The peatland / ice age hypothesis revised, adding a possible glacial pulse trigger.

File Size Format
49543_1.pdf 1529Kb Adobe PDF View
Title The peatland / ice age hypothesis revised, adding a possible glacial pulse trigger.
Author Franzen, Lars G.; Cropp, Roger Allan
Journal Name Geografiska Annaler
Year Published 2007
Place of publication Oxford, UK
Publisher Blackwell Publishing for the Swedish Society for Anthropology and Geography
Abstract Carbon sequestering in peatlands is believed to be a major climate-regulating mechanism throughout the late Phanerozoic. Since plant life first evolved on land, peatlands have been significant carbon sinks, which could explain significant parts of the large variations in atmospheric carbon dioxide observed in various records. The result is peat in different degrees of metamorphosis, i.e. lignite, hard coal and graphite. During phases of extensive glaciations such as the 330–240 Ma Pangea Ice Age, atmospheric carbon dioxide was critically low. This pattern repeats itself during the Pleistocene when carbon dioxide oscillates with an amplitude of c. 200–300 ppmv. This paper suggests that the ice age cycles during the Pleistocene are generated by the interglacial growth of peatlands and the subsequent sequestering of carbon into this terrestrial pool. The final initiation of ice age pulses towards the end of inter-glacials, on the other hand, is attributed to the cyclic influx of cosmic dust to the Earth surface, which in turn regulates cloud formation and the incoming shortwave radiation. These shorter cycles have a frequency of c. 1000-1250 years and might be connected to sunspot or other low frequency solar variations. In a wider context the ice age cycling could be regarded as an interplay between terrestrial life on the high latitudes of the northern hemisphere and the marine subsurface life in the southeast. If the results presented here are correct, the present global warming might just be the early part of a new warm period such as the Bronze Age and the Roman and Medieval Warm periods. This could be caused by entry into another phase of decreasing influx rates of cosmic dust. The increasing concentrations of atmospheric carbon dioxide might have contributed to this warming but, most important of all, it might temporarily have saved us from a new ice age pulse.
Peer Reviewed Yes
Published Yes
Publisher URI
Alternative URI
Copyright Statement Copyright 2007 Blackwell Publishing. This is the author-manuscript version of the paper. Reproduced in accordance with the copyright policy of the publisher. The definitive version is available at
Volume 89
Issue Number 4
Page from 301
Page to 330
ISSN 0435-3676
Date Accessioned 2008-02-29
Language en_AU
Faculty Faculty of Science, Environment, Engineering and Technology
Subject PRE2009-Biological Oceanography; PRE2009-Climatology (incl. Palaeoclimatology); PRE2009-Cross discipline
Publication Type Journal Articles (Refereed Article)
Publication Type Code c1

Show simple item record

Griffith University copyright notice