Permafrost Could Be Climate's Ticking Time Bomb

By Amanda Morris , Northwestern University

posted: 24 July 2009 08:28 am ET

Gregory Lehn , a Ph. D. student in the department of Earth and planetary sciences at Northwestern University on the left, and Matt Khosh, Ph.D. student in the department of marine sciences at the University of Texas, Austin on the right, talk with Jim McClelland, professor in the department of marine sciences at the University of Texas, Austin, a co-principal investigator on the project, in the center. Credit: Andrew D. Jacobson, Department of Earth and Planetary Sciences, Northwestern University

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Gregory Lehn , a Ph. D. student in the department of Earth and planetary sciences at Northwestern University on the left, and Matt Khosh, Ph.D. student in the department of marine sciences at the University of Texas, Austin on the right, talk with Jim McClelland, professor in the department of marine sciences at the University of Texas, Austin, a co-principal investigator on the project, in the center. Credit: Andrew D. Jacobson, Department of Earth and Planetary Sciences, Northwestern University

Andrew Jacobson of Northwestern University does fieldwork in Alaska to learn how rapidly permafrost is melting. Credit: Andrew D. Jacobson, Department of Earth and Planetary Sciences, Northwestern University

Thomas A. Douglas, research chemist at the Cold Regions Research and Engineering Laboratory, Fairbanks, Alaska, and co-principal investigator on the project, drills in tundra. Credit: Andrew D. Jacobson, Department of Earth and Planetary Sciences, Northwestern University

Andrew Jacobson of Northwestern University and a colleague hike along the Dalton Highway. The Alaskan pipeline is in the foreground. Credit: Andrew D. Jacobson, Department of Earth and Planetary Sciences, Northwestern University

This Behind the Scenes article was provided to LiveScience in partnership with the National Science Foundation.

The terrain of the North Slope of Alaska is not steep, but Andrew Jacobson still has difficulty as he hikes along the spongy tundra, which is riddled with rocks and masks multitudes of mosquitoes.

Jacobson, a professor of earth and planetary sciences at Northwestern University, extracts soil and water samples in search of clues to one of global warming's biggest ticking time bombs: the melting of permafrost.

Permafrost, or frozen ground, covers approximately 20 to 25 percent of the land-surface area in the northern hemisphere, and is estimated to contain up to 1,600 gigatons of carbon, primarily in the form of organic matter. (One gigaton is equivalent to one billion tons.)