This video segment from 'Earth: The Operators' Manual' explores how we know that today's increased levels of CO2 are caused by humans burning fossil fuels and not by some natural process, such as volcanic out-gassing. Climate scientist Richard Alley provides a detailed step-by-step explanation that examines the physics and chemistry of different "flavors" or isotopes of carbon in Earth's atmosphere.

This interactive tool allows viewers to explore, by county, the areas of California threatened by a rise in sea level through this century.

A collection of repeat photography of glaciers from the National Snow and Ice Data Center (NSIDC). The photos are taken years apart at or near the same location, illustrating how dramatically glacier positions can change even over a relatively short period in geological time: 60 to 100 years. Background essay and discussion questions are included.

This short video shows how different biomass feedstocks are processed and refined into sustainable biofuels via biochemical and thermochemical processes.

One of a suite of online climate interactive simulations, this Greenhouse Gas Simulator uses the bathtub model to demonstrate how atmospheric concentrations of CO2 will continue to rise unless they are lowered to match the amount of CO2 that can be removed through natural processes.

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.

This animated visualization represents a time history of atmospheric carbon dioxide in parts per million (ppm) from 1979 to 2011, and then back in time to 800,000 years before the present.

This introductory video addresses key points as well as pros and cons of oil as an energy source for transportation.

This video illustrates how atmospheric particles, or aerosols (such as black carbon, sulfates, dust, fog), can affect the energy balance of Earth regionally, and the implications for surface temperature warming and cooling.

This high-resolution narrated video shows levels and movements of CO2 globally through the course of a year.