This video is part two of a seven-part National Academies series, Climate Change: Lines of Evidence. The video outlines, with the use of recent research and historical data, how we know that the Earth is warming.

In this audio slideshow, an ecologist from the University of Florida describes the radiocarbon dating technique that scientists use to determine the amount of carbon within the permafrost of the Arctic tundra. Understanding the rate of carbon released as permafrost thaws is necessary to understand how this positive feedback mechanism is contributing to climate change that may further increase global surface temperatures.

In this video, students learn that the Exxon Valdez oil spill in Alaska in 1989 was not the sole cause of the decline of species in the local ecosystem. Rather, an explanation is posited for why some animal populations were already in decline when the spill occurred. Many of these animals share a common food: the sand lance, a fish whose populations have shrunk with the steady rise in ocean temperature that began in the late 1970s.

Two short, narrated animations about carbon dioxide and Earth's temperature are presented on this webpage. The first animation shows the rise in atmospheric CO2 levels, human carbon emissions, and global temperature rise of the past 1,000 years; the second shows changes in the level of CO2 from 800,000 years ago to the present.

This narrated slideshow describes the impact of sea level rise on Tuvalu, one of the low-lying island nations in the South Pacific. As the frequency and intensity of floods and cyclones increases, the island is shrinking and saltwater intrusion is affecting local food production on the plantations. As a result, many residents are moving off the island to New Zealand, where they face major cultural changes.

These flow charts show carbon dioxide emissions for each state, the District of Columbia and the entire United States. Emissions are distinguished by energy source and end use.

The video offers a simple and easy-to-understand overview of climate change. It poses basic questions such as 'What is it?' and 'How will it effect us?' and effectively answers those questions.

This graph, based on key ice core data sets and recent monitoring programs, shows the variations in concentration of carbon dioxide (CO2) in the atmosphere during the last 400,000 years.

This video segment highlights research that supports the idea that warmer oceans generate and sustain more intense hurricanes.

In this activity, students use a spreadsheet to calculate the net carbon sequestration in a set of trees; they will utilize an allometric approach based upon parameters measured on the individual trees. They determine the species of trees in the set, measure trunk diameter at a particular height, and use the spreadsheet to calculate carbon content of the tree using forestry research data.