Katharine Hayhoe is a climate scientist and chief scientist for The Nature Conservancy. She is also the Endowed Professor in Public Policy and Public Law and Paul W. Horn Distinguished Professor at Texas Tech University. She has been named a United Nations Champion of the Earth and one of Timeâs 100 Most Influential People, and serves as the climate ambassador for the World Evangelical Alliance. Katharine was a lead author for the US Second, Third, and Fourth National Climate Assessments, hosts the PBS digital series Global Weirding, and has written for The New York Times. Her TED Talk âThe Most Important Thing You Can Do to Fight Climate Change: Talk About Itâ has been viewed over 5 million times. She has a BSc in physics and astronomy from the University of Toronto and an MS and a PhD in atmospheric science from the University of Illinois at Urbana-Champaign.