This summer, China set aside $30 million for a controversial project that involves shooting salt-and-mineral-filled bullets into the sky.
Their mission? Make it rain.
The project is part of a larger campaign of so-called weather modification techniques that the country has been using since at least 2008, when they claim to have cleared the skies for the Beijing Olympics by forcing the rain to come early.
China is far from the only nation trying to bring (or stop) the rain. At least 52 countries — including the United States — have current weather modification programs, 10 more countries than five years ago, according to the World Meteorological Organization.
It all started in the 1940s, when a pair of scientists from General Electric Co. were experimenting with using super-cooled clouds to stimulate the growth of ice crystals while hiking Mount Washington. The mountain, located in New Hampshire, is often called the “stormiest mountain in the world” and it’s considered a prime spot for cold weather testing.
After a series of experiments there and in New York, the two researchers managed to make it rain using silver iodide bullets. They got a patent for their technique, referred to as cloud-seeding, in 1948.
A few decades later, the US military brought cloud-seeding to the battlefield. Between 1967 and 1972, during the Vietnam War, it spent roughly $3 million each year on weather modification campaigns designed to draw out the monsoon season and create muddy, difficult conditions for enemy fighters. One campaign involved an attempt to flood the Ho Chi Minh Trail, the main route that enemy fighters were using to deliver their supplies.
Here’s a snippet of a document from the Federation of American Scientists (FAS) detailing the campaign:
Federation of American Scientists
The program was also known as Operation Popeye, Operation Intermediary, and Operation Compatriot. Whenever too many people would learn the name, the military would change it. Whether the program worked or not is still a matter of debate. According to the FAS, its “effects were minimal.”
Scientists say this is one of the biggest problems with cloud-seeding programs: It’s tough to tell if they have any effect at all. Even with today’s improved techniques, it can be difficult to distinguish the weather that may have already occurred from the weather that the seeding could have caused.
“The question is always, if you didn’t do that, would it have rained anyway?” Alan Robock, a distinguished professor of geophysics at the department of environmental science at Rutgers University, told Business Insider.
In 2010, the American Meteorological Society released a statement on cloud-seeding saying that although the science of weather modification has improved significantly in the past five decades, “there remain limits to the certainty with which desired changes in cloud behavior can be brought about using current cloud seeding techniques.”
In other words, we need more research.
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