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.

In this learning activity, students use a web-based carbon calculator to determine their carbon footprint on the basis of their personal and household habits and choices. Students identify which personal activities and household choices produce the most CO2 emissions, compare their carbon footprint to the U.S. and global averages, and identify lifestyle changes they can make to reduce their footprint.

This video features changes in the land, sea, and animals that are being observed by the residents of Sachs Harbour, Northwest Territories, Canada â many of whom hunt, trap, and fishâbecause of their long-standing and intimate connection with their ecosystem. Scientists interview the residents and record their observations in order to deepen our understanding of climate change in the polar region. Background essay and discussion questions are included.

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 is a series of 10 short videos, hosted by National Science Foundation, each featuring scientists, research, and green technologies. The overall goal of this series is to encourage people to ask questions and look beyond fossil fuels for innovative solutions to our ever-growing energy needs.

This video discusses observations of two key warning signs of global change effects on the Southern Ocean: changes in Antarctic bottom water and ocean acidification.

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.

This Flash animation describes how hybrid-electric vehicles (HEVs) combine the benefits of gasoline engines and electric motors and can be configured to obtain different objectives, such as improved fuel economy, increased power, or additional auxiliary power for electronic devices and power tools.

This video and accompanying essay examine carbon capture and storage and clean-coal technology, providing statistics for overall annual U.S. consumption as well as average household usage. Turning solid coal into a clean-burning fuel gas (syngas) and capture and storage pros and cons are discussed.

This short video surveys the different current and potential sources of energy - both non-renewable and renewable. It provides some discussion of the pros and cons of the different sources and explains how they are used to produce energy that people can use.