On Earth and in space. This video for grades 10 to 12 is fourth in a 14 part collection that highlights biology on Earth and in space through a series of interviews with noted scientists. In this episode, Dr. James Kasting, Ames Research Center, discusses the history of Earth's carbon dioxide cycle and its relation to the greenhouse effect. Kasting examines the possibility that very high atmospheric carbon dioxide levels occurred during Earth's history. A diagram of the carbonate silicate cycle is used to explain the processes by which carbon dioxide is introduced and removed from the atmosphere.
Emphasis is placed on the role oceans play in regulating atmospheric carbon dioxide levels.
Topics of discussion include the use of biogeochemical models to predict future changes, measurement of carbon dioxide in ice cores, and recent changes in atmospheric carbon dioxide levels. Kasting explains the greenhouse effect, water vapor as a greenhouse gas, and the possibility of global warming. A final discussion compares the history of carbon dioxide levels on Mars, Venus, and Earth. ENC does NOT distribute this resource.