The Weekend Wonk: David Archer on Siberian Methane Feedbacks

April 11, 2015

Description:

Published on Mar 20, 2015

ARCTIC-WISE: Bridging Northern Knowledges of Change

Subsea Permafrost and the Methane Cycle on the Siberian Continental Shelf: Predictive Modelling for Climate Change
David Archer, Geophysical Sciences, University of Chicago
Tuesday, March 10, 2015, 5-6:30 pm

A numerical model called SpongeBOB is used to simulate the hydrology and methane cycle on the Siberian continental shelf. Lowered sea level during glacial time exposed the sediment surface to the cold atmosphere, forming permafrost to a depth of a kilometre or more. Now in the interglacial time the permafrost is flooded by higher sea level, leading to its eventual melting. The model is used to predict how the glacial cycles, and future global warming, affect the methane budget of this area. The model predicts that methane hydrate is only stable near the bottom of the permafrost zone, hundreds of metres below the sediment surface. The hydrates are insulated from any rapid change in temperature that might occur in the overlying ocean. There is enough carbon in frozen sediments in the Arctic to drive a substantial carbon release in response to climate warming, but only on time scales of thousands of years.

8 Responses to “The Weekend Wonk: David Archer on Siberian Methane Feedbacks”

  1. talies Says:

    I hope David Archer is right that the hydrates are relatively stable.

    But one thing he leaves out of the models are taliks, which would allow water to reach down to buried hydrates and melt them.


  2. You can find your Collapse Data Cheat Sheet in the link at the end of this post:

    ♪♪ mama don’t let ur daughters grow up to have babies ♪♪

    Why Barbie Hates Math

    ————————————

    ► 10 yrs – no water for 4 billion

    ► 30 yrs – mass extinction starts

    ► 60 yrs – human agriculture ends

    ► 70 yrs – oxygen unbreathable

    .

    How can we have to grow more food in 50 yrs than in the last 500?

    ► Because of something stupid as math.

    .

    We need 6 million hectares of new farmland per year.

    We lose 12 million hectares of farmland per year.

    This means earth has 60 years of agriculture left.

    ► Because of something stupid as math

    .

    How can a 1% annual decline of plankton mean no plankton in 70 years?

    ► Because of something stupid as math.

    We can breathe easy because plankton don’t do math.

    .

    ► Read,

    “Out of Thin Air” by Peter Ward

    “Ecocide” by Franz Broswimmer

    “Extracted” by Ugo Bardi

    “Green Illusions” by Ozzie Zehner

    “The Sixth Extinction” by Elizabeth Kolbert

    .

    ► Watch,

    Call of Life: Facing The Mass Extinction

    .

    ► Avoid,

    http://www.reddit.com/r/collapse/comments/311m7d/collapse_data_cheat_sheet/

    • dumboldguy Says:

      Great link. Some small bit of hyperbole and questionable data, but it looks to be 99+% right on from my perspective, and I’ve been “watching” the data accumulate for over 50 years.

      The “math” is indeed the problem. It is difficult to really predict the middle and far future—-we can only “project” and “extrapolate”—-and human nature is such that we can’t even come to grips with the very “near” future. I have just finished reading two books about Superstorm Sandy, and the level of “whistling past the graveyard” that occurred there was mind-boggling—-some people did nothing until the water came in the door.

    • redskylite Says:

      The sixth extinction now becomes the seventh extinction according to the Geological Society of America,

      New evidence adds the Capitanian extinction to the list of major extinction crises:-

      Thus the “Big 5” extinctions should now be considered the “Big 6.”

      http://www.eurekalert.org/pub_releases/2015-04/gsoa-nea041515.php

  3. redskylite Says:

    I’ve just realized who the speeches by Prof. David Archer remind me of and that is the great American stand-up comedian and actor Bob Newhart.

    Great lecture and dispels some of the panic I often feel around Arctic events and news, although we should listen to Arctic specialists like Jason Box, Igor Semiletov and Natalia Shakova, who know more from practical on-site experience.

    There’s a lot of Carbon stored in the Arctic ground, but it seems it will be released slowly and not in one almighty apocalyptic pulse, and we still have time (but not too much) to slow down the melt.

    Much in line with a recent study published in the journal Nature.

    “Thawing permafrost in the Arctic and sub-Arctic regions will likely produce a gradual and prolonged release of large quantities of greenhouse gases spanning decades as opposed to an abrupt release in a decade or less, says a new study published in the journal Nature.”

    http://www.sci-news.com/othersciences/climatology/science-frozen-soils-greenhouse-gas-emissions-02680.html


    • I don’t understand his logic myself. I lost faith when he illustrated that methane release at a given point of time is not relative later. I thought it would be. Climate inertia.

      Sure methane comes out of the system. But I can’t see how all the effects would. David Archer would need to explain more, using Earth’s processes to illustrate. He could use a release of 1% hydrate release (to the atmosphere) over a century and describe what he sees would the be effect.

    • dumboldguy Says:

      From the link:

      “Permafrost has warmed nearly 11 degrees Fahrenheit in the past three decades. In the 1980s, the average temperature of permafrost in Alaska, Russia and other Arctic regions was nearly 18 degrees Fahrenheit. Now the average is just over 28 degrees Fahrenheit”.

      “Thawing permafrost in the Arctic and sub-Arctic regions will likely produce a gradual and prolonged release of large quantities of greenhouse gases spanning decades as opposed to an abrupt release in a decade or less…”

      OK. Projecting forward, may we assume that the ‘average permafrost temperature” will be 39 degrees in another 30 years (and likely higher)? True, it will take a while for that heat to penetrate and melt the permafrost

      But will not that “gradual and prolonged release of large quantities pf GHG” lead to self-reinforcing positive feedbacks? “Spanning decades” may be some small comfort to the majority of humans who have difficulty looking beyond tomorrow, but the biosphere operates on a longer timescale and is not likely to be too impressed if it takes a century for it to be destroyed (and if that century doesn’t begin for some tens of decades).

      Is there something wrong with my math?


  4. I believe David Archer knows what he is talking about. He has a very long and detailed lecture series about Climate Science that I recommend to those who want to go into the details including the physics involved:

    http://forecast.uchicago.edu/lectures.html


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