In this activity, students explore the way that human activities have changed the way that carbon is distributed in Earth's atmosphere, lithosphere, biosphere and hydrosphere.

This is a photo essay linked to a New York Times story about climate-related stressors on forests -- including mountain pine beetles, forest fires, forest clearance, and ice storms -- and the importance of protecting forests as an important carbon sink.

This narrated slide presentation shows the carbon cycle, looking at various parts of this biogeochemical sequence by examining carbon reservoirs and how carbon is exchanged among them and the atmosphere.

This activity introduces students to different forms of energy, energy transformations, energy storage, and the flow of energy through systems. Students learn that most energy can be traced back to nuclear fusion on the sun.

This article and slide show from the New York Times, features several scientists from the University of Alaska, Fairbanks, who study the effects of thawing permafrost in Alaska.

This interactive shows the different components of the ocean biological pump, i.e., how carbon in the form of either plankton or particles moves into the ocean's depths. It illustrates the situation at the surface, 0-100 meters, 100-500 meters, and below 500 meters.

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 animation focuses on the carbon cycle and includes embedded videos and captioned images to provide greater clarification and detail of the cycle than would be available by a single static visual alone.

This is a basic animation/simulation with background information about the greenhouse effect by DAMOCLES. The animation has several layers to it that allow users to drill into more detail about the natural greenhouse effect and different aspects of it, including volcanic aerosols and human impacts from burning fossil fuels.

This is a short NASA video on the water cycle. The video shows the importance of the water cycle to nearly every natural process on Earth and illustrates how tightly coupled the water cycle is to climate.