"One environmental leader says if we keep doing what we're doing, the world will continue on a path toward economic decline and eventual collapse. Lester Brown heads up the Earth Policy Institute. He's written a series of books on changes that need to be made. The most recent book is 'Plan B 4.0.' Lester Graham talked with him about the complexities involved in a few commodities we take for granted." The interview aired on The Environment Report December 24, 2009.