This online calculator converts from one energy unit to another - from gallons to British thermal units (Btu), kilowatt/hours to megajoules, short tons to metric tons.

This web-based activity tackles the broad reasons for undertaking ocean exploration - studying the interconnected issues of climate change, ocean health, energy and human health. Students examine the types of technology ocean scientists use to collect important data.

This graph, based on key ice core data sets and recent monitoring programs, shows the variations in concentration of carbon dioxide (CO2) in the atmosphere during the last 400,000 years.

This hands-on activity will provide students with an understanding of the issues that surround environmental clean-up. Students will create their own oil spill, try different methods for cleaning it up, and then discuss the merits of each method in terms of effectiveness (cleanliness) and cost. They will be asked to put themselves in the place of both an environmental engineer and an oil company owner who are responsible for the clean-up.

This activity addresses naturally occurring climate change involving ENSO (El-NiÃo Southern Oscillation). In this activity, students play the role of a policy maker in Peru. First, they determine what sort of ENSO variation is occurring. Then, they must decide how to allocate Peru's resources to manage for possible weather-related problems.

This National Geographic video explains the origins of the El NiÃo Southern Oscillation using animations and shows the impacts on humans, wildlife and habitat, particularly in the United States.

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.

This video follows Bermuda scientists into the field as they collect data that documents a warming trend in ocean temperatures. BIOS Director Tony Knapp discusses some of the impact of warming temperatures on sea levels, storms, and marine ecosystems.

In this video, adapted from KUAC-TV and the Geophysical Institute at the University of Alaska, Fairbanks, viewers learn how one-celled organisms in permafrost may be contributing to greenhouse gas levels and global warming.

This interactive follows carbon as it moves through various components of the carbon cycle.