Abstract
Permafrost is thawing extensively due to climate warming. When permafrost thaws, previously frozen organic carbon (OC) is converted into carbon dioxide (CO2) or methane, leading to further warming. This process is included in models as gradual deepening of the seasonal non-frozen layer. Yet, models neglect abrupt OC mobilization along rapidly eroding Arctic coastlines. We mimicked erosion in an experiment by incubating permafrost with seawater for an average Arctic open-water season. We found that CO2 production from permafrost OC is as efficient in seawater as without. For each gram (dry weight) of eroding permafrost, up to 4.3 ± 1.0 mg CO2 will be released and 6.2 ± 1.2% of initial OC mineralized at 4 °C. Our results indicate that potentially large amounts of CO2 are produced along eroding permafrost coastlines, onshore and within nearshore waters. We conclude that coastal erosion could play an important role in carbon cycling and the climate system.
| Original language | English |
|---|---|
| Pages (from-to) | 11244-11252 |
| Number of pages | 9 |
| Journal | Geophysical Research Letters |
| Volume | 46 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - 28 Oct 2019 |
Funding
We are grateful for the financial support of the Helmholtz Young Investigators Groups “COPER” (Grant VH‐NG‐801 to H. Lantuit) and “TEAM” (Grant VH‐NG‐821 to T. Sachs), the Daimler and Benz Foundation (Grant 32‐02/15 to M. Fritz), and Nunataryuk (Grant 773421). We thank O. Burckhardt and I. Milczarek for their support in the lab and J. Strauss, G. Schwamborn, S. Liebner, A. Kiss, B. Koch, and J. Vonk for their expertise and scientific guidance. A. M. Irrgang, E. McLeod, and S. Stettner are thanked for assisting in the field and J. Kahl for logistical support. We especially acknowledge the logistical support in Canada provided by the Aurora Research Institute Inuvik and R. Gordon and the rangers from the Qikiqtaruk —Herschel Island Territorial Park. Finally, we thank C. O'Connor for language correction and proofreading as well as the Editor and reviewer for their helpful comments. Additional and supporting data can be accessed in the PANGAEA data repository ( https://doi.pangaea.de/10.1594/PANGAEA.905912 ).
| Funders | Funder number |
|---|---|
| Aurora Research Institute Inuvik | |
| Qikiqtaruk—Herschel Island Territorial Park | |
| Horizon 2020 Framework Programme | 773421 |
| Daimler und Benz Stiftung | 32‐02/15 |
Keywords
- Arctic
- carbon cycling
- climate warming
- coastal erosion
- greenhouse gases
- permafrost
