When a small coal-fired power plant opened in northern Germany last September, it was heralded as the first example of a technology that could save us from the ravages of global warming, while allowing us to keep burning cheap and plentiful coal. The demonstration plant, built and operated by the Swedish power company Vattenfall, was designed to capture its carbon dioxide emissions and to pump them deep underground in a process called carbon capture and storage (CCS). But the project has thus far been