this technology is becoming a multimillion-dollar global industry because of the impact it can have. Weather Modification Incorporated (WMI), based out of Fargo, North Dakota, was contracted by the Indian Government to carry out a cloud seeding programme. WMI is also doing the same work in places like Southeast Asia, South America, and the Middle East. WMI generates around $20 million in revenues each year from its various projects. According to the World Meteorological Organization, 52 or more countries have cloud seeding programmes, carried out by 34 private weather modification companies.

Lack of new findings has meant that cloud seeding has not really taken off across the globe in subsequent years. The main problem with cloud seeding is that it really cannot bring a region out of a drought. That’s because a drought is caused by the absence of clouds, and a seeding exercise will not work in these conditions. The only situation where a cloud seeding exercise will be effective is when it is utilised to increase rainfall over regions that act as water reservoirs.             

In terms of the area it covers, the precipitation it brings, and the length of the time it lasts, there is no substitute for the Indian monsoon. But cloud seeding can produce good rain over smaller areas, and can supplement the natural phenomenon.

Since timely rain, rather than a lot of it, is what is often more important for crops, seeding can help. It is now a fairly advanced science — even though more research is needed for a deeper understanding of cloud formations, so that more significant meteorological interventions can be made. Different types of clouds may exist over a region, and the same type of seeding may not be effective for all; sometimes seeding is effective only over certain areas.