Special advisor to President Obama and former chair of the hard left think tank Center for American Progress John Podesta called out environmental groups yesterday for being too radical. This comes as a slap in the face to big green activists, who expected him to be their marionette in the White House.

Podesta chastised them for their unscientific and unfeasible call to end all fossil fuel use and move directly to an economy based solely on renewable energy. “If you oppose all fossil fuels and you want to turn fossil fuels off tomorrow,” he said, “that’s a completely impractical way to move toward a clean-energy future.” He continued, “With all due respect to my friends in the environmental community, if they expect us to turn off the lights and go home, that’s an impractical suggestion.”

Leading the radical demand is the Sierra Club, whose executive director Michael Brune says, “We need to be very clear what we are fighting for: a 100 percent clean energy economy.” With only about 5 percent of U.S. energy consumption coming from Sierra Club-approved renewable sources, referring to this call as “impractical” is an understatement. Even the world’s top climate change scientists issued a joint statement recently recognizing renewable sources “cannot on their own solve the world’s energy problems.”

Podesta’s comments came in the context of his disagreement with environmentalists over their hypocritical opposition to natural gas, which many experts credit for helping the country reduce its greenhouse gas emissions to 1990s levels. “We remain committed,” he said “to developing the resource and using it.”