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

In this activity, students work in groups, plotting carbon dioxide concentrations over time on overheads and estimating the rate of change over five years. Stacked together, the overheads for the whole class show an increase on carbon dioxide over five years and annual variation driven by photosynthesis. This exercise enables students to practice basic quantitative skills and understand how important sampling intervals can be when studying changes over time. A goal is to see how small sample size may give incomplete picture of data.

This is the seventh of nine lessons in the 'Visualizing and Understanding the Science of Climate Change' website. This lesson addresses climate feedback loops and how these loops help drive and regulate Earth's unique climate system.

This click-through animation visualizes the ice-albedo feedback, soot's effect on sea ice and glacier melt, and ice melt's effect on land and sea.

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 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.

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.

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