We’re Radley Horton, Lamont Associate Research Professor at Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York and Sarah Doherty, Senior Research Scientist at the Joint Institute for the Study of the Atmosphere and Ocean at the University of Washington in Seattle. We were both Lead Authors on the recent Climate Science Special Report (http://www.globalchange.gov/content/cssr), which focused on climate change in the U.S. and part of the Fourth National Climate Assessment. We’re here to talk about how our climate is changing, what causes it, and what to expect in the years ahead. We’re looking forward to your questions! We’ll be back at 1pm ET to answer your questions, ask us anything! The AGU AMA series is conducted by the Sharing Science (sharingscience.org) program. Sharing Science: By scientists, for everyone. More at sharingscience.agu.org.