“Consider Fig. 1 showing the negative of the anomaly of atmospheric pressure in Darwin, Australia and used by Trenberth and Hoar (1997) as a measure of the strength of the Walker circulation. Fig. 2 displays the sea surface temperature (SST) Niño3.4 index commonly used as a measure of the strength of El Niño. Trenberth and Hoar(1997) infer that ENSO behavior shifted after about 1970 to more frequent and larger El Niño events. (The change was interpreted as the result of global warming and to be “unprecedented” in the historical record.) Solow (2006), however, noted that their anomalous test period, 1992-mid-1995, in Fig. 1 was not independent of the earlier interval of supposedly normal behavior; he used the subsequently longer record to recalculate the probability that the nature of ENSO had changed in some significant way. His conclusion was, in contrast, that while the test period appears different from the earlier one, subsequently there was essentially no evidence that the nature of the physics had changed. The comparatively dramatic story of the original authors is thus replaced by a much more ambiguous and unexciting, but presumably more soundly-based,description of the nature of ENSO.”
Carl Wunsch: Extremes, Patterns, and Other Structures in Oceanographic and Climate Records
Abstract: The human eye and brain are powerful pattern detection instruments. Coupled with the clear human need to perceive the world as deterministic and understandable, and the often counter-intuitive results of probability theory, it is easy to go astray in making inferences. In particular, many examples exist where attention was called to apparent extreme behavior, whether in time or space series, or in the appearance of unusual patterns, that are just happenstance. Used carefully, and with a residual open-mindedness, it is possible to employ some simple statistical tests to avoid the outcomes of inferring unusual behavior where none is present, nor in rejecting a major finding as being insignificant.
Climate Audit: ‘Carl Wunsch on Self-Deception’
Framing, what, eh? “Wunsch not duped”? Scientists do not try to ‘dupe’ each other, they propose ideas that are backed by evidence, which other scientists then try to prove right or wrong. They don’t go around trying to “dupe” each other.
Wunsch also believes the science of AGW is fundamentally sound, and a serious issue for the human race.
“I have omitted here discussion of the interesting phenomenon of “pathological science” (see Park, 2000).
Misuse or misinterpretation of statistics and probability is only one way for scientists to get into trouble. Wishful thinking and general self-delusion are not unknown.
The moral of the story is that statistical and probabilistic inference needs to be done carefully, with as many of the assumptions the investigator is aware of being made plain and explicit (National Research Council, 2006).
There are many ways to go astray, but in general, careful use of existing statistical methods, transparency, and lingering skepticism are safe harbors for the scientific investigator.”
Malcolm Hill says
remind people of the words of Oliver Cromwell to the
Church of Scotland (J. Kadane, private communication,
2007): “I beseech you, in the bowels of Christ, think it
possible you may be wrong” (Bartlett, 1968). Locale
aside, it seems like good advice for scientists.”
The very last comment in the paper referred to by Rog is the most appropriate.
Advice that would not have much carriage with the inhabitants if this blog, and the gaggle of Govt funded alarmists they represent.
What a dreadful piece of denialist spin – I’m shocked. Wunsch is not “duped”. WTF.
Solow asserts to have found a statistical error with Trenberth and Hoar. Well holey doley, a debate on a scientific paper (that’s still ongoing) – well gee that’s never happened before in the history of science. Trenberth and Hoar have set out to dupe “Wunsch” 10 years later. Golly gee what a terrific prediction.
They may have been incorrect or wrong, but no out of the entire paper they are out to “dupe”.
Wunsch then uses the debate as an illustration. Fair cop.
Hilarious that McIntyre and the denialists have picked up on this with fervour as some sort of anti-IPCC anti-tank weapon. Read on dillberries and see the serve handed out to misuse of statistics on solar cycles.
Has Archibald read it. Paul better send him a copy. Although E&E is a stats free zone. ROTFL.
Come in spinner guys !! READ IT AND NOTA BENE !
And to cap it off Rog and Malcolm who have demonstrated total ignorance of any principle of probability theory with countless posts are now embracing this paper and waving it around.
You nitwits have no idea of the statistical requirements of climate science so don’t pretend you’re onto something. Statistical advice is tricky stuff. As Wunsch’s little examples illustrate it’s easy for any of us (including myself) to get on the wrong foot.
Which is why statistician exist I guess. And even they have schools of thought.
Anyway – hilarious – let’s see a retitle where “Wunsch takes takes axe to statistical solar nonsense”.
The only duping that’s going on is with yourselves.
Wunsch has a point but needs to explain himself a bit better. The 1976 Great Pacific Climate Shift has moved the Pacific into a warmer state. The average southern oscillation index value (according to the Troup system) for the 25 years prior to 1976 was about +1.5 (i.e. slight La Nina bias) but for the 25 years following was about -2.5 (i.e. stronger El Nino bias).
McPhadden and Zhang estimated that the upwelling cold water has reduced by about 25%. That change has been over time so it not clear if this was the initial cause of the cause of the shift. There may have been some reduction in upwelling and this influenced the easterly winds, which in turn reduced the upwelling even further. The winds push the top layer of warm water to the west and and allow cooler water to rise to the surface.
(I have looked at the dates for French nuclear testing in the Pacific but could find no tests that correlated with a shift in the Southern Oscillation in the first few months of 1976.)
Back to Wunsch … the nature of ENSO has not changed but warmer ocean waters mean that the base condition has shifted.
Wunsch warns against “rhetorical excess” which is what Luke excels at.
As if Rog even knows what he’s reading.
the topic is a fine example of rhetorical excess. Take an opinion of Wunsch’s and completely misrepresent what he thinks of the science of global warming. Wunsch thinks it’s basically correct.
Wunsch discusses the conclusions of Trenberth and Hoare (described as a “comparatively dramatic story”) and then says “Another example of simple pitfalls…”
Forming a “superficial, non-objective, inference” is the pitfall he refers to.
SJT, thats the topic
Read the article Luke, you dill.
try to reconcile Wunsch with the topic headline.
BTW. Wunsch agrees that the science of AGW is basically sound.
Here are his own words
“I believe that climate change is real, a major threat, and almost surely has a major human-induced component. But I have tried to stay out of the `climate wars’ because all nuance tends to be lost, and the distinction between what we know firmly, as scientists, and what we suspect is happening, is so difficult to maintain in the presence of rhetorical excess. In the long run, our credibility as scientists rests on being very careful of, and protective of, our authority and expertise.”
He can’t be clearer than that.
Rog – try to read the entire article in context. I know it’s hard for you. There’s more to focus on than the singular Trenberth point. The fact you guys missed the implications with the solar cycles stats issue is the reason for my mirth.
Also the post lead is not derivative from that paper – “duping” indeed.
You may also be interested to know that Trenberth is still arguing. “Superficiality” is not that simple.
Anyway Wunsch makes good points. Nobody’s science is immune from a stats ream-out.
Many denialists should take close note with their own arguments.
Before you guys set off on another tangent..
Luke, talk to SJT and
SJT, talk to Luke
Try to work as a team OK?
Before you two get all hysterical about the word “dupe” it was Wunsch who did say “I was duped” so if its OK for Wunsch to use That Word it must be OK for the foot soldiers to mutter the same.
Basically you two are just all white noise, airborne chaff.
Hi SJT – Rog says we should talk. Well here’s what I reckon – sometimes in a debate you suddenly think – oh he’s not very bright and you realise you’re wasting your time. So let’s just smile and say thanks for your thoughts and see if he gets infantile fascination in another topic.
brilliant insight. “Many denialists” should not grasp at every straw that happens by on the blogosphere. Wunsch was talking about keeping the standard of science high, he would turn apoplectic at the curiosities from Arhcibald and others that are paraded around here as science.
Gawd what have I done, tweedeldum and tweedledee
“‘The time has come,’ the Walrus said,
‘To talk of many things:
Of shoes – and ships – and sealing wax –
Of cabbages – and kings –
And why the sea is boiling hot –
And whether pigs have wings.’
Total content posted by Rog
Such a cruel, cutting, incisive remark; I am in despair – totally gutted.
Your daddy will be proud, his little wunderkid has now graduated to the level of guttersnipe.
Where is Dad – peering into the Looking Glass?
Interesting style SJT – misses the Neo-Raphaelite grandeur of a Mottsian slag off – more your sly little central costian knife merchant technique. Rog & Pat is more at home in high discourse with political intelligensia such as http://graemebird.wordpress.com/2007/11/02/dobell-the-liberty-and-democracy-party-and-me-a-reply-to-rog-at-cattallaxy/
Now Luke is stalking me – should I be flattered with all this attention from a George Lucas creation?
Well yes and no.