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.

This figure, the famous Keeling Curve, shows the history of atmospheric carbon dioxide concentrations as directly measured at Mauna Loa, Hawaii. This curve is an essential piece of evidence that shows the increased greenhouse gases that cause recent increases in global temperatures.

This is an interactive graph that involves records of ice cover in two Wisconsin lakes - Lake Mendota and Lake Monona - from 1855-2010.

This straightforward calculator provides conversions from one unit of energy to the equivalent amount of CO2 emission expected from using that amount.

This video is accompanied by supporting materials including background essay and discussion questions. The focus is on changes happening to permafrost in the Arctic landscape, with Alaska Native peoples and Western scientists discussing both the causes of thawing and its impact on the ecosystem. The video shows the consequences of erosion, including mudslides and inland lakes being drained of water. An Inuit expresses his uncertainty about the ultimate effect this will have on his community and culture.

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 activity utilizes labs, online resources, and student ideas to build an understanding of polar climates, how changes in polar oceans can affect coastal climates, and how changes in polar regions affect climates elsewhere on Earth.

Two graphs from the NASA Climate website illustrate the change in global surface temperature relative to 1951-1980 average temperatures. The NASA plot is annotated with temperature-impacting historic events, which nicely connect an otherwise challenging graphic to real-world events.

This is a jigsaw activity in which students are assigned to research one step out of five in the geochemical process stages of the organic carbon cycle. Students then teach their step in cross-step groups until everyone understands all five process stages.

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.