Impacts of Arctic thaw

Discussion in 'Environment' started by Old Rocks, Oct 7, 2011.

  1. Old Rocks
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    Old Rocks Diamond Member

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    Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions

    Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions

    Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions
    Key Points
    The importance of atmospheric chemistry in response to permafrost emissions
    Ivar S. A. Isaksen

    Department of Geosciences, University of Oslo, Oslo, Norway

    Center for International Climate and Environmental Research–Oslo, Oslo, Norway

    Michael Gauss

    Department of Geosciences, University of Oslo, Oslo, Norway

    Norwegian Meteorological Institute, Oslo, Norway

    Gunnar Myhre

    Department of Geosciences, University of Oslo, Oslo, Norway

    Center for International Climate and Environmental Research–Oslo, Oslo, Norway

    Katey M. Walter Anthony

    Water and Environmental Research Center, Institute of Northern Engineering and International Arctic Research, University of Alaska, Fairbanks, Alaska, USA

    Carolyn Ruppel

    U.S. Geological Survey, Woods Hole, Massachusetts, USA

    The magnitude and feedbacks of future methane release from the Arctic region are unknown. Despite limited documentation of potential future releases associated with thawing permafrost and degassing methane hydrates, the large potential for future methane releases calls for improved understanding of the interaction of a changing climate with processes in the Arctic and chemical feedbacks in the atmosphere. Here we apply a “state of the art” atmospheric chemistry transport model to show that large emissions of CH 4 would likely have an unexpectedly large impact on the chemical composition of the atmosphere and on radiative forcing (RF). The indirect contribution to RF of additional methane emission is particularly important. It is shown that if global methane emissions were to increase by factors of 2.5 and 5.2 above current emissions, the indirect contributions to RF would be about 250% and 400%, respectively, of the RF that can be attributed to directly emitted methane alone. Assuming several hypothetical scenarios of CH 4 release associated with permafrost thaw, shallow marine hydrate degassing, and submarine landslides, we find a strong positive feedback on RF through atmospheric chemistry. In particular, the impact of CH 4 is enhanced through increase of its lifetime, and of atmospheric abundances of ozone, stratospheric water vapor, and CO 2 as a result of atmospheric chemical processes. Despite uncertainties in emission scenarios, our results provide a better understanding of the feedbacks in the atmospheric chemistry that would amplify climate warming.
     
  2. Old Rocks
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  3. Old Rocks
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    Fields of extensive methane outbursts found in Arctic region: Voice of Russia

    Russian and American scientists have discovered new fields of intensive methane outbursts in the eastern part of the Arctic region. Some scientists believe that these outbursts may provoke stronger greenhouse effect.

    The participants of an international expedition have fixed hundreds of torches-fountains of outgoing gas. This only a small part of what is hidden in permafrost, scientists say. On the bottom of the ocean methane is stored in hydrates - solid units, which began to fail at higher temperature emitting gas.
     
  4. Old Rocks
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    Information Bridge: DOE Scientific and Technical Information - Sponsored by OSTI

    Atmosphere Earth and Energy Division, Lawrence Livermore National Laboratory
    8
    9
    10
    11 Abstract. Alterations to the composition of seawater are estimated for microbial
    12 oxidation of methane from large polar clathrate destabilizations, which may arise in the
    13 coming century. Gas fluxes are taken from porous flow models of warming Arctic
    14 sediment. Plume spread parameters are then used to bracket the volume of dilution.
    15 Consumption stoichiometries for the marine methanotrophs are based on growth
    16 efficiency and elemental/enzyme composition data. The nutritional demand implied by
    extra CH4 17 removal is compared with supply in various high latitude water masses. For
    18 emissions sized to fit the shelf break, reaction potential begins at one hundred micromolar
    19 and falls to order ten a thousand kilometers downstream. Oxygen loss and carbon dioxide
    20 production are sufficient respectively to produce hypoxia and acidification in poorly
    21 ventilated basins. Nitrogen and the monooxygenase transition metals may be depleted in
    22 some locations as well. Deprivation is implied relative to existing ecosystems, along with
    23 dispersal of the excess dissolved gas. Physical uncertainties are inherent in the clathrate
    2
    1 abundance, patch size, outflow buoyancy and mixing rate. Microbial ecology is even less
    2 defined but may involve nutrient recycling, metal adsorption and anaerobic oxidizers.
     
  5. waltky
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    waltky Wise ol' monkey Supporting Member

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    New normal finds Arctic melting faster...
    :eusa_eh:
    Federal report: Arctic much worse since 2006
    1 Dec.`11 WASHINGTON – Federal officials say the Arctic region has changed dramatically in the past five years — for the worse.

     
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  6. waltky
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    waltky Wise ol' monkey Supporting Member

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    Uncle Ferd says it's pro'bly comin' from polar bear poop...
    :eusa_shifty:
    Massive methane gas bubbles in Arctic alarm scientists
    Thursday 15th December, 2011 - Giant plumes of methane gas, some a kilometre in diameter, have been discovered bubbling to the surface of the Arctic Ocean by Russian scientists, alarming those trying to protect the region.
     

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