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 NASA animation depicts thermohaline circulation in the ocean and how it relates to salinity and water density. It illustrates the sinking of water in the cold, dense ocean near Iceland and Greenland. The surface of the ocean then fades away and the animation pulls back to show the global thermohaline circulation system.

This video examines how scientists learn about the effects of climate change on the water cycle and what those effects might mean for our planet.

This video illustrates the advantages of woody biomass as a renewable, carbon-neutral energy source. Woody biomass is underutilized and often overlooked as a renewable fuel, and it can be harvested sustainably and burned cleanly.

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 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 NASA video discusses the impacts of the sun's energy, Earth's reflectance and greenhouse gases on the Earth System.

This map shows the pattern of thermohaline circulation. This collection of currents is responsible for the large-scale exchange of water masses in the ocean, including providing oxygen to the deep ocean. The entire circulation pattern takes ~2000 years.

In this activity, students examine the effects of hurricanes on sea surface temperature using NASA data. They examine authentic sea surface temperature data to explore how hurricanes extract heat energy from the ocean surface.

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.

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