Sen. Graham will ‘block any effort’ to slow oil sands imports

“I'd like to go to a low-carbon economy, but every barrel of oil we can buy from Canada is one less barrel of oil to have to buy from the Mideast,” he said.

Canada is the United States’s biggest source of oil, and oil sands account for an increasing share. Oil sands generate more greenhouse gases than many types of more conventional oil, but the degree of increased emissions has been hotly debated for years.

A recent study by the consulting firm Cambridge Energy Research Associates provided ammunition to oil sands advocates. It concluded that oil sands result in emissions that are, on average, 6 percent higher than the average crude oil used in the U.S. The figure is based on a so-called wells-to-wheels analysis, which considers production, transport, refining and use in engines.

Oil sands mining projects have also torn up hundreds of square kilometers of Alberta’s boreal forests. But Graham said that the effect has been modest overall.

“It's a huge wilderness area, and the actual mining sites are very, very small, and the reclamation process is working. There are environmental dangers to using any fossil fuel, but I was incredibly impressed with how small the mining footprint was and how the reclamation process works to restore the land,” he said.

Graham’s comments are another sign that his stint in the good graces of environmental groups is likely over.

Graham earlier this year said he favored greenhouse gas limits and spent months negotiating a climate change and energy bill with Sens. John KerryJohn Forbes KerryOvernight Cybersecurity: Tillerson proposes new cyber bureau at State | Senate bill would clarify cross-border data rules | Uber exec says 'no justification' for covering up breach GOP probes put new focus on State Will FISA secrecy doom democracy? MORE (D-Mass.) and Joe Lieberman (I-Conn.).

But Graham walked away from the effort in April over his frustration at the prospect of Democrats forging ahead with immigration legislation, which Graham said would create a toxic political atmosphere in which climate efforts could not survive.

The withdrawal of Graham – who was seen as a potential bridge to other GOP votes – was a critical blow to the climate effort, and the legislation collapsed months later and never came up for a vote.