Carbon Released Through Permafrost Melt May Not Affect Net Balance - NSF

[hatrack]

ARLINGTON, Va.- "The Arctic Ocean receives about 10 percent of Earth's river water and with it some 25 teragrams <28 million tons> per year of dissolved organic carbon that had been held in far northern bogs and other soils.

Now an international team of U.S. and German scientists, including some funded by the National Science Foundation, have used carbon-14 dating techniques to determine that most of that carbon is fairly young and not likely to affect the balance of global climate. They reported their findings in the March issue of Geophysical Research Letters, a publication of the American Geophysical Union.

Although the current carbon load does not seem likely to affect global climate significantly, they caution in their report that a well-documented Arctic warming trend could result in ancient carbon-a reservoir of the gas currently locked into peat bogs-being added to the mix and contributing to the well- documented Arctic warming trend.

"If current warming trends in the Arctic continue, we can expect to see more of the old carbon now sequestered in northern soils enter the carbon cycle as carbon dioxide. This will act as a positive feedback, tending to enhance the greenhouse effect and accelerate global warming," said Ronald Benner, an NSF-funded researcher at the University of South Carolina."

EDIT

http://www.spaceref.com/news/viewpr.html?pid=14096

[Viking12]

1. What about methane???

The article discusses largely ignores methane releases as permafrost melts?? There also appears to be some internal contradiction, i.e. "the current carbon load does not seem likely to affect global climate significantly" vs. "If current warming trends in the Arctic continue, we can expect to see more of the old carbon now sequestered in northern soils enter the carbon cycle as carbon dioxide. This will act as a positive feedback, tending to enhance the greenhouse effect"

[hatrack]

2. I assume they're focusing on carbon runoff to date

It may take a few more years for the ancient reservoirs to thaw and start the release process.

[jpak]

3. They were looking at terrestrial dissolved organic carbon runoff

into the Arctic Ocean.

The study didn't address methane/CO2 flux from soils (others have though).