The National Center for Atmospheric Research (NCAR) has responded to the pressing need for professional development in climate and global change sciences by creating the Climate Discovery online course series. This series was designed with the secondary geoscience educator in mind. The online courses are based on current and credible climate change science. Interactive learning techniques are built into the online course designs with assignments that encourage active participation. A key element of the online courses is the creation of a virtual community of geoscience educators who exchange ideas related to classroom implementation, student assessment, and lessons plans. Geoscience educators from around the country have participated in the online courses. The ongoing interest from geoscience educators strongly suggests that the NCAR Climate Discovery online courses are a timely and needed professional development opportunity.

The intent of NCAR Climate Discovery is to positively impact teachers' professional development by: (1) bringing the topic of climate change within reach of teachers who might not otherwise have access to scientifically authentic information, (2) experiencing guided practice in conducting activities and using ancillary resources in workshop venues, (3) gaining access to standards-aligned lesson plans, kits that promote hands-on learning, and scientific content that are easily implemented in their classrooms, and (4) becoming a part of a community of educators with whom they may continue to discuss the challenges of pedagogy and content comprehension in teaching climate change in the Earth system context.

Each course, instructed by science education specialists, combines geoscience content, information about current climate research, hands-on activities, and group discussion.

• CD 501 Introduction to Earth's Climate is designed to guide participants through the basics of climate science, integrating content, classroom activities, and community-building discussions to help middle and high school educators understand the answers to common questions about climate.

• CD 502 Earth System Science: A Climate Change Perspective explores Earth as a system from the perspective of climate and global change, describing the interactions between the various parts of the Earth system, including human activities, and how they all affect our climate.

• CD 503 Understanding Climate Change Today presents some of the current and predicted impacts of global warming on our planet and human societies. This course explores how climate models are developed and used to understand likely scenarios of future climate and how current scientific research is improving the quality of climate predictions.

The online courses use the web-based Moodle courseware system (open-source software similar to Blackboard & webCT), utilizing its features to promote dialogue as well as provide rich online content and media. A key element of the online courses is the development and support of an online learning community, an essential component in successful online courses (Berger Ehrlich 2002). Interactive learning techniques are built into the course designs with assignments that encourage active participation. Educators (both formal and informal) use the courses as a venue to exchange ideas and teaching resources. A unique feature of the courses is the emphasis on hands-on activities, a hallmark of our professional development efforts. This presentation will focus on the lessons learned in the development of the three online courses and our successful recruitment and retention efforts.