Expert assessment of vulnerability of permafrost carbon to climate change

TitleExpert assessment of vulnerability of permafrost carbon to climate change
Publication TypeJournal Article
Year of Publication2013
AuthorsSchuur E.AG, Abbott B.W, Bowden W.B, Brovkin V., Camill P., Canadell J.G, Chanton J.P, Chapin F.S, Christensen T.R, Ciais P., Crosby B.T, Czimczik C.I, Grosse G., Harden J., Hayes D.J, Hugelius G., Jastrow J.D, Jones J.B, Kleinen T., Koven C.D, Krinner G., Kuhry P., Lawrence D.M, McGuire A.D, Natali S.M, O'Donnell J.A, Ping C.L, Riley W.J, Rinke A., Romanovsky V.E, Sannel A.BK, Schadel C., Schaefer K., Sky J., Subin Z.M, Tarnocai C., Turetsky M.R, Waldrop M.P, Anthony K.MWalter, Wickland K.P, Wilson C.J, Zimov S.A
JournalClimatic ChangeClimatic ChangeClimatic Change
Date PublishedJul
ISBN Number0165-0009
Accession NumberISI:000321955100012
Keywordsdegradation, ecosystems, emissions, feedbacks, interior alaska, release, responses, soils, thermokarst, tundra

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.

Short TitleClimatic ChangeClimatic Change
Alternate JournalClimatic Change