In episode #9 we speak with Drs. Patrick Keys and Elizabeth Barnes of Colorado State University. Patrick is a lead research scientist in the School of Global Environmental Sustainability where his work focuses on a broad range of global sustainability challenges, including climate change impacts, anthropocene risks, and social-ecological teleconnections. Pat is a true interdisciplinary scientist and in our conversation we talk about the rewards and challenges of interdisciplinary collaboration.  Elizabeth (or Libby) is an Associate Professor in the Department of Atmospheric Science. Her award-winning research focuses on large-scale atmospheric and climate dynamics including jet-stream dynamics, Arctic-midlatitude connections, and subseasonal-to-decadal prediction of weather and climate. She is also very excited about data science methods for the earth sciences and her research group is developing a lot of innovative work in this area.  Our conversation with Pat and Libby is primarily about a recent paper on the human footprint index that they co-authored along with their collaborator Neil Carter. A quick note about the conversation: Pat and Libby are collaborators, and they are also married, so the nature of the conversation definitely reflects these two dimensions of their relationship.  Pat & Libby's new article: https://iopscience.iop.org/article/10.1088/1748-9326/abe00a/pdf Pat's website: https://sites.google.com/rams.colostate.edu/patrickkeys/home Libby's website: https://sites.google.com/view/barnesgroup-csu