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

In this 6-part activity, students learn about climate change during the Cenozoic and the abrupt changes at the Cretaceous/Paleogene boundary (65.5 million years ago), the Eocene/Oligocene boundary (33.9 million years ago), and the Paleocene/Eocene boundary (55.8 million years ago).

This static image from NOAA's Pacific Marine Environmental Laboratory Carbon Program offers a visually compelling and scientifically sound image of the sea water carbonate chemistry process that leads to ocean acidification and impedes calcification.

This visualization shows the molecular interaction of infrared radiation with various gases in the atmosphere. Focus is on the interaction with C02 molecules and resultant warming of the troposphere.

This animation depicts real-time wind speed and direction at selected heights above Earth's surface, ocean surface currents, and ocean surface temperatures and anomalies.

This is a figure from the 2007 IPCC Assessment Report 4 on atmospheric concentrations of carbon dioxide, methane and nitrous oxide over the last 10,000 years (large panels) and since 1750 (inset panels).

This set of activities is about carbon sources, sinks, and fluxes among them - both with and without anthropogenic components.

This is an interactive table with a comprehensive list of 29 greenhouse gases, their molecular structures, a chart showing a time series of their atmospheric concentrations (at several sampling sites), their global warming potential (GWP) and their atmospheric lifetimes. References are given to the data sets that range from the mid-1990s to 2008.

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.