Within five years, China intends to use a dubious geoengineering technology known as 'cloud seeding' to induce more than 60 billion cubic meters of additional rain each year, its government said this week.

Backers of the program—which involves rocket-launching chemicals such as silver iodide into the clouds to allegedly boost rainfall—say the strategy aims to mitigate China's severe and growing water scarcity problem, which is exacerbated by demand from the industrial and power-generating sectors. The silver iodide droplets provide a nucleus within a cloud around which water can coalesce, forming raindrops or snowflakes.

Critics have long warned that geoengineering projects could have unintended, unknown side effects. Last year, former vice president Al Gore called geoengineered solutions to global warming "insane, utterly mad and delusional in the extreme."

"[T]he truth is that geoengineering is itself a rogue proposition," Naomi Klein wrote in 2012. "By definition, technologies that tamper with ocean and atmospheric chemistry affect everyone. Yet it is impossible to get anything like unanimous consent for these interventions. Nor could any such consent possibly be informed since we don’t—and can’t—know the full risks involved until these planet-altering technologies are actually deployed."

While China has a fifth of Earth’s population yet only 7 percent of its freshwater resources, government reports have said that more than 70 percent of the country's rivers and lakes are polluted and almost half may contain water that is unfit for human consumption or contact.

The country launched its "human affected weather" program in 1958, and has since met a target of increasing artificial rain to more than 50 billion cubic meters per year.

According to Reuters:

China has already allocated funds of 6.51 billion yuan ($1.05 billion) for artificial weather creation since 2008, the State Council, or cabinet, said in a document setting out the programme from 2014 to 2020.

"Weather modification has an important role to play in easing water shortages, reducing natural disasters, protecting ecology and even safeguarding important events," it added.

The figure of 60 billion cu m is equivalent to more than one-and-a-half times the volume of the Three Gorges reservoir, part of the world's largest hydropower plant.

In December, the Wyoming Weather Modification Pilot Program showed that cloud seeding produced a 3 percent increase in precipitation with a 28 percent probability that this result happened by chance.