This series of activities is designed to introduce students to the role of sediments and sedimentary rocks in the global carbon cycle. Students learn how stable carbon isotopes can be used to reconstruct ancient sedimentary environments. Students will make some simple calculations, formulate hypotheses, and think about the implications of their results. The activity includes an optional demonstration of the density separation of a sediment sample into a light, organic fraction and a heavier, mineral fraction.
In this video, a spokesperson for the National Climactic Data Center describes the methods of using satellites (originally designed for observing changes in the weather) to study changes in climate from decade to decade. The video clearly illustrates the value of satellite data and begins to address connections between weather and climate.
In this activity, students work with climate data from the tropical Pacific Ocean to understand how sea-surface temperature and atmospheric pressure affect precipitation in the tropical Pacific in a case study format.
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.
This video features changes in the land, sea, and animals that are being observed by the residents of Sachs Harbour, Northwest Territories, Canada â many of whom hunt, trap, and fishâbecause of their long-standing and intimate connection with their ecosystem. Scientists interview the residents and record their observations in order to deepen our understanding of climate change in the polar region. Background essay and discussion questions are included.
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.
This video is the second of three short videos showcasing the dramatic changes in Alaska's marine ecosystems. The video highlights the marine mammals and birds and how they depend on Arctic sea ice, as well as questions about how these animals will cope in the face of climate change.
In this activity, students examine pictures of pollen grains representing several species that show the structural differences that scientists use for identification. Students analyze model soil samples with material mixed in to represent pollen grains. They then determine the type and amount of 'pollen' in the samples and, using information provided to them, determine the type of vegetation and age of their samples. Finally, they make some conclusions about the likely climate at the time the pollen was shed.
This video focuses on the conifer forest in Alaska to explore the carbon cycle and how the forest responds to rising atmospheric carbon dioxide. Topics addressed in the video include wildfires, reflectivity, and the role of permafrost in the global carbon cycle.