Al Gore is urging President Obama to regulate carbon dioxide emissions from existing power plants, a step the White House has not publicly embraced to date.

Gore made the case for Environmental Protection Agency (EPA) regulations for new and currently operating plants in an interview with the Guardian newspaper on Friday.

The former vice president also encouraged Obama to veto the proposed Keystone XL oil sands pipeline.

“This whole project [Keystone XL] is an atrocity but it is even more important for him to regulate carbon dioxide emissions,” Gore told the British paper.

The administration is weighing whether to green-light TransCanada Corp.’s pipeline that would bring oil sands crude from Alberta across the border en route to Gulf Coast refineries.