| Permafrost |
 | |  | |  |
Knowledge has advantages.
Permafrost (frozen ground)
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 1 billion
tons.)
By comparison, the atmosphere now contains around 850
gigatons of the element as carbon dioxide.
Permafrost historically has served as a carbon sink, largely
isolating carbon from participating in the carbon cycle. However,
global warming could transform the Arctic into a new carbon
source by accelerating the rate of permafrost melting. This
undoubtedly would have a dramatic effect on the global carbon
cycle.
Permafrost carbon will oxidize to carbon dioxide as melting
accelerates, causing a positive feedback to global warming. A
vicious cycle is created as a warmer climate facilitates more carbon
release, which in turn favors more warming.
Credit: Permafrost Could Be Climate's Ticking Time Bomb The
National Science Foundation, October 2009
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 1 billion
tons.)
By comparison, the atmosphere now contains around 850
gigatons of the element as carbon dioxide.
Permafrost historically has served as a carbon sink, largely
isolating carbon from participating in the carbon cycle. However,
global warming could transform the Arctic into a new carbon
source by accelerating the rate of permafrost melting. This
undoubtedly would have a dramatic effect on the global carbon
cycle.
Permafrost carbon will oxidize to carbon dioxide as melting
accelerates, causing a positive feedback to global warming. A
vicious cycle is created as a warmer climate facilitates more carbon
release, which in turn favors more warming.
Credit: Permafrost Could Be Climate's Ticking Time Bomb The
National Science Foundation, October 2009