Arctic carbon a potential wild card in climate change scenarios
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.
NSF is an independent federal agency that supports fundamental
research and education across all fields of science and
engineering, with an annual budget of nearly $5.58 billion.
National Science Foundation funds reach all 50 states through
grants to nearly 2,000 universities and institutions.
The team studied rivers in northern Russia and Alaska, along with
the Arctic Ocean itself. Benner conducted some of his research as
part of the Western Shelf-Basin Interactions
research project, which is jointly funded by NSF and the U.S.
Office of Naval Research.
Previously, scientists had not known the age of the carbon that
reaches the ocean. Was it recently derived from contemporary
plant material, or had it been locked in soils for hundreds or
thousands of years and therefore not part of Earth’s recent
carbon cycle?
The new findings complement recently published work by Laurence
C. Smith, an NSF-funded researcher at the University of
California, Los Angeles, indicating that massive Siberian peat
bogs, widely known as the permanently frozen home of untold
kilometers of moss and uncountable hordes of mosquitoes, also are
huge repositories for gases that are thought to play an important
role in the Earth’s climate balance.
Those gases, carbon dioxide and methane, are known to trap heat
in the Earth’s atmosphere, but the enormous amounts of the gases
contained in the bogs haven’t previously been accounted for in
climate-change models.
The full story of that finding is here:
http://www.nsf.aov/od/lpa/news/O4/prO406.htm
To read an abstract of the full article in Geophysical Research
Letters, see
http://www.agu.org/pubs/crossref/2004…/2003GLO19251.shtml
To read the full text of the AGU news release, see:
http://www.agu.org/sci_soc/prrl/prrlO412.htm/.
What the researchers say:
“Many scientists are wondering whether current warming trends in
the Arctic will pick the lock on aged soil carbon and release
this material back into the active carbon cycle and the
atmosphere. Our results suggest this hasn’t happened yet, but we
need to monitor this situation closely using multiple
approaches.”-Ronald Benner, principal investigator.
NSF comments regarding the research discovery:
“Identifying the fate of carbon compounds mobilized from the vast
areas of frozen wetlands in the Arctic will be a critical step in
understanding the Arctic system and how it will respond to the
climatic forces acting upon it. How much carbon goes to the
ocean, and how much to the atmosphere and in what form, are key
questions we need to answer in order to see the directions the
future holds for us.”-Nell Swanberg, director of NSF’s Arctic
System Science(ARCSS) Program.
Ronald Benner, University of South Carolina, (803) 777-9561,
Jackie Grebmeier, University of Tennessee, (865) 974-2592,
Laurence C. Smith, University of California, Los Angeles (310)
825-3154, Ismith@qeoq.ucla.edu
For more information about the Western Shelf-Basin Interactions
project, see http://sbi.utk.edu
The National Science Foundation is an independent federal agency
that supports fundamental research and education across all
fields of science and engineering, with an annual budget of
nearly $5.3 billion. National Science Foundation funds reach all
50 states through grants to nearly 2,000 universities and
institutions. Each year, NSF receives about 30,000 competitive
requests for funding, and makes about 10,000 new funding awards.
The National Science Foundation also awards over $200 million in
professional and service contracts yearly.
