Kassie Siegel is senior counsel and director of the Center for Biological Diversity’s Climate Law Institute. She develops and implements campaigns for the reduction of greenhouse gas and other air pollution and for the protection of wildlife and communities threatened by climate disruption. She authored the petition and litigated the cases leading to U.S. Endangered Species Act protection for the polar bear, and has been a leader in campaigns to keep fossil fuels in the ground. She was named one of the ten most influential California lawyers of the decade by the Daily Journal in 2010, and California Lawyer of the Year by California Lawyer Magazine in 2007 for her work in climate change and environmental law. She is a graduate of UC Berkeley School of Law and has spent her entire career in the new climate law field.