These flow charts show carbon dioxide emissions for each state, the District of Columbia and the entire United States. Emissions are distinguished by energy source and end use.

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 carbon calculator, developed by the EPA, guides students in calculating their carbon footprint and then using that information to make decisions about how to reduce their carbon emissions.

This video segment highlights how the U.S. military is the single largest user of energy in the nation, but it is also trying to reduce its carbon bootprint. Scenes taped at Fort Irwin and Camp Pendleton show the Army and Marines experimenting with wind and solar in order to reduce the number of fuel convoys that are vulnerable to attack.

This video is from the Energy 101 video series. It explains the process for converting micro-algae into fuel and makes the case that algae-based biofuels hold enormous potential for helping reduce our dependence on imported oil.

This video reviews the benefits and drawbacks associated with growing corn to make ethanol.

This video reviews how photovoltaic (PV) cells work, noting that technological innovations are decreasing costs and allowing PV use to expand.

In this interactive, students can investigate a typical hydrogen fuel cell prototype car from its fuel cell stacks to its ultracapacitor, a kind of supplementary power source.

The limited-production vehicle seen in this feature is a Honda 2005 FCX, which is typical of the kinds of hydrogen fuel cell cars that some major automakers are now researching and developing.

In this video clip from Earth: The Operators' Manual, host Richard Alley discusses China's efforts to develop clean energy technologies and to reduce CO2 in the atmosphere, by building coal plants using CO2 sequestration technology. (scroll down page for video)

This engaging video focuses on national and global wind energy potential by specifically highlighting Texas' role as wind energy leader and energy efficiency efforts in Houston, Texas.

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