Rewriting The Science

(CBS) As a government scientist, James Hansen is taking a risk. He says there are things the White House doesn't want you to hear but he's going to say them anyway.

Hansen is arguably the world's leading researcher on global warming. He's the head of NASA's top institute studying the climate. But this imminent scientist tells correspondent Scott Pelley that the Bush administration is restricting who he can talk to and editing what he can say. Politicians, he says, are rewriting the science.