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 video segment demonstrates carbon dioxide's role in the greenhouse effect and explains how increasing concentrations of C02 in the atmosphere may be contributing to global warming. Video includes an unusual demonstration of C02's heat-absorbing properties, using infrared film, a researcher's face, and a stream of C02 between them.

In this video Dr. Richard Alley poses and addresses a simple question: What does carbon dioxide have to do with global warming?

This NASA animation depicts thermohaline circulation in the ocean and how it relates to salinity and water density. It illustrates the sinking of water in the cold, dense ocean near Iceland and Greenland. The surface of the ocean then fades away and the animation pulls back to show the global thermohaline circulation system.

This interactive graphic outlines the carbon cycle, with clickable text boxes that explain and elaborate each component.

This static graph of changes in CO2 concentrations goes back 400,000 years, showing the dramatic spike in recent years.

This is an interactive table with a comprehensive list of 29 greenhouse gases, their molecular structures, a chart showing a time series of their atmospheric concentrations (at several sampling sites), their global warming potential (GWP) and their atmospheric lifetimes. References are given to the data sets that range from the mid-1990s to 2008.

In this video segment, two students discuss the greenhouse effect and visit with research scientists at Biosphere 2 in Arizona, who research the effects of global climate change on organisms in a controlled facility. Their current research (as of 2002) focuses on the response to increased quantities of CO2 in a number of different model ecosystems.

This is a basic animation/simulation with background information about the greenhouse effect by DAMOCLES. The animation has several layers to it that allow users to drill into more detail about the natural greenhouse effect and different aspects of it, including volcanic aerosols and human impacts from burning fossil fuels.

This interactive visualization from the NASA Earth Observatory website compares Arctic sea ice minimum extent from 1984 to that of 2012.