Stop now. Or we're toast: Hansen tells Congress

Well, they didn't get it when he explained the science, the first time.Exactly 20 years after warning America about global warming, a top NASA scientist says the situation has got so bad that the world's only hope is drastic action.James Hansen told US Congress today that the world has long passed the "dangerous level" for greenhouse gases in the atmosphere and needs to get back to 1988 levels.He