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Peatland data indicate that global warming might be natural

News: Dec 13, 2007

Research teams from Göteborg University, Sweden and Griffiths University, Australia present new results on climate variability during the Holocene and claim natural causes to the present global warming. The study of particles and geochemical signals in peatlands indicates that climate varies in a c. 1000-year cycle as shown by professors Lars Franzén and Roger Cropp. Franzén and Cropp state that climate might be regulated by the varying influx of cosmic dust.

Cosmic dust contains various minerals which could control the production of algae and bacteria in remote ocean surface waters. A high production during periods of peaking cosmic influx increases cloud formation catalyzed by dimethyl sulphide (DMS) production, following increased atmospheric albedo, decreased shortwave solar irradiation to Earth surface and subsequent cooling. The opposite situation would occur when cosmic dust influx is low.

The c. 1000-year cycle, which in turn seems to be regulated by solar activity variations, is clearly visible through human history. Cold spells coincide with so-called “Dark Ages” e.g. Fimbul Winters (c. 750-500 BC), the Era of the Great Migrations (c. 375-550 AD) and the Little Ice Age, whereas warm periods are e.g. the North European Bronze Age (c.1400-800 BC), the Antique Roman Era (c.400 BC-300 AD) and the Medieval Warm Period (c.600-1300 AD).

– If our theories are correct we are just entering the next warm phase, which will peak in about 300 years, then it will turn towards colder conditions again, Franzén says. Franzén further explains that a cold spell such as the Little Ice Age might serve as an initiation impulse of a new Ice Age.

In this latter respect, Franzén and Cropp put forward a hypothesis on ice age cycling, based on peatlands’ role in the global carbon cycle.
– The present anthropogenic release of carbon dioxide might just have saved us from another Ice Age, Franzén concludes. The results are presented in the latest issue of Geografiska Annaler (2007 Ser. A 89(4):301-331.


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In case of doubt or confusion, the Swedish version of this press release takes precedence.

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