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| Titel |
Stomatal proxy record of CO2 concentrations during the Last Termination demonstrates dynamic climate behaviour and an important role for CO2. |
| VerfasserIn |
Margret Steinthorsdottir, Barbara Wohlfarth, Malin E. Kylander, Maarten Blaauw, Paula J. Reimer |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250077272
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| Zusammenfassung |
| We present a new stomatal proxy-based record of CO2 concentrations spanning Greenland Interstadial 1 (Allerød pollen zone, GI-1a to 1c), Greenland Stadial 1 (Younger Dryas pollen zone, GS-1) and the first part of the Holocene (Preboreal pollen zone). The calibrated atmospheric CO2 concentrations are based on Betula nana (dwarf birch) leaves from a fossil lake sedimentary sequence in south-eastern Sweden. The stomatal proxy method relies on the inverse relationship between stomatal density on plant leaves and atmospheric CO2 concentrations to reconstruct variations in past CO2 concentrations.
The record presented here demonstrates that the overall pattern of CO2 evolution during this period was dynamic, with significant abrupt fluctuations in CO2 concentration when the climate moved from interstadial to stadial state and vice versa. The cooling at the GI-1/GS-1 transition was preceded by an abrupt warming, and the warming at the GS-1/Holocene transition was preceded by an abrupt cooling. This scenario is in contrast to CO2 records reconstructed from air bubbles trapped in ice, which indicate a gradual increase in concentrations, but largely in alignment with previously published stomatal proxy-based CO2 records. A new loss-on-ignition chemical record (used here as a proxy for temperature), from the same locality, lends independent support to the CO2 record. |
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