Stomatal proxy record of CO2 concentrations from the last termination suggests an important role for CO2 at climate change transitions


Autoria(s): Steinthorsdottir, Margaret; Wohlfarth, Barbara; Kylander, Malin E.; Blaauw, Maarten; Reimer, Paula J.
Data(s)

15/05/2013

Resumo

A new stomatal proxy-based record of CO<sub>2</sub> concentrations ([CO<sub>2</sub>]), based on Betula nana (dwarf birch) leaves from the Hässeldala Port sedimentary sequence in south-eastern Sweden, is presented. The record is of high chronological resolution and spans most of Greenland Interstadial 1 (GI-1a to 1c, Allerød pollen zone), Greenland Stadial 1 (GS-1, Younger Dryas pollen zone) and the very beginning of the Holocene (Preboreal pollen zone). The record clearly demonstrates that i) [CO<sub>2</sub>] were significantly higher than usually reported for the Last Termination and ii) the overall pattern of CO<sub>2</sub> evolution through the studied time period is fairly dynamic, with significant abrupt fluctuations in [CO<sub>2</sub>] when the climate moved from interstadial to stadial state and vice versa. A new loss-on-ignition chemical record (used here as a proxy for temperature) lends independent support to the Hässeldala Port [CO<sub>2</sub>] record. The large-amplitude fluctuations around the climate change transitions may indicate unstable climates and that " tipping-point" situations were involved in Last Termination climate evolution. The scenario presented here is in contrast to [CO<sub>2</sub>] records reconstructed from air bubbles trapped in ice, which indicate lower concentrations and a gradual, linear increase of [CO<sub>2</sub>] through time. The prevalent explanation for the main climate forcer during the Last Termination being ocean circulation patterns needs to re-examined, and a larger role for atmospheric [CO<sub>2</sub>] considered.

Identificador

http://pure.qub.ac.uk/portal/en/publications/stomatal-proxy-record-of-co2-concentrations-from-the-last-termination-suggests-an-important-role-for-co2-at-climate-change-transitions(c378a0e0-8e39-40bf-97db-a5f6ab92d7cd).html

http://dx.doi.org/10.1016/j.quascirev.2013.02.003

Idioma(s)

eng

Direitos

info:eu-repo/semantics/restrictedAccess

Fonte

Steinthorsdottir , M , Wohlfarth , B , Kylander , M E , Blaauw , M & Reimer , P J 2013 , ' Stomatal proxy record of CO2 concentrations from the last termination suggests an important role for CO2 at climate change transitions ' Quaternary Science Reviews , vol 68 , pp. 43-58 . DOI: 10.1016/j.quascirev.2013.02.003

Tipo

article