Mythic Reasoning about Climate Uncertainty

In her June 2011 paper, Reasoning about climate uncertainty, Dr. Judith Curry earns a place of honor in the pantheon of climate myth-makers.  The paper takes us on a perilous journey from climate science to the realms of semantics and psychology; along the way, we find we must do battle with a monster.  All the elements of an epic myth!

This paper argues that the IPCC has oversimplified the issue of uncertainty in its Assessment Reports, which can lead to misleading overconfidence.

An auspicious start, promising scientific insight above and beyond the now-famous "Wow."   But by "oversimplified the issue of uncertainty," isn't she really saying 'understated the uncertainty'?  What does the ambiguous "can lead to" mean?  That phrase could apply to just about anything (including the tendency of horses to refuse a drink).

The remainder of the paper neither presents new evidence nor makes any attempt to argue against existing evidence .  We find instead, this lesson in stylistic criticism:

In practice, primary conclusions in the AR4 included a mixture of likelihood and confidence statements that are ambiguous. Curry and Webster (2011) have raised specific issues with regards to the statement “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations,” that are related to apparent circular reasoning in the attribution argument and ambiguity in the attribution statement itself.  --emphasis added

According to Dr. Curry's online publication list (as of 20 Aug 2011), Curry and Webster 2011, entitled "Climate science and the uncertainty monster," is in review for publication in the Bull. of the American Meteorological Society.  An online preprint is available here.

The 'uncertainty monster' is given teeth here:

The “monster” is therefore the confusion and ambiguity associated with knowledge versus ignorance, objectivity versus subjectivity, facts versus values, prediction versus speculation, and science versus policy.  The uncertainty monster gives rise to discomfort and fear, ....

The vital question of scientific uncertainty has nothing to do with knowledge vs. ignorance or science vs. policy; it has everything to do with accurate determination of physical quantities, and the confidence one may place in the validity of those measurements.  This is given serious treatment by serious workers:   See this post by tamino, who draws a useful line between a trend and various types of noise that may obscure the trend, and this SkS post by hfranzen, who discusses uncertainty as inherent in the type of science being done.   Dr. Curry's paper has turned a serious question on its head; by anthropomorphizing the concept of uncertainty, it is something to be feared rather than understood.

We have thus entered a myth worthy of Lewis Carroll:

"Beware the Jabberwock, my son!
The jaws that bite, the claws that catch!
Beware the Jub-Jub bird, and shun
The frumious Bandersnatch!"


Look again at the IPCC statement labeled as ambiguous: 

“Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations”


The IPCC AR4 chapter 1 section 1.6 unambiguously specifies 'very likely' as more than a 90% probability of occurrence.  The only possible ambiguity is the word 'most' (and certainly we can agree that 'most' means 'more than 50%').   If the IPCC had stated a specific percentage, skeptics could just as easily pick at the number (or the number of significant digits).  Arguing the choice of words, rather than the evidence, is a sure sign that thre is little evidence on her side.  But myths don't need evidence.

What we read next comes sounds like psychological analysis:

“All else being equal, individuals tend to be significantly better at detecting fallacies when the fallacy occurs in an argument for a conclusion which they disbelieve, than when the same fallacy occurs in an argument for a conclusion which they believe.”

That statement, an outgrowth of confirmation bias, is surely a sword that cuts both ways!

"As more and more peers weigh in on a given issue, the proportion of the total evidence which consists of higher order psychological evidence [of what other people believe] increases, and the proportion of the total evidence which consists of first order evidence decreases . . .  “Over time, this invisible hand process tends to bestow a certain competitive advantage to our prior beliefs with respect to confirmation and disconfirmation. . . In deciding what level of confidence is appropriate, we should take into account the tendency of beliefs to serve as agents in their own confirmation.”

Unfortunately for this argument, it is the weight of the evidence of climate change in general and anthropogenic influence in particular that continues to grow; the 'invisible hand' has no documented effect on the scientific community.  Given all the public scrutiny, what climate scientist merely accepts the conclusions of his or her peers solely because 'that's what the experts say'?  Given the relative ease of access to data, why would anyone with a truly skeptical mind do that?

We find instead that this 'invisible hand' pushes those who self-identify as 'skeptics' to denying the data and the physics.  Denial pushes people towards increasingly radical positions, such as the rejection of science simply because of a lack of trust in 'experts.'  From there, it is a short trip to leveling accusations of manipulating data for financial gain and declaring that those are the opposite side are out to destroy their way of life.  Those in denial don't need to ask for evidence of any of these things; they know these things to be true because that's what their myths tell them to believe.  True skeptics and serious scientists don't think that way.

Finally, we read this:

The consilience of evidence argument is not convincing unless it includes parallel evidence-based analyses for competing hypotheses. Any system that is more inclined to admit one type of evidence or argument rather than another tends to accumulate variations in the direction towards which the system is biased. ... To be convincing, the arguments for climate change need to change from the one-sided consilience of evidence model to parallel evidence-based analyses of competing hypotheses.

This would be possible had the mythic uncertainty monster not left such a strong impression: We don't know enough or won't ever know enough to have a rational debate between competing hypotheses.  Pity there, because most of the 'competing hypotheses' are themselves myths already rebutted here at SkS.

Myths grow via retelling.  In this paper,  Dr. Curry acknowledges the "contributions of the Denizens of my blog Climate Etc. for their insightful comments."   In so doing, the myth-peddler sets a dangerous precedent.  Can scientists who also write blogs now repackage a selection of their followers' comments in the form of scientific publication?   If true, this is a quantum leap in the power and reach of the pseudo-science blog and a handicap for those that merely practice actual research.  We are truly at the door to the Land of Make Believe.  Or as Dr. Curry likes to put it, 'we've been busy slaying the skydragons'.

Carroll (a mathematician, whose real name was Charles Dodgson) would enjoy the metaphorical slaying of the 'uncertainty monster ':

"And, has thou slain the Jabberwock?
  Come to my arms, my beamish boy!
O frabjous day! Callooh! Callay!'
  He chortled in his joy.

Posted by muoncounter on Monday, 29 August, 2011

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