These flow charts show carbon dioxide emissions for each state, the District of Columbia and the entire United States. Emissions are distinguished by energy source and end use.

In this hands-on activity, students explore whether rooftop gardens are a viable option for combating the urban heat island effect. Guiding question is: Can rooftop gardens reduce the temperature inside and outside houses?

In this investigation learners research the effects of melting sea ice in the Bering Sea Ecosystem. They create research proposals to earn a place on the scientific research vessel Healy and present their findings and proposals to a Research Board committee.

This static graph of changes in CO2 concentrations is going back 400,000 years, showing the dramatic spike in recent years.

In this video segment, a team of scientists seeks evidence to support their hypothesis that atmospheric warming -- either now or in the past -- may explain why water has formed beneath the West Antarctic ice sheet, causing ice streams that flow much more quickly than the rest of the ice sheet. This phenomenon has important implications for potential sea level rise.

This is a classroom activity about the forcing mechanisms for the most recent cold period: the Little Ice Age (1350-1850). Students receive data about tree ring records, solar activity, and volcanic eruptions during this time period. By comparing and contrasting time intervals when tree growth was at a minimum, solar activity was low, and major volcanic eruptions occurred, they draw conclusions about possible natural causes of climate change and identify factors that may indicate climate change.

In this activity, students analyze data detailing global energy sources and sinks (uses) and construct a diagram to show the relative scale and the connections between them. Discussions of scale; historical, socio-environmental, and geographic variation in this data; and implications for future energy use are included.

This video reviews the benefits and drawbacks associated with growing corn to make ethanol.

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 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.