Computer simulations of global climate change have long indicated the world's polar regions should show the first and severest signs of CO2-induced global warming. If the models are correct, these signs should be especially evident in the second half of the 20th century, when approximately two-thirds of the modern-era rise in atmospheric CO2 occurred and earth's temperature supposedly rose, in the view of most climate alarmists, to a level unprecedented in the entire past millennium. In this review, we thus examine historic trends in Arctic glacier behavior to determine the credibility of current climate models with respect to their polar predictions.
In a review of "the most current and comprehensive research of Holocene glaciation," along the northernmost Gulf of Alaska between the Kenai Peninsula and Yakutat Bay, Calkin et al. (2001) report there were several periods of glacial advance and retreat over the past 7000 years. Over the most recent of those seven millennia, there was a general retreat during the Medieval Warm Period that lasted for "at least a few centuries prior to A.D. 1200." Then came three major intervals of Little Ice Age glacial advance: the early 15th century, the middle 17th century, and the last half of the 19th century. During these very cold periods, glacier equilibrium-line altitudes were depressed from 150 to 200 m below present values, as Alaskan glaciers "reached their Holocene maximum extensions."
Subsequent to this time, as the planet emerged from the depths of the Little Ice Age, the mass balance records of the 18 Arctic glaciers with the longest observational histories were studied by Dowdeswell et al. (1997). Their analysis showed that over 80% of the glaciers displayed negative mass balances over the periods of their observation, as would logically be expected for glaciers emerging from the coldest part of the past millennium. Nevertheless, the scientists report that "ice-core records from the Canadian High Arctic islands indicate that the generally negative glacier mass balances observed over the past 50 years [when the vast majority of the CO2 resulting from human activities entered the atmosphere] have probably been typical of Arctic glaciers since the end of the Little Ice Age [our italics]," when the magnitude of anthropogenic CO2 emissions was a whole lot less than it has been from 1950 onward.
These observations suggest that Arctic glaciers are not experiencing any adverse effects of anthropogenic CO2 emissions. In fact, Dowdeswell et al. say "there is no compelling indication of increasingly negative balance conditions which might, a priori, be expected from anthropogenically induced global warming." Quite to the contrary, they report that "almost 80% of the mass balance time series also have a positive trend, toward a less negative mass balance [our italics]." Hence, although most Arctic glaciers continue to lose mass, as they have probably done since the end of the Little Ice Age, they are losing smaller amounts each year, in the mean, which is hardly what one would expect in the face of what climate alarmists say is happening to earth's climate.
Additional evidence that the Arctic's glaciers are not responding to human-induced warming comes from the studies of Zeeberg and Forman (2001) and Mackintosh et al. (2002), who indicate there has been an expansion of glaciers in the European Arctic over the past few decades.
Zeeberg and Forman analyzed 20th-century changes in glacier terminus positions on north Novaya Zemlya -- a Russian island located between the Barents and Kara Seas in the Arctic Ocean -- providing a quantitative assessment of the effects of temperature and precipitation on glacial mass balance. The results of their study showed a significant and accelerated post-Little Ice Age glacial retreat in the first and second decades of the 20th century. By 1952, however, the region's glaciers had experienced between 75 to 100% of their net 20th-century retreat; and during the next 50 years, the recession of over half of the glaciers stopped, while many tidewater glaciers actually began to advance.
These glacial stabilizations and advances were attributed by the authors to observed increases in precipitation and/or decreases in temperature. For the four decades since 1961, for example, weather stations on Novaya Zemlya show summer temperatures were 0.3 to 0.5°C colder than they were over the prior 40 years, while winter temperatures were 2.3 to 2.8°C colder than they were over that earlier period. These observations, the authors say, are "counter to warming of the Eurasian Arctic predicted for the twenty-first century by climate models, particularly for the winter season"
Other glacier observations that run counter to climate model predictions are discussed by Mackintosh et al. (2002), who concentrated on the 300-year history of the Solheimajokull outlet glacier on the southern coast of Iceland. In 1705, this glacier had a length of about 14.8 km; and by 1740 it had grown to 15.2 km in length. Thereafter, it began to retreat, reaching a minimum length of 13.2 km in 1783. Rebounding rapidly, however, the glacier returned to its 1705 position by 1794; and by 1820 it equaled its 1740 length. This maximum length was maintained for the next half-century, after which the glacier began a slow retreat that continued to about 1932, when its length was approximately 14.75 km. Then it wasted away more rapidly, reaching a second minimum-length value of approximately 13.8 km about 1970, whereupon it began to rapidly expand, growing to 14.3 km by 1995.
The current position of the outlet glacier terminus is by no means unusual. In fact, it is about midway between its maximum and minimum positions of the past three centuries. It is also interesting to note that the glacier has been growing in length since about 1970. In addition, Mackintosh et al. report that "the recent advance (1970-1995) resulted from a combination of cooling and enhancement of precipitation."
Taken together, these observations from high northern latitudes, where CO2-induced global warming is supposed to be most evident, provide no evidence for that dreaded phenomenon. In fact, they suggest that nothing out of the ordinary is occurring at all. Hence, we once again have a situation where the predictions of today's best climate models fail to conform to reality.
References
Calkin, P.E., Wiles, G.C. and Barclay, D.J. 2001. Holocene coastal glaciation of Alaska. Quaternary Science Reviews 20: 449-461.
Dowdeswell, J.A., Hagen, J.O., Bjornsson, H., Glazovsky, A.F., Harrison, W.D., Holmlund, P. Jania, J., Koerner, R.M., Lefauconnier, B., Ommanney, C.S.L. and Thomas, R.H. 1997. The mass balance of circum-Arctic glaciers and recent climate change. Quaternary Research 48: 1-14.
Mackintosh, A.N., Dugmore, A.J. and Hubbard, A.L. 2002. Holocene climatic changes in Iceland: evidence from modeling glacier length fluctuations at Solheimajokull. Quaternary International 91: 39-52.
Zeeberg, J. and Forman, S.L. 2001. Changes in glacier extent on north Novaya Zemlya in the twentieth century. Holocene 11: 161-175.