Modifying clouds to fight global warming
Rhett A. Butler, mongabay.com
August 15, 2005
An article in The Sunday Times reports that a scientist is working a cloud manufacturing technique to counter global warming.
Professor Stephen Salter, professor emeritus of Engineering Design at Edinburgh University, has proposed that “highly reflective clouds could be used to bounce more of the sun’s rays back into space — counteracting rising temperatures caused by a build-up of greenhouse gasses in the Earth’s atmosphere,” according to the article by Paul Lamarra in the August 14, 2005 edition of The Sunday Times.
Salter’s technique, which will be published in Atmospheric Research, would involve “using a fine mist of sea spray to increase the density, and whiteness, of low-lying stratocumulus.” Salter believes that a 4% increase in the reflectivity of 1/3 of such clouds could counteract global warming.
Salter’s plan would use hundreds of unmanned radio-controlled boats positioned off the west coast of Africa and Peru. The article explains,
The forward movement of the boats — driven by wind-powered rotors — would turn underwater turbines attached to their hulls. These turbines would generate enough electricity to create an electrostatic field inside the rotors. Water sucked into the rotors would hit the electrostatic field, creating a very fine mist of sea water.
As the sea-spray evaporates, tiny particles of salt would be carried into the low-lying clouds by rising currents of air. These particles would create more water droplets, increasing the clouds’ density and making them more reflective.
Manipulation of clouds is not a new idea. Cloud seeding, the attempt to “change the amount or type of precipitation that falls out of clouds … by dispersing substances into the air which allow water droplets or ice crystals to form more easily” (Wikipedia), has been used for several decades by scientists in the United States and Russia in an effort to affect precipitation. Typically, silver iodide or dry ice, is used to increase precipitation in areas experiencing drought and to reduce the amount of fog or precipitation at sensitive times or locations.
You can read the full text of the article at www.timesonline.co.uk/article/0,,2090-1734536,00.html
This news item used information and quotes from The Sunday Times.