What was done
Utilizing a variety of palaeolimnological techniques, Battarbee et al. (2002) developed two-century-long temperature histories for seven remote mountain lakes in Europe.  In the present paper, Agusti-Panareda and Thompson use a different approach - multiple regressions between twenty monthly lowland air temperature series for the period 1781-1997 AD and nine monthly upland air temperature series of at least 30 years duration - to develop 216-year air temperature histories for eleven remote mountain lakes in Europe, including the seven lakes studied by Battarbee et al.

What was learned
In the words of the authors, "during the period 1801-1900, the western European lakes show no significant trend whereas annual mean air temperatures at the eastern European lakes decrease significantly."  For the period 1901-1997, on the other hand, they note there is a warming trend "at all but the Fennoscandian lakes."

Even more interesting is what one learns when the 20 years from 1781-1801 are also considered.  In terms of sliding decadal averages, four of the lakes depict net increases in air temperature over the 216-year period, as one would expect for a world that has just experienced a century of "unprecedented" global warming, as climate alarmists would have us believe.  Three of the lakes, however, exhibit no net change in temperature; and four of them actually depict net cooling.

What it means
Four warmings, four coolings, and three no changes add up to pretty much of a "no sale" for the climate alarmists who are attempting to sell the world a bill of global warming goods.  If close to a dozen European alpine and arctic lakes are no warmer now than they were during a short period of time back at the "beginning of the end" of the Little Ice Age, when atmospheric CO2 concentrations were fully 90 ppm less than they are nowadays, there is surely no reason to presume that a similar modern period of warmth need be caused by the CO2 increase we have experienced in the interim.

Reference
Battarbee, R.W., Grytnes, J.-A., Thompson, R., Appleby, P.G., Catalan, J., Korhola, A., Birks, H.J.B., Heegaard, E. and Lami, A.  2002.  Comparing palaeolimnological and instrumental evidence of climate change for remote mountain lakes over the last 200 years.  Journal of Paleolimnology 28: 161-179.
Reviewed 1 January 2003