This video is one of a series of videos from the Switch Energy project. It describes three types of geothermal sources -- rare ones in which high temperatures are naturally concentrated near the surface, deep wells that require fracturing the rock and then circulating water to bring heat to the surface, and low temperature sources that use constant temperatures just below the surface to heat or cool a building. The latter two are more widely available but cost-prohibitive today.

This video segment, adapted from Need to Know, discusses how the process of hydraulic fracturing (fracking) is used to extract natural gas and how the process may be polluting water resources with hazardous chemicals, leading to health concerns.

This collection of photos from the NASA Climate website features images related to global change. Not all images show change caused directly by climate change and energy use, and descriptive captions indicate causes for change in most of the images.

This animated slideshow introduces biodiesel as a fuel alternative. With concern about the use of petroleum-based fuels at an all-time high, biodiesel is experiencing a popularity surge. And algaeâotherwise known to some as pond scumâ are grabbing headlines as the next potential biodiesel superstar. But how and why do algae make oil? And why do they make so much of it? In this audio slide show, U.C. Berkeley's Kris Niyogi describes the process and its potential.

In this activity, students use Google Earth to investigate a variety of renewable energy sources and select sites within the United States that would be appropriate for projects based on those sources.

In this activity, students conduct a life cycle assessment of energy used and produced in ethanol production, and a life cycle assessment of carbon dioxide used and produced in ethanol production.

This video illustrates how atmospheric particles, or aerosols (such as black carbon, sulfates, dust, fog), can affect the energy balance of Earth regionally, and the implications for surface temperature warming and cooling.

This activity focuses on applying analytic tools such as pie charts and bar graphs to gain a better understanding of practical energy use issues. Also provides experience with how different types of data collected affect the outcome of statistical visualization tools.

This activity addresses climate change impacts that affect all states that are part of the Colorado River Basin and are dependent on its water. Students examine available data, the possible consequences of changes to various user groups, and suggest solutions to adapt to these changes.

This video from the U.S. National Academies summarizes the energy challenges the United States faces, the technological challenges, and the need for behavior and policy changes required to meet the challenge.