Activation of old carbon by erosion of coastal and subsea permafrost in Arctic SiberiaShow others and affiliations
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2012 (English)In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 489Article in journal (Refereed) Published
Abstract [en]
The future trajectory of greenhouse gas concentrations depends on interactions between climate and the biogeosphere(1,2). Thawing of Arctic permafrost could release significant amounts of carbon into the atmosphere in this century(3). Ancient Ice Complex deposits outcropping along the similar to 7,000-kilometre-long coastline of the East Siberian Arctic Shelf (ESAS)(4,5), and associated shallow subsea permafrost(6,7), are two large pools of permafrost carbon(8), yet their vulnerabilities towards thawing and decomposition are largely unknown(9-11). Recent Arctic warming is stronger than has been predicted by several degrees, and is particularly pronounced over the coastal ESAS region(12,13). There is thus a pressing need to improve our understanding of the links between permafrost carbon and climate in this relatively inaccessible region. Here we show that extensive release of carbon from these Ice Complex deposits dominates (57 +/- 2 per cent) the sedimentary carbon budget of the ESAS, the world's largest continental shelf, overwhelming the marine and topsoil terrestrial components. Inverse modelling of the dual-carbon isotope composition of organic carbon accumulating in ESAS surface sediments, using Monte Carlo simulations to account for uncertainties, suggests that 44 +/- 10 teragrams of old carbon is activated annually from Ice Complex permafrost, an order of magnitude more than has been suggested by previous studies(14). We estimate that about two-thirds (66 +/- 16 per cent) of this old carbon escapes to the atmosphere as carbon dioxide, with the remainder being re-buried in shelf sediments. Thermal collapse and erosion of these carbon-rich Pleistocene coastline and seafloor deposits may accelerate with Arctic amplification of climate warming(2,13).
Place, publisher, year, edition, pages
2012. Vol. 489
Keywords [en]
offshore permafrost shelf seas degradation sediments release matter laptev tundra cycle Science & Technology - Other Topics
Research subject
SWEDARCTIC 2008, ISSS-08
Identifiers
URN: urn:nbn:se:polar:diva-1940DOI: 10.1038/nature11392OAI: oai:DiVA.org:polar-1940DiVA, id: diva2:810200
Note
ISI Document Delivery No.: 999WW Times Cited: 27 Cited Reference Count: 30 Vonk, J. E. Sanchez-Garcia, L. van Dongen, B. E. Alling, V. Kosmach, D. Charkin, A. Semiletov, I. P. Dudarev, O. V. Shakhova, N. Roos, P. Eglinton, T. I. Andersson, A. Gustafsson, O. Semiletov, Igor/B-3616-2013; Vonk, Jorien/H-5422-2011; Sanchez-Garcia, Laura/N-1172-2013 Sanchez-Garcia, Laura/0000-0002-7444-1242 Knut and Alice Wallenberg Foundation; Far Eastern Branch of the Russian Academy of Sciences; Swedish Research Council; US National Oceanic and Atmospheric Administration; Russian Foundation of Basic Research; Swedish Polar Research Secretariat; Nordic Council of Ministers; Swedish Royal Academy of Sciences; EU Marie Curie grant; US National Science Foundation; NOAA OAR Climate Program Office We thank all ISSS-08 colleagues and crew, in particular M. Krusa, P. Andersson and V. Mordukhovich, who helped with sampling. The ISSS program is supported by the Knut and Alice Wallenberg Foundation, the Far Eastern Branch of the Russian Academy of Sciences, the Swedish Research Council, the US National Oceanic and Atmospheric Administration, the Russian Foundation of Basic Research, the Swedish Polar Research Secretariat and the Nordic Council of Ministers (Arctic Co-Op and TRI-DEFROST programs). O.G. and L.S.-G. acknowledge an Academy Research Fellow grant from the Swedish Royal Academy of Sciences and an EU Marie Curie grant, respectively. N.S. and I. P. S. acknowledge grants from the US National Science Foundation and the NOAA OAR Climate Program Office. 27 Nature publishing group London Multidisciplinary Sciences
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