Keystone XL Project: Final Supplemental Environmental Impact Statement
This is a report by the Bureau of Oceans and International Environmental and Scientific Affairs in the United States Department of State. It is titled: "Final Supplemental Environmental Impact Statement for the Keystone XL Project," Executive Summary, January 2014.
From a contemporary Bloomberg News story on the report:
"The proposed Keystone XL pipeline cleared a key hurdle today with a government study that found its impact on the climate would be minimal, which supporters said meets President Barack Obama’s test for allowing the project to be built.
"In its final environmental review, the U.S. State Department found the Canada-U.S. oil pipeline would not greatly increase carbon emissions because the oil sands in Alberta will be developed anyway."