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.

This activity covers the role that the oceans may play in climate change and how climate change may affect the oceans. It is lesson 8 in a nine-lesson module Visualizing and Understanding the Science of Climate Change.