On August 3rd, I posted a further note on the inquiries into the Climategate scandal. Joe Romm's criticism that the phrase "the trick to hide the decline" does not appear in the Climategate emails is correct. I have supplied the sentence that did appear, and corrected the other references to it. I've tried to clarify my position on Penn State's treatment of it. I have added sentences to underline what I am not saying about Climategate, and I've removed some words and phrases which were not as clear as they could have been. I apologise for not getting these things right first time round.

Below is a corrected and revised version of my August 3 post.

Joe Romm tells me to "retract [my] libellous misinformation and apologise to Michael Mann". He is referring to a post in which I suggested that the various inquiries supposedly vindicating the Climategate emailers have further diminished the credibility of climate science, rather than restoring it.

I think the only issue of substance in his complaint is the charge that I failed to notice that there were two Penn State investigations of Mann, not one, and that both had cleared the accused. Of course I was aware of the form of the inquiry, though I concede that the post was not as clear about the two phases as it should have been.

There was one inquiry with two stages. (Read the Penn State reports here and here.) In my opinion, the first stage does not deserve to be called an investigation. It consisted of little more than a review of the emails and interviews with Mann. I would characterise the result as a cursory dismissal of the charges. The second phase, which looked more carefully at one of the allegations, has a better claim to be called an investigation, but still, I think, falls way short of what would be required to convince a fair-minded reader that the reports were adequate.

I wrote: "Three of four allegations are dismissed out of hand at the outset: the inquiry announces that, for 'lack of credible evidence', it will not even investigate them." I should have written: "Three of the four allegations were dismissed after the inquiry's first phase on the basis of little more than a review of the emails and interviews with Mann." I also wrote: "Mann is asked if the allegations (well, one of them) are true, and says no." The words in parentheses were wrong, since Mann was indeed asked to explain himself in relation to all four allegations. I should have written: "Mann is asked if the allegations are true, and says no."

You be the judge. Read the reports and see if you find the inquiry convincing. I'd draw your attention especially to the finding that deals with the most discussed email in the Climategate stash. That email, from CRU's Phil Jones to Mike Mann and two other colleagues, included the sentence:

I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) amd [sic] from 1961 for Keith's to hide the decline.

On this, the first report says:

While a perception has been created in the weeks after the CRU emails were made public that Dr. Mann has engaged in the suppression or falsification of data, there is no credible evidence that he ever did so, and certainly not while at Penn State. In fact to the contrary, in instances that have been focused upon by some as indicating falsification of data, for example in the use of a "trick" to manipulate the data, this is explained as a discussion among Dr. Jones and others including Dr. Mann about how best to put together a graph for a World Meteorological Organization (WMO) report. They were not falsifying data; they were trying to construct an understandable graph for those who were not experts in the field. The so-called "trick" was nothing more than a statistical method used to bring two or more different kinds of data sets together in a legitimate fashion by a technique that has been reviewed by a broad array of peers in the field.

Well. It seems to me, and I dare say to other open-minded readers, that the talk in the emails of a "trick...to hide the decline" raised the reasonable suspicion that a trick had been used to hide the decline. "[T]o the contrary," says the report. The "trick" has no connotation of trickery, but merely denotes a "statistical method". Let us accept this. What about "hide"? Is it all right to employ a statistical method to hide the decline? Why was anybody trying to "hide the decline"?

Other inquiries and statements by the scientists have explained that a proxy temperature series-used to estimate temperatures going back centuries, before instrumental data were available-shows an anomalous decline in recent decades. This is what the "statistical method" was intended to hide. The purpose was not to fool anyone, but to avoid confusion. All right, but to claim that the issue goes away once you understand this would be wrong. How far to trust a series that breaks down in recent decades (for reasons not yet understood) in estimating temperatures over centuries is a judgment call. Whether it was right to hide the decline for the purposes of the WMO graph, not merely by curtailing the suspect series and ending it early, but by splicing on actual temperatures, is another. Such judgments are, or ought to be, open to question. And how forthright to be in explaining what has been done is another issue worthy of debate.

Here, by the way, is part of what the Muir Russell report had to say about that aspect of "hide the decline":

Finding: In relation to "hide the decline" we find that, given its subsequent iconic significance (not least the use of a similar figure in the TAR), the figure supplied for the WMO Report was misleading in not describing that one of the series was truncated post 1960 for the figure, and in not being clear on the fact that proxy and instrumental data were spliced together. We do not find that it is misleading to curtail reconstructions at some point per se, or to splice data, but we believe that both of these procedures should have been made plain - ideally in the figure but certainly clearly described in either the caption or the text.

I am not competent to discuss the science, and do not pretend to be. But here is what I see when I read the "trick" email and then the Penn State report. An explanation is required. The report offers only half an explanation: "trick" means "statistical method". No contrary opinions are sought or heard. On this basis the report finds "no substance" in the criticism.

Romm is entirely satisfied by this rigorous "investigation". Fine. I disagree with him.

Two other points. First, I want to emphasise that I do not suspect Mann or the others of outright scientific fraud - by which I mean the destruction or falsification of data. I understand that the other Climategate inquiries have cleared Mann and his colleagues of scientific misconduct, and do not question that finding. I understand that some critics, including Sarah Palin and other prominent US politicians, said that "hide the decline" referred to hiding a decline in measured temperatures, which was nonsense. Plainly, I do not believe that the Climategate emails have shown that mainstream climate science is a hoax, or that it has got the main things wrong. To repeat, I believe climate change poses a serious risk, and have argued that policy-I favour a carbon tax-should be designed to mitigate it. But for my purposes in this post and my previous one on the subject, this is beside the point.

According to what I read, for sensible critics of Mann and "The Team", destruction or fabrication of data is not the issue. The argument is about the dangers of groupthink, a preference for data that point in the right direction, efforts to deflect or neutralise opposing points of view, and the selective packaging of findings for public consumption (which is where "hide the decline" comes in). Fundamentally, the problem resides in the tension between the IPCC's role as both an advocacy organisation and a neutral gatherer of scientific analysis. It seems to me the Climategate emails give ample grounds for concern on all those points, and none of the inquiries into the matter has dealt with these issues adequately.

Second, and most important, the evident fondness of climate-change activists for delegitimising dissent and arranging the facts to make them more "understandable" is simply not working. Cap and trade just died for lack of public support. I think climate-change activists are partly to blame, as I argue in this recent FT column. They are harming their own cause.

Romm exemplifies the tendency to the point of caricature. He delights in splenetic hyperventilation. This is his brand, so to speak. It goes down well with the faithful - but persuading the faithful is not the challenge. He needs to convince the unconvinced. Operatic ranting is not, I would submit, likely to succeed.

Note how he responds when I say, "I think climate science points to a risk that the world needs to take seriously. I think energy policy should be intelligently directed towards mitigating this risk. I am for a carbon tax."

Uhh, Memo 1 to Crook:  Those exact same words could have been written by Bjorn Lomborg (or even the CEO of ExxonMobil).  They tell us absolutely nothing about where you stand on climate change.

Memo 2 to Crook:  In case you and your magazine missed it, the big climate change policy Congress has been wrangling over for the last year and a half are cap-and-trade bills, not a carbon tax.  Who cares whether you are for some unspecified and hence possibly meaningless carbon tax?

Supporting a carbon tax tells "us absolutely nothing about where you stand on climate change"? I'd say this borders on the unhinged. In any case, there is no capacity here to seek allies in the interests of better policy. Romm's absurd ferocity shuns that very segment of moderate opinion that needs to be brought round to the case for...a carbon tax. He and people like him are their own worst enemies.

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