A series of blogs analizing Thomas C. Peterson, William M. Connolley, and John Fleck’s (PCF) largely mistitled “The Myth of the 1970s Global Cooling Scientific Consensus” (Bulletin of the American Meteorological Society Volume 89, Issue 9, September 2008, pp 1325-1337). Previous considerations about a global cooling consensus in the 1960’s can be read here and here.
3 – GLOBAL COOLING: PRESENT VS. IMMINENT
In the previous blog in the series, we have seen how the very statements made by Thomas C. Peterson, William M. Connolley, and John Fleck’s (PCF) “The Myth of the 1970s Global Cooling Scientific Consensus” can be used to demonstrate that there was indeed a global cooling scientific consensus, in the 1970s.
The whole concept of the “myth” is merely based on definitions. But an even larger issue lies with PCF’s methodology, to the point of showing that despite their claims, they have not done “a review of the climate science literature from 1965 to 1979” looking for a global cooling consensus.
Rather, they have carefully made sure they could find no such a thing, under any circumstance.
PCF: “the literature search was limited to the period from 1965 through 1979. While no search can be 100% complete, this methodology offers a reasonable test of the hypothesis that there was a scientific consensus in the 1970s regarding the prospect of imminent global cooling”
Apparently, they have chosen to restrict their interest only to scientific works about future climate prospects (note the slightly different and unexplained definition for “global cooling”, as “the prospect for imminent global cooling”).
But this has meant disregarding all the (ultimately, scientifically right at its time) bibliography about global cooling up to around 1975. In fact: were “projections” of future climates really of much interest to scientists in the 1970s? Not really, as shown by PCF themselves:
PCF: “While some of these articles make clear predictions of global surface temperature change by the year 2000, most of these articles do not. Many of the articles simply examined some aspect of climate forcing.“
“Most” of the available articles for the chosen period 1965-1979 “do not […] make clear predictions”. Sounds like an apparent article-killing flaw, doesn’t it?
How do you conduct a survey when the subjects are not interested in responding?
And still, PCF decided to move on nevertheless. Where the texts would not reach, PCF’s interpretation will do:
PCF: “However, it was generally accepted that both CO2 and anthropogenic aerosols were increasing. Therefore, for example, articles that estimated temperature increases resulting from doubling CO2 or temperature decreases resulting from anthropogenic aerosols would be listed in Table 1 as warming or cooling articles, respectively. […] Articles were not included in the survey if they examined the climate impacts of factors that did not have a clear expectation of imminent change, such as increases in volcanic eruptions or the creation of large fleets of supersonic aircraft.“
This is why we cannot say that PCF have reviewed “the climate science literature from 1965 to 1979”. Simply, they have been looking at 30/40-year-old articles that would ultimately fit today’s patterns: making future climate predictions, and strictly fixated around “forcings”.
There was no chance for them to find many articles about “global cooling”. And they didn’t.
PCF’s work is about the 1965-1979 period. One would expect good care to be taken with the time series of events. That’s the topic for the next blog in the series.