Animals

Can Man-Made Clouds Save Us From The Drought?

California's drought is bad. If we could make clouds form, would it help solve the growing problem?

Related on TestTube:
Why the Ocean Can't Fix the Drought
How California's Drought Affects the Whole World

Clouds are condensed bodies of water vapor floating high in the atmosphere. When water droplets attach to other small particles in the air--usually dust--the vapor condenses around them and, if they get heavy enough, it starts to rain. Cloud seeding is the process in which tiny particles are released into clouds to force this process along. A study in the Journal of Applied Meteorology and Climatology found that this can improve rainfall by up to 15 percent. It's been in practice in the American west for decades, and water agencies in California spend between three-to-five million dollars a year on cloud seeding.

So, why aren't scientists using this process and end the record-setting drought in California? Cloud seeding has some critics: a study published in the journal Atmospheric Research found some cloud seeding attempts have a very low rate of success. Looking over a 50 year period, the researchers concluded that the total increase in rainfall over that time was the result of chance, not cloud seeding.

Some scientists think a modified version of this could even be used to tame hurricanes. A study published in Atmospheric Science Letters created climate models to look at how cloud-seeded clouds could be used to cool down the ocean temperatures. Hurricanes get started by warm waters in the ocean: as sea temperatures heat up, hurricanes get more energy. By creating clouds above ocean hot spots, the clouds could act like reflectors, cooling the water underneath them by shielding them from the sun's heat. There are some concerns, however, that these clouds could lead to reduced rainfall in the Amazon or cause other unintended consequences.

This is one of the main issues with the cloud seeding. Weather is a very complex and chaotic system that's hard to predict and even harder to control. Do you think scientists should be trying to control the weather or are the environmental risks too great? Let us know in the comments.

Learn More:

Scientists Create 52 Artificial Rain Storms in Abu Dhabi Desert (Time)
"Hail, lightning and gales came through the state's eastern region this summer thanks to scientist-puppetmasters."

Pollen shed in rain - brings more showers (The Guardian)
"Do you feel more sneezy after it has rained? Conventional wisdom suggests that rain showers bring a freshening influence: dampening down the dust and pollen in the air. But not all rain is so benign. Spring and summer rain can help to explode pollen grains, triggering "thunderclap asthma" for some."

Does cloud seeding work? (Scientific American)
"At long last, it snowed in northern China. The first snow of the year came to Hebei, the northern province surrounding Beijing. In the Chinese capital, it was the first real bout of precipitation since last October. The blizzard caused 12 area highways around Beijing to close."