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 critically evaluate the arguments about climate change raised in a climate contrarian newspaper op-ed. This exercise is intended to strengthen student critical thinking and content knowledge at the end of unit on the climate system.

This video highlights a team of scientists who work on reconstructing the mass extinction that occurred 250 million years ago, the end of the Permian Period, and wiped out the majority of life on our planet, resetting the evolution of life. Clues suggest that deadly bacteria might have set off a chemical chain reaction that poisoned the Permian seas and atmosphere.

In this activity, students examine global climate model output and consider the potential impact of global warming on tropical cyclone initiation and evolution. As a follow-up, students read two short articles on the connection between hurricanes and global warming and discuss these articles in context of what they have learned from model output.

This video from the U.S. National Academies summarizes the energy challenges the United States faces, the technological challenges, and the need for behavior and policy changes required to meet the challenge.

This Flash-based simulation explores the relationship between carbon emissions and atmospheric carbon dioxide using two main displays: (1) graphs that show the level of human-generated CO2 emissions, CO2 removals, and the level of CO2 in the atmosphere, and (2) a bathtub animation that shows the same information as the graphs. The bathtub simulation illustrates the challenges of reducing greenhouse gas concentrations in the atmosphere.

This is the ninth and final lesson in a series of lessons about climate change. This lesson focuses on the various activities that humans can do to mitigate the effects of climate change. This includes information on current and predicted CO2 emission scenarios across the globe, alternative energy sources, and how people are currently responding to climate change. Importantly, this lesson is motivating in showing students that they can make a difference.

This video clip highlights the effort on by a group of young students to ban the use of plastic shopping bag in the city of Santa Monica. The video documents the effort and provides visual testimony of the effects that trash and specifically plastic bags have on the ocean ecosystem.

This set of six interactive slides showcases how a typical photovoltaic cell converts solar energy into electricity. Explore the components of a photovoltaic cell, including the silicon layers, metal backing, antireflective coating, and metal conductor strips. Using animations, investigate why the silicon layers are doped with phosphorous and boron, and how an electric field is used to generate electricity from sunlight.

This video addresses acidification of the ocean and the ecological and economic implications of the resulting pH change on marine life. It includes information about how ocean acidification resulting from increased absorption of CO2 from the atmosphere is affecting ocean species such as sea urchins and oysters. Scientists from the University of California at Santa Barbara discuss their experiments with sea creatures in acidic sea water. There is an associated lesson plan and classroom activity that has students test the effects of CO2 on water pH.