Irish Bogs Provide Challenge for Climate Sceptics
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Written by SerenaStargazer
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Sunday, 02 October 2005 |
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A study of Irish bogs shows that while there are cyclical changes in both climate and the Sun’s activity, there is no obvious link between the two. This provides a challenge for sceptics who argue that the Earth’s warming climate could be explained by increased solar activity.
Chris Turney of the University of Wollongong in New South Wales, Australia, and colleagues used carbon dating of an archive of more than 750 excavated trees from Irish bogs, dating back 7,648 years, to gauge tree cover. Because a higher water table makes it harder for saplings to flourish, periods of sparser cover indicate cool, wet spells, while periods of more abundant cover indicate warm, dry spells. The team found a clear cycle of wet and dry phases, with shifts occurring about every 800 years. However, the peaks in solar activity do not coincide with the peaks in warmer conditions. |
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