Understanding the Carbon Cycle: A Jigsaw Approach
In this "jigsaw" exercise, each student is assigned one of five geochemical processes in the carbon cycle to research, fully understand, and then explain to others in groups of five. At the end of class all students will know about each of the five processes, and thus develop an integrated understanding of the entire carbon cycle.
Skills and concepts that students must have mastered
How the activity is situated in the course
Content/concepts goals for this activity
Higher order thinking skills goals for this activity
Other skills goals for this activity
A jigsaw approach encourages collaboration, cooperation, and avoids a lecture-based approach to delivering content. Each student becomes an expert and also must rely on others to complete their understanding. Students recognize the importance of each individual process, and how each process fits into the rather complex integrated carbon cycle. Additional processes can be added for advanced classes including long-term processes such as sedimentation and burial in rocks.
Description of the activity/assignment
Before class, each student is asked to research and understand one aspect of the carbon cycle. They write one to two pages describing this process, including answering the following questions:
- Where does this process occur in the biosphere and geosphere?
- What is the correct chemical equation to describe the process?
- What is the rate of the process, with correct units?
- What is the residence time of carbon in the reservoir that leads to this process?
- How does this process affect or control atmospheric CO2?
Determining whether students have met the goals
- understanding of one process as reflected in written assignment;
- class participation and engagement;
- understanding of entire carbon cycle assessed in examination.
Teaching materials and tips
- Activity Description/Assignment (Microsoft Word 22kB Oct1 06)
- Figure of carbon cycle (PowerPoint 398kB Oct1 06)
- Poster presentation given at workshop on "Teaching Climate Change" (PowerPoint 1.1MB Oct1 06)