Beijing doesn’t get much rain…so Beijing makes rain.
They do it using cloud-seeding technology, where a particulate substance is sent up into the atmosphere so that water droplets/ice crystals can form on the particles and make precipitation. China has been using silver iodide pellets shot into the sky with anti-aircraft weapons and rocket launchers.
They claim that it is working as China’s overall precipitation has increased by 7.4 trillion cubic feet. As a gauge, the US receives approximately about 200 trillion cubic feet of rain per year, so this increase isn’t trivial.
Cloud seeding was used to ensure that it did not rain during the opening and closing ceremonies of the 2008 Olympics by forcing it to to rain before-hand.
Controlling the weather would obviously be a great benefit to humans. We could make it rain on crops and avoid having to use ground water supplies for agriculture. Forest fires could be more easily extinguished. But what affect does it have on the environment?
How does cloud seeding affect the environment?
Two studies have shown that cloud seeding has minimal effect on the environment, meaning that silver accumulations in the vegetation and soil are not measurable above the background amount of silver that is already present in the environment.
People are also exposed to silver through tooth fillings and industrial waste much more so than through cloud seeding technology.
Other older studies (as far back as 1950) had inconclusive results.
It almost sounds too good to be true. Controlling precipitation can’t be that easy and impact-less… It seems that even if there is minimal chemical impact, there would certainly be other environmental impact.
Wouldn’t you sort of be ‘stealing’ rain from someone else? Are we going to end up in an arms race of silver iodide?
Does it actually work?
That is hard to test. Controlled experiments can’t be run. It’s impossible to know how much rain would have fallen if the cloud weren’t seeded.
Even with China’s significant increase in rainfall, it is entirely possible that the increase is due to natural fluctuations in precipitation.
Keep your eyes peeled for new research.
Flickr Creative Commons by IvyMike