Yes, peat bogs (as most things like trees, whales, & golf courses) soak up CO2 when forming and release it (or methane) when drying out or decaying.
"...Factors acting over long time scales, especially water table depth, strongly influenced the carbon budget on annual time scales. Net uptake was enhanced and respiration inhibited by multiple years of rainfall in excess of evaporative demand. Contrary to expectations, we observed no correlation between longer growing seasons and net uptake, possibly because of offsetting increases in ecosystem respiration. The results indicate that the interactions between soil thaw and water table depth provide critical controls on carbon exchange in boreal forests underlain by peat, on seasonal to decadal time scales, and these factors must be simulated in terrestrial biosphere models to predict response of these regions to future climate."
Global Change Biology
Volume 13 Issue 3 Page 577 - March 2007
also...(this is in relation to the European heatwave of 2003)
"...FLUXNET eddy-covariance data indicate that the drop in productivity was not primarily caused by high temperatures ('heat stress') but rather by limitation of water (drought stress) and that, contrary to the classical expectation about a heat wave, not only gross primary productivity but also ecosystem respiration declined by up to more than to 80 gC m2 /month."
Global Change Biology
Volume 13 Issue 3 Page 634 - March 2007
Bogs release methane even while frozen (from methanogens), but they are not like the oceanic methane clathrates which could "erupt" at some 'tripping' temperature.
Bogs are a good example of earth in general. they both absorb and emit lots of CO2 (and come close to balancing in the long term).
I think it's something like 130 GtC/yr that exchanges on a yearly basis (terrestrial only). Humans emit about 7 GtC/yr. If we could shift that balance (130 Gt exchange) just a couple of percent, we could sequester as much as we produce. Of course that would mean watering our 'lawns' much more than we do now (worldwide). And overall, the earth is drying out. So...I'm not a "Doom & Gloom" kind of guy either, but it's hard not to be....
Maybe grow a backyard bog (or any wetland)....
Which also leads me to ask about the oceans as an HNL.
Oceans are maybe larger than 130 GtC/yr. exchange (which also are not healthy, growing absorbers anymore) IMHO.
I know; "Ice retreat over the last 30 years has tripled the amount of CO2 the Arctic Ocean can absorb." (New Scientist online, 6 January 2007, from issue 2585, p. 16) I still think that both oceans and lands have shifted to be net producers of CO2 overall (due to human activities).
Sorry, I'm preaching again. Enough for now....
(I may be confusing C with CO2 in this 'hasty' post, but that's still only a factor of ~3.5) (also, I think 1 gC/m2 roughly translate as 1 MtC exchange). Hopefully the general idea comes across; make the world more productive and absorb excess CO2 (and feed ourselves as a side benefit?).
~SA
