Jump to content

salbers

Meteorologist
  • Posts

    612
  • Joined

  • Last visited

Posts posted by salbers

  1. Interesting timing since that was distributed just two weeks before they pulled the plug on in-situ monitoring of CH4 at Barrow.

    This was during the annual GMD conference held in the building where I work. I think this desire for more obs has been expressed a number of times over the years. Curiously I didn't much see much reference to the Arctic Ocean and ESAS methane in this conference program.

  2. The question was for the met I responded to. I wanted to know when he felt like it could occur.

    Hard to say exactly, though I haven't seen much in the way of rebuttal of what S&S are warning about. At a minimum we need much more thorough monitoring of this region to look for corroboration of any acceleration in release or related changes.

    Looking to the past, it's true this probably hasn't happened in the previous ice ages over the past 400000 years or so, though it's unclear whether these periods had the same setup and shallowness of the ESAS. Over Earth's history in general, this type of thing may well have happened, given the past greatly elevated levels of CO2.

  3. I hear you Rusty... I just keep going back to the thread title that not many seem to object to.

    catastrophic climatic calamity? really?

    Just a bit of alliterative humor. Though it is something that is possible, given the unique combination of warming temperatures with sediments on a shallow shelf becoming unstable...

  4. http://www.nasa.gov/...th20120422.html

    This is weird, and unsettling if true.

    NASA has detected CH4 coming from the ocean in the Arctic - seems to be leaking out from under the icepack.

    They do not think it is from the seabed, as the sites sampled were relatively deep.

    I thought that the ocean would fairly efficiently turn any CH4 produced into CO2, no?

    If not, then it could be a bit of a problem.

    Where the hell is it coming from - jellyfish?

    Yes, weird and not good ;) ?

    It's interesting that the article mentions possible biological activity in surface waters being the source. However the link below has an informative video that does show the flight path north of Alaska on the edge of the ESAS, and they do mention the shallow ocean sediments being a possible source of their enhanced methane measurements.

    http://hippo.ucar.ed...ns-from-hippo-i

  5. I wasn't talking about a minority amount and neither was the guy's post I was originally responding to. So the answer appears to be there is not peer reviewed papers that suggest a majority of the methane in the ESAS is in danger of being released in the next 100 years.

    Well I agree you've been talking about a majority amount, so in that context I'd suggest it's a somewhat irrelevant point.

  6. idk... A large portion typically means most of it... From what I hear there are massive amounts down there. I was looking for peer reviewed papers that suggest most of that methane is unstable enough to be released in the next 100 years. Honestly, you are one of the only people in this thread who I feel is even worth responding to in a good faith manner. So there you have it.

    The thing is that even a minority of the available methane would still be sufficient to cause a significant climate impact. And Wx Rusty is right about the short term CH4 being in tandem with the long term conversion to CO2. The latter is more of an irreversible process, as the mechanisms to pull CO2 from the atmosphere are somewhat limited. Which is more of a threat depends on the exact rate of release of CH4.

    The S&S and related papers are fairly suggestive of instability, aren't they?

    Over time more journal papers will likely be coming out, as it takes time to publish. So this is a nuanced discussion of risk assessment to be sure.

  7. You may have misread my OP. I was objecting to the idea that a large portion of the methane trapped in the ESAS has reasonable potential to be released in the next hundred years.

    Well this potential has been discussed in many posts so far. Perhaps you might want to clarify how many Gt per year of methane and the percent probability to give us a point of reference?

  8. It's not 100% definite, though this paper and other papers/letters that cite it suggest it is enough of a possibility to take seriously.

    Also, there's enough methane in the ESAS so only a relatively small proportion would still have a climate impact.

  9. Video from 2011 ESAS expedition, posted Jan 30. 2012...

    And here's an older 2010 video interview from Natalia S.

    TerryM,

    Do you know what journal S&S's paper will be in? Is this something beyond the SWIPA book chapter draft that is now available?

    Also, there is an upcoming S&S seminar on Feb 9th.

    http://www.iarc.uaf....d=1323818876406

    Looking ahead further, I wonder if this topic will be covered at the next ESRL/GMD global monitoring conference?

    http://www.esrl.noaa...nualconference/

    Thanks,

    Steve

    To update this earlier post, the Feb 9th IARC seminar has been rescheduled for May 31st. Abstract available here:

    http://www.iarc.uaf....nar-series/2011

    May 31st

    The IARC based Russia-US Siberian Shelf Studies (2003-2011): results and challenges

    Speakers: Natalia Shakhova, Igor Semiletov

    1:30 PM - 2:30 PM, 401 Akasofu Building

    The Arctic Ocean is surrounded by permafrost, which is being degraded at an increasing rate under conditions of warming which are most pronounced in Siberia and Alaska. Sub-sea permafrost is much more vulnerable than its terrestrial counterpart, because it experienced a drastic change in its thermal regime due to inundation by the ocean and consequent warming by as much as 12-17˚C, prior to the current ongoing climate change. Thaw and release of organic carbon (OC) from Arctic permafrost is postulated to be one of the most powerful mechanisms causing a net redistribution of carbon from land and ocean to the atmosphere. This report summarizes current understanding of transport and fate of OC to and within the East Siberian Arctic Shelf (ESAS) and processes determining carbon dioxide (CO2) and methane (CH4) fluxes from the ESAS to the atmosphere achieved from analyzing the data sets obtained on 20 expeditions performed from 1999 to 2011. The shallow ESAS is a unique area of the World Ocean where ~80% of predicted sub-sea permafrost exists. This study of the ESAS was aimed at investigating how redistribution of old carbon from degrading terrestrial and sub-sea permafrost and from coastal erosion contributes to the carbon pool of the ESAS, and which factors control CH4 and CO2 emissions from the ESAS. This report describes selected results achieved by a developing international scientific partnership that has been crucial at every stage of the study and will be even more important in the future.

  10. The line of best fit for below is ~1/ppb/yr.

    Barrow AK != the entire arctic.

    70-90N_anomaly_CH4-1.jpg?t=1328762952

    This shows the methane levels were roughly level from 2000-2006. And from 2006 onward, the period of the surface observation uptick, we see here on the order of 2.5 ppb/yr rise. This assumes the baseline has no trend beyond an annual cycle.

    Here's a link to another surface plot, from Mauna Loa showing roughly 6ppb yr since 2006.

    http://upload.wikime...s_obs_03437.png

  11. David archer has an online model for atmospheric methane release.

    http://forecast.uchi...ts/methane.html

    methane.rf.11181746.gif

    This is the result of releasing 16Gt over a 20 year period.(a 100 fold increase over the current 8Mt rate). This corrisponds to 1% of the known ESAS reserves being vented. With 5 watt forcing the permafrost would be vanishing very fast so lets release 1% of those reserves over the next 20 years 32Gt over 40 years.

    methane.rf.11181947.gif

    This is not good.

    Has it been mentioned yet this calculator has a thread on RealClimate?

    http://www.realclima...ere/#more-10545

    By the way, the methane concentration Y-axis on the previous post is a bit confusing to me, is it just 0.5 -3.0 parts per billion? That's 1000 times too small. Will be interesting to see the latest hourly data as well.

  12. S&S just published a new paper on the ESAS.

    http://iopscience.io..._7_1_015201.pdf

    On carbon transport and fate in the East Siberian Arctic land–shelf–atmosphere system

    It was submitted Aug 5, so it doesn't cover the recent findings.

    Thanks for the link. Any chance some revisions were made prior to the December acceptance date? I see though this is mainly a survey paper of previous findings.

  13. I'm waiting for the Skeptical Science interview that should be published next week, and of course S&S's paper that will debut in April.

    TerryM,

    Do you know what journal S&S's paper will be in? Is this something beyond the SWIPA book chapter draft that is now available?

    Also, there is an upcoming S&S seminar on Feb 9th.

    http://www.iarc.uaf....d=1323818876406

    Looking ahead further, I wonder if this topic will be covered at the next ESRL/GMD global monitoring conference?

    http://www.esrl.noaa.gov/gmd/annualconference/

    Thanks,

    Steve

  14. Here's the SWIPA website that I'm starting to look through (as in post #86). This will have the upcoming book chapter by Shakhova and Semiletov...

    http://amap.no/swipa/

    Here is their 80MB pre-print draft of Background Science. Chapter 5 covers permafrost and contains 62 pages. Section 5.3.4.3 talks about future subsea permafrost releases. The end of the draft section suggests 800Gt of CH4 could be ready for sudden release...

    http://amap.no/swipa/CombinedDraft.pdf

  15. Damn paywall. If you add in an equal amount from the arctic ocean you get this;

    methane.rf.14125935.gif

    About 8W GHG forcing by 2030, ignoring albedo feedback, which would be huge in the arctic. How could the permafrost melt not accelerate? How could the ice cap not melt? How could Greenland not melt? It seems that the "worst case scenario" is now the predicted norm. Do we need a new worst case scenario?

    Indeed - nice plot that helps give some perspective. We see methane going from about half the CO2 forcing at the present time to about twice the forcing in a few decades. That's kind of a good benchmark to see if the worst case scenario from either land-based or ESAS based methane could exceed 1Gt/yr of methane flux.

    Also, interesting that a 2 Gt/yr sustained release gives about the same maximum radiative forcing as a 50Gt instantaneous release.

  16. At a lecture from 12/2010 the 3.5 GT figure was used - this was prior to the expedition that found venting orders of magnitude worse than previous observations.

    http://webcache.googleusercontent.com/search?q=cache:PEIMdPkMpd8J:symposium2010.serdp-estcp.org/content/download/8914/107496/version/3/file/1A_Shakhova_Final.pdf+"esas"+3.5Gt&cd=5&hl=en&ct=clnk&gl=

    page 34

    Thanks for finding this. I was attempting to find this presentation in the 2011 symposium.

  17. All you are doing is taking the word ready out of context.

    Please try and elaborate further (beyond post #453) on the context with how it fits into the numbers I'm using. Most of the reasoning I'm presenting makes sense I think.

    What fraction of the 1400Gt "ready" to release can possibly be released over what time period? Are you confident it is less than 1/2000th of this over a 1 year time period? This in turn is about 100 times the current steady release component. The total release right now probably isn't much more than the 6-8Mt steady component, otherwise we'd have a faster global rate of rise.

    As Vergent mentions Archer in 2007 believes it is a relatively small fraction, though as we can see in the recent RC thread Vergent along with others seems to be able to challenge Archer on this. We'll see how the scientific debate continues with players like Shakhova and Archer.

  18. This entire thread has no business being on a scientific forum. The subject I have no problem with but some of the posts in this thread are a joke.

    We are trying to use scientific references when possible. That should qualify at least some of the posts in this thread? We are mainly speculating in advance of future publications that should help clarify things.

×
×
  • Create New...