Canadian Forest Service Publications

Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment. 2016. Abbott, B.W.; Jones, J.B.; Schuur, E.A.G.; Chapin III, F.S.; Bowden, W.B.; Bret-Harte, M.S.; Epstein, H.E.; Flannigan, M.D.; Harms, T.K.; Hollingsworth, T.N.; Mack, M.C.; McGuire, A.D.; Natali, S.M.; Rocha, A.V.; Tank, S.E.; Turetsky, M.R.; Vonk, J.E.; Wickland, K.P.; Aiken, G.R.; Alexander, H.D.; Amon, R.M.W.; Benscoter, B.W.; Bergeron, Y.; Bishop, K.; Blarquez, O.; Bond-Lamberty, B.; Breen, A.L.; Buffam, I.; Cai, Y.; Carcaillet, C.; Carey, S.K.; Chen, J.M.; Chen, H.Y.H.; Christensen, T.R.; Cooper, L.W.; Cornelissen, J.H.C.; de Groot, W.J.; DeLuca, T.H.; Dorrepaal, E.; Fetcher, N.; Finlay, J.C.; Forbes, B.C.; French, N.H.F.; Gauthier, S.; Girardin, M.P.; Goetz, S.J.; Goldammer, J.G.; Gough, L.; Grogan, P.; Guo, L.; Higuera, P.E.; Hinzman, L.; Hu, F.S.; Hugelius, G,; Jafarov, E.E.; Jandt, R.; Johnstone, J.F.; Karlsson, J.; Sasischke, E.S.; Kattner, G.; Kelly, R.; Keuper, F. ; Kling, G.W.; Kortelainen, P.; Kouki, J.; Kuhry, P.; Laudon, H.; Laurion, I.; Macdonald, R.W.; Mann, P.J.; Martikainen, P.J.; McClelland, J.W.; Molau, U.; Oberbauer, S.F.; Olefeldt, D.; Paré, D.; Parisien, M.-A.; Payette, S.; Peng, C.; Pokrovsky, O.S.; Rastetter, E.B.; Raymond, P.A.; Raynolds, M.K.; Rein, G.; Reynolds, J.F.; Robards, M.; Rogers, B.M.; Schädel, C.; Schaefer, K.; Schmidt, I.K.; Shvidenko, A.; Sky, J.;Spencer, R.G.M.; Starr, G.; Striegl, R.G.; Teisserenc, R.; Tranvik, L.J.; Virtanen, T.; Welker, J.M.; Zimov, S. Environmental Research Letters 11(2016)034014.

Year: 2016

Available from: Northern Forestry Centre

Catalog ID: 36630

Language: English

CFS Availability: PDF (download)

Available from the Journal's Web site.
DOI: 10.1088/1748-9326/11/3/034014

† This site may require a fee.

Abstract

As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

Plain Language Summary

This article is a key international synthesis of views from almost 100 permafrost scientists, gathered through expert assessments held in 2013. The permafrost region captures an average of 500 terragrams of carbon a year from the atmosphere, making it a carbon “sink.” Under climate change, much of the permafrost in the world’s Arctic and boreal regions is expected melt, releasing huge amounts of carbon into water and air, and increasing the risk of fire by up to four times by the end of the century. This release would represent 10% to 30% of greenhouse gas emissions required to push the global climate beyond the 2 ⁰C target. Some of this carbon release is expected help new plant life grow in Arctic and boreal regions, increasing the “biomass” that removes carbon from the environment. This biomass could initially respond quickly to warming, taking up some or all of the carbon release. But as the climate increasingly warms, the permafrost region will not be able to absorb as much carbon as it produces, making it a net carbon “source” by 2100, under all global climate models. There is a five-fold difference in emissions from permafrost depending on the climate change scenario that becomes reality, from a business-as-usual scenario to a scenario with active reductions in human emissions. The latter could avoid 65% to 85% of the carbon release from permafrost.

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