Hill: Democratic presidential hopeful Sen. Bernie Sanders (I-Vt.) says climate change poses major national security threat to the U.S. I mean, were talking about, according to the CIA, future, major national security issues when people are forced to migrate because their countries or their land are flooded, they cant grow food, Sanders said at a rally in Keene, N.H., on Saturday. Were talking about a major, major crisis. The Vermont senator said there is no longer any debate among scientists...