Can China solve its water problem with rain-making furnaces?
At 8 p.m. on August 8th, 2008 China’s big moment arrived: The Beijing Olympics began, with a lavish opening ceremony complete with elaborate performances and dazzling fireworks.
Eight is a lucky number in China, and it looked like fortune did favor the country on that day. No rain arrived to spoil the event, even though it was during the wet season.
But it might not have been down to luck. Beijing’s Weather Modification Office used aircraft and artillery to shoot silver iodide into the skies outside of the city -- so any rain would fall before it reached the stadium.
Now China wants to do it again... but on a much bigger scale.
Tens of thousands of chemical rainmakers -- furnaces that burn solid fuel to produce silver iodide -- will be scattered across the Tibetan plateau. As wet air from the Indian Ocean sweeps in, the chemicals blend in with clouds to accelerate rain and snowfall -- bringing much-needed water to one of the driest places on Earth.
“Sometimes snow would start falling almost immediately after we ignited the chamber. It was like standing on the stage of a magic show,” a researcher working on the system told the South China Morning Post.
The idea that humans can control the weather is both appealing and unsettling. But when people “create” rain, they aren’t miraculously producing water out of nowhere. Instead, they are diverting moisture from one place to another -- causing rain to fall in places where it wouldn’t naturally.
But will it work? One scientist told the South China Morning Post he’s skeptical about the Tibetan project, saying it could result in less rainfall in other parts of China.
But one example from the United States shows there’s another way to get more rain: Curbing air pollution.
Atlanta saw a 10% jump in annual average rainfall after the Clean Air Act went into effect in 1970. Turns out, clouds that are good at making rain are all formed from particles of different sizes. But air pollutants from factories are all very small. That’s why it rained less in Atlanta during the height of pollution in the city during the 1950s and 60s. But once the air got cleaner, rainfall started to return -- and has stayed that way since the 1980s.