ScienceScientists Warn Of Climate Change 'Time Bomb' Locked In World's Permafrost As nations gather for climate talks, researchers warn of a vicious global warming cycle that could be triggered by the thawing of permafrost. Northern Hemisphere permafrost holds twice the carbon already in the atmosphere, they say.by Jim Algar
WATCH: Runner Spends Year Using Exercise Tracker to Create Elaborate Stick Figure Art on City Streets