Article

Climatic Change

, Volume 119, Issue 2, pp 359-374

Open Access This content is freely available online to anyone, anywhere at any time.

Expert assessment of vulnerability of permafrost carbon to climate change

  • E. A. G. SchuurAffiliated withUniversity of Florida Email author 
  • , B. W. AbbottAffiliated withUniversity of Alaska Fairbanks
  • , W. B. BowdenAffiliated withUniversity of Vermont
  • , V. BrovkinAffiliated withMax Planck Institute for Meteorology
  • , P. CamillAffiliated withBowdoin College
  • , J. G. CanadellAffiliated withGlobal Carbon Project CSIRO Marine and Atmospheric Research
  • , J. P. ChantonAffiliated withFlorida State University
  • , F. S. ChapinIIIAffiliated withUniversity of Alaska Fairbanks
  • , T. R. ChristensenAffiliated withLund University
    • , P. CiaisAffiliated withLSCE, CEA-CNRS-UVSQ
    • , B. T. CrosbyAffiliated withUniversity of FloridaIdaho State University
    • , C. I. CzimczikAffiliated withUniversity of FloridaUniversity of California
    • , G. GrosseAffiliated withUniversity of Alaska Fairbanks
    • , J. HardenAffiliated withUniversity of FloridaUS Geological Survey
    • , D. J. HayesAffiliated withUniversity of FloridaOak Ridge National Laboratory
    • , G. HugeliusAffiliated withUniversity of FloridaStockholm University
    • , J. D. JastrowAffiliated withUniversity of FloridaArgonne National Laboratory
    • , J. B. JonesAffiliated withUniversity of Alaska Fairbanks
    • , T. KleinenAffiliated withMax Planck Institute for Meteorology
    • , C. D. KovenAffiliated withUniversity of FloridaLawrence Berkeley National Lab
    • , G. KrinnerAffiliated withUniversity of FloridaCNRS/UJF-Grenoble 1, LGGE
    • , P. KuhryAffiliated withUniversity of FloridaStockholm University
    • , D. M. LawrenceAffiliated withUniversity of FloridaNational Center for Atmospheric Research
    • , A. D. McGuireAffiliated withUniversity of FloridaU.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska
    • , S. M. NataliAffiliated withUniversity of Florida
    • , J. A. O’DonnellAffiliated withUniversity of Alaska FairbanksArctic Network, National Park Service
    • , C. L. PingAffiliated withUniversity of Alaska Fairbanks
    • , W. J. RileyAffiliated withUniversity of FloridaLawrence Berkeley National Lab
    • , A. RinkeAffiliated withUniversity of Alaska FairbanksAlfred Wegener Institute
    • , V. E. RomanovskyAffiliated withUniversity of Alaska Fairbanks
    • , A. B. K. SannelAffiliated withUniversity of FloridaStockholm University
    • , C. SchädelAffiliated withUniversity of Florida
    • , K. SchaeferAffiliated withUniversity of Alaska FairbanksNational Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado
    • , J. SkyAffiliated withUniversity of Alaska FairbanksUniversity of Oxford
    • , Z. M. SubinAffiliated withUniversity of FloridaLawrence Berkeley National Lab
    • , C. TarnocaiAffiliated withUniversity of Alaska FairbanksAgriFoods
    • , M. R. TuretskyAffiliated withUniversity of Alaska FairbanksUniversity of Guelph
    • , M. P. WaldropAffiliated withUniversity of FloridaOak Ridge National Laboratory
    • , K. M. Walter AnthonyAffiliated withUniversity of Alaska Fairbanks
    • , K. P. WicklandAffiliated withUniversity of Alaska FairbanksU.S. Geological Survey
    • , C. J. WilsonAffiliated withUniversity of Alaska FairbanksLos Alamos National Laboratory
    • , S. A. ZimovAffiliated withUniversity of Alaska FairbanksNorth-East Scientific Station

Abstract

Approximately 1700 Pg of soil carbon (C) are stored in the northern circumpolar permafrost zone, more than twice as much C than in the atmosphere. The overall amount, rate, and form of C released to the atmosphere in a warmer world will influence the strength of the permafrost C feedback to climate change. We used a survey to quantify variability in the perception of the vulnerability of permafrost C to climate change. Experts were asked to provide quantitative estimates of permafrost change in response to four scenarios of warming. For the highest warming scenario (RCP 8.5), experts hypothesized that C release from permafrost zone soils could be 19–45 Pg C by 2040, 162–288 Pg C by 2100, and 381–616 Pg C by 2300 in CO2 equivalent using 100-year CH4 global warming potential (GWP). These values become 50 % larger using 20-year CH4 GWP, with a third to a half of expected climate forcing coming from CH4 even though CH4 was only 2.3 % of the expected C release. Experts projected that two-thirds of this release could be avoided under the lowest warming scenario (RCP 2.6). These results highlight the potential risk from permafrost thaw and serve to frame a hypothesis about the magnitude of this feedback to climate change. However, the level of emissions proposed here are unlikely to overshadow the impact of fossil fuel burning, which will continue to be the main source of C emissions and climate forcing.