Students will review the carbon cycle focusing on its qualities as a system. The lesson begins with a class discussion in order to illicit students’ prior ideas about the carbon cycle in terms of where it comes from and where it goes in the earth’s system. Then the teacher presents a PowerPoint presentation that discusses the inputs and outputs of carbon into the atmosphere and stresses the role of photosynthesis and cellular respiration in the cycling of carbon among the various reservoirs on Earth. Students will then simulate the movement of carbon throughout the carbon cycle by playing a game. The class ends with a discussion of the impact of humans on the carbon cycle and the importance of greenhouse gases in global warming