This flow chart shows the sources and activities across the U.S. economy that produce greenhouse gas emissions.

This video discusses two key signs of global change in the Southern Ocean: changes in Antarctic bottom water and ocean acidification.

This is a polar map of permafrost extent in the Northern Hemisphere. A sidebar explains how permafrost, as it forms and later thaws, serves as both a sink and source for carbon to the atmosphere. Related multimedia is a slideshow of permafrost scientists from U. of Alaska, Fairbanks, collecting permafrost data in the field.

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

This video describes why tropical ice cores are important and provide different information than polar ice cores, why getting them now is important (they are disappearing), and how scientists get them. The work of glaciologist Lonnie Thompson is featured, with a focus on his work collecting cores of ice from high mountain glaciers that contain significant data about past climate change.

This video shows 15 years of data obtained via Polar-orbiting satellites that are able to detect subtle differences in ocean color, allowing scientists to see where there are higher concentrations of phytoplankton - a proxy for the concentration of chlorophyll in the ocean.

In this activity, students reconstruct past climates using lake varves as a proxy to interpret long-term climate patterns. Students use data from sediment cores to understand annual sediment deposition and how it relates to weather and climate patterns.

This short video shows how humanity uses energy today; what sources we use; and why, in the future, a growing global population will require more energy.

In this video, students learn how scientific surveys of wildlife are performed at a site in Yosemite, California. These surveys, in conjunction with studies from the early 1900s, provide evidence that animal populations in Yosemite have shifted over time in response to rising temperatures.

In this video, students learn that scientific evidence strongly suggests that different regions on Earth do not respond equally to increased temperatures. Ice-covered regions appear to be particularly sensitive to even small changes in global temperature. This video segment adapted from NASA's Goddard Space Flight Center details how global warming may already be responsible for a significant reduction in glacial ice, which may in turn have significant consequences for the planet.