New York Times: Ever since President Obama said in June that a litmus test for the proposed Keystone XL oil pipeline from Canada was whether it would significantly worsen global warming, Canadian government officials have insisted it would not. They reasoned that because the pipeline would not have any major effect on rate of development of Canadas oil sands, as a State Department environmental review concluded in March, it would not significantly raise the amount of carbon emitted. But documents obtained by...