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| Titel |
Abrupt carbon release at the onset of the Bølling/Allerød: Permafrost thawing with inter-hemispheric impact |
| VerfasserIn |
Peter Köhler, Gregor Knorr, Edouard Bard |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250089677
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| Publikation (Nr.) |
 EGU/EGU2014-3887.pdf |
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| Zusammenfassung |
| Atmospheric carbon dioxide (CO2) during the last deglaciation (~18–10 kyr BP) switched
around 14.6 kyr BP from a rather gradual rise to an abrupt jump, which is recorded in
ice cores as an increase of 10 ppmv in less than two centuries. So far the source
of that CO2 excursion could not be identified and the climatic implications are
largely unknown. Here we use highly resolved U/Th dated atmospheric Δ14C from
Tahiti corals as independent age control for CO2 changes. This provides a temporal
framework to show that the northern high latitude warming into the Bølling/Allerød
occurred quasi-synchronous to this CO2 rise within a few decades. Furthermore we
show that an abrupt release (within two centuries) of long-term immobile nearly
14C-free carbon (~125 PgC) from thawing permafrost might explain the observed
anomalies in atmospheric CO2 and Δ14C, in line with CH4 and biomarker records from
ice and sediment cores. In transient climate simulations we show that the abrupt
carbon release in the northern high latitudes and associated CO2 changes bear the
potential to modulate Antarctic temperature. These findings are in agreement with
the observed onset of the Antarctic Cold Reversal about two centuries after the
beginning of the Bølling/Allerød, as detected in independent annual layer-counted
ice cores from both hemispheres. Based on the timing, magnitude, origin and the
inter-hemispheric impact we speculate that this abrupt deglacial release of long-term stored
carbon via thawing permafrost might have provided the final push out of the last ice
age. |
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