Atmospheric methane, record from a Greenland Ice Core over the last 1000 year
Article first published online: 7 DEC 2012
Copyright 1993 by the American Geophysical Union.
Geophysical Research Letters
Volume 20, Issue 20, pages 2219–2222, 22 October 1993
How to Cite
1993), Atmospheric methane, record from a Greenland Ice Core over the last 1000 year, Geophys. Res. Lett., 20(20), 2219–2222, doi:10.1029/93GL02414., , , , , , and (
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 24 AUG 1993
- Manuscript Received: 24 MAY 1993
The atmospheric methane concentration in ancient times can be reconstructed by analysing air entrapped in bubbles of polar ice sheets. We present results from an ice core from Central Greenland (Eurocore) covering the last 1000 years. We observe variations of about 70 ppbv around the mean pre-industrial level, which is confirmed at about 700 ppbv on a global average. According to our data, the beginning of the anthropogenic methane increase can be set between 1750 and 1800. Changes in the oxidizing capacity of the atmosphere may contribute significantly to the pre-industrial methane concentration variations, but changes in methane emissions probably play a dominant role. Since methane release depends on a host of influences it is difficult to specify clearly the reasons for these emission changes. Methane concentrations correlate only partially with proxy-data of climatic factors which influence the wetland release (the main source in pre-industrial times). A good correlation between our data and a population record from China suggests that man may already have influenced the CH4-cycle significantly before industrialisation.