GHCN Adjusted Data Isn't Good Enough for D'Arrigo et al

May 7, 2007 – 12:18 PM

D’Arrigo, Wilson et al 2007 is an interesting article on the Divergence Problem, about which I plan to post from time to time. Since we’ve been discussing temperature data recently – with special discussions of GHCN data problems in Russia, China and Australia, I thought that it would be interesting to draw attention to an interesting aside in D’Arrigo, Wilson et al 2007 in which they reject GHCN adjusted data for Dawson, Yukon on the basis that it has inserted an unrealistically large trend. Continue reading →

By Stephen McIntyre | Posted in Divergence, Hansen, Surface Record | Comments (24)

RMS and Sulphate Emissions

May 6, 2007 – 7:33 AM

I had nothing to do with the Swindle presentation, and by and large the issues presented in Swindle are ones that I have not discussed here. I’m discussing these issues merely because it’s in the news.

A few days ago, I discussed the accusation by RMS and the 37 profs that Swindle had not used Hansen global data and that the 1940-mid 1960s decline in Swindle was greater than in Hansen data. As shown here, these claims were incorrect; given the demand by RMS and the 37 profs for due diligence, I expressed surprise that they would have made an allegation which could be shown to be invalid with minimal investigation.

A similar situation is discussed here in their claims about the course of sulphate emission, where the claim as articulated in the RMS letter is readily shown to be inconsistent with the discussion in the recent IPCC AR4 Second Draft, which was available at the time.
Continue reading →

By Stephen McIntyre | Posted in TGGWS | Tagged | Comments (209)

Unthreaded #10

May 5, 2007 – 11:11 AM

Continuation of Unthreaded #9

By John A | Posted in General | Comments (352)

Spot the Hockey Stick #17: Lloyds of London

May 5, 2007 – 8:32 AM

Following the discussion on insurers, RMS and climate change, someone pointed out that Lloyds of London also quotes a certain reconstruction of past temperatures. It wasn’t on the front page, but it wasn’t difficult to spot.

From the document linked as “Adapt or Bust” but included as part of a document on “Catastrophe” as part of the “360 Report” series (page 14) comes this:
Continue reading →

By John A | Posted in Spot the Hockey Stick! | Comments (11)

More on Hegerl et al 2006 Non-Confidence Intervals

May 4, 2007 – 11:06 AM

There are a few other blogs that from time to time do detailed analyses of what people are doing, not dissimilar in format to what I do. Last year, in Apr 2006 shortly after publication, I observed here that the upper and lower confidence intervals of Hegerl et al crossed over.

In Feb 2007, Tapio Schneider published a Comment in Nature observing that the confidence intervals in Hegerl et al were wrong. Hegerl published a Reply and replaced the Supplementary Information with new data (I kept the old version in case anyone wants a comparison.) James Annan recently discussed the matter , linking to my graph, acknowledging it in a business-like way. About the new Supplementary Information, he said:

There is now a file giving the reconstruction back to 1500 with new confidence intervals, which no longer vanish or swap over. This new data doesn’t match the description of their method, or the results they plotted in their Fig 1 (which is almost surely a smoothed version of the original supplementary data).

He went on to say:

Hegerl et al used a regression to estimate past temperatures anomalies as a function of proxy data, and estimated the uncertainty in reconstructed temperature as being entirely due to the uncertainty in the regression coefficient. The problem with this manifests itself most clearly when the tree ring anomaly is zero, as in this event the uncertainty in the reconstructed temperature is also zero!

Maybe UC (or Jean S who we haven’t heard from for a while) can comment on this. This comment still doesn’t seem right to me as I can’t think of why the uncertainty would be zero merely because all of the uncertainty was allocated to the regression coefficient. I still can’t get a foothold on what they’re doing here; Annan said that Tapio Schneider had been unsuccessful in getting Hegerl to document what they did in any of the calculations. I’ll write but I’m not optimistic about my chances. I’m up to about 20 emails with Crowley trying to find out how they got their Mongolia and Urals series, without any success.

Eli Rabett observed that Huang et al appeared to have done the same thing in a borehole study. In the caption, Huang refer to Bayesian methods being used, so maybe there’s a clue for someone. Whatever these folks are doing, it’s not a totally isolated incident. Who knows – one day,we might even find out how the MBH99 confidence intervals were calculated – presently one of the 21st Century Hilbert Problems in climate science.

References:
Hegerl JClim 2006 here
Hegerl Nature 2006 here
Hegerl SI here

By Stephen McIntyre | Posted in Hegerl 2006 | Tagged | Comments (25)

More on the Divergence Problem

May 4, 2007 – 7:56 AM

Two new things on the Divergence Problem. The IPCC First and Second Drafts did not contain a whisper of a mention of the divergence between ring widths and density in the second half of the 20th century, although this is rather an important issue. It came up at the NAS Panel and was completely unresolved in the hearings discussed here, where D’Arrigo was only able to refer to Briffa’s cargo cult explanation of the phenomenon.

In the absence of a substantiated explanation for the decline, we make the assumption that it is likely to be a response to some kind of recent anthropogenic forcing. On the basis of this assumption, the pre-twentieth century part of the reconstructions can be considered to be free from similar events and thus accurately represent past temperature variability.

In their report, the Panel adopted the view of Cook et al on the matter, which I’ve analyzed previously, in which bristlecones and foxtails seduce the Team once more. The final version of IPCC contains a lengthy paragraph on the Divergence Problem excerpted in full below. D’Arrigo, Wilson also have a new article, which I’ve not seen yet, but which is discussed at Pielke Sr here .

It appears that Cook et al 2004 is relied upon in this article. I discussed this article previously as More Cargo Cult. It will be interesting to see whether D’Arrigo, Wilson et al considered the issues raised in this post (not because they are obligated to deal with issues raised at this blog, but because they are obligated to deal with germane issues) . Continue reading →

By Stephen McIntyre | Posted in Divergence, IPCC, Proxies | Tagged , , | Comments (63)

Risk Management Solutions Ltd and the 37 Professors

May 3, 2007 – 2:51 PM

In the complaint about Swindle by Risk Management Solutions Ltd., endorsed by a gaggle of 37 professors, they allege that the Swindle graphic of 20th century claims in connection with 20th century temperature change contains the following misrepresentations:

Measurements from meteorological stations that have been published by NASA and other agencies show that the there was an overall slight decline in global average temperature between about 1940 and 1976, but much less than that shown on the graph presented in the programme.

and

this graph does not correspond to any figure for global average temperature that has been published by NASA

(This is one of many claims about misrepresentation in Swindle, but one where I happen to be familiar with the data and in a position to evaluate it. In connection with 20th century temperature change, they also argue that the Swindle failure to discuss aerosols is a “misrepresentation” of a fact or view, an issue which I may return to on another occasion.)

When a corporation, which has contracts with major insurers, makes highly visible public allegations like this, you’d think that they’d go to the trouble to ensure that the claims are correct. Likewise, when 37 climate scientists sign onto the claim, including temperature specialist, Phil Jones, you’d think that they’d also go to the trouble to ensure that the claim is correct. When they go on to argue that communications with the public – into which category their Open Letter to Martin Durkin published on a website surely qualifies – should have proper due diligence, you’d think that they’d double check that a specific claim like this was true.

But hey, this is climate science.

Since the matter is in controversy, I spent some time collecting as many different versions of the Hansen data as I could locate, including a version from Willie Soon used in the Robinson article referred to in the complaint, from which the Swindle graphic appears to have been derived. Continue reading →

By Stephen McIntyre | Posted in TGGWS | Tagged , | Comments (266)

von Storch and Zorita blog on the Hockey Stick

May 3, 2007 – 12:06 PM

At a Nature climate change blog, von Storch and Zorita write:

In October 2004 we were lucky to publish in Science our critique of the hockey-stick’ reconstruction of the temperature of the last 1000 years. Now, two and half years later, it may be worth reviewing what has happened since then.

The publication in 2004 was a remarkable event, because the hockey-stick had been elevated to an icon by the 3rd Assessment Report of the IPCC. This perception was supported by a lack of healthy discussion about the method behind the hockey-stick. In the years before, due to effective gate keeping of influential scientists, papers raising critical points had a hard time or even failed to pass the review process. For a certain time, the problem was framed as an issue of mainstream scientists, supporting the concept of anthropogenic climate change, versus a group of skeptics, who doubted the reality of the blade of the hockey stick. By framing it this way, the real problems, namely the wobbliness’ of the shaft of the hockey-stick, and the suppressing of valid scientific questions by gate keeping, were left out.

They then proceed to discuss various articles on the Hockey Stick mentioning Bürger, Moberg, borehole papers, the NAS report, but failing to mention McIntyre and McKitrick. Pretty annoying.

By Stephen McIntyre | Posted in General, MM, News and Commentary | Tagged , | Comments (84)

The Swindle Complaint and Myles Allen

May 2, 2007 – 10:45 PM

Bob Ward, who you may remember as the author of various complaints from the U.K. Royal Society, is now employed at Risk Management Solutions Ltd. In his business capacity as Director, Global Science Networks, Risk Management Solutions Ltd., he has filed a complaint about Swindle under a section of the broadcasting code which states: “Views and facts must not be misrepresented”. I could understand Ward complaining as an individual citizen, but I’m surprised that he is doing so in his capacity as an employee of Risk Management Solutions. It’s intriguing that Risk Management Solutions perceives itself as having a business interest in suppressing the distribution of Swindle as it stands.

In addition to Ward’s initial complaint, on April 24, 2007, a number of scientists – including Myles Allen of climateprediction.net and Phil Jones – piled on with an Open Letter to Martin Durkin published online here in which they stated:

However, we believe that it is in the public interest for adequate quality control to be exercised over information that is disseminated to the public to ensure that it does not include major misrepresentations of the scientific evidence and interpretations of it by researchers.

Now I happen to agree with that particular sentence. This type of standard applies to mining speculations and I’ve consistently advocated that climate scientists should, at a minimum, meet standards applicable to mining promoters. (By saying this, I’m not advocating any particular system of enforcing such standards, only that this is a reasonable standard to at least measure non-compliance. ) I’m pleased that such an eminent set of British scientists has endorsed a standard advocated for such a long time at climateaudit. Perhaps we’re turning a corner here. Obviously there is no shortage of candidates for Ward’s Truth Squad to consider. Continue reading →

By Stephen McIntyre | Posted in Archiving, News and Commentary, TGGWS | Tagged , | Comments (133)

Exponential Growth in Physical Systems #2

May 2, 2007 – 9:12 PM

Continuation of Exponential Growth # 1. Consult the original thread for an interesting dialogue.

By Stephen McIntyre | Posted in General | Comments (553)