This morning Chicago was rated the worst air quality in the world. Although things are getting better slowly, it looks like this smog will stick around for a few more days. John Landecker sits down with Daniel Westervelt, Associate Research Professor at Columbia University’s Lamont Doherty Earth Observatory in Palisades, NY. Listen to the interview below, hear some of the causes, and see if any more plumes could be coming our way in the future.