In my submission to the Parliamentary Committee, I observed that the “trick” wasn’t “clever” – it was the deletion of inconvenient data.
The IPCC “trick” was not a “clever” mathematical method – it was merely the deletion of inconvenient data after 1960. Post-1960 values were even deleted in the reconstruction archived version at NOAA.
I provided an explanation with a graphic – which wasn’t quoted or cited. They cited a less precise submission by Peter Taylor on this point.
They noted that “UEA interpreted the use of the word “trick” differently” citing the following portion of the UEA submission [discussing the trick email describing the WMO 1999 graphic, not the TAR graphic – June 13, 2010]:
as for the (now notorious) word ‘trick’, so deeply appealing to the media, this has been richly misinterpreted and quoted out of context. It was used in an informal email, discussing the difficulties of statistical presentation. It does not mean a ‘ruse’ or method of deception. In context it is obvious that it is used in the informal sense of ‘the best way of doing something’. In this case it was ‘the trick or knack’ of constructing a statistical illustration which would combine the most reliable proxy and instrumental evidence of temperature trends.
Contrary to UEA’s claims, there is no valid statistical procedure supporting the substitution of tree ring proxy data going the wrong with instrumental temperature data to create a false rhetorical impression of the coherence of the proxy data. Indeed, as I observed in my submission, Mann himself had condemned the merging of instrumental and proxy data as follows:
No researchers in this field have ever, to our knowledge, “grafted the thermometer record onto” any reconstruction. It is somewhat disappointing to find this specious claim (which we usually
find originating from industry-funded climate disinformation websites) appearing in this forum [realclimate].
Unfortunately, NIgel Lawson – who, to my knowledge, does not have in-depth knowledge of Climate Audit issues – was invited by the Committee to testify on Climate Audit issues and made incorrect and exceedingly ill-judged comments on the topic, comments that were seized upon by the Committee as follows:
These [ UEA]interpretations of the colloquial meaning of “trick” have been accepted by even the staunchest of critics:
Lord Lawson of Blaby: The sinister thing is not the word ‘trick’. In their [UEA’s] own evidence they say that what they mean by ‘trick’ is the best way of doing something.
Chairman: You accept that?
Lord Lawson of Blaby: I accept that.
From these ill-judged comments, the Committee concluded:
[The trick] appears to be a colloquialism for a “neat” method of handling data.
This is absurd. The trick was not a “neat” way of handling data, nor a recognized form of statistical analysis. The trick was a clever way of tricking the readers of the IPCC 2001 graphic into receiving a false rhetorical impression of the coherency of proxies – a point understood at the beginning by Jon Stewart of the Daily Show, but now misunderstood due to continued disinformation.
The Committee went on to consider Lawson’s testimony on “hide the decline” as follows:
61. Lord Lawson did, however, describe CRU’s treatment of the data as “reprehensible”, because, in his view, Professor Jones deliberately hid data that demonstrated a decline in temperatures.
62. The data that he believed to be “hidden” are a set of tree ring data that disagree with other data sources regarding temperature trends. Lord Lawson said: “when the proxy series […] departed from the measured temperature series, a normal person will say maybe that means the proxy series is not all that reliable”. In that context he made two specific claims:
• that the tree ring data were flawed because “for a long period before 1421 they relied on one single pine tree”; and
• that the divergence problem was not just for data after the 1960s, “it is not a good fit in the latter half of the nineteenth century either”.
Again, these comments by Lawson were ill-considered. I have no idea what he had in mind in his comment about the lone pine tree nor what his 19th century comment was about. Jones was able to rebut each of Lawson’s comments and the Committee accepted Jones’ rebuttal of Lawson’s comments.
On these points, the Committee did not consider or rebut any of my written points, preferring to deal with easier targets.
The Committee cited the UEA denial that they had ever sought to “hide the decline”:
CRU never sought to disguise this specific type of tree-ring “decline or divergence”. On the contrary, CRU has published a number of pioneering articles that illustrate, suggest reasons for, and discuss the implications of this interesting phenomenon.
Again, as so often, you have to watch the pea under the thimble. It is true that the decline was reported in publications by CRU authors – but this does not mean that CRU never sought to disguise the “decline or divergence”. As I pointed out in my submission (and others also), CRU authors – in their capacity as IPCC contributors – sought to disguise the decline in the influential IPCC spaghetti graph (and elsewhere, through such measures as not archiving post-1960 reconstruction values.)
Given that the IPCC report is the most influential representation of the data, this is hardly a minor incident.
The Committee reached the following conclusion on this matter:
66. Critics of CRU have suggested that Professor Jones’s use of the words “hide the decline” is evidence that he was part of a conspiracy to hide evidence that did not fit his view that recent global warming is predominantly caused by human activity. That he has published papers—including a paper in Nature—dealing with this aspect of the science clearly refutes this allegation. In our view, it was shorthand for the practice of discarding data known to be erroneous. We expect that this is a matter the Scientific Appraisal Panel will address.
Here the Committee either failed to watch the pea under the thimble or is itself moving the pea. Once again, the fact that the decline is discussed in a Nature paper does not justify the deletion of the inconvenient data in the IPCC spaghetti graph in order to provide the false rhetorical consistency that IPCC was seeking. The issues are entirely separate and the Committee should have been able to discern this.
In addition, their suggestion that Jones and others were doing nothing more than “discarding data known to be erroneous” is simply absurd. There was no testimony to the Committee (nor has it ever been suggested) that the tree ring data was measured incorrectly or that the data was “erroneous” – the data is what it is. The tree ring data goes down instead of up – but that doesn’t make it “erroneous”. It only means that the data is a bad proxy – something that was concealed from IPCC readers.
It is discouraging to read such bilge.