The activity follows a progression that examines the CO2 content of various gases, explores the changes in the atmospheric levels of CO2 from 1958 to 2000 from the Mauna Loa Keeling curve, and the relationship between CO2 and temperature over the past 160,000 years. This provides a foundation for examining individuals' input of CO2 to the atmosphere and how to reduce it.

This video describes the foundation Plant for the Planet, a foundation created by a 9-year-old German boy, Felix. This foundation has planted more than 500,000 trees in Germany, which he says help sequester carbon and reduce greenhouse gas emissions. The student rallies, first his community and then other children, to plant millions of trees to offset our energy-use emissions.

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 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.