This is a polar map of permafrost extent in the Northern Hemisphere. A sidebar explains how permafrost, as it forms and later thaws, serves as both a sink and source for carbon to the atmosphere. Related multimedia is a slideshow of permafrost scientists from U. of Alaska, Fairbanks, collecting permafrost data in the field.

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 animation depicts the carbon cycle in a fashion that is suited for younger audiences. The video discusses how carbon enters and exits the environment through both natural and human-driven ways.

This is a photo essay linked to a New York Times story about climate-related stressors on forests -- including mountain pine beetles, forest fires, forest clearance, and ice storms -- and the importance of protecting forests as an important carbon sink.

This is an interactive visualization of the Carbon Cycle, through short-term and long-term processes.