Richard Seager, a climate scientist and the Palisades Geophysical Institute/Lamont Research Professor at Lamont-Doherty Earth Observatory of Columbia University, joins John to talk about changes in aridity in North America around the 100th Meridian, and how climate change is going to affect the heartland of the U.S. and the Mississippi river basin. Richard’s current work is focused on how global hydroclimate will change in the near-term future as a result of rising greenhouse gases, and how that will affect people and food systems.