In this work, we present the design, implementation, and initial outcomes of the Climate Academy, a hybrid professional development program delivered through a combination of face-to-face and online interactions, intended to prepare formal and informal science teachers (grades 5-16) in teaching about climate change. The Climate Academy was designed around core elements of successful environmental professional development programs and aligned with practices advocated in benchmarked science standards. Data were collected from multiple sources including observations of professional development events, participants' reflections on their learning, and collection of instructional units designed during the Academy. Data were also collected from a focal case study teacher in a middle school setting. Case study data included classroom observations, teacher interviews, and student beliefs toward climate change. Results indicated that the Climate Academy fostered increased learning among participants of both climate science content and pedagogical strategies for teaching about climate change. Additionally, results indicated that participants applied their new learning in the design of climate change instructional units. Finally, results from the case study indicated positive impacts on student beliefs and greater awareness about climate change. Results have implications for the design of professional development programs on climate change, a topic included for the first time in national standards.