Climate change and the permafrost carbon feedback

Journal name:
Nature
Volume:
520,
Pages:
171–179
Date published:
DOI:
doi:10.1038/nature14338
Received
Accepted

Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to target poorly understood aspects of permafrost carbon dynamics.

At a glance

Figures

  1. Soil organic carbon maps.
    Figure 1: Soil organic carbon maps.

    a, Soil organic carbon pool (kg C m−2) contained in the 0–3 m depth interval of the northern circumpolar permafrost zone12. Points show field site locations for 0–3 m depth carbon inventory measurements; field sites with 1 m carbon inventory measurements number in the thousands and are too numerous to show. b, Deep permafrost carbon pools (>3 m), including the location of major permafrost-affected river deltas (green triangles), the extent of the yedoma region previously used to estimate the carbon content of these deposits13 (yellow), the current extent of yedoma region soils largely unaffected by thaw-lake cycles that alter the original carbon content17 (red), and the extent of thick sediments overlying bedrock (black hashed). Yedoma regions are generally also thick sediments. The base map layer shows permafrost distribution with continuous regions to the north having permafrost everywhere (>90%), and discontinuous regions further south having permafrost in some, but not all, locations (<90%)96.

  2. Potential cumulative carbon release.
    Figure 2: Potential cumulative carbon release.

    Data are given as a percentage of initial carbon. a, Cumulative carbon release after ten years of aerobic incubation at a constant temperature of 5 °C. Thick solid lines are averages for organic (red, N = 43) and mineral soils (blue, N = 78) and thin solid lines represent individual soils to show the response of individual soils. Dotted lines are the averages of the 97.5% CI for each soil type. b, Cumulative carbon release after one year of aerobic and anaerobic incubations (at 5 °C). Darker colours represent cumulative CH4-carbon calculated as CO2-carbon equivalent (for anaerobic soils) on a 100-year timescale according to ref. 38. Positive error bars are upper 97.5% CI for CO2-carbon and negative error bars are lower 97.5% CI for CH4-carbon. N = 28 for organic soils and N = 25 for mineral soils in anaerobic incubations. Aerobic cumulative carbon release is redrawn from ref. 36 and anaerobic cumulative carbon release is calculated based on ref. 37.

  3. Model estimates of potential cumulative carbon release from thawing permafrost by 2100, 2200, and 2300.
    Figure 3: Model estimates of potential cumulative carbon release from thawing permafrost by 2100, 2200, and 2300.

    All estimates except those of refs 50 and 46 are based on RCP 8.5 or its equivalent in the AR4 (ref. 97), the A2 scenario. Error bars show uncertainties for each estimate that are based on an ensemble of simulations assuming different warming rates for each scenario and different amounts of initial frozen carbon in permafrost. The vertical dashed line shows the mean of all models under the current warming trajectory by 2100.

  4. Abundance of abrupt thaw features in lowland and upland settings in Alaska.
    Figure 4: Abundance of abrupt thaw features in lowland and upland settings in Alaska.

    Left panels (a, c) show thermokarst lake (TKL) abundance, expansion, and drainage on the Seward Peninsula, Northwest Alaska, between 1950 and 200668, with collapsing permafrost banks (photo credit G.G.). Right panels (b, d) show extensive distribution of ground collapse and erosion features (ALD, active layer detachment slide; RTS, retrogressive thaw slump; GTK, thermal erosion gullies) in upland tundra in a hill slope region in Northwest Alaska61, and thawing icy soils in a retrogressive thaw slump (photo credit E.A.G.S.).

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Author information

Affiliations

  1. Center for Ecosystem Science and Society and Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona 86011, USA

    • E. A. G. Schuur &
    • C. Schädel
  2. Department of Biology, University of Florida, Gainesville, Florida 32611, USA

    • E. A. G. Schuur &
    • C. Schädel
  3. US Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska Fairbanks, Alaska 99775, USA

    • A. D. McGuire
  4. Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, 14473 Potsdam, Germany

    • G. Grosse
  5. US Geological Survey, Menlo Park, California 94025, USA

    • J. W. Harden
  6. Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA

    • D. J. Hayes
  7. Department of Physical Geography, Stockholm University, 10691 Stockholm, Sweden

    • G. Hugelius &
    • P. Kuhry
  8. Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

    • C. D. Koven
  9. National Center for Atmospheric Research, Boulder, Colorado 80305, USA

    • D. M. Lawrence
  10. Woods Hole Research Center, Falmouth, Massachusetts 02540, USA

    • S. M. Natali
  11. Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada

    • D. Olefeldt &
    • M. R. Turetsky
  12. Department of Renewable Resources, University of Alberta, Edmonton, Alberta T6G 2H1, Canada

    • D. Olefeldt
  13. Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA

    • V. E. Romanovsky
  14. Tyumen State Oil and Gas University, Tyumen, Tyumen Oblast 625000, Russia

    • V. E. Romanovsky
  15. National Snow and Ice Data Center, Boulder, Colorado 80309, USA

    • K. Schaefer
  16. Earth Systems Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, New Hampshire 03824, USA

    • C. C. Treat
  17. Department of Earth Sciences, Utrecht University, 3584 CD Utrecht, The Netherlands

    • J. E. Vonk

Contributions

This manuscript arose from the collective effort of the Permafrost Carbon Network (http://www.permafrostcarbon.org); all authors are working group leaders within the network. E.A.G.S. and A.D.M. wrote the initial draft, with additional contributions from all authors. C.S. provided assistance with final editing and submission of the manuscript, and helped to organise the Permafrost Carbon Network activities that made this possible. Figure 1 was prepared by G.H., Fig. 2 by C.S., Fig. 3 by K.S., Fig. 4 by G.G. and the Box 1 Figure by E.A.G.S.

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The authors declare no competing financial interests.

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