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 short, engaging video created by NASA presents a complex topic via a simple analogy. The idea of positive and negative feedback is demonstrated by Daisyworld - a world with black and white flowers growing on it.

This Changing Planet video documents scientists' concerns regarding how melting Arctic sea ice will increase the amount of fresh water in the Beaufort Gyre, which could spill out into the Atlantic and cause major climate shifts in North America and Western Europe. The video includes interviews with scientists and a look at the basics of how scientists measure salinity in the ocean and how ocean circulation works in the Arctic.

This video shows where and how ice cores are extracted from the West Antarctic Ice Sheet (WAIS), cut, packaged, flown to the ice core storage facility in Denver, further sliced into samples, and shipped to labs all over the world where scientists use them to study indicators of climate change from the past.

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 video segment, from the 'Earth: The Operators' Manual' featuring climate expert Richard Alley, shows how ice cores stored at the National Ice Core Lab provide evidence that ancient ice contains records of Earth's past climate - specifically carbon dioxide and temperature.

Students investigate how much greenhouse gas (carbon dioxide and methane) their family releases into the atmosphere each year and relate it to climate change. To address this, students use the Environmental Protection Agency Personal Emissions Calculator to estimate their family's greenhouse gas emissions and to think about how their family could reduce those emissions.

In this role-playing activity, learners are presented with a scenario in which they determine whether the Gulf Stream is responsible for keeping northern Europe warm. They must also address the potential future of the Gulf Stream if polar ice were to continue melting. The students work in small groups to identify the issue, discuss the problem, and develop a problem statement. They are then asked what they need to know to solve the problem.

This video examines how scientists learn about the effects of climate change on the water cycle and what those effects might mean for our planet.

This animation presents the characteristics of wind power as a source of clean energy. The force of moving air generates electricity, by rotating blades around a rotor. The motion of the rotor turns a driveshaft that drives an electric generator.