Today there is much interest in teaching secondary students about climate change. Much of this effort has focused directly on students' understanding of climate change. We hypothesize, however, that in order for students to understand climate change they must first understand climate as a system and how changes to this system due to both natural and human influences result in climatic and environmental changes and feedbacks. The purpose of this article is to articulate a climate system framework for teaching about climate change and to stimulate discussion about what secondary students should know and understand about a climate system. We first provide an overview of the research on secondary students' conceptions of climate and climate change. We then present a climate system framework for teaching about climate and climate change that builds on students' conceptions and scientific perspectives. We conclude by articulating a draft conceptual progression based on students' conceptions and our climate system framework as a means to inform curriculum development, instructional design, and future research in climate and environmental education. (Contains 2 tables and 2 figures.)