Global cooling, again.

I wrote about the Global cooling myth on RealClimate a while ago; and there is a more complete but less organised set of stuff at http://www.wmconnolley.org.uk/sci/iceage/. I had hoped that the RC peice would throw up some interesting new references; but only one appeared: From Physical Geology by Eugene Mitacek, 1971: WILL THE ICE AGES RETURN? Climatologists report that the world's weather is turning sharply cooler. Signs of this are evident. Drifting icefields have hindered access to Iceland's ports for the first time in this century. Since 1950 the growing season in England has been shortened by two weeks. Director Reid Bryson of the Institute for Environmental Studies at the University of Wisconsin reports that, if this trend continues, it will affect the whole human populace. A long term study of climactic conditions would place the first half of the twentieth century into an exceptionally warm period. The warming trend peaked in 1945, and the temperatures have been dropping since. The drop to date is on 1.5 degrees C, far from the 10 degrees C drop necessary for a new Ice Age. If this trend is not reversed, however, the planet may be caught in an ice-forming cycle similar to that of the Pleistocene. That quote is probably copied from http://www.kuro5hin.org/story/2001/3/2/03449/27856. Note that the drop-to-date of 1.5 oC is wrong (by todays climatology, and probably by what they had then). The global cooling from peak (1940's) to trough (1970's) is barely 0.2 oC (see the SPM) and the northern hemisphere only somewhat larger (about 0.3 oC: see fig 2.7). If you took peak-to-trough for individual years (which you shouldn't, because only slightly different years would then get you a warming) you might get 0.6 oC. But not 1.5 oC. However, thats from modern records: what was available at the time might be wilder. The reference turns out to be wrong (initially I suspected it might simply be invented, but no). The real ref is Physical Geology, Principles, Processes, and Problems by Charles J. Cazeau, Robert D, Hatcher, Jr.; and Francis T. Siemankowski, 1976 (not 1971; thats a relief because 1971 would be an implausible date for a quote of this sort). The confusion arises because the endpapers are a geological chart by Mitacek, which *is* copyright 1971. With the ref sorted out (thanks JM) I got a copy from abebooks, which arrived today (the wonders of the internet; once apon a time getting hold of a copy would have been too tedious to bother with). However although the ref needed correction the quote, somewhat to my surprise, is in context (you wouldn't believe the out-of-context quoting that goes on elsewhere). The book continues (thanks JM): Long range weather forecaster Edward M. Brooks believes that the present cooling trend follows a 40-year cyclic pattern. He feels that this trend will continue until 1985. We will not need to wait much longer to see if the trend will reverse. Both Bryson and Brooks are in agreement, however, that the world is heading into a period of weather unfavorable for agriculture. This is extremely bad news because of the explosion of population in many countries of the world. It appears as if we will be producing less, rather than more, food. As food reserves dwindle we may move into a period of massive, unimaginable tragedy. Long-range plans to feed as ever-growing population must be made. In the last paragraph of the chapter it also says the following: It is difficult to forecast the outcome of the present cooling trend. Climatologists differ regarding whether a new Ice Age lies ahead. There is agreement, however, in predictions of shorter growing seasons and lower crop yields for the next 10 years. Now, what do I say to this? Bad news for the good guys? Well no (surprised?). I think it accurately reports Brysons views, but not the general views of the time. The views of the time were "we don't have good enough theory and measurements to predict the future (100 years) climate, and we know it" (see, e.g., the conclusions of the NAS report, 1975). This is a textbook, not the primary literature. So how do we explain the presence of this stuff in a textbook? Its only a tiny fraction (less than one page out of more than 500) and its a geology book not a climatology book. Textbooks are (I presume) not peer-reviewed in the way papers are; and even if it was reviewed it would have been sent to geologists, since its a geology book. People often make mistakes when they go out of their field... On the authors: Charles J. Cazeau (1931-1999) was a prof of geology at the State University of New York at Buffalo: this is the major google hit :-); he also seems to have been marginally invovled in debunking "nessie". Robert D. Hatcher is rather easier to find: he is currently Tectonics and Structural Geology UT Distinguished Scientist and Professor of Geology Department of Geological Sciences University of Tennessee. Francis T. Siemankowski I couldn't find much on - mostly refs to this book. The book says he is in the dept of science education, so he may well not be a geologist, somewhat supported by this.

Refs

* [Added 2021] Reid Bryson: The crisis climatologist