Former Secretary of State George Shultz is calling for a carbon tax to reduce U.S. greenhouse gas emissions and oil consumption, according to an interview released today by Stanford University.

Shultz, who served as secretary of state under President Ronald Reagan as well as a number of other roles under previous Republican administrations, is heading up the Hoover Institution’s Task Force on Energy Policy will calls for boosting energy efficiency, reducing dependence on oil exports to improve national security, and putting a price on carbon. While the last of those objectives has been an anathema to many Republicans of late, Shultz said his party could eventually support a carbon tax.