There is no doubt that the global temperature has had a slightly increasing trend since 1850; nor can it be disputed that the CO
2 concentration in the atmosphere has been increasing over the last several decades. What is very much under dispute are the reasons for the increase of the two, whether there is any connection between them, and if so, whether it is due to the Greenhouse effect.I have previously pointed out [AtE Aug 88] that the latter hypothesis is contradicted by the historical evidence, and that it ignores other possible mechanisms. One such mechanism is the effect of solar activity on the terrestrial climate and temperature. Such a connection has often been suspected in the past, but has always been rejected as statistically insignificant or contradicting parts of the record. But in November came news of a correlation that has so far passed all statistical tests with flying colors, though its physical substance is still unclear.
The sun, a ball of hot gases undergoing nuclear reactions, spews out streams of charged particles
¾strong and frequent bursts in years of high solar activity, and fewer of them when it is quiescent. The period between successive maxima of activity averages about 11 years. High solar activity is also accompanied by flares, protuberances, and sun spots; the latter were observed by Galileo, and in bygone ages some of them were so large that they could be seen by the unaided (but well protected) eye. In the 1940s Czech astronomer F. Link searched European and Chinese chronicles for such historical evidence and claimed to have found a correla-tion between it and the global climate. But it was a crude com-parison which did not make much headway, and other researchers producing more persuasive numerical evidence were usually defeated by historical counterexamples.This may well have been due to not taking account of a recently discovered phenomenon, the QBO or Quasi-Biennial-Oscillation, a reversal of stratospheric winds over the equator with an irregular period averaging 13 months. Apparently the effect of solar activity on the climate is opposite in alternative phases of the QBO; but when only years of, say, the west phase of the QBO are considered, a clear correlation emerges from what used to appear as chaotic data. This was discovered by two scientists of the National Center for Atmospheric Research in Boulder, Colo., H. van Loon and K. Labitzke ("Association between the 11-year solar cycle, the QBO, and the atmosphere," J. Climate, vol. 1, p. 905, 1988; see also Science 11/25/88, pp.1124-5). The figure shows the opposing varia-tion of the average temperatures in Charleston and Nashville during west-phase years on one hand, and that of solar activity (flux) on the other.
Although the result seems to be beyond doubt, there is much discussion and little understanding of the actual physical mechanism that produces the correlation. It is not known, of course, whether the phenomenon can account for the observed warming trend by itself; but it is clearly one of the factors that have not been considered by those who seek to explain the warming exclusively by the flimsy evidence for the Greenhouse Effect.
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Vol. 16, No. 5
Newsletter: Access to Energy Newsletter Archive Volume: Issues Issue/No.: Vol. 16, No. 5 Date: December 01, 2004 02:20 PM Title: The privilege of irresponsibility
Copyright © 2004 - Access to Energy Newsletter Archive
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