EcoWatch: In June President Obama set a climate test for his decision on the Keystone XL tar sands pipeline. He said he will not approve the pipeline if it would significantly exacerbate the problem of carbon pollution. Today the Sierra Club, Oil Change International and 13 partner groups have released a report that settles the issue unequivocally: Keystone XL would be a climate disaster. The State Department, though, tried to ignore this 181-million metric ton elephant. It argued in its environmental review...