Washington Unplugged: "Politics" Hampers Obama on Climate

"I think people were really expecting an agreement on targets, so it is something of a failure if we don't get them," he said. "It's very hard to see how we can get to agreement on what we're going to do in the next ten years if we can't agree on where we need to be in almost half a century."

Levy said President Obama is limited in what he can do on climate change by "American politics."

"American politics say that the United States is not going to commit to the sorts of numbers that the Europeans, the Chinese, the Indians are agitating for," he said.

Watch the entire episode, which opens with a debrief from CBS News' Bill Plante from Italy on the president's trips to Russia and to the G-8 in L'Aquila, Italy, above.