From wmc@unixa.nerc-keyworth.ac.uk (William Connolley) Newsgroups: sci.environment Subject: Cooling; was: Re: CFCs in the atmosphere (was Re: Why do Date: 25 Jan 1996 17:36:02 GMT In article 3ss@news2.delphi.com, arussell@BIX.com (Andrew Russell) writes: >Dean Myerson wrote: >>As I remember, Newsweek and Time predicted global cooling. Are you >>aware of any climatologists, or peer-reviewed articles in general, >>that predicted global cooling? >Try Steven Schneider: > > 1971, in the July 9 issue of Science: "Temperatures do not > increase in proportion to an atmoshperic increase in CO2. > Even and eight-fold increase over present levels might warm > earth's surface less than 2 degrees Centigrade, and this is > highly unlikely in the next several thousand years." He also > said in the article that quadrupling aerosols "could decrease > the mean surface temperature (of Earth) by as much as 3.5 > degrees K. If sustained over a period of several years, such a > temperature decrease could be sufficient to trigger an ice age!" >Andrew Russell This is a much better try than any previous efforts, but is still a clear failure. The game was, find a reference that *predicts* "a new ice age" "immenently" or if you can't do that, find a reference to *predict* global cooling. This reference, as quoted above, makes no predictions at all about Earths future climate, but does predict the response of the climate to a postulated increase in aerosols or CO2. There are some other interesting points about the article itself, which are noted in the article: 1. the temperature increase with CO2 found is about 1/3 of Manabe and Wetherald. This is accounted for by different CO2 abs coeffs, different lapse rate specs, and different CO2/H20 overlaps. 2. The model used is a 1-d model lacking many feedbacks (eg, ice-albedo). The authors point out that the model is applicable to *small* changes in single parameters. They do not point out that 8*CO2 or 4*aerosol depth are not small changes. The title of the article itself is "Atmospheric Carbon Dioxide and Aerosols: effects of Large increases on Global Climate", which suggests (correctly) that the article is a sensitivity study for large changes rather than a prediction for expected changes. Fans of exact quotation accuracy may like to know that the "quote" AR gives above is not found word-for-word in the paper, but is essentially accurate (including the perhaps rather unfortunate "!"). --- William M Connolley | wmc@bas.ac.uk | http://www.nbs.ac.uk/public/icd/wmc/ Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself