Cloud Seeding: Blessing or Curse?
“The Beijing Weather Modification Office spent a lot of time researching how to prevent rain in the city during the Aug. 8 opening ceremony of the 2008 Summer Olympics. The government even guaranteed clear skies for the event — a promise it managed to deliver on.” The feat only took the launch of 1,104 rain dispersal rockets from 21 sites in the city to pull off.”
“There’s some water in the sky and clouds even in low-humidity areas. Rains occurs after moisture collects around naturally forming particles in the air, causing the air to reach a level of saturation, at which point it can no longer hold in that moisture. Cloud seeding helps that process along, providing additional particles around which water condenses. These particles can be salts, calcium chloride, dry ice or silver iodide, which the Chinese use. Silver iodide is effective because its form is similar to ice crystals. Calcium chloride is often used in warm or tropical areas.”
Northern China, where Beijing is located, doesn’t receive much rain, and relies heavily on cloud seeding. Zhiang Qiang, who runs the Beijing Weather Modification Office, told the Asia Times that “water levels in Beijing’s water basins have increased up to 13 percent due to cloud seeding Cloud seeding also has been used to cool Beijing on hot days.”
STATIC, DYNAMIC AND HYGROSCOPIC CLOUD SEEDING
This is the standard procedure for the process:
Static cloud seeding involves spreading a chemical like silver iodide into clouds. The silver iodide provides a crystal around which moisture can condense. The moisture is already present in the clouds, but silver iodide essentially makes rain clouds more effective at dispensing their water.
Dynamic cloud seeding boosts vertical air currents, which encourages more water to pass through the clouds, translating into more rain. Up to 100 times more ice crystals are used in dynamic cloud seeding than in the static method. The process is considered more complex than static clouding seeding because it depends on a sequence of events working properly.
Hygroscopic cloud seeding disperses salts through flares or explosives in the lower portions of clouds. The salts grow in size as water joins with them. In his report on cloud seeding, Cotton says that hygroscopic cloud seeding holds much promise, but requires further research.
Cloud seeding is expensive, though potentially cheaper than other methods, like diverting rivers, building new canals or improving irrigation systems. If areas are experiencing drought due to climate change, isn’t effort better spent tackling the causes of global warming?
There is also the question of toxicity from the chemicals used in seeding clouds, which are also known as “chem trails.” Despite reassurances from cloud-seeding companies, concerns remain about exposure to silver iodide toxicity, barium, strontium, mercury, arsenic and soil contamination – all of which have been alleged to be in these seeds. These chemicals are harmful to people, animals and all living things.
Scientists may not be sure if cloud seeding actually works, but despite the skepticism, China is moving forward. The nation spends $60 to $90 million a year on weather modification, in addition to the $266 million spent from 1995 to 2003.
“Is cloud seeding just a way of sweeping pollution and climate change under the rug and playing God to ensure you don’t have to schedule a rain date? Or is it merely a matter of tweaking weather to your advantage? However you look at it, it’s not likely to go away any time soon. In fact, scientists have already proposed building fleets of massive, unmanned ships to seed clouds over Earth’s oceans to provide a cooling counter to carbon dioxide-induced global warming. If cloud seeding is ultimately a way to “fake it” when guests come to visit or crops need a sprinkle, do we really want a world where we have to manually adjust the planet’s atmosphere just to stave off environmental disaster?”