title: Temperature and atmospheric CO2 concentration estimates through the PETM using triple oxygen isotope analysis of mammalian bioapatite.
abstract: The Paleocene-Eocene Thermal Maximum (PETM) is a remarkable climatic and environmental event that occurred 56 Ma ago and has importance for understanding possible future climate change. The Paleocene-Eocene transition is marked by a rapid temperature rise contemporaneous with a large negative carbon isotope excursion (CIE). Both the temperature and the isotopic excursion are well-documented by terrestrial and marine proxies. The CIE was the result of a massive release of carbon into the atmosphere. However, the carbon source and quantities of CO2 and CH4 greenhouse gases that contributed to global warming are poorly constrained and highly debated. Here we combine an established oxygen isotope paleothermometer with a newly developed triple oxygen isotope paleo-CO2 barometer. We attempt to quantify the source of greenhouse gases released during the Paleocene-Eocene transition by analyzing bioapatite of terrestrial mammals. Our results are consistent with previous estimates of PETM temperature change and suggest that not only CO2 but also massive release of seabed methane was the driver for CIE and PETM.
authors.affiliation: Geowissenschaftliches Zentrum, Geowissenschaftliches Museum, Georg-August-Universität, D-37077 Göttingen, Germany; agehler@gwdg.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Gehler
authors.affiliation: Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109; Museum of Paleontology, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Philip D
authors.identifier: 0000-0002-1550-2674
authors.initials: PD
authors.lastname: Gingerich
authors.affiliation: Geowissenschaftliches Zentrum, Abteilung Isotopengeologie, Georg-August-Universität, D-37077 Göttingen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Pack
mesh_terms: D001031:Apatites / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry; D002245:Carbon Dioxide; D057231:Climate Change; D003743:Dental Enamel / Q000737:chemistry*; D005580:Fossils; D000074382:Greenhouse Gases; D008697:Methane; D010103:Oxygen Isotopes / Q000032:analysis*; D013696:Temperature
chemical_list: D001031:Apatites; D000074382:Greenhouse Gases; D010103:Oxygen Isotopes; D002245:Carbon Dioxide; D008697:Methane
keywords: CO2 concentration; PETM; mammals; temperature