More on Permafrost thawing contribution to GW from the National Snow and Ice Data Center (NSIDC).

[Bill USA]

http://thinkprogress.org/climate/2011/02/17/207552/nsidc-thawing-permafrost-will-turn-from-carbon-sink-to-source-in-mid-2020s-releasing-100-billion-tons-of-carbon-by-2100/
(emphases my own)

"The thaw and release of carbon currently frozen in permafrost will increase atmospheric CO2 concentrations and amplify surface warming to initiate a positive permafrost carbon feedback (PCF) on climate…. [Our] estimate may be low because it does not account for amplified surface warming due to the PCF itself…. We predict that the PCF will change the arctic from a carbon sink to a source after the mid-2020s and is strong enough to cancel 42-88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration."

That’s the stunning conclusion from “Amount and timing of permafrost carbon release in response to climate warming” (subs. req’d), a major new study in Tellus by NOAA and the National Snow and Ice Data Center (NSIDC). As we’ll see, the figure above is almost certainly too conservative post-2080.

The permafrost permamelt contains a staggering “1.5 trillion tons of frozen carbon, about twice as much carbon as contained in the atmosphere, much of which would be released as methane. [font color="red"]Methane is 25 times as potent a heat-trapping gas as CO2 over a 100 year time horizon, but 72 times as potent over 20 years! One of the most conservative assumptions the study made, the lead author Dr. Kevin Schaefer confirmed in an email, is that all of the carbon would be released as CO2 and none as methane[/font].

The carbon is locked in a freezer in the part of the planet warming up the fastest (see “Tundra 4: Permafrost loss linked to Arctic sea ice loss“). Countless studies make clear that global warming will release vast quantities of GHGs into the atmosphere this decade. Yet, no climate model currently incorporates the amplifying feedback from methane released by a defrosting tundra. Heck, the NSIDC/NOAA study itself doesn’t even incorporate the CO2 released by the permafrost carbon feedback into its warming model!


The NSIDC-led study acknowledges that it almost certainly underestimates the warming the PCF will cause. [font color="red"] As noted, it assumes all of the carbon released will come out as CO2, [font size="3"]not methane[/font][/font].


(more)

[OnlinePoker]

1. Curious as to why you would post a 2-1/2 year old story

There's enough current doom and gloom without rehashing old info.

[Bill USA]

2. it's amazing to me that they did not include something in their study they knew was a factor

... and a significant factor.


I don't think it's practical to ignore those parts of reality which are unpleasant. GW is pretty much beyond our ability to pull it back. Still, we should try to do our utmost,but the addition of the defrosting permafrost which was not included in temperature increase forcasts that we have been paying attention to, underscores the seriousness of our situation. IF (and I do mean IF) noting this could stimulate people to realize we need to make much greater efforts to counter-act, slow GW then it's worth posting even if there is just a little bit of a chance it might spur people into more realistic thinking.

Many people who think they are sensitive to the GW issue think we have 20 years to get some reductions in GHG emissions. We DO NOT have 20 yrs to wait for, oh say, 10% to 15% reductions in GHG emissions. IF we are going to do something it needs to produce results much faster and bigger than that.


For what it's worth.

[NickB79]

3. Bad news: the IPCC's latest report changes methane's warming potential

Unfortunately, not in a good way either:

http://thinkprogress.org/default/2013/10/01/2708911/

But the IPCC’s latest report, released Monday (big PDF here), reports that methane is 34 times stronger a heat-trapping gas than CO2 over a 100-year time scale, so its global-warming potential (GWP) is 34. That is a nearly 40% increase from the IPCC’s previous estimate of 25.