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Arctic Warming: Is It as Real and as CO2-Induced as Climate Alarmists Claim?
Volume 10, Number 21: 23 May 2007

In a short communication in the May 2005 issue of Ambio - published by the Royal Swedish Academy of Sciences - Wibjorn Karlen (Professor of Physical Geography and Quaternary Geology, Stockholm University) asks if temperatures in the Arctic are "really rising at an alarming rate," as the world's climate alarmists claim they are. His short answer is a resounding no; his explanation follows.

Focusing on Svalbard Lufthavn (located at 78N latitude), which he later shows to be representative of much of the Arctic, Karlen reports that "the Svalbard mean annual temperature increased rapidly from the 1910s to the late 1930s," that "the temperature thereafter became lower, and a minimum was reached around 1970," and that "Svalbard thereafter became warmer, but the mean temperature in the late 1990s was still slightly cooler than it was in the late 1930s," indicative of an actual cooling trend of 0.11C per decade over the last seventy years of the 20th century.

In support of his contention that cooling was truly the norm in the Arctic over this period, Karlen goes on to state that (1) "the observed warming during the 1930s is supported by data from several stations along the Arctic coasts and on islands in the Arctic, e.g. Nordklim data from Bjornoya and Jan Mayen in the north Atlantic, Vardo and Tromso in northern Norway, Sodankylaeand Karasjoki in northern Finland, and Stykkisholmur in Iceland," and that (2) "there is also [similar] data from other reports; e.g. Godthaab, Jakobshavn, and Egedesmindde in Greenland, Ostrov Dikson on the north coast of Siberia, Salehard in inland Siberia, and Nome in western Alaska." All of these stations, to quote him further, "indicate the same pattern of changes in annual mean temperature: a warm 1930s, a cooling until around 1970, and thereafter a warming, although the temperature remains slightly below the level of the late 1930s [our italics]." In addition, he says that "many stations with records starting later than the 1930s also indicate cooling, e.g. Vize in the Arctic Sea north of the Siberian coast and Frobisher Bay and Clyde on Baffin Island." Last of all, Karlen reports that the 250-year temperature record of Stockholm "shows that the fluctuations of the 1900s are not unique," and that "changes of the same magnitude as in the 1900s occurred between 1770 and 1800, and distinct but smaller fluctuations occurred around 1825."

Noting that the IPCC suggests that the lion's share of the temperature increase during the 1920s and into the 1930s (which in the Arctic was the most dramatic warming of the 20th century) was primarily due to solar effects (because the increase in CO2 over this period was so small they had to go with something else), Karlen next notes that subsequently, "during the 50 years in which the atmospheric concentration of CO2 has increased considerably, the temperature has decreased [our italics]," which leads him to conclude that "the Arctic temperature data do not support the models predicting that there will be a critical future warming of the climate because of an increased concentration of CO2 in the atmosphere." And especially is this so when it is remembered, in Karlen's words, that the model-based prediction "is that changes will be strongest and first noticeable in the Arctic."

Consequently, seeing that the first and only period of net warming in the Arctic occurred at a time when CO2 could not possibly have been its cause, it should be clear to all that the modern theory of CO2-induced global warming within the context of earth's complex climate system is a totally unreliable guide to the future.

Sherwood, Keith and Craig Idso

Reference
Karlen, W. 2005. Recent global warming: An artifact of a too-short temperature record? Ambio 34: 263-264.