Washington Post: James Hansen — perhaps the best-known scientific advocate for curbing greenhouse gas emissions — sent a letter recently to the head of one of the nation’s largest power companies calling on him to confront the role that his coal-fired plants play in global warming. Hansen proposed they meet. On Wednesday, James Rogers of Duke Energy accepted Hansen’s invitation, though he made clear he does not foresee calling off plans to build more of the power plants that Hansen considers a main …