Open this photo in gallery A Chinese worker fires rockets for cloud seeding in an attempt to make rain in Huangpi, central China's Hubei province, on May 10, 2011. AFP

Even Chinese scientists say it’s far-fetched to think their country can fix a long-standing water shortage by draining the heavens.

But backers of China’s “Sky River” project are pressing ahead with plans for what ranks as one of the more ambitious geoengineering programs ever conceived. Their goal is to use chemicals, electromagnetic systems and even sound beams to coax so much vapour out of “atmospheric rivers” in the sky that they can increase the country’s surface water resources by a full 10 per cent.

For several years now, Sky River has occupied a place somewhere between plausible science fiction and punchline − a notion of sufficiently breathtaking ambition that it has won the attention, and cautious support, of foreign scientists.

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Now, however, it is also attracting the derision of China’s own academics.

“This is an absurd fantasy project with neither scientific foundation nor technical feasibility,” Lu Hancheng, a scholar at the National University of Defense Technology, wrote as part of a scathing review of the project recently published by ScienceNet, China’s most important hub for scientific discussion.

Other scientists openly criticized the spending of public funds devoted to the project − at least $20-million, and counting. And they questioned whether it was reasonable to imagine that even the best tools of modern science could shape something as complex as meteorological systems.

But Sky River backers are carrying on, preparing for the launch of six monitoring satellites − the first could be in orbit by 2020. In addition, they are working on a program to ground test tools for wringing precipitation from the air.

At the heart of the concept is the existence of high-moisture corridors in the sky that move a bit like a long, narrow lofted river.

Chinese scientists set out to show that in some places, at some times, it is possible to generally predict where they form − such as when monsoon systems navigate the mountainous terrain of the high-altitude Tibetan plateau.

“They’ve shown that there are some preferential pathways. And therefore that they could potentially do this,” said Peter Scales, a University of Melbourne professor who was director of the Australia-China Joint Research Centre on Water Resources Management from 2013 to 2016, and attended an international symposium on Sky River this summer.

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Such channels bring water vapour to the Tibetan plateau from the Indian Ocean, Central Asia and the Yunnan-Guizhou plateau in southern China.

China is already a world leader in cloud seeding, and Sky River scientists first started experimenting in 2015, firing rockets with silver iodide to trigger precipitation. By early 2018, they had installed 500 ground-based burners to produce silver iodide particles in Tibet, Xinjiang and elsewhere, one researcher told the South China Morning Post earlier this year.

Plans for the system developed by China Aerospace Science and Technology Corporation, a state-owned giant, call for tens of thousands of burners to bring artificial rainfall over an area larger than Quebec. They hope to swell the rivers of the Yellow River, a key source of water for northern China.

Early results have shown promise.

“When they turn on these devices, it starts snowing instantly,” Prof. Scales said. “At one level, it’s pie in the sky. On the other level, it has got some science behind it.”

That’s nowhere close to suggesting Sky River will ultimately succeed in harnessing the firmament, a threshold that can only be met by weighing costs against the amount of water that can be wrested from the air. But initial tests have created “considerable” precipitation, said Ji Chen, a water-resources expert at the University of Hong Kong. He also attended the Sky River symposium this summer.

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“We don’t want to just write theoretical articles. We want to write tangibly, on soil,” said Wang Guangqian, an academician with the Chinese Academy of Sciences who has led the Sky River concept, in a state media interview published this week.

The problem they are confronting is as well-known as it is difficult to solve. Northern China does not have enough water to support its population. The shortfall has already prompted construction of one megaproject, the South–North Water Transfer Project. It has redirected some of the Yangtze River to more northerly reaches of the country, using canals and pipelines to deliver drinking water 1,432 kilometres to Beijing. It’s the world’s largest water-diversion project, built at a staggering cost.

Even so, it has addressed little more than 10 per cent of the northern water shortage.

So “we are thinking of other ways,” Mr. Wang said.

Still, the scientists have had to fight off notions that they are engaged in a quest for supernatural powers. This is “scientific exploration, not a process of ‘summoning the wind and ordering the rain’ or artificially intervening with weather on a large scale,” Zhang Chuhan, a Tsinghua University professor and academician with the Chinese Academy of Sciences, told Chinese state media this week.

Both Prof. Wang and Prof. Zhang declined repeated interview requests about the criticism they’ve faced.

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The controversy over Sky River in recent days emerged as another Chinese scientist stirred global concern − and a fierce domestic backlash − after heralding the creation of the world’s first gene-edited babies. The simultaneous debates raised pointed questions over where the limits might lie for a country keen on becoming a global technological leader.

In that atmosphere, the only Chinese scientist associated with Sky River willing to speak with The Globe and Mail declined to clearly answer even a basic question about whether the project remains under way.

“I can not say yes or no. Or what is yes and what is no,” said Fu Xudong, a professor in the department of hydraulic engineering at Tsinghua University. (Professors Wang and Zhang told state media Sky River is ongoing).

More than 10 Sky River-related experiments have already taken place, Prof. Fu said.

But it remains far too early to judge success, he said, citing the need to analyze results and the difficulties of what he called “geographical factors.”

“Whether these experiments could solve the water-shortage problem,” he said, “it’s not that easy.”

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With reporting by Alexandra Li