Global methane emissions from natural wetlands and carbon release from permafrost thaw have a positive feedback on climate, yet are not represented in most state-of-the-art climate models. Furthermore, a fraction of the thawed permafrost carbon is released as methane, enhancing the combined feedback strength. We present simulations with an inverted intermediate complexity climate model, which follows prescribed global warming pathways to stabilization at 1.5 or 2.0 °C above pre-industrial levels by the year 2100, and which incorporates a state-of-the-art global land surface model with updated descriptions of wetland and permafrost carbon release. We demonstrate that the climate feedbacks from those two processes are substantial. Specifically, permissible anthropogenic fossil fuel CO2 emission budgets are reduced by 17–23% (47–56 GtC) for stabilization at 1.5 °C, and 9–13% (52–57 GtC) for 2.0 °C stabilization. In our simulations these feedback processes respond more quickly at temperatures below 1.5 °C, and the differences between the 1.5 and 2 °C targets are disproportionately small. This key finding holds for transient emission pathways to 2100 and does not account for longer-term implications of these feedback processes. We conclude that natural feedback processes from wetlands and permafrost must be considered in assessments of transient emission pathways to limit global warming.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from $8.99

All prices are NET prices.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.


  1. 1.

    Copenhagen Accord FCCC/CP/2015/L.9/Rev.1 (UNFCCC, 2009).

  2. 2.

    Adoption of the Paris Agreement FCCC/CP/2015/L.9/Rev.1 (UNFCCC, 2015).

  3. 3.

    Huntingford, C. et al. The link between a global 2 °C warming threshold and emissions in years 2020, 2050 and beyond. Environ. Res. Lett. 7, 014039 (2012).

  4. 4.

    Rogelj, J., McCollum, D. L., Reisinger, A., Meinshausen, M. & Riahi, K. Probabilistic cost estimates for climate change mitigation. Nature 493, 79–83 (2013).

  5. 5.

    Huntingford, C. & Mercado, L. M. High chance that current atmospheric greenhouse concentrations commit to warmings greater than 1.5°C over land. Sci. Rep. 6, 30294 (2016).

  6. 6.

    IPCC Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) (Cambridge Univ. Press, 2013).

  7. 7.

    Cox, P. M., Betts, R. A., Jones, C. D., Spall, S. A. & Totterdell, I. J. Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model. Nature 408, 184–187 (2000).

  8. 8.

    Gedney, N., Cox, P. M. & Huntingford, C. Climate feedback from wetland methane emissions. Geophys. Res. Lett. 31, L20503 (2004).

  9. 9.

    Shindell, D. T., Walter, B. P. & Faluvegi, G. Impacts of climate change on methane emissions from wetlands. Geophys. Res. Lett. 31, L21202 (2004).

  10. 10.

    Burke, E. J. et al. Quantifying uncertainties of permafrost carbon–climate feedbacks. Biogeosciences 14, 3051 (2017).

  11. 11.

    McGuire, A. D. et al. Variability in the sensitivity among model simulations of permafrost and carbon dynamics in the permafrost region between 1960 and 2009. Glob. Biogeochem. Cycles 30, 1015–1037 (2016).

  12. 12.

    Burke, E. J., Chadburn, S. E., Huntingford, C. & Jones, C. D. CO2 loss by permafrost thawing implies additional emissions reductions to limit warming to 1.5 or 2 °C. Environ. Res. Lett. 13, 024024 (2018).

  13. 13.

    Millar, R. J. et al. Emission budgets and pathways consistent with limiting warming to 1.5 °C. Nat. Geosci. 10, 741–747 (2017).

  14. 14.

    Tokarska, K. B. & Gillett, N. P. Cumulative carbon emissions budgets consistent with 1.5 °C global warming. Nat. Clim. Change 8, 296–299 (2018).

  15. 15.

    Taylor, K. E., Stouffer, R. J. & Meehl, G. A. An overview of CMIP5 and the experiment design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012).

  16. 16.

    Schädel, C. et al. Potential carbon emissions dominated by carbon dioxide from thawed permafrost soils. Nat. Clim. Change 6, 950 (2016).

  17. 17.

    Schuur, E. A. G. et al. Climate change and the permafrost carbon feedback. Nature 520, 171–179 (2015).

  18. 18.

    Crill, P. M. & Thornton, B. F. Whither methane in the IPCC process? Nat. Clim. Change 7, 678 (2017).

  19. 19.

    Huntingford, C. et al. Flexible parameter-sparse global temperature time profiles that stabilise at 1.5 and 2.0 °C. Earth Syst. Dynam. 8, 617–626 (2017).

  20. 20.

    Best, M. et al. The Joint UK Land Environment Simulator (JULES), model description–Part 1: energy and water fluxes. Geosci. Model Dev. 4, 677–699 (2011).

  21. 21.

    Clark, D. et al. The Joint UK Land Environment Simulator (JULES), model description–Part 2: carbon fluxes and vegetation dynamics. Geosci. Model Dev. 4, 701–722 (2011).

  22. 22.

    Huntingford, C. & Cox, P. M. An analogue model to derive additional climate change scenarios from existing GCM simulations. Clim. Dynam. 16, 575–586 (2000).

  23. 23.

    Huntingford, C. et al. IMOGEN: an intermediate complexity model to evaluate terrestrial impacts of a changing climate. Geosci. Model Dev. 3, 679–687 (2010).

  24. 24.

    Chadburn, S. et al. An improved representation of physical permafrost dynamics in the JULES land-surface model. Geosci. Model Dev. 8, 1493–1508 (2015).

  25. 25.

    Burke, E. J., Chadburn, S. E. & Ekici, A. A vertical representation of soil carbon in the JULES land surface scheme (vn4. 3_permafrost) with a focus on permafrost regions. Geosci. Model Dev. 10, 959–975 (2017).

  26. 26.

    Morice, C. P., Kennedy, J. J., Rayner, N. A. & Jones, P. D. Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: the HadCRUT4 data set. J. Geophys. Res. 117, D08101 (2012).

  27. 27.

    Meinshausen, M. et al. The RCP greenhouse gas concentrations and their extensions from 1765 to 2300. Clim. Change 109, 213 (2011).

  28. 28.

    van Vuuren, D. P. et al. Energy, land-use and greenhouse gas emissions trajectories under a green growth paradigm. Glob. Environ. Change 42, 237–250 (2017).

  29. 29.

    Brown, J., Ferrians, O. Jr, Heginbottom, J. & Melnikov, E. Circum-Arctic Map of Permafrost and Ground-Ice Conditions (National Snow and Ice Data Center, 1998).

  30. 30.

    Chadburn, S. E. et al. An observation-based constraint on permafrost loss as a function of global warming. Nat. Clim. Change 7, 340–344 (2017).

  31. 31.

    Zhang, B. et al. Methane emissions from global wetlands: an assessment of the uncertainty associated with various wetland extent data sets. Atmos. Environ. 165, 310–321 (2017).

  32. 32.

    Poulter, B. et al. Global wetland contribution to 2000–2012 atmospheric methane growth rate dynamics. Environ. Res. Lett. 12, 094013 (2017).

  33. 33.

    Turetsky, M. R. et al. A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands. Glob. Change Biol. 20, 2183–2197 (2014).

  34. 34.

    Saunois, M. et al. The global methane budget 2000–2012. Earth Syst. Sci. Data 8, 697–751 (2016).

  35. 35.

    Jones, C. et al. The HadGEM2-ES implementation of CMIP5 centennial simulations. Geosci. Model Dev. 4, 543 (2011).

  36. 36.

    Zona, D. et al. Cold season emissions dominate the Arctic tundra methane budget. Proc. Natl Acad. Sci. USA 113, 40–45 (2016).

  37. 37.

    McNorton, J. et al. Role of regional wetland emissions in atmospheric methane variability. Geophys. Res. Lett. 43, 433–444 (2016).

  38. 38.

    Clark, D. et al. The Joint UK Land Environment Simulator (JULES), model description–Part 2: carbon fluxes and vegetation dynamics. Geosci. Model Dev. 4, 701–722 (2011).

  39. 39.

    Gedney, N. & Cox, P. M. The sensitivity of global climate model simulations to the representation of soil moisture heterogeneity. J. Hydrometeorol. 4, 1265–1275 (2003).

  40. 40.

    Marthews, T., Dadson, S., Lehner, B., Abele, S. & Gedney, N. High-resolution global topographic index values for use in large-scale hydrological modelling. Hydrol. Earth Syst. Sci. 19, 91–104 (2015).

  41. 41.

    Klein Goldewijk, K., Beusen, A., Van Drecht, G. & De Vos, M. The HYDE 3.1 spatially explicit database of human‐induced global land‐use change over the past 12,000 years. Glob. Ecol. Biogeogr. 20, 73–86 (2011).

  42. 42.

    Sitch, S., Cox, P. M., Collins, W. J. & Huntingford, C. Indirect radiative forcing of climate change through ozone effects on the land-carbon sink. Nature 448, 791–794 (2007).

  43. 43.

    Stohl, A. et al. Evaluating the climate and air quality impacts of short-lived pollutants. Atmos. Chem. Phys. 15, 10529–10566 (2015).

  44. 44.

    Etminan, M., Myhre, G., Highwood, E. J. & Shine, K. P. Radiative forcing of carbon dioxide, methane, and nitrous oxide: a significant revision of the methane radiative forcing. Geophys. Res. Lett. 43, 614–623 (2016).

  45. 45.

    IPCC Climate Change 2001: The Scientific Basis (eds Houghton, J. T. et al.) (Cambridge Univ. Press, 2001).

Download references


This work was undertaken as part of the UK Natural Environment Research Council’s programme ‘Understanding the Pathways to and Impacts of a 1.5 °C Rise in Global Temperature’ through grants NE/P015050/1 CLIFFTOP (to E.C.-P., G.H. and S.E.C.), NE/P014909/1, MOC1.5 (to W.J.C., C.P.W., C.H., P.M.C. and S.S.) and NE/P014941/1 CLUES (to A.B.H., P.M.C. and T.P.). The authors also acknowledge support for E.J.B. and N.G. through the Joint UK BEIS/Defra Met Office Hadley Centre Climate Programme (GA01101), E.J.B. through CRESCENDO (EU project 641816), A.B.H. through an EPSRC Fellowship ‘Negative Emissions and the Food–Energy–Water Nexus’ (EP/N030141/1), and C.H. through CEH National Capability Funding. The authors also acknowledge the wetland extent data products provided by B. Zhang of Auburn University and B. Poulter of the NASA Goddard Space Flight Center.

Author information


  1. Centre for Ecology and Hydrology, Wallingford, UK

    • Edward Comyn-Platt
    • , Garry Hayman
    •  & Chris Huntingford
  2. University of Leeds, Leeds, UK

    • Sarah E. Chadburn
  3. University of Exeter, Exeter, UK

    • Sarah E. Chadburn
    • , Anna B. Harper
    • , Tom Powell
    • , Peter M. Cox
    •  & Stephen Sitch
  4. Met Office Hadley Centre, Exeter, UK

    • Eleanor J. Burke
  5. University of Reading, Reading, UK

    • William J. Collins
    •  & Christopher P. Webber
  6. Met Office Hadley Centre, Joint Centre for Hydrometeorological Research, Wallingford, UK

    • Nicola Gedney


  1. Search for Edward Comyn-Platt in:

  2. Search for Garry Hayman in:

  3. Search for Chris Huntingford in:

  4. Search for Sarah E. Chadburn in:

  5. Search for Eleanor J. Burke in:

  6. Search for Anna B. Harper in:

  7. Search for William J. Collins in:

  8. Search for Christopher P. Webber in:

  9. Search for Tom Powell in:

  10. Search for Peter M. Cox in:

  11. Search for Nicola Gedney in:

  12. Search for Stephen Sitch in:


G.H., E.J.B., S.E.C. and E.C.-P. conceived and developed the project. E.C.-P. and C.H. led the development of the inverse IMOGEN model system. E.J.B. and S.E.C. contributed code and expertise on permafrost and soil carbon modelling. N.G., S.E.C. and E.C.-P. contributed code and expertise on the JULES wetlands methane scheme. A.B.H. and T.P. contributed land-use change data, W.J.C. and C.P.W. ozone ancillary data and S.S. contributed expertise on the ozone damage effects, respectively. E.C.-P., C.H., G.H., E.J.B., S.E.C., W.J.C., C.P.W., P.M.C., A.B.H. and T.P. contributed to the design of the IMOGEN model runs. All authors contributed to the interpretation of the results and to the writing of the paper.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Edward Comyn-Platt.

Supplementary information

  1. Supplementary Information

    Supplementary Figures and Tables

About this article

Publication history