Climate of the Past Discussions www.clim-past-discuss.net 1814-9340 1814-9359 5 3 2009 10.5194/cpd-5-1521-2009 http://www.clim-past-discuss.net/5/1521/2009/ http://www.clim-past-discuss.net/5/1521/2009/cpd-5-1521-2009.html http://www.clim-past-discuss.net/5/1521/2009/cpd-5-1521-2009.pdf 1521 1552 2009-05-27 Last nine-thousand years of temperature variability in Northern Europe H. Seppä heikki.seppa@helsinki.fi A. E. Bjune R. J. Telford H. J. B. Birks S. Veski Department of Geology, P.O. Box 65, 00014, University of Helsinki, Helsinki, Finland Bjerknes Centre for Climate Research, c/o Department of Biology, University of Bergen, Allégaten 41, 5007 Bergen, Norway Department of Biology, University of Bergen, Allégaten 41, 5007 Bergen, Norway Environmental Change Research Centre, University College London, Gower Street, London WC1E 6BT, UK Institute of Geology, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia The threat of future global warming has generated a major interest in quantifying past climate variability on centennial and millennial time-scales. However, palaeoclimatological records are often noisy and arguments about past variability are only possible if they are based on reproducible features in several reliably dated datasets. Here we focus on the last 9000 years, explore the results of 35 Holocene pollen-based July mean and annual mean temperature reconstructions from Northern Europe by stacking them to create summary curves, and compare them with a high-resolution, summary chironomid-based temperature record and other independent palaeoclimate records. The stacked records show that the "Holocene Thermal Maximum" in the region dates to 8000 to 4800 cal yr BP and that the "8.2 event" and the "Little Ice Age" at 500–100 cal yr BP are the clearest cold episodes during the Holocene. In addition, a more detailed analysis of the last 5000 years pinpoints centennial-scale climate variability with cold anomalies at 3800–3000 and 500–100 cal yr BP, a long, warmer period around 2000 cal yr BP, and a marked warming since the mid 19th century. 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