A simplified representation of the terrestrial carbon cycle side by side with the ocean carbon cycle. Fluxes and reservoirs expressed in gigatons are included.

In this activity, students explore the way that human activities have changed the way that carbon is distributed in Earth's atmosphere, lithosphere, biosphere and hydrosphere.

This narrated slide presentation shows the carbon cycle, looking at various parts of this biogeochemical sequence by examining carbon reservoirs and how carbon is exchanged among them and the atmosphere.

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

This video addresses acidification of the ocean and the ecological and economic implications of the resulting pH change on marine life. It includes information about how ocean acidification resulting from increased absorption of CO2 from the atmosphere is affecting ocean species such as sea urchins and oysters. Scientists from the University of California at Santa Barbara discuss their experiments with sea creatures in acidic sea water. There is an associated lesson plan and classroom activity that has students test the effects of CO2 on water pH.

In this activity, students explore the role of combustion in the carbon cycle. They learn that carbon flows among reservoirs on Earth through processes such as respiration, photosynthesis, combustion, and decomposition, and that combustion of fossil fuels is causing an imbalance. This activity is one in a series of 9 activities.

This article and slide show from the New York Times, features several scientists from the University of Alaska, Fairbanks, who study the effects of thawing permafrost in Alaska.

This activity describes the flow of carbon in the environment and focuses on how much carbon is stored in trees. It goes on to have students analyze data and make calculations about the amount of carbon stored in a set of trees at three sites in a wooded area that were to be cut down to build a college dormitory.

This interactive shows the different components of the ocean biological pump, i.e., how carbon in the form of either plankton or particles moves into the ocean's depths. It illustrates the situation at the surface, 0-100 meters, 100-500 meters, and below 500 meters.

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.