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| Titel |
Productivity feedback did not terminate the Paleocene-Eocene Thermal Maximum (PETM) |
| VerfasserIn |
A. Torfstein, G. Winckler, A. Tripati |
| 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 ; 6, no. 2 ; Nr. 6, no. 2 (2010-04-16), S.265-272 |
| Datensatznummer |
250003448
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| Publikation (Nr.) |
 copernicus.org/cp-6-265-2010.pdf |
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| Zusammenfassung |
| The Paleocene-Eocene Thermal Maximum (PETM) occurred approximately 55
million years ago, and is one of the most dramatic abrupt global warming
events in the geological record. This warming was triggered by the sudden
release of thousands of gigatons of carbon into the atmosphere and is widely
perceived to be the best analogue for current anthropogenic climate change.
Yet, the mechanism of recovery from this event remains controversial. A
massive increase in the intensity of the marine biological pump
("productivity feedback") has been suggested to cause a drawdown of
atmospheric CO2 and subsequent carbon sequestration in the ocean. A
re-evaluation of the "productivity feedback hypothesis", based on biogenic
barium mass accumulation rates (Ba-MARs) for a site in the Southern Ocean,
finds that any increase in export production lagged the initial carbon
release by at least ~70 000 years. This implies that export production
did not facilitate rapid removal of excess carbon from the atmosphere. Thus,
the most likely mechanism for carbon removal appears to be silicate
weathering, which occurred at much slower rates than previously assumed. |
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