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lucidkoan writes
"Environmentalists have long argued about whether geoengineering (using technology to alter the climate) is a good way to tackle climate change. But the tactic has some heavy hitters on its side, including Bill Gates. The Microsoft founder recently announced plans to invest $300,000 into research for machines that suck up seawater and spray it into the air, seeding white clouds that reflect rays of sunlight away from Earth. The machines, developed by a San Francisco-based research group called Silver Lining, turn seawater into tiny particles that can be shot up over 3,000 feet in the air. The particles increase the density of clouds by increasing the amount of nuclei contained within."
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icebike writes
"In our recent discussion of the phenomenon of noctilucent clouds, there was some suggestions that these might be the product of global warming due to moisture being lofted high into the atmosphere. It now appears that these clouds are simply the product of Shuttle launches. In a story about the Tunguska blast, Science News says: 'Each launch of a space shuttle, which burns a combination of liquid hydrogen and liquid oxygen as fuel, pumps about 300 metric tons of water vapor into the atmosphere at altitudes between 100 and 115 kilometers. Soon after the January 16, 2003, launch of the shuttle Columbia, a liftoff that took place just after the height of summer in the Southern Hemisphere, noctilucent clouds appeared over Antarctica. Similarly, a widespread display of the night-shining clouds showed up over Alaska two days after the shuttle Endeavour blasted off on August 8, 2007. Previous studies show that in both instances those clouds included material from the shuttle plumes.' So, man-made after all?"
