In this audio slideshow, an ecologist from the University of Florida describes the radiocarbon dating technique that scientists use to determine the amount of carbon within the permafrost of the Arctic tundra. Understanding the rate of carbon released as permafrost thaws is necessary to understand how this positive feedback mechanism is contributing to climate change that may further increase global surface temperatures.

This is a jigsaw activity in which students are assigned to research one step out of five in the geochemical process stages of the organic carbon cycle. Students then teach their step in cross-step groups until everyone understands all five process stages.