Did you say green coal? For many people, coal might seem like one of the environment's worst enemies. Coal contains 25 to 90 percent carbon, which, when burned, creates noxious greenhouses gases such as carbon dioxide, sulfur and nitrogen oxide. Those gases are responsible for global warming [source: Captain].
Using a process called gasification, scientists have found a way to use the carbon in coal to strip oxygen from water, which produces clean-burning hydrogen gas for fuel. That gas can then be used to run a turbine, which produces electricity. The emissions from the process are then pumped underground, while other pollutants are converted into solids that can be burned [source: Captain].