Greenland, Methan

BEACH RIDGE: The scientists believe that this beach ridge in North Greenland formed by wave activity about 6000-7000 years ago. This implies that there was more open sea in this region than there is today. (Click the picture for a larger image) Photo: Astrid Lyså, NGU (http://wattsupwiththat.com/)

6-12° b/s Orion ist wieder da, Fledermäuse fliegen noch. 4571 8519 67,21 WTI Apple gute Zahlen

- " Methane concentration. ... the rapid increase of the arctic sea ice.
The 'artic domino theory' states in short: first goes the artic sea ice, which leads to warming of the permafrost areas in Sibiria and North America, which in a second step then release methane in unprecedented
amounts, which is a strong and positive feedback to further warming and
will thirdly eventually melt the Greenland glacier. This will start during our times (tipping point is already transgressed) and will inevitably lead to global warming of a few degrees Celsius at the end of the century, including the raise of the sea level of 1 m or more. (official statement of e.g., the German goverment of summer 2008). The global warming of the last 30 years has indeed also left its mark
on the permafrost areas in Sibiria and elsewhere. It is claimed that
methane is released more than ever before
http://groups.google.com/group/globalchange/browse_thread/thread/5f220743161efa46
and work by Dr. Walter:
http://www.abc.net.au/science/news/stories/2006/1735049.htm
Now I have also looked up the time dependence of the methane
concentration in the atmosphere:
http://www.worldclimatereport.com/index.php/2007/04/13/methane-matters/
and http://www.co2science.org/articles/V11/N42/C1.php
You see the methane increase is saturating!!!
Inspite of all permafrost thawing in recent years.
The pre-industrial concentration of methane is given as 0.7 ppm (in 1750
- I wonder how they got this number - to 1.8 ppm in 2007.
This corresponds to roughly 10**15 grams of methane in the atmosphere.
A methane molecule has a lifespan in the atmosphere of 7 - 10 years, further, one ton of water can absorb 35 grams of methane (at 17 Celsius),otr, in total roughly 10**20 grams. Indeed methane absorption
takes place, and leads to the formation of clathrate ice, the 'burning' ice found at continental shelfs (see wikipedia).
How the doubling of the methane concentration is explained, there is debate:
enhanced land use, enhanced number of ruminants, cattle, sheeps for food
and wool production, oil and coal production, the use of natural gas: The present day production of natural gas is roughly 1 billion metric tons,or 10**15 grams per year. It is transported by liquid gas tankers and by pipelines. Pipeline losses of order 1 % are admitted by any pipeline operating company, losses of 10 % or more are suspected in the pipeline system of the old Sowiet union. For a compilation of sources, see: http://www.epa.gov/methane/sources.html .
Sincerely, Werner Weber