The Amazon rainforest used to absorb greenhouse gases. Now it may be emitting them and that's bad news for the climate. Reporter Sam Eaton has more. Plus, Inside California prisons, inmates have been segregating themselves along ethnic and racial lines. And, a laser has helped reveal a lost civilization.
Just a few years ago, Republican Party leaders couldn’t stop warning us about the perils of the debt. But once in power, their voices have gone silent. The US is now one of the most indebted nations on earth.