Browse by author
Lookup NU author(s): Dr Luke Handley
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
The Palaeocene-Eocene thermal maximum (PETM), a period of intense, global warming about 55 million years ago(1), has been attributed to a rapid rise in greenhouse gas levels, with dissociation of methane hydrates being the most commonly invoked explanation(2). It has been suggested previously that high-latitude methane emissions from terrestrial environments could have enhanced the warming effect(3,4), but direct evidence for an increased methane flux from wetlands is lacking. The Cobham Lignite, a recently characterized expanded lacustrine/mire deposit in England, spans the onset of the PETM5 and therefore provides an opportunity to examine the biogeochemical response of wet-land-type ecosystems at that time. Here we report the occurrence of hopanoids, biomarkers derived from bacteria, in the mire sediments from Cobham. We measure a decrease in the carbon isotope values of the hopanoids at the onset of the PETM interval, which suggests an increase in the methanotroph population. We propose that this reflects an increase in methane production potentially driven by changes to a warmer(1,6) and wetter climate(7,8). Our data suggest that the release of methane from the terrestrial biosphere increased and possibly acted as a positive feedback mechanism to global warming.
Author(s): Pancost RD, Steart DS, Handley L, Collinson ME, Hooker JJ, Scott AC, Grassineau NV, Glasspool IJ
Publication type: Article
Publication status: Published
Journal: Nature
Year: 2007
Volume: 449
Issue: 7160
Pages: 332-335
ISSN (print): 0028-0836
ISSN (electronic): 1476-4687
Publisher: Nature Publishing Group
URL: http://dx.doi.org/10.1038/nature06012
DOI: 10.1038/nature06012
Altmetrics provided by Altmetric
