Politicians these days, especially Senators Obama and Clinton, routinely bash the oil companies and call for more efforts to come up with cleaner alternative fuels.

FORBES: Fact and Comment

Once the bane of environmentalists, the nuclear industry enjoyed newfound "green" credentials as a cleaner alternative to coal-fired plants that belch greenhouse gases to produce electricity.

CNN: STORY HIGHLIGHTS

Nuclear fusion, a theoretical way of harnessing power by fusing atoms which is still under development, may one day provide a cleaner alternative to the world's energy problem.

BBC: Impact of global warming may be severe and wide-ranging