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Caspar and the Jesus paper

There has been the most extraordinary series of postings at Climate Audit over the last week. As is usual at CA, there is a heavy mathematics burden for the casual reader, which, with a bit of research I think I can now just about follow. The story is a remarkable indictment of the corruption and cyncism that is rife among climate scientists, and I'm going to try to tell it in layman's language so that the average blog reader can understand it. As far as I know it's the first time the whole story has been set out in a single posting. It's a long tale - and the longest posting I think I've ever written and piecing it together from the individual CA postings has been a long, hard but fascinating struggle. You may want to get a long drink before starting, and those who suffer from heart disorders may wish to take their beta blockers first.

At some time or another, most people will have seen the hockey stick - the iconic graph which purports to show that after centuries of stable temperatures, the second half of the twentieth century saw a sudden and unprecedented warming of the globe. This was caused, we were told, by mankind burning fossil fuels and releasing carbon dioxide into the atmosphere. For a while, the hockey stick was everywhere - unimpeachable evidence that mankind was  damaging the planet - an impact that would require drastic measures to reverse.  The stick's most famous outing however was just a couple of years ago when it made a headlining appearance in Al Gore's drama-documentary, An Inconvenient Truth. The revelation of the long, thin graph with its dramatic temperature rise in the last few decades, and the audience gasps that accompanied it, is something of a key moment for many environmentalists.

Shortly after its publication, the hockey stick and its main author, Michael Mann, came under attack from Steve McIntyre, a retired statistician from Canada. In a series of scientific papers and later on his blog, Climate Audit, McIntyre took issue with the novel statistical procedures used by the hockey stick's authors. He was able to demonstrate that the way they had extracted the temperature signal from the tree ring records was biased so as to choose hockey-stick shaped graphs in preference to other shapes, and criticised Mann for not publishing the cross validation R2, a statistical measure of how well the temperature reconstruction correlated with actual temperature records. He also showed that the appearance of the graph was due solely to the use of an estimate of historic temperatures based on tree rings from bristlecone pines, a species that was known to be problematic for this kind of reconstruction.

The controversy raged for several years, involving blue riband panels, innumerable blog postings, endless name-calling and dark insinuations about motivations and conflicts of interest. In May 2005, at the height of the controversy, and on the very day that McIntyre was making a rare public appearance in Washington to discuss his findings, two Mann associates, Caspar Amman and Eugene Wahl, issued a press release in which they claimed that they had submitted two manuscripts for publication, which together showed that they had replicated the hockey stick exactly, confirmed its statistical underpinnings and demonstrated that McIntyre's criticisms were baseless.  This was trumpeted as independent confirmation of the hockey stick. A few eyebrows were raised at the dubious practice of using a press release to announce scientific findings. Some also noted that on the rare occasions that this kind of announcement is made, it tends to be about papers that have been published, or at least accepted for publication. To make such a dramatic announcement about the submission of a paper was unusual in the extreme.

The first of these papers ("the GRL paper") was submitted to Geophysical Research Letters, the journal of the American Geophysical Union. It took the form of a rebuttal of a McIntyre paper that had attacked the hockey stick and had been published in the same journal. From the first, the McIntyre paper had been controversial. Apart from Amman and Wahl's paper, there were three other papers taking issue with it. However, it turned out that some of these attempted rebuttals were less well formed  than others. In fairly short order, Amman and Wahl's paper was rejected, many of its criticisms either relating to other McIntyre papers than the one at hand, or relying on the second paper for their arguments. Since the second paper was unpublished, it was effectively impossible for McIntyre to defend himself against these criticisms. Shortly after Amman and Wahl's paper was rejected, another of the rebuttals, that of a physicist called David Ritson, was also shot down by the journal's editors.

Meanwhile the second, longer paper ("the CC paper") had started its long road to publication at the journal Climatic Change. This article purported to be a replication of the hockey stick and confirmation of its scientific correctness. However, in a surprising turn of events, the journal's editor, prominent global warming catastrophist Steven Schneider, mischievously asked none other than Steve McIntyre to be one of the paper's anonymous peer reviewers. 

We have seen above that one of the chief criticisms of the hockey stick was the fact that its author, Michael Mann, had withheld the validation statistics so that it was impossible for anyone to gauge the reliability of the reconstruction. These validation statistics were to be key to the subsequent story. At the time of their press release Wahl and Amman had made public the computer code that they'd used in their papers. By the time their paper was submitted to Climatic Change, McIntyre had reconciled their work with his own so that he understood every difference. And he therefore now knew that Wahl and Amman's work suffered from exactly the same problem as the hockey stick itself: the R2 number was so low as to suggest that the hockey stick had no meaning at all, although another statistic, the reduction of error statistic (or RE) was relatively high. It was only this latter figure that had been mentioned in the paper. In other words, far from confirming the scientific integrity of the hockey stick, Wahl and Amman's work confirmed McIntyre's criticisms of it! McIntyre's first action as a peer reviewer was therefore to request from Wahl and Amman the verification statistics for their replication of the stick. Confirmation that the R2 was close to zero would strike a serious blow at Wahl and Amman's work.

Caspar AmmanWahl and Amman's response was to refuse any access to the verification numbers, a clear flouting of the journal's rules. As a justification of this extraordinary action, they claimed that they had shown that McIntyre's criticisms had been rebutted in their forthcoming GRL paper, despite the fact that the paper had been rejected by the journal some days earlier. At the start of July, with his review of the CC paper complete, McIntyre took the opportunity to probe this point, by asking the journal to find out the anticipated publication date of the GRL paper. Wahl and Amman were forced to admit the rejection, but they declared that it was unjustified and that they would seek publication elsewhere.

Sir John HoughtonWith the replication of the hockey stick in tatters, reasonable people might have expected some sort of pause in the political momentum. Seasoned observers of the climate scene, however, will be unsurprised to hear that global warming eminences grises like Sir John Houghton and Michael Mann continued to cite the Wahl and Amman papers despite the CC paper being in publishing limbo and the GRL paper being apparently dead and buried. The Wahl and Amman press release was not withdrawn either.

Events soon took another surprising turn., It was announced that the editor in chief of Geophysical Research Letters, Jay Famiglietti, had taken over the file for the McIntyre paper and its responses. This was justified he claimed, because of the high number of responses - four - that the McIntyre paper had received. That two of those responses had been rejected and were no longer in play was not mentioned. The reason for the change quickly became apparent though when, at the end of September, the rejected response from David Ritson turned out not only to have been re-submitted but had also been accepted for publication. This was another clear breach of the journal's rules, which required that an article's author should be able to comment on responses before they were accepted. Famiglietti however refused to make any on-the-record comments about why he behaved as he did.

Jay Famiglietti

If McIntyre had any suspicions about the implications of Famiglietti's malfeasance, he must have been quite certain when, shortly afterwards, hockey stick author Michael Mann commented on his RealClimate blog that both the CC and the GRL papers were going to be accepted shortly. Sure enough, in the last week of September, the GRL paper was resubmitted and revisions were made to the CC paper. Both papers were back in play again.

As 2005 neared its end, two important events loomed large. The first was the year end deadline for submission of papers for the IPCC's Fourth Assessment Report on the state of the climate, and realisation soon dawned on McIntyre and the observers of the goings-on at GRL:

the IPCC needed to have the Wahl and Amman papers in the report so that they could continue to use the hockey stick, with its frightening and unprecedented uptick in temperatures. Mountains were going to be moved to keep the papers in play.

The other important happening was the fall meeting of the American Geophysical Union, which would be attended by many of the big names in paleoclimate and at which both McIntyre and Amman would be making presentations.  McIntyre's plan was to use the question and answer session after Amman's presentation to once again press for the R2 number for the hockey stick, a figure that had never been released, despite it being constantly requested over the previous years by McIntyre, journals, politicians and journalists. Sure enough, when confronted, Amman once again prevaricated.

After the session, McIntyre attempted to clear the air by inviting Amman to lunch. In the circumstances, this seems to have been a relatively amicable affair, but McIntyre's suggestion that he and Amman write a joint paper outlining where they agreed and where they differed was not taken up. When McIntyre later formalised this offer in an email, Amman failed even to acknowledge it.

While the AGU was meeting in San Francisco, Climate Change had provisionally accepted Wahl and Amman's CC paper, any objections which might have been raised by McIntyre swept aside by simple means of not inviting him to review the second draft. The resubmitted version of the paper turned out to be almost identical to the old one, except that a new section on the statistical treaments had been added, presumably as a condition of acceptance. And here there was an upside because, buried deep within the paper, Amman and Wahl had quietly revealed their verification R2 figures, which were, just as McIntyre had predicted, close to zero for most of the reconstruction, strongly suggesting that the hockey stick had little predictive power. Their decision to reveal these key data is necessarily obscure, but may well have been prompted by McIntyre's decision to file a complaint of academic misconduct about Amman with his employers, UCAR. Although the complaint was rejected, it may well have put sufficient pressure on Amman and the journal to show the numbers that everyone wanted to see.

The CC paper's provision acceptance date was December 12th, just a few days before the AR4 deadline. Strangely the version that was accepted seems to have been dated 24th Feb 2006, so according to its rules the IPCC shouldn't have been able to considered it. And what is more, it appears that the new sections discussing the statistical verifications were only added in this post year-end version. As McIntyre put it

So under its own rules, is IPCC allowed to refer to Ammann and Wahl [2006]? Of course not. Will they? We all know the answer to that. When they refer to Ammann and Wahl [2006], will they also refer to its confirmation of our claims about MBH verification r2 statistics. Of course not. That information was not available to them in December. But wait a minute, if Ammann and Wahl was in press in December, wouldn’t that information have been available to them? Silly me.

In other words, the version of the paper which had gone forward to the IPCC didn't include the adverse verification statistics, but the version accepted by the journal did. The IPCC got their rebuttal of McIntyre and the journal got a fig leaf of respectability to cover up its duplicity.

By March, the CC paper had been fully accepted, but there was to be another hiccup that would threaten its existence. After all the shenanigans at GRL with the replacement of the editor and the resubmission of letters, the journal decided once again to reject Wahl and Amman's attempt to rebut McIntyre's work. Ostensibly this was because the arguments were "already out there", but the truth was surely that there were so many holes in the statistical arguments as to make their publishing an embarrassment to the journal.

This new rejection was a problem for the CC paper, as I will explain below.  When using an R2 verification, researchers can refer to tables of benchmarks to gauge the significance of their results. Now that the fact that the hockey stick and Amman and Wahl's replication of it were public, Amman was arguing that the correct measure of significance was in fact the alternative RE statistic. His problem was that for RE statistics, there are no tables of benchmarks for the researcher to refer to - he has to establish a benchmark of his own by other means. And Amman had done this in the GRL paper which had just been rejected. Without the GRL paper, he couldn't even argue that his results in CC were statistically significant.

There is a rule of thumb for RE statistics: this says that positive RE numbers have some significance while negative ones do not. Unfortunately for Amman, this rule applies only to linear regressions; as the hockey stick was clearly not linear, it couldn't apply. The original hockey stick authors had claimed that they had created a benchmark through other means, and that the figure was still zero.  Now, while they had been silent on the issue in their original GRL submission, Amman and Wahl announced in their resubmission that they had performed benchmarking calculations and that had confirmed that the significance level for the RE should remain at zero.

However, now that the resubmission had been rejected by GRL, the "establishment" of this benchmark was cancelled out, and the statistical arguments in the CC paper which relied on it could no longer be maintained.

And then silence. A year later, the CC paper was nowhere to be seen, despite having been accepted for publication. It was stuck in a kind of publishing limbo once again. This left the IPCC and Climatic Change with a problem. McIntyre observed:

I’m intrigued as to what the final Wahl and Ammann version will look like. They have an intriguing choice: the inclusion of a reference to this article in AR4 was premised on their article being “in press” which would prohibit them from re-working their article to deal with the GRL rejection. But the article needs to be re-worked since it will look pretty silly to describe their GRL article as “under review” over 18 months after it has been rejected.


In the background, howevrer, much had been happening. Suddenly in September 2007, and with the IPCC report published, the CC paper suddenly appeared, preceded in the same journal by another paper by the same authors. What had happened was that Wahl and Amman were quietly allowed to rewrite their rejected GRL paper and submit it to Climatic Change instead. All reference to the rejected GRL paper in the CC paper could be replaced by reference to the new paper, (which I will call the Jesus paper, in light of its extraordinary resurrection and for lack of any less confusing name). With identical authorship, and a maze of cross-references between them, the two CC papers were carefully designed to make understanding how their arguments relied on each other as difficult as possible. 

The beauty of this approach was that it allowed for  retention of the original acceptance date for the CC paper, and hence its inclusion in the IPCC process. It did leave them with the embarrassing problem that a paper that was allegedly accepted in March 2006 relied upon another paper that even the journal itself said was only received until August (and in reality, is was even later than that) Readers should note that this matters because unless the paper was accepted by the journal by the deadline, it should not have been accepted by IPCC for inclusion in the Fourth Assessment Report. But the IPCC needed the CC paper and despite the inconsistency being pointed out to them, the IPCC they waved the objections aside as irrelevant.

The CC paper argument leads from the text, to the appendix and then onto the Jesus paper. At places in the Jesus paper the argument referred back to the CC paper creating a neat, if logically flawed, circular argument. One notable feature of the CC paper and the Jesus paper was that they relegated some of their key argumentation to their Supplementary Information (SI) sections, online appendices to the published papers. In particular, the Jesus paper stated that the statistical discussions and more precisely, the establishment of RE benchmarks could be seen there. To have key arguments in the SI was most unusual and it quickly became apparent why it had been done: the SI was nowhere to be seen. Even the peer reviewers appear not to have had access, and once again, Amman refused McIntyre's request for the data and code. His reply to this request was startling (and remember that Amman is a public servant):

Under such circumstances, why would I even bother answering your questions, isn’t that just lost time? 

Again, everything fell silent. For the next year nothing more was heard of the two papers. McIntyre pressed from his blog for release of the SI and the politicians were able to quietly take advantage of the political space created by the IPCC report. Then, just a few weeks ago, and entirely unannounced, Wahl and Amman's Supplementary Information suddenly appeared on Caspar Amman's website, some three years after that first press release announcing the refutation of McIntyre's work. With it, and a godsend to McIntyre, was the code used to establish the benchmark for the RE statistic.  With no more than a few days work, McIntyre was able to establish exactly what had been done.

You will remember that Amman and Wahl had claimed that they had established a benchmark of zero for a 99% significant RE score - that is to say, there is only a 1% chance that you might have got that score by chance. McIntyre had, much earlier, shown that if you ran red noise through the process, you could get RE scores of more than 0.5. (Red noise is best described as a "random walk" - a line which wiggles at random, but is not entirely random like white noise.) To reduce your chance of random error to 1% you actually needed to score 0.54 for RE.  How Amman had come up with zero as his benchmark was a mystery.

Now, with the code in front of him, McIntyre could see exactly what Wahl and Amman had done. And what they had done was to calculate almost exactly the same figure as he had! The number they had arrived at was 0.52, just a whisker away from McIntyre's own 0.54, but they had reported to the world that it was sufficient only to score a positive number! Of course, this wasn't picked up by the peer reviewers because, as we've seen, they didn't have access to the Supplementary Information, but the IPCC's purposes had been served - the hockey stick found its way intact into the Fourth Assessment Report, unscathed by skirmishes with inconvenient statistical truths.

However, the figure of 0.52 was insufficient for W&A's purposes. Their problem was that the key component of the hockey stick had a verification RE of 0.48, leaving it tantalisingly just below the calculated benchmark. They needed it to be in the top rank and getting it there was going to be tricky. For each simulation, a thousand runs through the statistical sausage machine were perfomed and the RE number, the correlation with the temperature record, was recorded. Then all the runs were sorted in order of RE value, the best runs having the highest RE and the worst the lowest.  W&A needed to show that the hockey stick RE was right up there with the best simulations - in the top one percent.  While its RE was high, it wasn't good enough. And it was no good simply removing runs which had a higher score than the hockey stick, since this would not increase its position enough - they would have been reducing the total number of runs as well as the number of runs which were scoring better than the hockey stick. To get the answer they needed, the higher scoring runs had to be made to be lower than the hockey stick, but left in the calculation.

To do this, Wahl and Amman came up with a value which they called a calibration/verification RE ratio. As the name suggests, this was the ratio of the two RE numbers for calibration and verification. This ratio is however, entirely unknown to statistics, or to any other branch of science. But it was not plucked out of the air. The ratio and the threshold value which was set for it by Wahl and Amman was carefully calculated. They argued that any run with a ratio less than 0.75 should be assigned a score of -9999. Since the hockey stick had a score of 0.813, 0.75 was pretty much the highest level you could go to without rejecting the hockey stick itself. However if you set your ratio threshold too low, not enough runs would be rejected and the hockey stick would no longer be "99% significant". Some of the results of this ratio were entirely perverse - it was possible for a run that had scored a reasonably good RE in the calibration (there was a good correlation between it and the actual temperatures) to be thrown out of the final assessment on the grounds that it had done very well in the verification - the correlation with actual temperatures was considered too good!

With this new, and pretty much entirely arbitrary hurdle in place, Wahl and Amman were able to reject several of the runs which stood between the hockey stick and what they saw as its rightful place as the gold standard for climate reconstructions. That the statistical foundations on which they had built this paleoclimate castle were a swamp of misrepresentation, deceit and malfeasance was, to Wahl and Amman, an irrelevance. For political and public consumption, the hockey stick still lived, ready to guide political decision-making for years to come.

12 Aug: Minor updates for typos etc. Also, I think I'm right in saying that the correct usage in UK English is "blue riband", not "blue ribbon", or that they are at least valid alternatives. Apologies to my North American readers. :-)Dissenting opinions welcome in the comments.

4 Sept. It was pointed out that I've used the term "CC paper" before defining it. I've changed the relevant paragraph to read "second paper".

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References (11)

References allow you to track sources for this article, as well as articles that were written in response to this article.
  • Response
    Says the man from the Devil's Kitchen: Bishop Hill has pieced together the full story of the hockey-stick graph and it is, in the opinion of your humble Devil, fucking dynamite. Pardon his French. Unlike DK, I have not read this posting of BH's yet, although I most certainly will be ...
  • Response
    I dip my toe into Climate Audit regularly and despite Professor Dawkin's best efforts I can't claim to understand the statistics or the whole unraveling of the claims and machination of the AGW industry. Thank goodness that his ecclesiastical eminence...
  • Response
    A blogger calling himself Bishop Hill has written a fascinating post on the machinations behind the famous and influential "hockey stick" model of historical trends in global temperatures. (Thanks to AOG, who notes, sadly, "...But, then reality set it....
  • Response
    Response: Once Upon A Time
    There was a man and a hockey stick... The story is a remarkable indictment of the corruption and cyncism that is rife among climate scientists, and I'm going to try to tell it in layman's language so that the average...
  • Response
    To pretend that their "scientific consensus" is anything more than inserting And then a miracle occurs into their work to try and prove that we're melting the planet. Let me be frank: dickwads like those referred to in this article...
  • Response
    There has been the most extraordinary series of postings at Climate Audit over the last week. As is usual at CA, there is a heavy mathematics burden for the casual reader, which, with a bit of research I think...
  • Response
    "Bishop Hill" has done it again. He's posted another tale, understandable by laymen, of a scientific detective at work. It's similar to his classic Caspar and the Jesus paper. Nowadays, alas, the job of a truth-seeker is often to uncover the deceits of scientists themselves... (It's probably hard for most...
  • Response
    A. W. Montford posts a great list of 33 of the more outrageous emails from the Climatic Research Institute over at Bishop Hill Blog. Here are the first ten: Climate cuttings 33Welcome Instapundit readers! Hope this is useful for you....
  • Response
    For those of you who don’t know of the blog Bishop Hill, let me say that he is a succinct and careful writer who has earned praise from many (including myself and Steve McIntyre) in taking a difficult niche subject such as the Hockey Stick and paleo
  • Response
    Response: click here
    - Bishop Hill blog - Caspar and the Jesus paper
  • Response

Reader Comments (134)

thank you
Aug 13, 2008 at 8:58 PM | Unregistered Commenterjc

Yes, I think insertion of the word "particularly" might be more accurate.
Aug 13, 2008 at 9:07 PM | Registered CommenterBishop Hill
Just to say thank you for the most cogent account I've read so far of the whole appalling Hockey Stick affair. I'm an occasional lurker on Climate Audit but find the maths just a wee bit challenging, so this is a very welcome and lucid summary of what must be one of the most significant pieces of scientific detective work for many years. Well done.
Aug 13, 2008 at 11:03 PM | Unregistered CommenterAlex Cull
You Brits (Monckton/Bishop) are awesome. Great job:)
Aug 13, 2008 at 11:53 PM | Unregistered CommenterJim Black
Excellent blog post. Should be compulsory reading at high school (science and/or maths). I hereby award you an honourary Nobel Peace Prize. Until you receive it, perhaps Al Gore will lend you his (after all, then it won't be confiscated from him when the scam finally collapses).
Aug 14, 2008 at 12:47 AM | Unregistered CommenterRoss Nixon
Interesting article - to the layman it's still very confusing, but clearly points to bending the data to fit the desired outcome.

The only piece missing in the jigsaw though seems to be - what would the graph look like if well accepted statistical measurement were used against the data that is now in the public domain? would the line flatten out? would there still be an upward trend?

To put it another way - what the hell is really going on? (Sorry about the language Bishop).
Aug 14, 2008 at 12:52 AM | Unregistered CommenterRoo
The Bishop has done a service by putting a comprehensive story together. It conforms to the pieces I was prevously aware of. Unfortunately, few other than blog visitors and other blogsters will learn of it and take note of it. I suggest that the Bishop consider submitting it as an article to an appropriate popular periodical. Perhaps he could expand it to include mention of other recent reconstructions such as Moberg which show much more natural variation, while avoiding statistical problems and do not conflict with human historical records. It will take some thought and effort to identify one and get it accepted, but perhaps other visitors can help on this.

When the definitive story of the global warming fiasco is written, and someone will write it, the hockey stick chapter will figure prominently. It is appropriate and timely to publish this chapter to this point.
Aug 14, 2008 at 1:15 AM | Unregistered CommenterRoger

The story I've told here is mainly about the statistical verification procedure for the hockey stick. That is to say, once you have your model of what you think the temperature in the past looked like, how how well does it peform against temperatures in the recent past, which you know about from historic temperature records. The point of the story was that by the standard statistical measure, the R-squared, the hockey stick failed completely - its score was about as bad as it's possible to be.

The story of the shape of the stick was an earlier chapter, which was to do with bristlecone pines, and principal components. I haven't attempted to tell this tale, but the suffice it to say that it's almost as scandalous as the one in this posting.

There's a translation of a Dutch popular science article about this earlier scandal here:
Aug 14, 2008 at 6:44 AM | Registered CommenterBishop Hill
Apologies to Bernie and thanks to the Bish for the Cordon Bleu Art.
Aug 14, 2008 at 7:32 AM | Unregistered Commenterkim
Outstanding post your grace

Well done.

I looked in vain for a comment from your old chum Roger Harrabin.
Aug 14, 2008 at 8:56 AM | Unregistered CommenterWat Tyler
Excellent summary. As I have always said, ignore the models and look at the data. The alarmists never look at the data, or if they do they cherry pick. Not the sceintific method methinks. Keep up the good work!
Aug 14, 2008 at 10:13 AM | Unregistered CommenterJohn Marshall
In the time of the 'little ice age' witches like Wahl and Amman and Mann would have got there just rewards for there lies and deceit, but as the 'little ice age' was conveniently left out of the hockey stick it looks like the modern day witches are going to achieve something, take the human race back a thousand years,
Thank you Bishop we need people like you on the IPCC ( to dissolve it in boiling water.)
Aug 14, 2008 at 12:19 PM | Unregistered CommenterAlan Chappell
Thank you Bishop. I hope you publish. What about the idea of an "alternative climate science wiki" where pieces like yours can go, to build up a picture for newcomers that is informed, easy to understand, in bite-size chunks, accurate, updatable, and above all transparently open to scientific checking and auditing?

Though I still believe that Gore and many others started out of perfectly reasonable concern, the tactics used by Gore, IPCC and WA to convince people are the same tactics as those used by Kramer and Sprenger to get Malleus Maleficarum published. Forge approval by censors and Pope, and by the time the forgery is realized it's rather too late, and the Pope has been cornered into actually giving his approval.
Aug 14, 2008 at 2:14 PM | Unregistered CommenterLucy Skywalker
Most reverend Sir,
Thank you very much for this piece. I have taken the liberty of referring to it on our blog, with a link back to you, since this is a matter which interests our readers as I have been bagning on rather uselessly about the fraud for some time!
Aug 14, 2008 at 3:03 PM | Unregistered CommenterDavid Davis (not that one)
Excellent article! Very nice summary of this whole debacle. Blue riband? Love it!

Paul wrote: Another thing that could be made a bit more explicit is that the 'RE statistic' itself is an invention of climate scientists. You won't find it in any statistics textbook I dont think.

I don't think it's a new thing even though I didn't remember what it was the first time I saw it in the climate debate. I had to look it up--hey, it's been a long time. I think it is limited to modeling reconstructions, though. There is also a PRE (proportional reduction in error), and a Data Reduction and Error Analysis. I'm pretty sure that most use the PRE, which is simply a measurement of increased accuracy (i.e. reduction in error) in predicting the characteristics of sample on one variable that one obtains if the values of a second variable are known, compared with not knowing the second variable. In other words, it's related to the association between the two variables. I don't know if PRE and RE are exactly the same thing, though.

My husband is an engineer. I'll ask him--he despises the AGW doomsayers anyway.
Aug 14, 2008 at 3:45 PM | Unregistered CommenterKatie

As an American college student (in the biological sciences) who has to deal with constant climate alarmism from my friends, I have found this article to be an invaluable resource in discussing the hockey stick graph. Thank you for your work.

As you may already know, this blog posting was placed on yesterday in the "dissenting" section on climate change. Opposite your article was a defense of the hockey stick graph by Amman and Caspar themselves from the RealClimate blog.

Just thought I would give you the heads up! Thank you for your work.
Aug 14, 2008 at 4:10 PM | Unregistered CommenterMike
Your Grace, as a humble petitioner, I appluad your work. This is an excellent tome on the hockey games that should be read by all.
Aug 14, 2008 at 5:41 PM | Unregistered Commenterjnicklin
ScientificAmerican is running a story on a press conference that is going to talk about the found remains of Bigfoot.

Seems to me they could do a story on Steve McIntyre's findings.
Aug 15, 2008 at 1:09 AM | Unregistered CommenterMark T
As the "Jesus" paper was Michael Mann's second-coming, Steve McIntyre's indefatigable work shall always be thought of as the redux of the debuniking of the Piltdown Man--exposing and demolishing in relatively short order, as McIntyre does, the fake constructions of Mann's fatuous cranium and aped jawboning.
Aug 15, 2008 at 6:28 AM | Unregistered Commenterwagathon
I realize that the period of stabilized or falling temperatures observed since 1998 is too short to draw major conclusions, but how does it compare with the extrapolation of the "hockey stick"?
Aug 15, 2008 at 7:32 AM | Unregistered CommenterAntipodes

There are a number of issues with comparing recent temperatures with tree rings from the same period. Firstly that the dendroclimatologists have, on the whole, resolutely failed to update the tree ring series. When they have done so, the rising temperatures at the end of the twentieth century did not lead to the expected ring width increases. This is called the "divergence" problem, and it is brushed aside by the IPCC.
Aug 15, 2008 at 12:20 PM | Registered CommenterBishop Hill
This is all somewhat interesting, but it seems like much ado about nothing. In the end, we're still left with the fact of a big anthropogenic temperature increase over the past 50 years. I do think it's worth getting the statistics right --- it's important to say that it is only "very likely" that the past 50 years is the warmest in the past 1000 years, and not "definitely" the warmest in the past 1000 years --- but I don't see why my fellow commenters are so excited about this.
Aug 15, 2008 at 8:34 PM | Unregistered CommenterPhil

Because if it is not possible to show that the temperatures we are experiencing are unprecedented (which is what would happen if the tree ring temperature reconstructions are shown to be flawed) then the case for drastic action is much weaker. "We've got a computer model which says we're going to fry" is not so convincing as "Current temperatures are unprecedented and our computer model show why, and it also says that we're all going to fry".
Aug 15, 2008 at 8:52 PM | Registered CommenterBishop Hill
Phil, because the same fraud and scientific malfeasance that had people thinking this modern warm period was historically unusual is also responsible for people like you believing that the modern warm period is anthropogenic.
Aug 15, 2008 at 8:54 PM | Unregistered CommenterKZ
Great stuff Bishop. I also try to follow CA but have difficulty with the math as many others do. Imo the larger problem about chasing our tail on AGW is that environmental issues that are we can actually do something about are being neglected. The "Hockey Team" are surely not doing the earth any favours.
Aug 16, 2008 at 1:19 AM | Unregistered CommenterDear John
Its become apparent for some time that the disasturbationist malthusian socialists at the Club of Rome are desperate for support for this fictitious figleaf.

What I'd really like to see is something no researchers have been IMHO sufficiently cross examining, which is specifically in the future projections part of IPCC, the 6 degree warming is largely dependent on the IPCC projection that we will consume over the course of the 21st century TEN TIMES more oil than the Peak Oilers claim is in the ground.

The real kicker is that AGW and Peak Oil theories are both the original propaganda products of the Club of Rome. That these two theories mutually contradict each other is IMHO not being investigated but SHOULD.

The agenda of the Club of Rome of course is to use politics to convince the US to hamstring its economy with a socialist welfare state much as the EU has so the EU can compete economically against the US. That the EU uses their carbon tax revenues to pay for welfare state entitlements and NOT CO2 reduction or sequestration to any significant percentage belies the agenda is driving the 'science'.
Aug 16, 2008 at 2:51 AM | Unregistered CommenterIntLibber
Aug 16, 2008 at 9:18 PM | Unregistered CommenterFrederick Davies
A large bouquet from me, a long-time technical author, on making such machinations so clear and digestible. It's curious what lengths the AGW bandwagoneers will go to, to support an argument that they claim is so universally accepted, but I suppose the hockey-stick is rather central to their cause!

I look forward to more from you on the 'divergence' problem.. :-)
Aug 16, 2008 at 10:04 PM | Unregistered CommenterJames Pickett
I entered a reference in wikipedia, but it was censored out.
Aug 16, 2008 at 10:59 PM | Unregistered CommenterHans Erren
this was one of the best ppata I've read in a long time keep up the good work
Aug 17, 2008 at 6:07 AM | Unregistered Commenterjohn mathon

I was surprised you even tried. It would be interesting to cross post this on, say, Pielke Snr's site. If Wikipedia is going to argue that it can refer to RC, then surely they have to accept links to RPSnr too?
Aug 17, 2008 at 10:00 AM | Registered CommenterBishop Hill
As an Australian farmer I see so much about the Global Warming comment which doesnt' ring true. I see hypothesis being presented and acted on as if it were science. I see violent rejection of critical comment. I even see one of the principal protagonists, a man of high position, calling for his opponents to be jailed.

Here in Australia we have a federal government funded scientific research organisation called the CSIRO, which was originally set up to socialise our industrial and scientific research, for the purpose of providing a critical mass of facilities which most of our local industry was too small to provide for itself. It worked very well over the years, quite marvellously in fact.

Then in the 1980s the Hawke government put the national president of their Labor Party in charge of the CSIRO. He was a lawyer politician, not a scientist. They put their brand of political scientists in charge of the real scientists.

Prior to that time the CSIRO was driven by the needs of industry and science, with support from government. Since that time the CSIRO has been driven primarily by politicians.

It has become quite clear that since that time the rules for science have been changed. Changed to suit the politicians, not the quality and integrity of the science

Recently the Australian government, a "Labor" government elected last November, announced that it will introduce a carbon emissions trading scheme by 2010 whether the rest of the world does or not. During the weeks preceding this announcement we were subjected to a bombardment of hysterical announcements emanating from the CSIRO and the Bureau of Meteorology which were clearly intended to prime the electorate to accept this so called emissions trading scheme.

There has to be an unstated agenda in all of this. Their ETS will bring a new economic order. The urgency of their ETS seems to be driven by the fear that their "science" will be demolished before they get their new economic order installed.

I think it will be, and before 2010.

Incidentally, Hawke and the current Rudd governments are from the same side of politics as Al Gore.
Aug 17, 2008 at 12:51 PM | Unregistered CommenterFarmer Ted
Thanks so much for this summary of events. You did an incredible job and it is much appreciated.

You MUST make this a series and summarize even more of Steve McIntyre's exploits. Particularly his reverse engineering of NASA temperature data and the Y2K problems found therein. I love that story!

you rock!!
Aug 17, 2008 at 6:47 PM | Unregistered CommenterJames
"I noticed in answering a recent comment at Real Climate that Gavin Schmidt distanced himself from the importance of paleoclimate reconstructions. "

I found that Gavin runs a dishonest blog. He fails to post responses where he has been shown to have made mistakes. He was shown by me to holding contradictory claims about Patrick Franks article and failed to publish that comment at all. He's a fraud on that account.

Climatologists are ruining science.
Aug 18, 2008 at 2:56 AM | Unregistered CommenterBrian Macker
Outstanding work. And work it must have been to put a summary covering a scientific subject with a complex web of obfuscation over such a long period into a form that intelligent lay people can understand.

This essay deserves wide attention. Thank you.
Aug 18, 2008 at 6:35 AM | Unregistered CommenterJohn Scott

Over at, I posted three posts. I just realized that while other posts time stamped after mine have made it on to the website, my comments are still "awaiting moderation." I do not believe my comments should be censored and ask that you publish them here.

My first post was time-stamped August 17th, 2008 4:39 pm and reads:

I agree with Tony. I do not have time to correct all of the errors in Dave’s post, but I will address a few. McIntyre and McKitrick did indeed publish in GRL. A good source of published papers on the Hockey Stick controversy is provided at McIntyre’s blog, which interestingly was voted the Best Science Blog of 2007.

Mann’s paper was thoroughly refuted (and McIntyre and McKitrick’s criticism confirmed) by the Wegman Report which was produced for the benefit of the US Congress and looked specifically at statistical issues. The Congress also requested the National Research Council to produce a report looking more generally at the science and not just the statistics. While the NRC’s report was more polite to the authors of MBH, it sided with McIntyre and McKitrick on all of the important points of science. For example, they agreed with M&M that strip bark bristlecone pine series is not a temperature proxy and should not be used.

Unfortuately for Dave’s argument, all of the subsequent studies that supposedly support MBH make this same mistake. They are not independent studies at all. A temperature reconstruction by Craig Loehle which avoided tree rings altogether restored the traditional view of a very warm Medieval Warm Period and very cool Little Ice Age. This shows there is nothing exceptional about 20th century temperatures.

For me, the best story on the Hockey Stick was published in the Dutch science magazine Natuurwetenschap & Techniek. An English translation is available here.

My second post was time stamped August 17th, 2008 4:47 pm and reads:

I was confused regarding Dave’s claim that M&M’s GRL paper did not show up in Google Scholar, so I tested it myself. I found the GRL paper listed first. See for yourself.
My third post was time-stamped August 18th, 2008 7:22 am


It is amazing that you can make so many mistakes in one post. Hans Von Storch was not part of Wegman’s team. The Wegman Report was authored by Edward J. Wegman of George Mason University, David W. Scott of Rice University and Yasmin H. Said of Johns Hopkins University. These men are leading statisticians. The Wegman Report confirmed MM05 finding that the MBH method resulted in a Hockey Stick even when trendless red noise was used as data. This is known as the Artificial Hockey Stick (AHS). See the Wegman Report

Hans Von Storch and Eduardo Zorita did their own replication of MBH and found the same thing. Von Storch and Zorita said this did not really matter because MBH9x had so many other problems. See

Von Storch published a blog posting on the decay of the Hockey Stick in 2007. His posting was criticized because he did not give McIntyre proper credit. But you might enjoy reading it as well:
Aug 18, 2008 at 6:37 AM | Unregistered CommenterRon Cram
I read and reread every word of this compelling report and what I took away from it is this; What good is peer review when this is even possible?

I care far less about what the politicians are doing with this inaccurate data and find myself in a state of shock over the fact that these scientific journals are not only failing at fulfilling their very purpose but worse, bastardizing the process through what can only be seen as overt corruption and manipulation of their own bylaws and guidelines!

There can be no room for this kind of un-science and I hope that there is some process by which to make them all to answer for their malfeasance.
Aug 18, 2008 at 7:13 PM | Unregistered CommenterEmery Emery
just laying the hockey stick aside for the time being, surely the point is that there are a multitude of observations which have established the reality of climate change beyond any reasonable doubt. A confirmation of this is the absence of any scientific papers disputing the broad lines of consensus on this issue--guys, the IPCC in fact underplays the reality and urgency of climate change--how is this? IPCC is an Intergovernmental Panel on Climate Change--the Saudis, US, Japan, Russia etc. have to approve every publication so the science is actually being skewed constantly but in a precisely opposite direction to the one most, if not all, respondents on this forum seem to be assuming.
Back to basics: greenhouse gases absorb heat that would otherwise escape back into space--this radiation physics is harsh: more greenhouse gases means more heat trapped. So if you want to see that global warming isn't happening then you really really have to get round the physics (and of course you can't.)
So come on guys, stop denying what is obvious to plain basic human observation: the climate is changing, the global atmosphere is warming. (What--you haven't noticed? Where have you been these last few years? Underneath Yucca Mountain?)
& hey, there are shedloads of scientific papers across a dizzying array of disciplines which back up this up and expand upon it.
Yes, zealous sceptics can dig up seemingly contrary 'facts', usually supplied by very well funded think tanks--but this is all much of a muchness with OJ Simpson being found 'not guilty'--expert argument leading to a distortion of the truth.
Aug 18, 2008 at 9:04 PM | Unregistered Commenterjim woolridge

You do not seem to understand what the ‘debate’ is about. Few, if any, dispute that climate changes or that it is, on average, a little warmer now that a century ago. Few actually dispute that human activity can cause a change in the average global temperature and most would agree that the net effect of human activity will be warming to some extent. The ‘debate’ is about how much, and indeed if it is detectable in the ‘noise’ of a random chaotically coupled climate system.

As to your basic physics you only mention those bits that suit an alarmist point of view. Greenhouse gases emit as well as absorb radiant energy. They can also gain and loose energy by conduction, and transport energy by convection. High in the atmosphere, where there is little water vapour they make a significant contribution to cooling the earth. So it is a bit more complicated than you suggest, and one way to look at the situation by observations.

By looking at the increase in greenhouse gases and the increase in temperature over the last century you can see that if ALL the warming was from the increase in greenhouse gas concentrations (GHGC) it would suggest that sensitivity to doubling CO2 is about 1 deg C – not that alarming. In fact it is generally agreed that some of the warming is not due to greenhouse gases. The ‘most’ term in the IPCC headline says the 49.9% may be nothing to do with mankind.

There are other observations that give difficulties for the theory of greenhouse gas warming – and remember it is only a theory. First, it warmed almost as much in the first half of the last century when there were only modest rises in GHGC as it did in the last few decades of the century. Second it cooled about the time GHGC began to rise more steeply and of course in the last decade despite a 5% increase in GHGC, we have seen no commensurate increase in temperature.

But the biggest problem for the theory is that the warming from the increase in GHGC should be detectable at higher levels in the lower atmosphere and it is not.

Another observation. If you believe Al Gore’s graph, it showed that it was significantly warmer in most of the previous interglacial periods with lower GHGC. Not only does that put the whole greenhouse gas theory in question but it makes the alarming ‘enhanced’ or tipping point tipping point theory look less likely since we did not see ‘runaway' warming then.

Then of course you can write computer programmes to simulate your theory but to get close to observations you have to add in all sorts of fudges like aerosols for which there is very little real data. And still the predictions are falsified. We are still being told that climate change will mean warmer dryer summers here.

Your suggestion that governments water down the IPCC report might apply to WGII and WGII, but even there I doubt it. On the important WGI scientific basis the governments of the world leave the IPCC on auto pilot. They can not be bothered to read what the ‘thousands of experts’ commented on the drafts or what the referees of the assessment process reported – or to be more exact signed off.

The issue is not science but disclosure and due diligence. What has been reported here is what always happens when you allow people to conceal information. If Mann’s pathetic calculation of RE significance level had been published in his paper we would never have seen the ‘hockey stick’.
Aug 19, 2008 at 10:26 AM | Unregistered CommenterDavid Holland
Jim Wollridge wrote:

> surely the point is that there are a multitude of
> observations which have established the reality of climate
> change beyond any reasonable doubt.

If there were a "global temperature" which is increasing, I would like to know how it is defined and where (location, height) it is measured. The definitions and measurements we are given e.g. by NASA[1] seem to change every time they are challenged.

Even if accepted that there is something like a "global temperature" (defined how? measured where and when?) and that it is increasing, this by itself does not prove that
a) Temperatures rise significantly due to human interference. In fact, most local temperatures have been rising since the end of the little ice age.
b) Energy taxes will do anything to prevent any climate trend
c) Impoverishing us through energy taxes will help our ability to deal with the consequences of any climate trend

> A confirmation of this is the absence of any scientific
> papers disputing the broad lines of consensus on this issue
> (...) how is this?

Where you get your information about scientits' judgements on the matter? As far as I know, there is no consensus [2],[3],[4]. And even if there were, I prefer relying on my ownabilty to understand the explanations and distrust the contradictions than falling prey to an argument to authority.

> IPCC is an Intergovernmental Panel on Climate Change--the
> Saudis, US, Japan, Russia etc. have to approve every
> publication so the science is actually being skewed
> constantly but in a precisely opposite direction to the
> one most, if not all, respondents on this forum seem to be
> assuming.

I do not normally impute objectives I cannot verify in order to find truth. But if I did, I'd observe that government officials themselves never are the ones to pay for their mistaken judgements. For them, IPCC alarmism could just as well be a welcome excuse to raise more taxes.

> Back to basics: greenhouse gases absorb heat that would
> otherwise escape back into space--this radiation physics
> is harsh: more greenhouse gases means more heat trapped.
> So if you want to see that global warming isn't happening
> then you really really have to get round the physics (and
> of course you can't.)

You are aware of CO2 being of much less significance as a greenhouse gas than water vapour, aren't you? That greenhouse models that have the same tropical surface as is observed demand that atmospheric temperature trends to be 2-3 times greater that ground trends -- which is simply not the case[5]? And you do know that convection and dissipation counter heat absorption?

> So come on guys, stop denying what is obvious to plain
> basic human observation: the climate is changing, the
> global atmosphere is warming.

That's anecdotal evidence, isn't it? Over here in central Europe we experienced one of the coldest summers of recent years. Nevertheless, I'd wager -- with no more basis that the alarmists -- that most local temperatures have continued to rise in the last century; as they have been since the end of the little ice age. But whatever caused that assumed warming in those 300 years ending in 1998, it was not us.

> (What--you haven't noticed? Where have you been these
> last few years? Underneath Yucca Mountain?)

The Appeal to Ridicule is a fallacy. Mockery does not substitute evidence or logic.

> & hey, there are shedloads of scientific papers across
> a dizzying array of disciplines which back up this up and
> expand upon it.

Key ones of which have been demonstrated as being false: The Hokey Stick is but one example. Other are the claim that the Maledives and the Tuvalu islands would soon disappear due to sea level rises, caused by global warming. Sea Levels around the Maedives and Tuvalus have not been rising but falling [6],[7]. Another would be the claim of melting polar ice sheets. The polar ice sheets are not melting, but increasing mass [8],[9]. The "scientific" predictions of increasing tropical thunderstorms don't far emuch better.

> Yes, zealous sceptics can dig up seemingly contrary
> 'facts', usually supplied by very well funded think
> tanks

Ah yes, the Vast Sceptic Conspiracy.

> but this is all much of a muchness with OJ Simpson being
> found 'not guilty'--expert argument leading to a
> distortion of the truth.

When you observe how alarmists behave -- as evidenced how they forge supposedly scientific findings to use as a club against sceptics, as evidenced by their treatment of dissenters like Bjorn Lomborg -- can you still be so sure anymore who is rational and who are the zealots?

[1] John Goetz, "Rewriting History, Time and Time Again" ( (On average 20% of the historical record was modified 16 times in the last 2 1/2 years. The largest single jump was 0.27 C. This occurred between the Oct 13, 2006 and Jan 15, 2007 records when Aug 2006 changed from an anomaly of +0.43C to +0.70C, a change of nearly 68%.)
[2] U.S. Senate Environment and Public Works Committee, "Over 400 Prominent Scientists Disputed Man-Made Global Warming Claims in 2007" ("Over 400 prominent scientists from more than two dozen countries recently voiced significant objections to major aspects of the so-called "consensus" on man-made global warming. These scientists, many of whom are current and former participants in the UN IPCC (Intergovernmental Panel on Climate Change), criticized the climate claims...")
[3] Richard S. Lindzen, "Scientists' Report Doesn't Support the Kyoto Treaty", The Wall Street Journal, June 11, 2001 ("We are not in a position to confidently attribute past climate change to carbon dioxide or to forecast what the climate will be in the future. That is to say, contrary to media impressions, agreement with the three basic statements tells us almost nothing relevant to policy discussions. (...) Science, in the public arena, is commonly used as a source of authority with which to bludgeon political opponents and propagandize uninformed citizens. This is what has been done with both the reports of the IPCC and the NAS. It is a reprehensible practice that corrodes our ability to make rational decisions.")
[4] James M. Taylor, "What Climate Scientists Really Say about Global Warming", Heartland Policy Study No. 111 (2007)
[5] David H. Douglass, John R. Christy, Benjamin D. Pearson, S. Fred Singer, "A comparison of tropical temperature trends with model predictions", Int. J. Climatol. (2007)
[6] Nils-Axel Mörner, Michael Tooley, Göran Possnert, "New perspectives for the future of the Maldives", Global and Planetary Change 40 (2004) 177–182 ("Novel prospects for the Maldives do not include a condemnation to future flooding. The people of the Maldives have, in the past, survived a higher sea level of about 50–60 cm. The present trend lack signs of a sea level rise. On the contrary, there is firm morphological evidence of a significant sea level fall in the last 30 years.")
[7] Nils-Axel Mörner "Sea level change: Are low-lying islands and coastal areas under threat?", "The impacts of climate changes. An appraisal for the future", p 29-35. International Policy Press.
[8] Ola M. Johannessen, Kirill Khvorostovsky, Martin W. Miles, Leonid P. Bobylev, "Recent Ice-Sheet Growth in the Interior of Greenland", Science 310 (5750), 1013 - 1016 ("Averaged over the study area, the increase is 5.4 ‘ 0.2 cm/year, or ~60 cm over 11 years, or ~54 cm when corrected for isostatic uplift. Winter elevation changes are shown to be linked to the North Atlantic Oscillation.")
[9] Curt H. Davis, Yonghong Li, Joseph R. McConnell, Markus M. Frey, Edward Hanna, "Snowfall-Driven Growth in East Antarctic Ice Sheet Mitigates Recent Sea-Level Rise", Science 308 (5730), 1898 - 1901 ("Satellite radar altimetry measurements indicate that the East Antarctic ice-sheet interior north of 81.6°S increased in mass by 45 ‘ 7 billion metric tons per year from 1992 to 2003.")
Aug 19, 2008 at 3:48 PM | Unregistered Commenterjpj
In the discussion of a possible thickening in the Greenlan ice sheet in jpj's post I just want to add that Rignot and Kangaratnam (2006), Chen et al. (2006) and Velicogna and Wahr (2006) all found a thinning of the Greenland ice sheet in their studies.

Chen, J.L., Wilson, C.R. & Tapley, B.D. 2006: Satellite Gravity Measurements Confirm Accelerated Melting of Greenland Ice Sheet. Science 313, 1958-1960.

Rignot, E. &Kangaratnam, P. 2006: Changes in the Velocity Structure of the Greenland Ice Sheet. Science 311, 986-990.

Velicogna, I. & Wahr, J. 2006: Acceleration of Greenland ice mass loss in spring 2004. Nature 443, 329-331.
Aug 19, 2008 at 4:10 PM | Unregistered CommenterJ
This confirms my conclusions after months of study of the climate change controversy; global warming is an artifact of questionable data manipulated by less than ethical, so-called scientists to promote their own agendas. Perhaps it's to get their names in the spotlight, perhaps for money. The delay or non-disclosure of methods used to obtain published results tells the entire story; they can't back up their claims of impending disaster. Their prevarications and predictions should be disregarded and held in contempt. Thank you, sir, for clarifying these events.
Aug 20, 2008 at 4:40 AM | Unregistered CommenterRJ Hendrickson
You clearly haven't read either MBH98 or Ammann and Wahl's papers because both of them present R-squared data- MBH in figure 3 and Amman & Wahl in Appendix 1.

[Snip - mind your language please]
Aug 20, 2008 at 10:28 PM | Unregistered Commenterpunkscience

You are welcome to post here, if you are willing to mind your language. If you just want to shout abuse there are plenty of other places you can do that.

IIRC, Figure 3 of MBH refers to the AD1820 step, not the critical AD1400 step, am I right? To the extent that they have provided some figures that support their case, you are right. To the extent they have refused to provide access to figures which show that their case is flawed, you are just being misleading.
Aug 21, 2008 at 6:16 AM | Registered CommenterBishop Hill
J wrote:

> In the discussion of a possible thickening in the Greenlan
> ice sheet in jpj's post I just want to add (snip
> citations contradicting Johannessen et al.)

I am sure it'll be appreciated that I'll not enter a citation war. Instead, allow me to present some details on the mentioned publications.

Johannessen et al.[1] used altimetry measurements to determine ice cover changes. Velicogna and Wahr[2] as well as Chen, Wilson and Tapley[3] used gravimetry methods. As you surely are aware, measuring ice cover by gravimetry is the far less accurate method and far more prone to interferences by other effects.

Rignot and Kanagaratnam report measured widespread glacier acceleration[4]. Their claims of total Greenland ice mass, however, were not measured. Rignot and Kanagaratnam merely tried to calculate them. In particular, they relied on the calculations by Hanna et al.[5]. Hanna et al however did not measure but merely modelled ice accumulation and runoff.

When one does measure total Greenland ice mass with reliable methods as Johannessen et al. did or, to give another example, Zwally et al.[6], one finds that despite Greenland's glaciers transporting ice into the sea at a faster pace, this is offset by earth's hydrologic cycle sucking water out of the ocean and depositing it on Greenland as snow at an even faster pace.

And to confuse alarmists who entertain the notion that Greenland was melting with one more incovenient fact, local temperatures have not been rising. They either fail to show any trend[7a] or are dropping[7b]. This does not confuse those who do not allow their understanding to be informed by alarmism, but by awarness of well-studied phenomena like the North Atlantic Oscillation.

[1] Ola M. Johannessen, Kirill Khvorostovsky, Martin W. Miles, Leonid P. Bobylev, (2005) "Recent Ice-Sheet Growth in the Interior of Greenland", Science 310 (5750), 1013-1016.
[2] I. Velicogna, J. Wahr (2006), "Acceleration of Greenland ice mass loss in spring 2004", Nature 443, 329-331.
[3] J.L. Chen, C.R. Wilson B.D. Tapley (2006), "Satellite Gravity Measurements Confirm Accelerated Melting of Greenland Ice Sheet", Science 313, 1958-1960.
[4] Eric Rignot, Pannir Kanagaratnam, (2006) "Changes in the Velocity Structure of the Greenland Ice Sheet". Science 311 (5763), 986-990.
[5] E. Hanna, P. Huybrechts, I. Janssens, J. Cappelen, K. Steffen, A. Stephens, (2005) Journal of Geophysical Research 110, 10.1029.
[6] H.J. Zwally, M.B. Giovinetto, J. Li, H.G. Cornejo, M.A. Beckley, A.C. Brenner, J.L. Saba, D. Yi (2005), "Mass changes of the Greenland and Antarctic ice sheets and shelves and contributions to sea-level rise: 1992-2002", Journal of Glaciology 51, 509-527.
[7] a) R. Przybylak (2000) "Temporal and spatial variation of surface air temperature over the period of instrumental observations in the Arctic", International Journal of Climatology 20, 587-614; b) E. Hanna, J. Cappelen, (2003) "Recent cooling in coastal southern Greenland and relation with the North Atlantic Oscillation", Geophysical Research Letters 30, 1132.
Aug 21, 2008 at 9:36 AM | Unregistered Commenterjpj
Thank God for the internet. (or should that be Al Gore?) It may be that one of the goals of the greens in their bogus quest for CO2 reduction is to reduce the number of servers required to maintain this important and unprecedented data exchange medium without the editing/suppression by the mainstream media. To the inquiring mind there exists a vast amount of information available online for self education on this important subject of climate change and I have been using it. Is the climate changing? Of course. When hasn't it? Is it bad? Probably not unless we face serious global cooling. If that's the case stock up on fur coats. Is the infamous "hockey stick" graph bogus and politically motivated? Absolutely. Is the green movement not about the environment and instead about power over humans? Again, absolutely. Are the efforts by the greens to keep millions of humans of an "indigenous" and "natural" ilk in third world countries chained to a "lifestyle" of poverty, disease, brutality, and short life spans morally acceptable? Most assuredly not. If it was so desirable they would be giving up their private jets, getting their homes off the grid, and going "natural" themselves. I.E. foraging for wood and dung to cook their food off earthen hearths in their kitchens while breathing the smoke along with their children and accepting the attendant health disasters. They would be using totally "green" energy sources like solar and wind, but those unfortunately don't cut it. If they won't take themselves seriously why should anyone else? The proponents of fraud at this level, all of them, should be lined up against the wall and shot. Here's the bottom line: Life without energy is brutal and short. Here's another hot tip: Plants produce oxygen and they just love CO2. Final hot tip: This subject represents all out war. Educate yourselves and all you know. Never, ever, underestimate your enemy and trust me, this is a fight to the death.
Aug 26, 2008 at 2:45 AM | Unregistered CommenterJR
I'm not really sure what all the huff about one particular set of authors is about. The reality is that the scientific community has reached a near consensus years ago that climate change and global warming are real and dangerous threats to our planetary ecosystem and humans as a species.

Yes, it is true that we do not have all the facts, and that much research needs to still continue. However there is really no scientific debate on several key points.
*CO2 levels in our atmosphere have skyrocketed dramatically in the last 70 years.
*Most of this increase can be traced to human activities, namely the burning of fossil fuels and an increase in livestock farming.
* Global temperatures are on the increase and this increase is getting more pronounced every decade.
*Ecosystems are seeing unprecedented effects including drought, flooding, more severe storms and desertification.
*Polar ice caps and glacial ice worldwide are shrinking at an ever increasing rate.
*Sea level rise is already being documented and is expected to increase dramatically when certain thresholds are met.

If you don't believe any of this, then you really are at odds with 99% of the scientific community, as evidenced by exhaustive summaries of hundreds of peer reviewed scientific research papers. These same researchers are also concluding that many of those thresholds will be attained once we reach around 450 ppm of atmospheric CO2 (by volume, not mass). We are currently around 390 ppm. At predicted rates, this gives us about 20 years to get our act together and make some big changes in the way we run our civilization, or face dire consequences.

But wait. Even if this is all a bunch of hooey, and the liberal scare mongers and doomsdayers are whipping up a frenzy to get their political agenda through, can we afford to take a chance? Will we jeopardize our children and grandchildren’s opportunity to lead a healthy and prosperous life so that we can continue to drive our Escalades to NASCAR events? There ARE other options for sustainability. And yes, they will require us to make some painful lifestyle changes.

Will this be the generation that blows it for all the rest to come? Can we afford to gamble with the future? Think about it.
Aug 30, 2008 at 12:41 AM | Unregistered CommenterRev Freeheels
Fantastic, this must have taken forever to put together. Great work though. I am going to post a link to it at
Aug 31, 2008 at 5:46 PM | Unregistered CommenterJeff Id
Nice and good summary. I would recommend to address the following for clarity:

"In fairly short order, Amman and Wahl's paper was rejected, many of its criticisms either relating to other McIntyre papers than the one at hand, or relying on the CC paper for their arguments."

You've invoked the "CC" moniker without explaining first what "CC" means. It's not entirely obvious that it refers to Climate Change when it is first invoked. Notably, one of the hardest things I find reading the Climate Audit blog is becoming accustomed to the made-up abbreviations and nicknames for various things. For a lay presentation, I would advise avoiding this as much as possible.
Sep 4, 2008 at 2:25 AM | Unregistered CommenterJulian Droms

Thank-you for this. Someone actually pointed it out earlier in the thread, but I missed the fact that I'd used it before defining it - too dim perhaps. I will fix this.
Sep 4, 2008 at 8:08 AM | Registered CommenterBishop Hill

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