Monckton over (niet zo) BEST

Gisteren schreef ik over Richard Muller, die onlangs in 'The New York Times' had bekend dat hij zich van klimaatscepticus tot aanhanger van de menselijke broeikashypothese had bekeerd (AGW = Anthropogenic Global Warming), als gevolg van nieuwe bevindingen die uit het BEST-project naar voren waren gekomen (BEST = 'Berkeley Earth Surface Temperature Project').

Onder de titel, 'Müller lite: Why Every Scientist Needs a Classical Training', schrijft Christopher Monckton dat hij twijfelt aan deze bekering. Volgens hem heeft Muller zich voorheen slechts voorgedaan als scepticus om vervolgens met veel fanfare te verklaren van mening te zijn veranderd. Bovendien wijst Monckton op een aantal zwakke plekken in de logica waarvan Muller zich bedient. Dat is overigens een algemeen verschijnsel in de klimatologie. Het meest saillante voorbeeld daarvan is de cirkelredenering die wordt toegepast in het hoofdstuk over 'attributie' (de identificatie van de rol van CO2 in de opwarming van de aarde) in de IPCC-rapporten. Voor zover mij bekend is het het AGW-establishment tot op heden nog niet opgevallen dat het hier om een drogredenering gaat.
 
Monckton:

About 18 months ago, as soon as I heard of Dr. Richard Müller’s Berkeley Earth Temperature project, I sent an email to several skeptical scientists drawing their attention to his statement that he considered his team’s attempt to verify how much “global warming” had occurred since 1750 to be one of the most important pieces of research ever to be conducted in the history of science. This sounded too much like propaganda.
 
He was posing, I said, as a skeptical scientist; his results would broadly confirm the pre-existing temperature series; when his research ended, he would declare himself to have been converted from scepticism to the belief that merely because the world had warmed the warming must be our fault; and publication of his results would be exploited as a triumphant and final confirmation of the “global warming” orthodoxy.
 
My doubts about Dr. Müller’s motivation intensified after I met him at the Los Alamos Climate Conference in Santa Fe, New Mexico, late last year. We lunched. He was visibly disappointed when I said that I was happy to accept the official temperature record, at least for the sake of argument. And he subsequently seemed uninterested in getting to grips with the real divide between skeptics and true-believers, which has little to do with the accuracy of the temperature record and much to do with climate sensitivity – the question how much warming we will cause.

Monckton wijst er op dat de temperatuurfluctuaties vanaf 1750 binnen de natuurlijke klimaatvariabiliteit vallen. Ook de geringe zonneactiviteit van het Maunder Minimum, dat met extreme koude gepaard ging, biedt een sterke indicatie voor de invloed van de zon op ons klimaat. En zo gaat Monckton door.

The greatest error in the Berkeley team’s conclusion is in Dr. Müller’s assertion that the cause of all the warming since 1750 is Man. His stated reason for this conclusion is this: “Our result is based simply on the close agreement between the shape of the observed temperature rise and the known greenhouse gas increase.”
 
No Classically trained scientist could ever have uttered such a lamentable sentence in good conscience. For Dr. Müller here perpetrates a spectacular instance of the ancient logical fallacy known as the argument from false cause — post hoc, ergo propter hoc. However closely the fluctuations in one dataset appear to follow the fluctuations in another, one cannot legitimately assume that either caused the other. ...
 
Dr. Müller describes the current stasis in global temperature as “the ‘flattening’ of recent temperature rise that some people claim”. Yet the failure of temperatures to warm at all over the past 15 years is plainly evident in all the principal datasets. If Dr. Müller were as “careful and objective” as he claims, he would surely concede that there has indeed been no global warming for a decade and a half. He would not have described it merely as a phenomenon “that some people claim”.
 
He is entitled to his opinion that “the ‘flattening’ of recent temperature rise that some people claim” is not statistically significant. However, I beg to differ. Since CO2 emissions have risen at a record rate during the past 15 years, it necessarily follows that the failure of the planet to warm at all over that period points to a natural influence strong enough to overcome — at least temporarily — the rather weak warming effect of the large additional volume of CO2.
 
What might that natural influence be? Step forward the Pacific Decadal Oscillation, a naturally-occurring warming and cooling cycle. In 1976, the PDO switched suddenly from its cooling to its warming phase. Global temperature rose rapidly till late in 2001, when the PDO switched just as suddenly to its cooling phase, since when there has been no global warming.
 
The global temperature anomalies since 1850, compiled by the Hadley Centre for Forecasting, show three periods of warming that lasted more than a decade: 1860-1880; 1910-1940; and 1976-2001. These periods coincide with the cyclical warming phases of the PDO. ...

Muller beklemtoonde dat uit zijn onderzoek bleek dat de gevoeligheid van het klimaat voor een verhoging van de CO2-concentratie groter was dan het VN-Klimaatpanel (IPCC) beweerde. Met een berekening die op de achterkant van een envelop past, toont Monckton aan dat hij zich vergist.

Conclusie:

If Dr. Müller had had a Classical training, he would have been made familiar with the dozen logical fallacies first codified by Aristotle 2300 years ago. He would not have attempted to draw any firm scientific conclusions as to causality merely from a superficial and in any event inadequate and uncertain correlation; and still less from a monstrous argumentum ad ignorantiam. Perhaps it is time to ensure that every scientist receives a Classical training, as nearly all of them once did.

Lees verder hier.

Muller zondigt op cruciale punten tegen de wetten van de logica. Maar hij staat niet alleen. Dit is symptomatisch voor de huidige stand van de klimatologie.

 

Voor mijn eerdere DDS-bijdragen, zie: