OSLO (Reuters) - A little-known technology that may be able to take the equivalent of China's greenhouse gas emissions out of the carbon cycle could be the radical policy shift needed to slow climate change this century, a draft U.N. report shows. Using the technology, power plants would burn biomass - wood, wood pellets, or plant waste like from sugar cane - to generate electricity while the carbon dioxide in the biomass is extracted, piped away and buried deep underground. Among techniques, a chemical process can strip carbon dioxide from the flue gases from combustion. The process - called bio-energy...