The Hill: A group of prominent climate scientists say President Obamas legacy is on the line as he mulls whether to approve the Keystone XL oil sands pipeline.
We hope, as scientists, that you will demonstrate the seriousness of your climate convictions by refusing to permit Keystone XL; to do otherwise would be to undermine your legacy, the 18 scientists wrote in a public letter to Obama released Tuesday.
Scientists signing the letter include James Hansen of Columbia University and NASA, Stanford...