New York Times: Nearly every mainstream climate scientist has said that a big portion of the fossil fuels now in the ground must remain there if the world is to avoid the worst consequences of global warming. That simple fact lay at the heart of President Obamas decision on Friday to say no to the Keystone XL oil pipeline from Canada. Stories from Our Advertisers The decision, which ends seven years of legal and political wrangling, was correct, on moral as well as scientific grounds. The pipeline, when completed,...