Yawn, just another tundra scare story peppered with could,can etc. The organic matter got there because conditions were favourable for it to occur and accumulate in the first place. Now all of a sudden this is not natural?. This is unprecedented like how?
I would really like to know with what basis they so confidently state that the arctic accounts for 10 to 15% of the earths carbon sink. Can we see the proof for this please? No, of course not because it is pure conjecture at best and pure fantasy at worst.
Most if not all of the accumulated organic matter that they are referring to was accreted since the last ice age during warm periods as they say. So it makes sense that a sufficiently warm period now would lay down even more carbon rich sediment or layers in the form of peat etc besides the fact that there would be some outgassing of methane etc. Where is the issue? It has happened before and will happen again in the future.

Doesn't wet soil trap and hold heat better than dry soil? I wonder how much heat all that soggy, wet soil will soak up during the long Arctic summer. Could that also lead to more clouds at night, due to the increased humidity in the atmosphere? That might also cause warming, melting ice at higher elevations (and delaying the formation of the winter snowpack).

Yep! Tunnels also reverse this trend also.Perhaps David McGuire may like the Tunnel idea.

"Also, the expansion of shrubs in tundra and the movement of treeline northward could sequester more carbon in vegetation. So there is still some uncertainty here in regards to the results of this study."
That might depend on what happens first. Some reports already show the ground is thawed (people moving as a result of village dwellings sinking into the ground), but a tree line takes a while to move.

These are potential feedbacks not considered by your average GCM, in part because of the uncertainties (if, when, and magnitude of feedback). Another potential contribution.

"In an alarming yet little-noticed series of recent studies, scientists have concluded that Canada's precious forests, stressed from damage caused by global warming, insect infestations and persistent fires, have crossed an ominous line and are now pumping out more climate-changing carbon dioxide than they are sequestering.

Worse yet, the experts predict that Canada's forests will remain net carbon sources, as opposed to carbon storage "sinks," until at least 2022, and possibly much longer.

"We are seeing a significant distortion of the natural trend," said Werner Kurz, senior research scientist at the Canadian Forest Service and the leading expert on carbon cycles in the nation's forests. "Since 1999, and especially in the last five years, the forests have shifted from being a carbon sink to a carbon source.""

http://www.chicagotribune.com/news/nationworld/chi-canada-trees_wittjan02,0,539661.story

If anyone would like to hear what two PHDs have to say about this (arctic dirt),try -

http://www.wunderground.com/blog/solaradvocate/comment.html?entrynum=0

This was a fun paper to read. At least the authors ar not making grandiose claims about what it means although it appears that the press release wants to do.

They appear to do a good job discussing the uncertainty in their review and the potential sources of the uncertainty. An interesting table is "Table 2" which gives inversion-based estimates of surface-atmosphere CO2 fluxes in the Arctic. In this table the total flux estimated by three studies appears to be almost identical; however the individual elements of the flux (North America, Eurasia, Arctic Ocean) vary substantially with the North American one varying between sink and source between the three studies. Since it is highly unlikely that they have a means of actually measuring the total uptake or deposition of carbon at the macro-scale encompassing the entire global region, the highly variable estimates of the three regions would indicate that the various models have a lot of work to do to come up with independently accurate estimates. It looks like the similar total numbers is more a function of look than some real physical process. Imagine three separate people rolling a total of 10 by rolling a dice three time each. one person rolls 6, 3, 1. Another person rols 3, 3, 4 while the third rolls 2, 2, 6. This is similar to what the table shows, but in the case of the dice you wouldn't ascribe it to anything but chance.

Some of the standard deviations of the estimated values in this table are larger than the estimated values in some cases. This generally does not fill one with warm fuzzies that either the magnitude or direction of the carbon transfer should be considered understood. The authors seem to understand that - I wonder if other people do too.

Their initial sentences in their recommendations for further research are

"Analyses to date indicate that the sensitivity of the C cycle of the Arctic during the remainder of the 21st century is highly uncertain. Applications of regional terrestrial ecosystem models suggest that there is potential for CH4 emissions to increase dramatically in response to warming and that there is the potential for substantial release of CO2 to the atmosphere from
increased wildfire activity and the decomposition of soil organic matter. However, analyses indicate that a net release of CO2 to the atmosphere is most likely to occur if the uptake of C by terrestrial vegetation is not enhanced by increases in atmospheric CO2. There have not been applications of regional marine ecosystem models that allow us to identify the degree of uncertainty in responses of the marine C cycle of the Arctic. Because there has been limited progress in regional modeling efforts about how the C cycle of the Arctic will respond to climate change, it is not surprising that coupled carbon–climate models do not represent processes that are thought to be important in the C cycle
of the Arctic."

Basically, they are saying that there could be big releases of CO2 and methane, but there may not be especially if the vegetation up there grows better in the future when things warm up.

It is also interesting that their last sentence in the quote above points out that current coupled caron-climate models don't properly model the Arctic carbon sink/source that everyone claims is so critical.

As a taxpayer, these folks look like they could be worthwhile backing with grants over the next few years to better understand the Arctic carbon sinks and sources. What I did not see is anything to indicate to me that the "science is settled" and that we should reshape the world's economy based on studies like this.

There are seven "could"(s) in the above verbiage and the headline rightly contains the word.

CO2 saturation is an interesting topic. Its especially relevant in the artic because it is a dryer atmosphere. The dryer the atmosphere the more relevant co2 is to warming. Another relevant area is the upper atmosphere where there is little water vapor. Mix in lower albedo in the artic with warming and greener plants moving northward in growing areas the earth absorbs more heat for a positive feedback.

http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/

The basic logic was neatly explained by John Tyndall back in 1862: "As a dam built across a river causes a local deepening of the stream, so our atmosphere, thrown as a barrier across the terrestrial [infrared] rays, produces a local heightening of the temperature at the Earth’s surface."

John Tyndall got it in 1862.

Didn’t the fact that water vapor thoroughly blocks infrared radiation mean that any changes in CO2 are meaningless? Again, the scientists of the day got caught in the trap of thinking of the atmosphere as a single slab. Although they knew that the higher you went, the drier the air got, they only considered the total water vapor in the column.

(a) You’d still get an increase in greenhouse warming even if the atmosphere were saturated, because it’s the absorption in the thin upper atmosphere (which is unsaturated) that counts

(b) It’s not even true that the atmosphere is actually saturated with respect to absorption by CO2,

(c) Water vapor doesn’t overwhelm the effects of CO2 because there’s little water vapor in the high, cold regions from which infrared escapes, and at the low pressures there water vapor absorption is like a leaky sieve, which would let a lot more radiation through were it not for CO2, and

(d) These issues were satisfactorily addressed by physicists 50 years ago, and the necessary physics is included in all climate models.

Warmer temperatures would mean more plant growth in the Arctic and elsewhere, which would mean that more CO2 would be taken out of the atmosphere.

the science is still young on this, but here is an interesting article about how cosmic rays appear to correlate better to spruce tree ring growth in the UK better than the correlation with climate factors such as temperature and precipitation: http://news.bbc.co.uk/earth/hi/earth_news/newsid_8311000/8311373.stm

If true, a lot of rethinking will likely be necessary with the use of tree rings as a proxy for temperature.

We're one of the first generations to suddenly do an about face and decide that warmer is worse than colder. We're the ONLY generation ever to be stupid enough to think arctic thawing would be a bad thing.

There are some small (generally temporary) problems caused by melting permafrost, glaciers and snow pack...but in the end all it does is make it a more biologically viable area instead of a dead zone. Permafrost doesn't support significant plant life and ice/snow support NO plant life.

In the end there assuming it "continues" to warm (LOL, ignoring the temperature drop) there may be a small methane release, but methane is temporary. There may also be a small CO2 release, but not enough to do very much by ANY climate sensitivity suggested, much less the low sensitivity suggested by actual observational data.

Journalista-

You 'could' be right and you 'could' be wrong.
What if you ask a question that has no answer?
signed Shades of Gray

There is an important new story in Science this week: http://www.sciencemag.org/cgi/content/short/326/5952/527

Apparently the carbon emission accounting procedures in the Kyoto protocol and other simlar agreements view forests as more valuable dead and burned than alive and growing even though the alive and growing condition has less actual net carbon emissions. They just forgot to put a couple of additional lines of carbon sink and source accounting in the agreement. It appears that the AGW alarmist policies may literally create a scorched earth policy to wean the world off of fossil fuels.

Beware of politicians negotiating treaties on complex issues when they are in a panic.