Doubtful impact of cloud seeding

The state cabinet has approved the cloud seeding project in three river basins — Cauvery, Malaprabha and Tungabhadra. The defici­ent rainfall during the ongoing monsoon period in the state and the acute drought conditions during the third consecutive year have forced the state government to resort to weather modification to enhance the precipitation with the hope of bringing some water to parched land.

This project with an estimated cost of Rs 30 crore is suppo­sed to be implemented within 60 days by private firm Hosysala Projects Ltd. Will this improve the condition of the farmers thr­ough additional rainfall and inc­rease the water flow in these river basins to aid irrigation dams?
Though the government has approved this only after getting expert opinion form the Indian Institute of Science and the State Natural Disaster Monitoring Centre, history of three decades of cloud seeding in the state should have been considered before final decision was taken.

In 2002, the then S M Krishna government implemented cloud seeding project but it did not bring any positive result. In the early 1980s, the experiment did bring some rain, but not in those areas where it was supposed to increase rainfall.

Cloud seeding essentially entails injecting silver iodide into the rain bearing clouds using aircraft or strategically placed ‘rain rockets’ propelled form the ground. However, this year, this chemical will be sprayed into the clouds by special aircraft flying at low altitude. Cloud seeding worldwide has been in practice since 1940s, and 60 countries have tried this technology. China claims to be the leader that produces an additional annual rainfall of 60 billion cubic meters.

The results are still ambiguous. While injecting these chemicals it is essential to assess the type of clouds, background particles in atmosphere and level of pollution as they play a major role in enhancing precipitation. Importantly, the pilot needs to be trained to fly into the clouds, whereas most of them are trained to fly over the clouds.

“Conventional pilots are ta­ught not to fly in so close to or straight into storm clouds. The pilot who is engaged in cloud seeding needs to keep track of big picture as well as navigate couple of unpredict­able storms,” says Hans Ahlness, of Weather Modification Inc.

Is the Karnataka government going to ensure that such experienced cloud seeding pilots are hired to implement the project? The most important variation in a tropical country like India, especially during the monsoon months, is that the moisture levels in the clouds are heavy with salt and the clouds may behave differently and would not accomplish positive outcomes.

‘Clouds continue to be complex and mysterious creatures and getting fuller understanding of the atmospheric science is the biggest challenge’ says Bruintjes, a cloud seeding expert from the World Metrological Organisation. Though the state government has given the approval for cloud seeding as an act of desperation to tackle drought, we need to understand the actual capabilities and limitations of cloud seeding. It is too unrealistic to expect big results leading to water augmentation in the entire river basins.

We need to address the root causes of climatechange and changing weather patterns, especially the erratic monsoon rains. Tweaking weather though cloud seeding is not going to replace the monsoon rains. Never­theless, our politicians and technocrats present this short-term tool as a solution to address the larger issue of climate change.

The environmental issues of cloud seeding are rarely addressed over these years. What impact the chemicals used during the process of cloud seeding will have on the soil and atmosphere? What are the adverse effects on the climate of adjoining areas where this experiment is being carried on? The state government needs to address these questions based on the experiences conducted over the years. If these issues are ignored, it might lead to more problems and add to the complexities of understanding weather pattern.

The American Meteorological Society has categorically stated: “the use of untested weather modification techniques during severe droughts, as a means of increasing precipitation, is not recommended. Opportunities to increase precipitation are typically minimal during droughts and only well-tested techniques should be considered, realising that only limited precipitation augmentation will probably result”.

It is high time that we heed to this warning and evaluate the merits of the cabinet decision in approving this doubtful technology. Water conservation strategies needs to be implemented in the long run to address the recurring drought rather than opting for short-term, doubtful solutions like cloud seeding.