May 3, 2010 - Scientists Take Aim at Drought Using Lasers

Researchers at Switzerland's University of Geneva have been toying with a very interesting idea to make it rain - targeting unsuspecting clouds and shooting lasers at them.

Sure, the strategy seems a bit like science fiction but the team hopes that the lasers will prove to be successful in increasing rainfall in various dry areas that really need the added precipitation.

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The team, being led by Jerome Kasparian, first tested the method in a lab setting. Essentially the researchers shot a 220-millijoule laser beam into a below-freezing, water-saturated chamber, which in turn enabled the scientists to create clouds. For those of us who have no idea what a millijoule is and how powerful such a laser is; 220 millijoules is equivalent to the intensity of 1,000 power plants!

Controversy has arisen from the lab demonstration however (high-humidity at extremely low temperatures doesn't mimic real-world conditions), though Kasparian still asserts that the process showed very encouraging results in the field. For example, the team shot laser beams 60 meters into the air in Berlin, Germany and although clouds couldn't be seen by the naked eye, LIDAR weather tracking systems confirmed that the laser boosted the density and size of water molecules in the air.

Clearly this process will have its critics, a laser that awesomely powerful in the wrong hands could produce disastrous results. Still, scientists are working on optimizing the infrared laser's wavelength, focus and pulse duration to produce large enough droplets to make it rain.