Learn how plants respond to higher atmospheric CO2 concentrations

How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic


A Multi-Proxy Approach to Peat-Based Climate Reconstruction
Reference
Blundell, A. and Barber, K.  2005.  A 2800-year palaeoclimatic record from Tore Hill Moss, Strathspey, Scotland: the need for a multi-proxy approach to peat-based climate reconstructions.  Quaternary Science Reviews 24: 1261-1277.

What was done
Utilizing plant macrofossils, testate amoebae and degree of humification as proxies for environmental moisture conditions, the authors developed a 2800-year "wetness history" from a peat core extracted from Tore Hill Moss, a raised bog in the Strathspey region of Scotland.

What was learned
Based on the results they obtained from the three proxies they studied, Blundell and Barber derived a relative wetness history that begins 2800 years ago and extends all the way to AD 2000.  The most clearly defined and longest interval of sustained dryness of this entire history stretches from about AD 850 to AD 1080, coincident with the well known Medieval Warm Period, while the most extreme wetness interval occurred during the depths of the last stage of the Little Ice Age.

Also evident in their wetness history is a period of relative dryness centered on about AD 1550, which corresponds to a period of relative warmth that has previously been documented by several other studies and to which we have given the name Little Medieval Warm Period.  In addition, preceding the primary Medieval Warm Period, Blundell and Barber's hydro-climate reconstruction reveals a highly chaotic period of generally greater wetness that corresponds to the Dark Ages Cold Period.  Also evident are dryness peaks representing the Roman Warm Period and two other periods of relative dryness located about 500 years on either side of its center.

What it means
In local contradiction of the climate-alarmist claim that the late 20th century was the warmest period experienced by the globe over the past two millennia, the correlation this study demonstrates to exist between relative wetness and warmth in Scotland strongly suggests that the temperature of the late 20th century was nowhere near the highest of the past two millennia in that particular part of the world.  In fact, it suggests there were five other periods over the past 2800 years that were considerably warmer.  In addition, Blundell and Barber cite many studies that report findings similar to theirs throughout much of the rest of Europe and the North Atlantic Ocean.  Consequently, the regional challenge this group of studies provides to the IPCC-endorsed hockeystick temperature history is substantial.

Reviewed 1 June 2005