English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  Local TagsRelease HistoryDetailsSummary

Released
Journal Article

Carbon Dioxide and Methane Release Following Abrupt Thaw of Pleistocene Permafrost Deposits in Arctic Siberia

Authors

Knoblauch,  Christian
External Organizations;

Beer,  Christian
External Organizations;

Schuett,  Alexander
External Organizations;

Sauerland,  Lewis
External Organizations;

/persons/resource/sliebner

Liebner,  Susanne
3.7 Geomicrobiology, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

Steinhof,  Axel
External Organizations;

Rethemeyer,  Janet
External Organizations;

Grigoriev,  Mikhail N.
External Organizations;

Faguet,  Alexey
External Organizations;

Pfeiffer,  Eva‐Maria
External Organizations;

External Ressource
No external resources are shared
Fulltext (public)

5008709.pdf
(Publisher version), 2MB

Supplementary Material (public)
There is no public supplementary material available
Citation

Knoblauch, C., Beer, C., Schuett, A., Sauerland, L., Liebner, S., Steinhof, A., Rethemeyer, J., Grigoriev, M. N., Faguet, A., Pfeiffer, E. (2021): Carbon Dioxide and Methane Release Following Abrupt Thaw of Pleistocene Permafrost Deposits in Arctic Siberia. - Journal of Geophysical Research: Biogeosciences, 126, 11, e2021JG006543.
https://doi.org/10.1029/2021JG006543


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5008709
Abstract
The decomposition of thawing permafrost organic matter (OM) to the greenhouse gases (GHG) carbon dioxide (CO2) and methane forms a positive feedback to global climate change. Data on in situ GHG fluxes from thawing permafrost OM are scarce and OM degradability is largely unknown, causing high uncertainties in the permafrost-carbon climate feedback. We combined in situ CO2 and methane flux measurements at an abrupt permafrost thaw feature with laboratory incubations and dynamic modeling to quantify annual CO2 release from thawing permafrost OM, estimate its in situ degradability and evaluate the explanatory power of incubation experiments. In July 2016 and 2019, CO2 fluxes ranged between 0.24 and 2.6 g CO2-C m−2 d−1. Methane fluxes were low, which coincided with the absence of active methanogens in the Pleistocene permafrost. CO2 fluxes were lower three years after initial thaw after normalizing these fluxes to thawed carbon, indicating the depletion of labile carbon. Higher CO2 fluxes from thawing Pleistocene permafrost than from Holocene permafrost indicate OM preservation for millennia and give evidence that microbial activity in the permafrost was not substantial. Short-term incubations overestimated in situ CO2 fluxes but underestimated methane fluxes. Two independent models simulated median annual CO2 fluxes of 160 and 184 g CO2-C m−2 from the thaw slump, which include 25%–31% CO2 emissions during winter. Annual CO2 fluxes represent 0.8% of the carbon pool thawed in the surface soil. Our results demonstrate the potential of abrupt thaw processes to transform the tundra from carbon neutral into a substantial GHG source.