Fw: [CCG] update: methane flux
---------- Forwarded Message ----------
Source: European Geosciences Union
Posted: April 5, 2006
Methane Flux From Arctic Tundras: It's The Hydrology, Stupid!
Many fear that, in the coming years, large amounts of methane will be
released into the atmosphere. Methane is a much stronger greenhouse
gas than carbon dioxide and global warming could lead to melting of
the arctic tundras, setting free large volumes of methane, scientists
have reported at the European Geosciences Union's General Assembly
being held in Vienna, Austria. This would in its turn increase global
Methane fluxes from the arctic permafrost areas attract scientific
attention because the release of this powerful greenhouse gas may act
as a positive feedback to climate warming. Methane release,
generally, is enhanced by increasing the metabolic activity of
methane bacteria in warmer arctic soils, or by the release of methane
from melting permafrost.
However, research in the Northeast Siberian tundra has shown the
importance of floodplain hydrology. The floodplains of arctic lowland
rivers are major methane sources, where methane fluxes may be 5 times
as high as in non-flooded tundra bogs. Moreover, these fluxes are
very sensitive to river discharge fluctuations and the incidence of
river floods. During a two year field campaign the drier year
resulted in a 75% reduction of the methane flux. Currently, both air
temperature and river discharges are rising significantly in the
Oral Presentation: Ko Van Huissteden, Dolaman, A.J., Maximov, T.C.
Floodplain hydrology and spatial/temporal variation of methane fluxes
inarctic tundra, North East Siberia.
Cold Mountain, Cold Rivers
Working at the Crossroads of Environmental and Human Rights since 1990
PO Box 7941
Missoula Montana 59807