Can cloud seeding reveal the pot of gold at the end of the rainbow?

Water scarcity is forcing governments around the world to adopt increasingly outlandish
schemes to protect access to the precious resource

By Roshni Rangwani

5.4 billion. That’s the UN’s estimate of the number of people that will be living under water stress by 2025, roughly equalling 2/3 of the global population. As global weather patterns grow ever less reliable due to climate change, it is easy to understand why countries are scrambling to find ways to ensure their future water security. While harvesting melting icebergs or powering desalination with the Sun may seem like science fiction, they are prospects that several governments are investing heavily into. Following in this vein, ‘cloud seeding’ is a measure that has quickly gained traction in recent years.

Beginning from the 1990s, the U.A.E has been a poster child for this little-known process. Its current iteration involves The National Centre of Meteorology deploying planes with ‘flares’ of salt and magnesium to coalesce clouds into rain as required. As an oil-rich state averaging 100 millimetres of precipitation annually, it has both the means and incentive to tweak Mother Nature in its favour. From boosting tourism to helping along agriculture in a bid to allow the desert nation a modicum of nutritional independence, the administration has high hopes for its cloud-seeding endeavours. This may explain why it has conducted 95 of these exercises in the first quarter of 2020 alone, when the coronavirus pandemic slashed imports of fresh food.

The Emirati cloud-seeding count is all the more staggering given that there is little scientific consensus on its effectiveness at all. Idaho’s 2017 SNOWIE project, one of the only randomised studies on cloud-seeding, concluded that it only boosts precipitation by 5-10%. While significantly cheaper than alternatives like desalination, the findings still imply the use of sizable public funds for little real impact. Furthermore, even modest increases in showers can tax infrastructure, offsetting any potential economics gains. For example, increased seeding has been partially blamed for floods in Dubai and Abu Dhabi in the Spring of 2020, which were built assuming little drainage was necessary. In the longer-term, some ecologists have speculated whether draining the clouds faster than they are able to re-humidify (which grows more likely if seeding is performed often), could backfire in the form of droughts in the future.

As the U.A.E. illustrates, cloud seeding is far from a roaring success even on a small-scale. And as the ambition of its future applications swells, so do the ethical problems it poses. Conspiracy theorists have recently gained attention by accusing the Chinese government of using seeding to deter people from breaking lockdowns in COVID-affected regions. However, China’s ongoing ‘Sky River’ project is a more compelling moral conundrum. The largest artificial precipitation experiment in the world, it aims to divert the South Asian monsoon to shower 1.6 million square kilometres of the Tibetan plateau (for context, about three times the area of Spain). Its audacious scope has a proportionately sweet projected payoff, estimated at 7% of the nation’s annual water consumption. If all goes to plan, it could give China remarkable control over rivers such as the Brahmaputra and Mekong. In other words, nearby countries like India, Vietnam, and Thailand could have reason to perceive a legitimate geopolitical threat. However, even the domestic scientific community is skeptical of this possibility—Lu Hancheng of University of Science and Technology of China called it an “absurd fantasy project”.

Fantasy or not, the funds being poured into cloud-seeding are very real—and, interestingly, do not seem to be dying up in the face of a lack of evidence of success. Is this no seeding no more than an unusual form of a market bubble, powered by no more than wishful thinking? After all, participating countries seem far away from the pot at the end of the rainbow. Or is a breakthrough just on the horizon, given the pressing need it could answer? One thing is for certain: weather manipulation is a field that merits closer attention. □

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