A mock oil pipeline is carried during a Keystone XL tar sands oil pipeline demonstration near the White House in Washington, D.C., U.S., on Sunday, Nov. 6, 2011. Pipeline opponents say extracting crude from sand emits three times more carbon than conventional oil production, contributing to global warming that Obama pledged to fight. They say their protest in Washington reflects public anger at corporate greed. Photographer: Andrew Harrer/Bloomberg via Getty Images