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| Titel |
Climate-vegetation modelling and fossil plant data suggest low atmospheric CO2 in the late Miocene |
| VerfasserIn |
M. Forrest, J. T. Eronen, T. Utescher, G. Knorr, C. Stepanek, G. Lohmann, T. Hickler |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 11, no. 12 ; Nr. 11, no. 12 (2015-12-16), S.1701-1732 |
| Datensatznummer |
250117490
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| Publikation (Nr.) |
 copernicus.org/cp-11-1701-2015.pdf |
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| Zusammenfassung |
| There is an increasing need to understand the pre-Quaternary warm climates, how
climate–vegetation interactions functioned in the past, and how we can use
this information to understand the present. Here we report vegetation
modelling results for the Late Miocene (11–7 Ma) to study the mechanisms of
vegetation dynamics and the role of different forcing factors that influence
the spatial patterns of vegetation coverage. One of the key uncertainties is
the atmospheric concentration of CO2 during past climates. Estimates
for the last 20 million years range from 280 to 500 ppm. We simulated
Late Miocene vegetation using two plausible CO2 concentrations, 280 ppm
CO2 and 450 ppm CO2, with a dynamic global vegetation model
(LPJ-GUESS) driven by climate input from a coupled AOGCM (Atmosphere-Ocean
General Circulation Model). The simulated vegetation was compared to
existing plant fossil data for the whole Northern Hemisphere. For the
comparison we developed a novel approach that uses information of the
relative dominance of different plant functional types (PFTs) in the
palaeobotanical data to provide a quantitative estimate of the agreement
between the simulated and reconstructed vegetation. Based on this
quantitative assessment we find that pre-industrial CO2 levels are
largely consistent with the presence of seasonal temperate forests in Europe
(suggested by fossil data) and open vegetation in North America (suggested
by multiple lines of evidence). This suggests that during the Late Miocene
the CO2 levels have been relatively low, or that other factors that are
not included in the models maintained the seasonal temperate forests and
open vegetation. |
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