$200 Million Dollars a Year Could Reverse Climate Change, Says Wave Energy Pioneer

dryriver writes: BBC Future reports on a geoengineering technique called 'marine cloud brightening' that makes marine Stratocumulus clouds -- which currently reflect almost 30% of total Solar radiation back into space -- whiter, causing them to reflect more sunlight away from earth. Professor Stephen Salter of Edinburgh University, a well-known 1970s wave and tidal power pioneer, has designed an unmanned hydro-foil ship, computer-controlled and wind-powered, which pumps an ultra-fine mist of sea salt toward the cloud layer, causing it to turn white: ''Spraying about 10 cubic meters per second could undo all the [global warming] damage we've done to the world up until now,' Salter claims. And, he says, the annual cost would be less than the cost to host the annual UN Climate Conference -- between $100-$200 million each year. Salter calculates that a fleet of 300 of his autonomous ships could reduce global temperatures by 1.5C. He also believes that smaller fleets could be deployed to counter-act regional extreme weather events. Hurricane seasons and El Nino, exacerbated by high sea temperatures, could be tamed by targeted cooling via marine cloud brightening. Salter boasts that 160 of his ships could 'moderate an El Nino event, and a few hundred [would] stop hurricanes.' The same could be done, he says, to protect large coral reefs such as the Great Barrier Reef, and even cool the polar regions to allow sea ice to return. So, what's the catch? Well, there's a very big catch indeed. The potential side-effects of solar geoengineering on the scale needed to slow hurricanes or cool global temperatures are not well understood. According to various theories, it could prompt droughts, flooding, and catastrophic crop failures. Another major concern is that geoengineering could be used as an excuse to slow down emissions reduction, meaning CO2 levels continue to rise and oceans continue to acidify -- which, of course, brings its own serious problems.'

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