Stanford University seeks to educate students by strengthening teachers' fundamental knowledge of the climate system, how it affects society and the resources and ecosystems on which we rely, and the current and projected impacts of climate change, as well as options to mitigate and respond to those impacts. Stanford seeks to enhance teachers' skills, confidence, and curricula to address these critical issues. To provide professional development for K-12 teachers, the proposed project brings together Stanford faculty and graduate students who study global climate change and mitigation science, policy and engineering; faculty and staff of the Stanford Teacher Education Program; and STEP's significant network of K-12 partner schools. Since effective professional development efforts need to be sustained and systemic, Stanford proposes a year-long program starting with a comprehensive summer institute followed by support to teachers in their classrooms during the academic year.