Subsea permafrost carbon stocks and climate change sensitivity estimated by expert assessment

Sayedeh Sara Sayedi, Benjamin W. Abbott, Brett F. Thornton, Jennifer M. Frederick, Jorien E. Vonk, Paul Overduin, Christina Schädel, Edward A.G. Schuur, Annie Bourbonnais, Nikita Demidov, Anatoly Gavrilov, Shengping He, Gustaf Hugelius, Martin Jakobsson, Miriam C. Jones, Dong Joo Joung, Gleb Kraev, Robie W. Macdonald, A. David McGuire, Cuicui MuMatt O’Regan, Kathryn M. Schreiner, Christian Stranne, Elena Pizhankova, Alexander Vasiliev, Sebastian Westermann, Jay P. Zarnetske, Tingjun Zhang, Mehran Ghandehari, Sarah Baeumler, Brian C. Brown, Rebecca J. Frei

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

The continental shelves of the Arctic Ocean and surrounding seas contain large stocks of organic matter (OM) and methane (CH4), representing a potential ecosystem feedback to climate change not included in international climate agreements. We performed a structured expert assessment with 25 permafrost researchers to combine quantitative estimates of the stocks and sensitivity of organic carbon in the subsea permafrost domain (i.e. unglaciated portions of the continental shelves exposed during the last glacial period). Experts estimated that the subsea permafrost domain contains ∼560 gigatons carbon (GtC; 170–740, 90% confidence interval) in OM and 45 GtC (10–110) in CH4. Current fluxes of CH4 and carbon dioxide (CO2) to the water column were estimated at 18 (2–34) and 38 (13–110) megatons C yr1, respectively. Under Representative Concentration Pathway (RCP) RCP8.5, the subsea permafrost domain could release 43 Gt CO2-equivalent (CO2e) by 2100 (14–110) and 190 Gt CO2e by 2300 (45–590), with ∼30% fewer emissions under RCP2.6. The range of uncertainty demonstrates a serious knowledge gap but provides initial estimates of the magnitude and timing of the subsea permafrost climate feedback.

Original languageEnglish (US)
Article number124075
JournalEnvironmental Research Letters
Volume15
Issue number12
DOIs
StatePublished - Dec 2020

Bibliographical note

Funding Information:
This work was supported by the Brigham Young University Graduate Studies and the Permafrost Carbon Network through the National Science Foundation (NSF) Study of Environmental Arctic Change (SEARCH) Grant No. 1331083. Benjamin Abbott was supported by NSF award number 1916565. Cuicui Mu was supported by The National Key R&D Program of China (2019YFA0607003). Gleb Kraev was supported by the Russian Science Foundation (project 19-77-10065). Nikita Demidov was supported by the Russian Science Foundation (project 19-77-10066). Alexander Vasiliev was supported by the Russian Foundation for Basic Research, project No. 18-05-60004. Christian Stranne was supported by the Swedish Science Foundation (VR, project 2018-04350). Jennifer M Frederick was supported by the Laboratory Directed Research and Development program at Sandia National Laboratories, a multimis-sion laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525. We thank Sebastien Wetterich and Vladimir Romanovsky for providing input on the manuscript and M Bayani Cardenas for input on the questionnaire and conceptual framing of the project. The background drawings in figure 1, were created by Anna Wright.

Publisher Copyright:
© 2020 The Author(s). Published by IOP Publishing Ltd

Keywords

  • Carbon stocks
  • Climate change
  • Expert assessment
  • Subsea permafrost

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