Changing boreal methane sources and constant biomass burning during the last termination

Fischer, Hubertus; Behrens, Melanie; Bock, Michael; Richter, Ulrike; Schmitt, Jochen; Loulergue, Laetitia; Chappellaz, Jerome; Spahni, Renato; Blunier, Thomas; Leuenberger, Markus; Stocker, Thomas F. (2008). Changing boreal methane sources and constant biomass burning during the last termination. Nature, 452(7189), pp. 864-867. London: Macmillan Journals Ltd. 10.1038/nature06825

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Past atmospheric methane concentrations show strong fluctuations in parallel to rapid glacial climate changes in the Northern Hemisphere superimposed on a glacial–interglacial doubling of methane concentrations. The processes driving the observed fluctuations remain uncertain but can be constrained using methane isotopic information from ice cores. Here we present an ice core record of carbon isotopic ratios in methane over the entire last glacial–interglacial transition. Our data show that the carbon in atmospheric methane was isotopically much heavier in cold climate periods. With the help of a box model constrained by the present data and previously published results, we are able to estimate the magnitude of past individual methane emission sources and the atmospheric lifetime of methane. We find that methane emissions due to biomass burning were about 45 Tg methane per year, and that these remained roughly constant throughout the glacial termination. The atmospheric lifetime of methane is reduced during cold climate periods. We also show that boreal wetlands are an important source of methane during warm events, but their methane emissions are essentially shut down during cold climate conditions.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Climate and Environmental Physics
08 Faculty of Science > Physics Institute

UniBE Contributor:

Fischer, Hubertus; Schmitt, Jochen; Spahni, Renato; Blunier, Thomas; Leuenberger, Markus and Stocker, Thomas

Subjects:

500 Science > 530 Physics

ISSN:

0028-0836

Publisher:

Macmillan Journals Ltd.

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 15:23

Last Modified:

15 Jul 2021 15:02

Publisher DOI:

10.1038/nature06825

Web of Science ID:

000255026000046

BORIS DOI:

10.48350/37307

URI:

https://boris.unibe.ch/id/eprint/37307 (FactScience: 207473)

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