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The Canary in the Coal Mine: Singing a Song of Something ? But Certainly Not CO2
Volume 7, Number 10: 10 March 2004

A long succession of climate models has consistently predicted that CO2-induced global warming should be significantly amplified in earth's polar regions and that the first signs of man's expected impact on the world's weather should thus be manifest there; or as Donella Meadows (2001) has described it, "the place to watch for global warming - the sensitive point, the canary in the coal mine - is the Arctic." That being the case, let's take a look at it.

One of the most comprehensive analyses of climate change in the Arctic was conducted by Overpeck et al. (1997), who combined paleoclimatic records from lake and marine sediments, trees and glaciers to develop a 400-year history of circum-Arctic surface air temperature. From this record they determined that the most dramatic warming of the last four centuries (1.5C) occurred between 1840 and 1955, over which period the air's CO2 concentration rose from approximately 285 ppm to 313 ppm, or by 28 ppm. Then, from 1955 to the end of the record (about 1990), the mean circum-Arctic air temperature actually declined by 0.4C, while the air's CO2 concentration rose from 313 ppm to 354 ppm, or by 41 ppm.

On the basis of these observations, which apply to the entire Arctic, it is not possible to assess the influence of atmospheric CO2 on surface air temperature within this region, or even conclude that it has any effect at all. Why? Because over the first 115 years of warming, as the air's CO2 concentration rose by an average of 0.24 ppm/year, the air temperature rose by an average of 0.013C/year; while over the final 35 years of the record, when the increase in the air's CO2 content really began to accelerate, rising at a mean rate of 1.17 ppm/year (nearly five times the rate at which it had risen in the prior period), the rate of rise of surface air temperature did not accelerate anywhere near that fast. In fact, it did not accelerate at all. In fact, it decelerated, to a mean rate of change (0.011C/year) that was nearly the same as the rate at which it had previously risen but in the opposite direction, i.e., downward. Clearly, there was something that totally overpowered whatever effect the rise in the air's CO2 content over the first period may, or may not, have had on the temperature of the Arctic, as well as the effect of the nearly five times greater rate of rise in the air's CO2 content over the second period. And people call this behavior an early warming of an impending CO2-induced climatic catastrophe? Give us a break!

So what about earth's other polar region: the Antarctic? Here, too, one can conclude essentially nothing about the influence of atmospheric CO2 on surface air temperature. Why? Because for the continent as a whole (excepting the Antarctic Peninsula), there has been a net cooling over the past several decades, stretching back to at least 1966 (Comiso, 2000; Doran et al., 2002; Thompson and Solomon, 2002). And when the real-world air temperature declines when the theoretical climate forcing factor is rising, one cannot even conclude that the forcing exists, much less determine its magnitude.

Additional insights into the subject are provided by the study of Villalba et al. (2003), who used instrumental records and tree-ring data from southern South America to produce "the most consistent view of temperature variations in the southern Andes during the past 360 years." And what did they find? They found "a well-defined cold interval from ~1640-1850, which conforms with the consensus view of the 'Little Ice Age'," followed by a warming "close to 1.4C per century during the 1850-1950 interval," as in the Arctic, which was followed by a decline in temperature up to the end of the record (1990), also as in the Arctic.

Clearly, the canaries in the coal mines of the high latitudes of both hemispheres have yet to keel over and die. In fact, they are alive and well, singing the same melodious climate history song in marvelous harmony, while "keeping their cool" in the face of atmospheric CO2 concentrations higher than any experienced over the past 420,000 years (Petit et al., 1999), and maybe even millions of years. If these perceptive creatures are truly as sensitive to CO2-induced climate change as the world's climate alarmists claim they are, it would appear we have little to fear about the IPCC's outrageous predictions of current and impending unprecedented warming. There's not a sign of it to be seen where it is supposed to be most evident and first expressed.

Thank goodness for canaries!

Sherwood, Keith and Craig Idso

Comiso, J.C. 2000. Variability and trends in Antarctic surface temperatures from in situ and satellite infrared measurements. Journal of Climate 13: 1674-1696.

Doran, P.T., Priscu, J.C., Lyons, W.B., Walsh, J.E., Fountain, A.G., McKnight, D.M., Moorhead, D.L., Virginia, R.A., Wall, D.H., Clow, G.D., Fritsen, C.H., McKay, C.P. and Parsons, A.N. 2002. Antarctic climate cooling and terrestrial ecosystem response. Nature 415: 617-620.

Meadows, D.H. 2001. Polar bears and 3-year-olds on thin ice. AlterNet.org. Posted 6 February 2001.

Overpeck, J., Hughen, K., Hardy, D., Bradley, R., Case, R., Douglas, M., Finney, B., Gajewski, K., Jacoby, G., Jennings, A., Lamoureux, S., Lasca, A., MacDonald, G., Moore, J., Retelle, M., Smith, S., Wolfe, A. and Zielinski, G. 1997. Arctic environmental change of the last four centuries. Science 278: 1251-1256.

Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.-M., Basile, I., Bender, M., Chappellaz, J., Davis, M., Delaygue, G., Delmotte, M., Kotlyakov, V.M., Legrand, M., Lipenkov, V.Y., Lorius, C., Pepin, L., Ritz, C., Saltzman, E., and Stievenard, M. 1999. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399: 429-436.

Thompson, D.W.J. and Solomon, S. 2002. Interpretation of recent Southern Hemisphere climate change. Science 296: 895-899.

Villalba, R., Lara, A., Boninsegna, J.A., Masiokas, M., Delgado, S., Aravena, J.C., Roig, F.A., Schmelter, A., Wolodarsky, A. and Ripalta, A. 2003. Large-scale temperature changes across the southern Andes: 20th-century variations in the context of the past 400 years. Climatic Change 59: 177-232.