UCAR Webcast of Bradley, Crowley, Ammann – Apr 6, 2005

The webcast of the April 6, 2005 presentations by Bradley, Crowley and Ammann is here. There’s lots that could be said about this presentation. I can only pick off a few points here.

Around minute 11:24, Bradley puts on a slide with the MBH99 title page. For background, here’s what the original press release of March 3, 1999 said:

Researchers at the University of Massachusetts who study global warming have released a report strongly suggesting that the 1990s were the warmest decade of the millennium, with 1998 the warmest year so far”⤮ "Temperatures in the latter half of the 20th century were unprecedented," said Bradley. “⤠The latest reconstruction supports earlier theories that temperatures in medieval times were relatively warm, but "even the warmer intervals in the reconstruction pale in comparison with mid-to-late 20th-century temperatures," said Hughes.

Here’s a comment from Mann in IPCC TAR:

Self-consistent estimates were also made of the uncertainties… The uncertainties (the shaded region in Figure 2.20) expand considerably in earlier centuries because of the sparse network of proxy data. Taking into account these substantial uncertainties, Mann et al. (1999) concluded that the 1990s were likely to have been the warmest decade, and 1998 the warmest year, of the past millennium for at least the Northern Hemisphere.

Here’s how Bradley now represents the matter (I’ve tried to make the transcript accurate and apologize for any inaccuracies):

Here we come to the famous hockey stick. Someone characterized the variations of the last 1000 years as a hockey stick. Here’s one example. It’s often cited. It was used in the IPCC report many times. It’s a simple icon, or a representation of what has gone on. It shows temperatures declining from about 1000 AD, then this abrupt warming, obviously this abrupt warming in the last 100 years or so The warmest period in this record was in the 12th century 1146-1195. The coldest period was in the 15 century, latter half of 1400s, and also early 19th century. This warmer period has been described as the Medieval Warm Period; this period in here as the heart of the Little Ice Age. The graph ended in 1998, but in fact I’ll show you “⤠

By the way, I just want to point out this graph which has caused so much discussion: This was the title of the paper: Northern Hemisphere temperatures during the past millennium: inferences, uncertainties and limitations. The whole point of this paper, the whole purpose of the paper was to point out how difficult, how uncertain these reconstructions can be. This was not the statement that says that this is exactly how it was for the last 1000 years. This is a working hypothesis put out there in the literature. People can take potshots at it, as they did. People can improve on it, the normal scientific process. We’re not wedded to this graph as though this was truth which must be defended at all costs.

I certainly don’t get the idea that they were pointing out "how difficult, how uncertain" these reconstructions were to the public. I would say that their public promotions had exactly the opposite effect – that of minimizing the uncertainties.

There’s some statements by Crowley that I find quite ironic “€œ Crowley says “Show me the data.”‘? Both he and Bradley emphasized how "big" the prospective warming was and he illustrated it by showing a large boulder in the middle of the prairies deposited by water. For someone who mostly minimizes the extent of natural variation, this seemed a pretty strange image. Crowley made some remarks about M&M in the question period. Before discussing Crowley in question period, here’s some correspondence – my entire file is here. In March 2005, Crowley asked me for a digital version of our alleged reconstruction. I explicitly told him that we did not purport to make a "reconstruction" and the figure is intended to illustrate the non-robustness of MBH98. Crowley replied on March 21 asknowledging this, but pointing out that some people were "misinterpreting" this and he wanted a copy for his records (which I provided him on April 6.)

Mar. 19, 2005 Crowley to McIntyre Hello, may I get a copy of your time series showing the prominent warming in 1400s? tom crowley

Mar. 19, 2005 McIntyre to Crowley [with attachments] Enclosed are our recent articles. If you read the articles themselves, including the E&E article,you will see that our position is that the MBH98 reconstruction lacks statistical significance – we estimate the R2 in the 15th century step in their version to be 0.0 and we show that their RE statistic is spurious. Mann et al. have refused to disclose their R2 statistic or the digital version of their 15th century step and have only replied with a critique of the R2 statistic, so it’s pretty clear that our estimation of their R2 statistic is pretty close. We also show that their PC method mines for hockey stick shaped series, putting the controversial bristlecone pine series in dominaiton of their PC1. We show that, contrary to their claims of robustness, their results are not robust to the presence/absence of bristlecone pines (showing the effect of the bristlecones in the PC4 if the PC results are calculated correctly.) We show that the high 15th century values result from MBH98-type calculations using the archived version of the Gasp” series (rather than the editing in MBH98), correct principal components calculations and the roster of retained PCs used in MBH98. We do not ourselves argue that 15th century temperatures were high – only that Mann et al. are not entitled to claim under their methods that 20th century values are robustly higher than 15th century temperatures. Mann et al have argued that they can retain 5 PCs in their calculation under a variation of Preisendorfer’s Rule N applied to tree ring networks, which was not mentioned in MBH98 and which cannot be reconciled with retained PC rosters in other networks. Be that as it may, their own current position shows the lack of robustness which we point out. I hope that this clarifies your question. Regards, Steve McIntyre

Mar. 21, 2005 Crowley to McIntyre Steve, thanks for the clarification. would it still be possible to obtain the temperature reconstruction showing the large warming – it is my understanding that some people are misinterpreting that series and i would like to have a copy for my records, tom ps it was not clear to me from your description whether the R2 statistic using your approach is different than 0.0 for the 15th c. – can you clarify? tom crowley

So here’s what Crowley said in the quesiton period (starting about 1:14):

With respect to McIntyre, he calculated that temperatures were warmer in the 1400s. You look at the raw data and it’s just not there. ,,,because McIntyre’s got a lot more press attention with this … Let me tell you. You see the raw data. You do not see a warming in the 1400s, yet he sees a giant warming”⤠

The analogy that I’d like to use is an Index of Leading Indicators. Suppose someone told you that there was a 6% rise in the index in the last year or so, one of the things that you’d want to know is what factors were responsible for that rise: heavy industry, agriculture whatever. Suppose you then look and find that for none of the indices was the rise more than 2%. Then you’d say this is crazy. how can you can get a 6% rise when you see no more than 2% in the individual indices? The only way to explain that is a methodological flaw. And McIntyre has made some points with respect to the Mann et al. reconstruction, but you can’t just focus on Mann et al. When you go back and you look at the raw data, there’s no way that you can crank up a warming in the 1400s that is consistent with the raw data. And so McIntyre himself has made a much more egregious methodological error by estimating this temperature rise that is completely out of whack with the original data. There’s this phrase in the bible that says: criticize not the speck in your neighbor’s eye before you remove the plank from your own. McIntyre is banging away at Mann and there are some legitimate reasons for thinking that Man can be improved now … we actually. ..as Ray says”⤮ but if you lock on Mann you distort the discussion as to what you have in the other evidence.

Given our emails of March 19 and 21, this is a pretty astonishing misrepresentation of our position. But then this is the same guy who accused me of "threatening" him. It’s interesting to contrast Crowley’s assertion that I made a “much more egregious methodological error”‘? with Ammann’s comments a little bit later (1:17:20), shown here:

Let me add one more thing I think that it is very important for the McIntyre and McKitrick research. This has focused on this reconstruction – a very complex statistical reconstruction of Mann and people have reported that they can’t reproduce this thing. With McIntyre, they have found some criticisms where they would think that there is a presetting.of a hockey stick and also a very warm 15th.century. What we are going to put out at the end of this week, it’s going to be submitted, is a tool for the research community, which does reproduce exactly Mann, Bradley, Hughes. It doesn’t say that this is the best reconstruction, it just gives a tool that everyone can apply. It’s going to be very simple, you can run on it your PC, Mac, Linux, whatever you have. Everybody can do this. Everyone can do the McIntyre-McKitrick exercises that they propose in these papers. The only thing that I can tell you here, what you find out is that you can generate this 15th century that is warm. But you’ll find that the statistical model has no skill in prediction. You have statistical measures of how skillful a tool is, based on a particular network that you are looking at – the 1400s, 1400-1449. That’s when they get these warm temperatures. If you look at their papers, they never report what the skill is, because the skill is not there for this particular period. So the warmth that they get in this framework of MBH given the model and data, it has no skill so you should not use it. You can calculate almost anything, but this is something that is not meaningful in a climatological sense. And this tool will be out and everyone here can reproduce this and see these statistical measures. I think that is going to be a good important contribution that we test not only Mann, but in general all the climate reconstructions. That’s where they wanted to point to.

A few points on Ammann. First he says that he has “exactly”‘? reproduced MBH. This is simply untrue. He’s obtained a result that is similar to MBH (as we did in our emulation using their erroneous PC series series and edited Gasp” series). But he doesn’t replicate their residuals for the 15th century for example. It’s not an exact replication. I really wish that these guys would not misrepresent these matters. Secondly, Ammann recognizes that you can get high 15th century results with the MBH98 method with very slight tweaks to the proxy network “€œ as we reported. So when Crowley says that a high 15th century result (which we simply presented as a reductio ad absurdum) is an “egregious methodological error”‘?, Ammann should have stepped in and contradicted Crowley saying that you can get high 15th century results using MBH98 methods.

Ammann realizes that you can get high 15th century without the bristlecones; he argues that you need to leave them in to get adequate statistical skill. This is a quite different argument. But not using bristlecones is hardly an "egregious methodological error"; using them might be if they are flawed proxies. Ammann criticizes us for not reporting verification statistics for "our" reconstruction. However, we were simply showing non-robustness, not asserting a warm 15th century. Ammann is hten really cure about statistics- he talks about statistical measures, but then withholds his R2 statistic, which, as readers of this site know, the MBH98 reconstruction fails. He certainly does not tell the Washington audience that the MBH98 reconstruction has a catastrophic failure of hte R2 statistic. Ironically, if you look at the statistic used to describe reconstruction success elsewhere in this presentation, it is always the r2 statistic: be it the resemblance between the Luterbacher and Mann reconstructions or the relationship of coral àŽⳏ18 to SST – so they would assume, to the extent that they thought about it, that Ammann was calculating statistics similarly to Crowley and Bradley, rather than using a highly questionable and almost certainly spurious RE statistic of MBH98.


  1. John Hekman
    Posted Jul 12, 2005 at 2:06 PM | Permalink

    Steve: I was driving by the area of the bristlecone pines last week after spending some time at Mammoth. Was thinking “bristlecone pine anomaly”. What could explain the more rapid growth of these trees during the 20th century? One possible place to look is in volcanic activity, since there is a lot of that in the area. Hot vents, hot springs, etc. This could have promoted growth. While looking on the web for anything to shed light on this, I came across another big change that was coincident in the 20th century–Owens Lake. http://geochange.er.usgs.gov/sw/impacts/geology/owens/ says:
    “Water was first diverted from the Owens River to the City of Los Angeles in 1913, and by 1926 Owens Lake was dry. The dry bed of Owens Lake has produced enormous amounts of windblown dust since the desiccation of the lake…The lake bed is probably the largest single source of PM10 dust (aerosol particles smaller than 10 microns in aerodynamic diameter) in the United States; by one estimate, 900,000-8,000,000 metric tons per year (Gill and Gillette, 1991).” This dust, starting in 1913 or so, could have had an effect on the local climate. I wonder…

  2. John
    Posted Jul 12, 2005 at 2:07 PM | Permalink

    Compare and contrast:

    The warmest period in this record was in the 12th century 1146-1195. The coldest period was in the 15 century, latter half of 1400s, and also early 19th century. This warmer period has been described as the Medieval Warm Period; this period in here as the heart of the Little Ice Age.

    Malcolm Bradley, at UCAR, 2005

    For instance, skeptics often cite the Little Ice Age and Medieval Warming Period as pieces of evidence not reflected in the hockey stick, yet these extremes are examples of regional, not global, phenomena.

    Michael Mann, Scientific American, 2005

    You’d swear they were talking about two different studies, wouldn’t you?

  3. John
    Posted Jul 12, 2005 at 2:09 PM | Permalink

    The dust could have had a radical effect on the fertility of the soil as well…

  4. JerryB
    Posted Jul 12, 2005 at 3:51 PM | Permalink


    That should have been Raymond Bradley, not Malcolm Bradley.

  5. Ed Snack
    Posted Jul 12, 2005 at 10:26 PM | Permalink

    Ye Gods Steve, that’s a pretty blatant bit of misrepresentation, indeed is pretty close to fraudulent misrepresentation I would assert, given the content of your email to Crowley. He can’t argue he was misinformed, he has the exact explanation of your efforts and lack of skill measurements. Great pity there was not someone at the meeting to ask the pertinent questions. The saddest part is no doubt Tim Lambert and all the other Mannians (good classification that) will no doubt jump on the bandwagon. Their strategy is quite clear. Pity Roger Pielke didn’t have a bit more to say, he seems to have had a reasonable grasp of the issues before now.

  6. Steve McIntyre
    Posted Jul 13, 2005 at 12:07 AM | Permalink

    It’s really quite astonishing to see these guys misrepresent situations that are easily proven wrong. Mann did something similar in 2000 when he claimed that I’d asked for an Excel spreadsheet when I hadn’t. It makes it very hard to take these guys seriously.

  7. Posted Jul 13, 2005 at 7:56 AM | Permalink

    The saddest part is no doubt Tim Lambert and all the other Mannians (good classification that) will no doubt jump on the bandwagon.

    I find Lambert pathetic. For example, he hammered away at John Lott, and with the work of others such as Levitt and Donohue, we see that there are indeed problems with Lott & Mustard’s work. Fine, despite the fact that I’m a supporter of the right to carry guns, even concealed if you are a law abiding citizen, I have to accept this. But, when it comes to one of Lambert’s cherised positions being challenged and quite well he just can’t bring himself to admit it. He is a hypocrite.

  8. John
    Posted Jul 13, 2005 at 8:20 AM | Permalink

    You should know that Lambert’s scientific knowledge is *ahem* “challenged”. Ask him if he’s discovered what entropy is and how it applies to closed thermodynamic systems.

    What a guy.

  9. John
    Posted Jul 13, 2005 at 8:22 AM | Permalink

    Dang! My shield of perfection is breached!

    Good call. My bad.

  10. Ross McKitrick
    Posted Jul 13, 2005 at 8:48 AM | Permalink

    For whatever reason we keep finding ourselves up against the same misrepresentation/misunderstanding of our position. The argument, stated more elsewhere but in the background of the above excerpts, is: M+M are offering a novel climate reconstruction based on (a) a new method and (b) an edited version of the MBH data base; but they’re wrong because (c) you shouldn’t throw out good data and (d) the MBH graph (which Ammann, ahem, reproduced) has a higher RE score than theirs: QED.

    At the risk of repeating material already spelled out elsewhere on this site, including in Steve’s comments to Crowley above, here are the problems with this argument.

    The main one is that we are not offering a new reconstruction or an argument for the medieval warm period, we are arguing against the evidence that supposedly disproved the medieval warm period. We have specifically argued the MBH principal components algorithm looks for hockey stick shapes and exaggerates the proportion of variance they explain in a matrix. In the MBH data set their PC method ranked the hockey stick shape as the #1 pattern, accounting for 38% of the total variance in the matrix. Had they subtracted the proper mean rather than the 20th century subsample mean the hockey stick pattern would fall to PC4 and it would account for under 8% of the variance.

    Regarding (a) We talked about variations on the PC methods in our papers but demonstrated the effect in the MBH method itself. Ammann and others have looked at variations on the PC methods and found instances where using the short-segment mean doesn’t matter. So have we, and we discussed this in GRL and EE. But first, we need to agree on the effect in the context that matters, namely the MBH98 methodology.

    On (b), we’re all using the entire data base, now that there seems to be a canonical version thanks to Steve keeping Nature’s feet to the fire. The real question concerns the bristlecone pines. Including them (16 of ~400 series) yields a hockey stick, excluding them destroys the hockey stick, regardless of the number of PCs used or any other methodological variation. Even if they were “good” proxies this would indicate the hockey stick is not robust.

    (c) The fact that they are known to be bad proxies for temperature only makes the situation worse. If adding in a small bit of bad data reverses your conclusions, your new conclusions can’t be taken seriously even if they thereby become more interesting or striking or even if this helps reconcile them to those of other studies. We’re not talking about “throwing out data” this is just common sense. Another point raised in drafts but not written up yet is that the CO2 adjustment called for in MBH99 seems not to have been applied to the bristlecones after 1400.

    (d) Ammann got no closer than Steve to reproducing MBH, save for the effect of a variance rescaling applied in his code but not stated in MBH98. Reconciling this and the other minor code differences yields exact replication between Ammann and Steve, but neither exactly reproduces Mann.

    In any case, all these reconstructions–Mann’s, Ammann’s, ours; are insignificant in the 15th century, based on RE tests and the R-squared stat of ~0. We are hardly in a position to argue for (or against) a medieval warm period having shown that the data/methods in question are uninformative about the pre-1500 period.

    Quoting Ammann: “it has no skill so you should not use it. You can calculate almost anything, but this is something that is not meaningful in a climatological sense.” He’s referring to what he claims is “our” reconstruction, but it applies to his and everyone else’s too.

  11. John
    Posted Jul 13, 2005 at 1:38 PM | Permalink

    Another point raised in drafts but not written up yet is that the CO2 adjustment called for in MBH99 seems not to have been applied to the bristlecones after 1400.

    I wonder why not? What would have happened if they had?

  12. fFreddy
    Posted Jul 13, 2005 at 2:26 PM | Permalink

    Ross, it seems to me that at least some of the problem is that much of the audience doesn’t understand the maths. This implies there might be some benefit in trying a more mathematically inclined audience. Have you considered submitting a paper to the American Statistical Association or some such ?

  13. Paul Gosling
    Posted Jul 14, 2005 at 3:18 AM | Permalink


    While I accept that M+M have made an important contribution the debate, this blog does look sometimes like it is attacking the people rather than their science. Particularly threads like this, which seem only interested in catching people out …. ah ha, they said this last Wednesday, but four months ago they said something slightly different… well aren’t we all guilty of this?

    The danger is that it begins to look like harassment and intimidation rather than reasoned debate on the science, sound familiar?

  14. fFreddy
    Posted Jul 14, 2005 at 4:21 AM | Permalink

    Incidentally, with reference to eminent scientists making basic statistical blunders, please see :


  15. Posted Jul 14, 2005 at 4:40 AM | Permalink

    Actually, I think that the real problem with this debate is that many “scientists” have either forgotten, or never knew, what the scientific method entails, or how to comply with it. Science is about measurable facts, not opinions. At school (in the 1950s) my science teachers drummed into me how important it is to carefully write up the experiments that we undertook – the objectives, the methodology, the findings, and in particular to focus on setting down sufficient information that another interested party, following our methods, could replicate our results.

    Also, in contrast to what the green lobby seems to be saying, science is not about “a consensus of the majority of scientists”, of course, with no supporting statistics at all about the actual numbers of “scientists” and scientists for and against. For the sake of their what seems to me propagandist position, they conveniently ignore the large number of scientists who have expressed their reservations about the whole process by signing the Oregon Petition.

    Ask Copernicus about consensus. A consensus of “scientists” in his day had the sun revolving around the earth!!!

    My observation is that many “scientists” demonstrably fail to understand, or ignore, the basics of the scientific method. In particular, they seem not to understand the method of hypotheses. Ie to explain a particular phenomenon (lets take an issue I have some familiarity with – the expanding earth hypothesis). A real scientist would recognise that there are numerous hypotheses to explain the paths by which the current observed earth was formed. He would a) identify the alternative hypotheses (including of course the unknown hypothesis), and b) evaluate the evidence for and against each hypothesis. Very often, all that he can actually achieve is to downgrade some hypotheses on the basis of the evidence, and advance others to the fore. In many cases, the only position is agnostic – I don’t know. The real scientist then devises experiments, analyses and tests in an effort to try to better differentiate the hypotheses.

    An appalling example of ad hominem propaganda, masquerading as science, was the remarkable Scientific American set of articles attacking Bjorn Lomborg. His attackers were permitted to vent their spleen, without Lomborg being given an opportunity (to this day) to reply. Fortunately, independent reviews that objectively evaluated Lomborg’s work were able to find in Lomborg’s favour for around 95% of his points. I understand that this work was instrumental in the Danish Government asking the Danish Committee for Scientific Dishonesty to explain their findings against Lomborg. Apparently, when they were unable to do so, they had no choice but to drop their outrageous charges.

    The fact is, there is much sloppy “science” in the climate area that smacks of propaganda rather than science. It is entirely appropriate that advocates of views on both sides of the debate be required to observe high standards of disclosure and reporting. M&M, in my view, have done a sterling job in trying to raise the level of the debate. There really is no room at all for ad hominem attacks, misrepresentation – even lies, and such like when it comes to such important matters.

  16. John
    Posted Jul 14, 2005 at 4:40 AM | Permalink

    Excuse me, but that’s ridiculous. This is not some idle chit-chat about whether some people have been consistent or not, but whether people whose views appear to have had global impact have lied to the world about the scientific work they have done.

    As Steve McIntyre has said, we’re not interested in the private lives of these people, but their public pronouncements on key matters of scientific methodology and environmental policy. There are no “no go” areas in science. Academics do not possess a “Get Out of Critical Scrutiny” card that we must obey.

  17. Peter Hearnden
    Posted Jul 14, 2005 at 5:09 AM | Permalink

    Lied? A fairly typical and derogatory John A. sad hom I’m afraid.

    You do have a ‘get out of scrutiny’ card, don’t you :). We can’t scrutines your public pronouncements except those you make on the web as John A. Why? Because we don’t know who you are, we don’t know of any public pronouncement you might make under your real name. Yet you seek to judge and jury the words of other others! There’s a word (probably several) for that.

  18. John
    Posted Jul 14, 2005 at 5:17 AM | Permalink

    Lied as in “not told the truth about what they had done”. Not an ad hominem but a straight documented fact.

    You are perfectly able to scrutinize my public pronouncements, but alas, you can’t touch my private life, which you are clearly desperate to involve. You are desperate to turn this debate into a personal diatribe because you cannot and will not justify your beliefs with reference to verifiable facts.

    After comparing my previous opinions to the political acts of Joe McCarthy, you are not on any moral elevation to criticise others for “ad homs” despite you using your real name on the Internet.

  19. Paul Gosling
    Posted Jul 14, 2005 at 5:26 AM | Permalink

    I think you have all just proved my point quite beautifully.

  20. John
    Posted Jul 14, 2005 at 5:54 AM | Permalink

    Then your point was a troll, wasn’t it?

    How, for example, does anyone “intimidate” a person by simply comparing what they say in a public forum with what they have already disclosed? How is it “harassment and intimidation” to politely request a scientist making a claim to send their data and methodology for independent evaluation (which they said they would do so but never did)? Since when did “harassment and intimidation” become academic defences against proper scientific scrutiny?

  21. Peter Hearnden
    Posted Jul 14, 2005 at 5:59 AM | Permalink

    snip – please , chill Peter. I’m not trying to be biased on this and will snip other flaming as I notice, but I don’t want to babysit. Steve

  22. Paul Gosling
    Posted Jul 14, 2005 at 6:49 AM | Permalink

    I think it is certainly harrasment if rather than addressing the persons work and the faults with that, you address the person and the faults with them. MBH98 has now been pretty well discredited due to M + M and well done to them, it was clearly rubbish. It was done by addressing the piece of work, not the person. Increasingly the debate, especially on this site, but the hockey team are guilty as well, is focused on rubbishing the people, not their work. So we get papers critisised before they are even published… it must be bias, its not independant because this person or that person wrote it.

    I switch off when I hear the debate degenerate in this way. What I want to hear is a debate about the science, not a debate about wheather some person who wrote a paper x years ago really has lost some of the data they used when they moved buildings or whetehr they are hiding something.

  23. Dave Dardinger
    Posted Jul 14, 2005 at 7:08 AM | Permalink

    Well, when papers are trumpeted in the media as ‘disproofs’ of the M&M work when they’re submitted rather than accepted, let alone published, why are you complaining about the paper being criticized here?

    And the criticism was based on the content of the paper, or more precisely, the content of the computer codes, etc. posted on-line. And the ‘criticism’ was not personal, unless you call pointing out the ‘business’ relationships between the parties as making the claim of ‘independence’ dubious, can be considered personal.

    As to John and even Steve getting testy with individuals, you need to actually look at what they’ve posted concerning interactions with the individuals involved.

  24. Steve McIntyre
    Posted Jul 14, 2005 at 7:12 AM | Permalink

    Paul, I acknowledge your comments. While it may seem to you that our critique of MBH is accomplished, it remains controversial and MBH and Wahl and Ammann are not conceding an inch. When Crowley accuses me of “thretening” him and it gets reported by a responsible reporter, it does get under my skin a little. (I’ve been the subject of a really tiresome amount of accusations and misreprentations by climate people over the last couple of years and by and large, I think that I’ve stayed pretty cool about it.) Maybe I should just ignore it, but then the accusations get a life of their own. Thus, I thought that on balance that I would document exactly what happened. As to discussing consistency between past and present positions, I come at this from a prospectus perspective. If you’re an investor, you are quite entitled to go back and look at a prospectus – events change, but you’re entitled to full, true and plain disclosure at all times. I try to examine past statements from a contemporary point of view – i.e. I am very critical of Mann’s withholding of the R2 statistic or bristlecone non-robustness in MBH98 and then in IPCC TAR – this isn’t 20-20 hindsight backbiting. But point taken, Steve

  25. Paul Gosling
    Posted Jul 14, 2005 at 8:20 AM | Permalink


    To be fair to you my, criticism of this blog was aimed less at you and more at some of the other people who post on here and who can be quite vitriolic in their attacks on the hockey team at times. I think it would be best for all concerned if everyone could take a step back from the personal stuff going in both directs (I concede, from what I know, they started it, to use that quaint school yard phrase) and return to a debate about the science in the scientific press. However, I don’t see this happening now, people have their careers resting on this and it has all become embroiled in the politics of global warming. None the less I do think that some of the posts on here can appear to someone who is neutral and trying to get to the truth petty and at times quite nasty. That will be my last word on the subject.

  26. Ross McKitrick
    Posted Jul 14, 2005 at 8:29 AM | Permalink

    I think we need to keep the technical debate in the climate journals, since that’s the audience we want to win over. While some of the audience doesn’t follow the math, we’ve heard from a critical mass who have gone through the details and engaged the argument at a formal level. The new wrinkle here is having a large audience of interested outsiders, partly due to the Internet and partly due to the global warming issue and its politics. For instance I got invited in April to address the ‘International Forum on Greenhouse Gas Management in Agriculture’ in Victoria and specifically was asked to summarize this debate. That was an audience of agriculture specialists, and yet they were interested enough to fly me out and have me give a keynote talk. So the interested audience is pretty wide, but the group we really want to persuade are more likely to read GRL than JASA.

  27. Peter Hearnden
    Posted Jul 15, 2005 at 1:08 AM | Permalink

    (snip) Peter, I’m trying to tone down the bickering; I’ll try to be evenhanded but I don’t want to babysit. Email me off air if there’s something that you think should be snipped.

    More generally for Peter and others, I think that there is a distinction between name-calling between people commenting here and making strong comments about published works. I’ve stated that MBH98 contained misrepresentations, which is pretty strong language and the existence of misrepresentations is pretty fundamental to my view of this corpus of work.

    How does one draw a line between being able to make such comments, which I intend to do, and have a debate here which does not spiral off into flaming? I don’t exactly know. I’m a bit ad hoc in my snipping since it bores me, but most people can figure out when they are starting to flame and I would appreciate less of it from everyone.

  28. Paul Gosling
    Posted Jul 15, 2005 at 1:59 AM | Permalink

    I may be the case that your school experiments were producing simple scientific “truth’ but I am afraid that in the complex real world the scientific process IS one of consensus. Science aims to produce a robust consensus based on inquiry, which allows for continued scrutiny, re-examination, and revision of theory. Within the scientific community, different individuals may weigh the same evidence differently and adhere to different standards of demonstration. Even apparent immutable truths, such as the speed of light in a vacuum are no more than the consensus position. Of course you are correct in saying that the consensus may be wrong, testing those consensus positions that it what science is about.

    It is interesting that you pick Lomberg as your standard bearer of scientific truth. a) he is not a scientist. b) his book was riddled with inaccuracies and gross misrepresentations but very little science and c) he completely missed the point.

  29. Ed Snack
    Posted Jul 15, 2005 at 3:09 AM | Permalink

    Paul, petty and nasty, have you seen what passes for “scientific debate” on this subject at realclimate, Tim Lambert, Chris Mooney, and other boards/blogs ! A bit free with the adjectives sometimes yes, but pretty mild stuff. Even our resident troll sticks to the milder ad homs. Still, I hope you found the comparison between what Crowley was told on 19 March and what he said on 6 April illuminating in regard to trying to get at the truth.

  30. Paul Gosling
    Posted Jul 15, 2005 at 4:45 AM | Permalink

    Quite frankly I am confused by the debate

    Steve M says that they have not done a reconstruction, but if they have reanalysed MBH data in order to find the faults with it have they not? Does this not count as a reconstruction? Do only published reconstructions count?

    If you ask me what the time is I may tell you – its exactly ….., when if I think about it I know that is not true. That is the problem with having this debate in University dining halls, press conferences and the like. When the argument gets heated it is easy exaggerate a point to emphasis it or miss out a fact which clouds and issue. That is why I would like to se the debate return to the scientific press, where people are more considered in what they write and we have an accurate record. You are right about RealClimate, there is no debate there, but there is little debate here either. If you were to come to this blog blind so to speak, and read many of the posts you would conclude that the Hockey team are liars who are deliberately trying to mislead the world by falsifying their data. Is that true? I don’t think so. Trying to cover their backs after publishing some sloppy work several years ago, I think that is fair, but you can hardly blame them with people baying for blood.

    Steve: Paul, the nuance is this: we have emulated the MBH98 reconstruction methodology as best we can on the present record and have accomplished an emulation just as good as Wahl and Ammann (using Mann’s own tree rnig PCs and edited Gaspe data). We have then done a sensitivity analyses showing various impacts of using conventionally calculated PCs (retaining different numbers in the NOAMER tree ring data set, with and without Gaspe editing, with and without bristlecones) etc. We found that theie 15th century result was not robust to (for example) the presence/absence of bristlecones or to methodological variations that enhanced the weighting of the bristlecones. We have disavowed MBH98 methodology or proxy selection processes and accordingly we do not claim that slight tweaking of MBH98 methodology produces a representation of past climate. Our position is entirely critical: that MBH98 cannot make claims about 20th century uniqueness or that its findings are robust or that they have statistical skill, based on what they’ve done.

    I agree with the debating hall aspect of this. Unfortunately some of the scientific press is little better. The Wahl and Ammann (for example) submission to GRL was somewhat fancied up version of a realclimate posting, as is the comment about MM03 in Rutherford, Mann et al. [2005?]. If I were the IPCC or the US National Science Foundation and I thought that the issue was important enough to resolve, I’d start by getting Mann’s source code available for examination so that the matter could be reconciled precisely.

  31. Peter Hearnden
    Posted Jul 15, 2005 at 6:29 AM | Permalink

    OK, Steve, I’ve tried twice to put the record straight. I really don’t see what so unacceptable about that, especially as others are able to call people lairs… Whatever, where is you’re Email address?

  32. Jeff Norman
    Posted Jul 15, 2005 at 9:44 AM | Permalink

    Tim says:

    “Following the link, we find an anonymous person defending McKitrick’s false claim that average temperature has no physical meaning. I had explained that the physical meaning of the average temperature of two bodies was the equilibrium temperature you obtain when you let heat flow from the hotter body to the cooler one and that this was just the weighted average.”

    As an engineer I have used average temperature for calculating enthalpy. ASME, US EPA and ISO standards tell me how to measure average temperature.

    I have always had problems with the assertion that “average temperature has no physical meaning” or words to that effect.


  33. Posted Jul 15, 2005 at 11:46 AM | Permalink

    Steve V, you must have missed my Tech Central Station column on the hockey stick.

  34. Dave Dardinger
    Posted Jul 15, 2005 at 12:47 PM | Permalink

    Hmm. A, neither is Steve here a scientist in the way you mean it. I don’t suppose you’d care to clarify what you mean by bringing that up?
    B The book wasn’t riddled with inaccuracies. There are some points of debate possible, but I’d be interested in precisely what inaccuracies you’re referring to and if you’ve read his defenses of his book? I do have his book handy and the link to his website still works (last time I checked) so we should be able to check things out pretty readily.
    B-1 The book was not a book concerning the science per se. Instead it cites the science, primarily by references to official documents. The purpose of the book was to compare tha actual state of the world with the doomsday conclusions expounded by leading environmental organizations. Read the first paragraph on the first page inside the cover and you’ll see this stated quite clearly
    C Therefore I think it’s you who missed the point of his book, but again that’s arguable.

  35. (Another) John
    Posted Jul 15, 2005 at 3:55 PM | Permalink

    John A:

    Could you expand a little on your comment about entropy and thermodynamic systems.


  36. Paul Gosling
    Posted Jul 18, 2005 at 3:17 AM | Permalink

    Dave D

    This is not really the place to discuss Lombergs work, so I will be very brief.

    Steve M is not a scientist, but he is not commenting on the physics of climate, he is commenting on the math of the analysis. Math is something Steve knows about. While Lomberg is quite at liberty to comment on science he needs at least to read the papers rather than the second or third hand reports of it, I would expect that even of a 1st year undergrad.

    Even Lomberg has admitted on his own web site there are inaccuracies, lots in chapter on forests for eg. He is also very good at selecting the opinions of those that support his ideas even if they contradict everyone else in the field.

    He missed the point in two aspects. First, he is primarily concerned with the human environment, but that is not what environmentalism is about. Second, most of the improvements in the environment he talks about have occurred because of legislation, something he does not fully acknowledge.

    If there is somewhere to disciss this more fully point the way.

  37. Dave Dardinger
    Posted Jul 18, 2005 at 8:08 AM | Permalink

    I’ll be equally succinct since you don’t present any specific complaint.

    1. Yes Lombard admits his mistakes. (Would that Mann did the same). AFAIK none of them have any measurable affect on his results. The only forest one I recall, has to do with the % of a tract of land where the tree crowns are touching. I don’t recall that there were ‘lots’ of errors in the forest chapter, however.
    2. You’re right many environmentalists aren’t really interested in human beings. I regard that as more a negative than a positive, but I can’t deny it. Anyway Lomborg’s book has one whole section (Part III) primarily on the situation in the natural world, and various chapters and paragraphs elsewhere (e.g. Chapters 16 & 23
    3. The book is admittedly not written as a paean to big government, but it’s also not a polemic urging more unfettered free enterprise. Bjorn is, after all, basically a leftist and not at all disinclined to typical European-style government.

    Google on my name and you’ll find out where I hang out, but I’d rather you present one or two specific complaints here than a long drawn-out discussion in a back-room, so to speak, somewhere else. Neither of us is going to convert the other if my experience debating Lomborg-bashers is any guide, so what’s the point?

  38. Paul Gosling
    Posted Jul 19, 2005 at 2:04 AM | Permalink


    Sorry to hijack your site like this, please tell us if you want us to take this elsewhere.

    As I have not read it for some time and don’t have a copy handy I can only remember two factual errors off the top of my head. The forest cover one you mention and the reduction of forest cover in eastern N. America, which he claims fell to 1-2%, but it did nothing of the sort. I also seem to remember he claimed that this resulted in only one bird species going extinct, when it was actually 4.

    I claimed errors and gross misrepresentations, the latter are more serious. For eg equating primary forest with plantation forest. Even in the defence of his book he can’t help repeating this practice. He uses the eg of Argentina, saying that 60% of Argentina’s timber comes from plantations, which make up only 2.2% of forest cover, therefore saving the other 98% of forest. a) how much of the other 98% is being felled for timber exports? b) the main reason for clearing the forests of Argentina is for agriculture, not timber, so the plantations do nothing to stop this. 98% of Argentina’s forests are not protected, though he gives that impression.

    The factual errors repeat the mistakes he claims the environmental movement makes, which tends to undermine his argument. His misrepresentations followed by retractions on obscure web sites are equivalent to the worst sort of tabloid journalism. Banner headlines giving incorrect information, which plant the idea in peoples mind. Followed by a one paragraph retraction hidden on the middle pages. The damage has been done, but the author is able to say, look I am reasonable I have corrected my “mistake’.

  39. Dave Dardinger
    Posted Jul 19, 2005 at 1:42 PM | Permalink

    I’ll start with just one point which isn’t about your specific complaints but which needs discussing.

    1. “retractions on obscure web sites” Did you actually think about this before writing it? It’s Bjorn Lomborg’s own website. http://www.lomborg.com/ How obscure can a website be which carries the name of the author of the very work in question? The subtitle says: “This is the official web page for The Skeptical Environmentalist & Bjorn Lomborg, named one of the world’s 100 most influential people by Time Magazine.”

    2. For Peter’s benefit (who has great difficulty in seeing journalistic bias), please note that this is an excellent example of bias. Use a word with a negative context like “obscure” to minimize the manifest fact that Lomborg printed corrections to his work. Then use this slur to help in justifying a comparison to “the worst sort of tabloid journalism.”

    3. What’s especially laughable about your putdown of where Lomborg posted his corrections is that he only had to do so because the people who printed smear articles about his book, most especially in Scientific American, refused to allow him to respond to their complaints. Indeed they tried at first to not allow him to use the articles to respond to them. Since then he’s been able to post his responses on the SA website. (Hardly an obscure site, BTW).

    I’ll post another reply which addresses your specific complaints.

  40. Paul Gosling
    Posted Jul 20, 2005 at 1:44 AM | Permalink

    So did Time Magazine, or The Economist, or the Washington Post, or the Daily Telegraph or the New York Post, which is where most people would have read about the book and what it said, publish corrections or articles by scientists pointing out his mistakes or refuting his conclusions? I don’t know, but I doubt it. The corrections were placed on a web site, presumably set up some time after the book was published (thought again I don’t know). So anyone who wanted to find the corrections would have to go onto the internet and look, equivalent to the mid page correction in a newspaper. I realise Lomborg has no control over what is published in these titles, but this is all rather by the by. My main point was that the book contained gross misrepresentations of the facts which were able to grab the headlines and fix ideas in peoples minds, any retraction after that, especially if done sometime latter in a low profile way is bound to struggle against the original idea. This is exactly what Mann et al could be accused of, which is why I originally questioned your holding up of Lomborg an example of the scientific ideal in the first place. Both Mann et al and Lomborg can both be considered to have been at best sloppy and at worst dishonest in their seminal works.

  41. Dave Dardinger
    Posted Jul 20, 2005 at 7:50 AM | Permalink

    re # 41

    A couple more intermediate remark before settling down to examine your particular complaints. (BTW, glad to see we have the remark numbers back now. It makes it a lot easier to refer to specific remarks. I guess threaded remarks are not officially defunct)

    1. It sounds to me like you’ve not really embraced the internet yet. If I were looking for a correction to a book, I’d no more go looking for them in the back pages of the NYT than I would on the back shelf of my linen closet. I’d automatically go to a website dedicated to the book in question. And I’d actually start with “Book name” +corrections on Google. This would undoubtedly lead me to both the author’s website and that of any major critics.

    2. “…the book contained gross misrepresentations of the facts which were able to grab the headlines and fix ideas in peoples minds….” This is really pretty funny since it’s precisely what Lomborg was complaining about in the MSM when it comes to info about the state of the world. Headlines are published that the world’s environment is coming to an end and then the actual facts are hidden away in obscure papers and government reports and while reputable scientists will give you the straight scoop, it’s too little, too late to avoid fixing doomsday scenarios in the minds of people.

    Alright, not I need to go looking to see if I can find the things you’re complaining about and discuss them. Hopefully I’ll get back to you yet today.

  42. Victor Irby
    Posted Jul 20, 2005 at 7:55 AM | Permalink

    Maybe someone can help me out here. As a Ph.D. physicist, I find something rather odd regarding Crowley’s estimates of greenhouse-gas heating as presented in the webcast.

    According to Crowley’s estimates on climate forcing (graph presented at about 37: 25 into webcast), in 1999 greenhouse gases accounted for ~ 5 W/m2. (five watts per square meter). This is ~ 2 W/m2 above normal background of 3 W/m2. Since we are talking about “global” warming, this needs to be multiplied by the surface area of the earth, resulting in 1.02 x 10 (15) W (ten to the 15 th power).

    How much energy does this correspond to in one year? Multiplying by the number of seconds in a year results in 322 x 10(20) J of energy. Keep in mind that this is the “extra” energy dumped into the environment by us humans.

    In comparison, what was the total amount of energy consumed by the entire world’s population in 1999? (Including all forms, coal, gasoline, nuclear, etc..) According to the Physics Factbook (http://hypertextbook.com/facts/2001/JenniferGreen.shtml) the human world consumed 382 quadrillion BTU or ~ 4.03 x 10(20) J.

    Thus, according to Crowley, greenhouse gas emissions somehow result in an energy gain of over 80 times the entire energy consumed by the world in 1999. Either the 2 W/m2 forcing proposed by Crowley is a gross overestimate, or we have discovered the most efficient natural resource of energy to date.

  43. Paul Gosling
    Posted Jul 20, 2005 at 9:10 AM | Permalink


    It has got nothing to do with embracing anything.

    Having read the articles in the popular press saying how wonderful the book was or even the book itself, the reaction of most people would not be to go searching to see if it was correct. Especially as one of the central arguments of Lomborg was that those in the environmental movement make gross misrepresentations, while he in contrast was present facts. Lomborg falls into the same pattern as those he criticises, at least we are agreed on that, but in my opinion that totally undermining his arguments. He is not an example of how science should be done, as you seem to claim, but a propagandist, just the same as those he criticises.

  44. Dave Dardinger
    Posted Jul 20, 2005 at 10:46 AM | Permalink


    Greenhouse warming is entirely different than energy consumption. Energy consumption is a one-time thing, and as you show, pretty small potatoes compared to the putative global warming. The latter is a continuing affect due to the ability of greenhouse gases to slow down the escape to space of IR heat produced primarily by absorption of solar radiation by the earth’s surface. The atmosphere absorbs more IR as it tries to escape and sends (some of) this IR back to the surface for a second try. This additional recycled IR is the sum and substance of what’s at issue. You’ll find some skeptics, and surprisingly some warmers, who don’t understand / accept this, but that’s pretty much a signal of whether or not the person you’re talking to is worth continuing to talk to.

  45. Victor Irby
    Posted Jul 20, 2005 at 10:55 AM | Permalink

    Re: 45
    Granted I am not an expert on greenhouse warming, but I do understand principles such as Conservation of Energy, Thermodynamics, etc.
    In regard to the 322 x 10(20) J, where does this come from? If it does not come from the sun it must come from the earth. Which means something had to cool. Greenhouse gases do not “create” energy.

  46. Dave Dardinger
    Posted Jul 20, 2005 at 10:57 AM | Permalink

    Ok, Paul, I’ve not gathered some data about the specific problems you mentioned concerning Lomborg’s book.

    Specific complaints:

    A “remember two factual errors off the top of my head. Concerning the forest cover…” concerning this one we both mentioned here’s his correction.

    p375, endnote 767: “The two long time-series of forest area depicted are Forests and Woodland, which was discontinued from 1995 onwards, whereas the new estimates are for closed forest, i.e. 20 percent of forest cover in the industrialized world and 10 percent in the developing world (FAO 1997c:173-4).” Here the last part of the sentence should read: “i.e. with tree canopy cover of more than 20 percent in the industrialized world and more than 10 percent in the developing world (FAO 1997c:173-4).” Thanks to WRI/WWF.

    I’d forgotten, however, that the proper canopy cover terminology was given in footnote 770 which goes into more detail on the subject. So this was clearly just an oversight by Lomborg in one footnote, not a misunderstanding of the definition of forest.

    B the reduction of forest cover in eastern N. America, which he claims fell to 1-2%, but it did nothing of the sort.

    Here’s a complaint from the Nature review of his book and Lomborg’s reply:

    Nature: On future trends based on forest losses, his flawed examples are unoriginal. “In the US, the eastern forests were reduced … to fragments totalling just 1–2% of the original area … this resulted in the extinction of only one forest bird”. The correct percentage is close to 50%, and the number of extinctions four, plus two seriously wounded. Those extinctions constitute 15% of the bird species found only within the region (the only ones at risk of global extinction). They strikingly confirm the predictions made from the species-area models that Lomborg disparages.

    Lomborg: This example, as well as the forest and bird loss, is from the biologist Simberloff, writing for the World Conservation Union (IUCN), as referenced in the text. If he is wrong, Pimm & Harvey should criticize him. That the argument is unoriginal is entirely correct — I merely quote other scientist’s research.

    Looking at the actual text (p254) however explains the whole thing. The words actually used were “primary forest”. This would mean what we now commonly call “old-growth forest.” It would seem to me entirely possible that the old forests along the Atlantic seaboard were reduced to 1-2% of what they started with over a period of a couple of centuries even while the total forested area never dipped below 50%.

    C . I also seem to remember he claimed that this resulted in only one bird species going extinct, when it was actually 4.

    Here it’s helpful to look at footnote 2046 on p409:

    2046 Simberloff 1992:85. Simberloff writes here that three species of birds became extinct, but that forest clearance was probably not responsible in two of these cases.

    Not having the reference handy, I don’t know what bird was left out, but is the difference between 3 and 4 birds really all that important in finding something to castigate Lomborg about?

    D “equating primary forest with plantation forest.”

    Here you’re distorting the purpose of the paragraph you’re quoting from. He’s defending the use of plantation forests, not equating them with tropical forests. And he’s defending them on the basis that while they’re not as biodiverse as other forests, they take the pressure off those more pristine forests for logging. This, he says, means that “it’s not obvious that plantations reduce overall biodiversity.”

    Final point. You talk about how Lomborg was going for the headlines, but let me tell you, I had a hard time finding the particular things above even having the table of contents, index and his notes handy.

  47. Victor Irby
    Posted Jul 20, 2005 at 11:02 AM | Permalink

    continuation of 46

    Can greenhouse warming be described in an analgous fashion as a transitor? The sun supplies all energy. Greenhouse gases act like the “throttle” controlling how much energy is actually absorbed by the earth? (I have yet to find a clear explanation. That doesn’t mean I disagree with greenhouse warming).

  48. Victor Irby
    Posted Jul 20, 2005 at 1:20 PM | Permalink

    Dave Dardinger,
    do you know how Crowley arrived at his figure of 5 W/m2 for CO2 greenhouse warming?
    What about H2O (which is far more effective of a greenhouse gas than CO2)?

  49. Dave Dardinger
    Posted Jul 20, 2005 at 2:13 PM | Permalink

    re: #46, #48
    The important thing is that the forcings are measures of energy/time. But temperature is a measurement of average energy. So the amount of energy flow doesn’t mean so much, it’s got to balance in the long run. What matters is how the thermal energy is distributed at a given point in time. If more of it is stored up in the atmosphere then the atmosphere and thus the surface will become warmer.

    re: #49

    I know the IPCC’s Climate Change 1994 has 4.63 w/m^2 for the instantaneous forcing with no feedbacks for doubling the CO2 from 300 to 600 ppmv. I would have to ckeck to see if there’s been changes in that figure recently and whether this is the figure Crowley uses or not.

  50. JerryB
    Posted Jul 20, 2005 at 5:39 PM | Permalink


    An oversimplified, and unsubstantiated, introduction to atmospheric “greenhouse effect”:

    Most of the atmosphere consists of N2 and O2, and they are relatively transparent to both visible light and infra-red radiation.

    Some visible light is reflected from the surface of the earth, and exits the atmosphere. Other visible light, as well as incoming IR radiation, are absorbed at Earth’s surface, and heat that surface.

    Some of that heat results in emission of outgoing IR radiation, and some of that radiation is absorbed by so called “greenhouse gasses” in the atmosphere, (e.g. water vapor(H2O), CO2, CH4), and they in turn emit IR radiation in all directions, i.e. both towards space, as well as back to Earth’s surface. This activity constitutes the atmospheric “greenhouse effect” of “greenhouse gasses”.

    Some caveats: the atmospheric “greenhouse effect” is sometimes asserted to be the (implied one and only) reason that average near surface temperatures are estimated to be about 33 C above what they would be if there were no such atmospheric radiative “greenhouse effect”. Not so. Surface-atmosphere conduction also contributes to near surface temperatures. Evaporation of H2O, and the subsequent release of its latent heat, contributes more than either conduction, or the atmospheric “greenhouse effect” to average near surface temperatures. Such evaporation in the tropics, particularly in the ITCZ (intertropical convergence zone), and especially in the “warm pool” areas of the Pacific, and Indian, oceans, drive the Hadley circulation of the atmosphere, which transports much tropical heat from lower latitudes to higher latitudes.

    Clouds complicate the subject immensely, so they are otherwise omitted from this introduction.

  51. Paul Gosling
    Posted Jul 21, 2005 at 2:00 AM | Permalink

    Dave Re 47

    So there is no dispute that Lomborgs book contained a not insignificant number of factual mistakes, I say insignificant because though I can only remember a couple there were certainly more. This would not be so important if the whole thesis of the book was not that the green movement used factual inaccuracies and misrepresentations to enhance their message. In effect Lomborg is saying the green movemnet is a bunch of liars, but how can we believe him when we can’t trust what he writes.

    I fully stand by the misrepresentations

    Lomborg in defense – “It would seem to me entirely possible that the old forests along the Atlantic seaboard were reduced to 1-2%” so not a fact then, just speculation.

    There is no evidence presented that plantations protect primary forest, again just speculation, thought it is presented as fact. I pointed out the example of Argentina, do you dispute it? Another example – in the UK we now have more forest cover than for over 100 years. Most of the increase is in plantations. Lomborg would no doubt argue this is protecting the ‘primary’ forest. However, the plantations were largely to replace imports, they made no difference to the primary forest, and in many cases the plantations were established not on the site of old forests but on areas which had not supported forest cover for thousands of years if ever. Some of these sites had high consevation value in themselves, so plantations were destroying biodiversity, not saving it.

    Remember my original point was that Lomborg should not be used as an example of high quality writing, beacuse TSE contained many factual errors, which you do not dispute and misrepresentations, which I don’t think you have been able to refute. Lomborg and you maintian that this does not alter the thesis. However this is just what Mann et al are saying, there maybe some slight errors and maybe we gave misleading information in the original paper, but here are some corrections and it does not influnce our results anyway. Lomborg and Mann grabbed the headlines and the image stuck.

  52. Dave Dardinger
    Posted Jul 21, 2005 at 7:44 AM | Permalink

    re #52

    The Skeptical Environmentalist is 515 pages long. It has 2930 notes. It was originally written in Danish. It’s a first edition. It’s going to have some errors. That’s a given. I’ve read lots of books and almost always they have some errors. You’re trying to imply that the level of error in Lomborg’s book is too high. That’s not true.

    Per the 1-2% item, Lomborg didn’t make the remark you call speculation, I did. I thought I was clear about that I was switching back to my own voice, but obviously I needed to be more explicit. OTOH, you might have gone to the trouble of actually having gone to Lomborg’s site and read what he had to say. Somehow I doubt that you ever actually read his book in its entirity in the first place. You may have glanced at it and skimmed a few paragraphs here and there, but your complaints are just too much like the remarks of someone who’s read other’s critiques and is now doing your best to recall them.

    Moving on to plantations, I’m somewhat amazed at what you call speculation. I’m not sure just how one would prove that plantations relieve pressure on other forest. Bjorn’s argument is a logical argument, not a deductive proof. I’m not sure what you mean by “example of Argentina”. If you mean that you indicated that most forest conversion comes from farmers wanting more cropland, that has nothing to do with Bjorn’s point and I said so before. The plantations are designed to produce timber and this reduced the pressure on getting the timber elsewhere. That it can reduce the demand in a jungle somewhere else is not just moot, it’s an argument in favor of doing the plantations in non-jungle areas since jungles are so biodiverse.

    BTW, you claim that some of the non-forest lands converted to plantations had high conservation value, but of course that’s just speculation so I can ignore it

    Also BTW, don’t put words in my mouth. I said that there were some errors in Lomborg, not MANY.

    And AFAIK you only really provide one example of a ‘misrepresentation’ and I think I refuted it properly.

    Finally, aren’t you risking the wrath of the Mann people if you try saying that the errors in Mann aren’t any worse than those in Lomborg, who I expect they’d think is beyond the pale? And of course I disagree from the opposite side. Lomborg admits the true mistakes and typos which were found while Mann admits nothing. At most even the ‘misrepresentations’ by Lomborg are trivial compared to the large number of examples, graphs, etc. in the book. Meanwhile Mann’s ‘little errors’ cast considerable doubt on the entire thesis of MBH98.

  53. Victor Irby
    Posted Jul 21, 2005 at 12:02 PM | Permalink

    Re: 51 Jerry B

    Thanks for the insightful description. Radiant forced heating of our planet is much more complicated than I imagined.

    In regard to Crowley’s estimation of CO2 forcing (Re: 43), I now strongly feel that it is a gross overestimation. It could be correct if we doubled the amount of H2O vapor in the atmosphere since H2O comprises something on the order of 2 %. (CO2 only comprises 0.03 %)

    A correct estimate of gaseous forcing should involve both the numerical increase in concentration and the actual initial quantity (like thermal expansion : change in length being proportional to the product of change in temperature and initial length).

    However, I could very well be wrong. I am interested in hearing other viewpoints.

  54. JerryB
    Posted Jul 21, 2005 at 4:20 PM | Permalink


    First, a correction with apologies. In my sentence:

    Evaporation of H2O, and the subsequent release of its latent heat, contributes more than either conduction, or the atmospheric “greenhouse effect”, to average near surface temperatures.

    the clause:

    or the atmospheric “greenhouse effect”

    is not correct in that context. The sentence should have read:

    Evaporation of H2O, and the subsequent release of its latent heat, contributes more than conduction to average near surface temperatures.

    Meanwhile, for some additional discussion, you might try a couple of Richard Lindzen’s articles. At the link:


    item 198 is somewhat introductory. Item 181 gets into more details. There may be others that might find interesting.

  55. McCall
    Posted Jul 22, 2005 at 12:01 AM | Permalink

    Dr Irby — the AGW models and arguments assume some contribution of CO2 in IR absorption, and a huge NET MAGNIFYING WARMING FEEDBACK FACTOR due to the increased vapor pressure of atmospheric H2O resulting from anthropogenic CO2 forcing temp increase. If H2O is a NET MAGNIFIER after all forcings/feedbacks, then the AGW proponent models trend towards their doomsday rise — if H2O is not a NET MAGNIFIER (never the AGW proponent assumption, even though Dr Lindzen among others presumes as much), then the causational threat is bogus.

    Also blamed as anthropogenic is CO2 released naturally, starting 200-800 years after prolonged upturn in temperatures as found by Monnin JAN’01 in the Southern Ocean/Antarctic Ice core analysis but presumed for tropic and Northern Oceans too — this should be a magnifying feedback under most reasoned arguments (the watch being “reasoned”), but often becomes part of a projected “forcing” CO2 alarmist discussion, without mentioning its true origin.

  56. Paul Gosling
    Posted Jul 22, 2005 at 8:54 AM | Permalink

    Dave D Re 53

    Your first point. Many of the factual mistakes Lomborg made were not in the translation but incorrect figures eg p30,1: “global catch has increased by 75 percent” should be 55 percent. (from Lomborgs web site).

    Your second. No I have not read all of the book. After the furore erupted I decided I needed to make up my own mind. I read the chapters on Forests loss, Our chemical fears and Biodiversity, all of which I have some (professional) knowledge of. Though the chapter on our chemical fears was not so bad the other two were enough to convince me that the book was not an objective assessment but a piece of propaganda. I had my answer and therefore only read bits of the rest of the book. I do not own a copy.

    On plantations, it should not be difficult to find evidence of countries where increased plantations have been at least associated with a decline in forest clearance, given Lomborgs apparent willingness to trawl through huge numbers of reports, if this were actually what happens. The example of Argentina comes from Lomborgs letter to Scientific American. The vary fact that you/he feel the need to separate out the economic pressures from logging, say that plantations reduce this, without showing any evidence at all, implying that this means all is well and the forests are protected, when they are not protected from other pressures, is a perfect example of the misrepresentations which blight the book.

    “BTW, you claim that some of the non-forest lands converted to plantations had high conservation value, but of course that’s just speculation so I can ignore it.”

    Sorry not idle speculation, try

    79 (1): 87-90 JAN 1997

    38 (6): 1208-1220 DEC 2001

    141 (1-2): 31-42 FEB 1 2001

    Which concludes that although forests containing exotic species in the UK are better for wildlife than agriculture states

    “introduced trees have been ecologically
    damaging in several ways:

    reductions in biodiversity when semi-natural woodland
    is replaced;

    loss of semi-natural habitats, especially upland

    elimination of small populations of rare and local

    site degradation, e.g. by drainage associated with

    allowing some native invertebrates to become pests;

    If you can’t get hold of journals try looking at the RSPB or Scottish Natural Heritage web sites search under under Flow Country.

    Finally Mann admits nothing? — read Nature 392, 779–787 (1998). Mann does exactly whta Lomborg does. Makes excuses for the errors but then goes on to say that they make no difference.

  57. Dave Dardinger
    Posted Jul 22, 2005 at 1:19 PM | Permalink

    re #57
    1. Again, nobody denies there were some mistakes in Lomborg’s book. But they’re rare considering how large it is. If you were at his site, you know they weren’t large in number. If you know of ones which can be proven and he hasn’t posted, please present them.
    2. “On plantations, it should not be difficult to find evidence of countries where increased plantations have been at least associated with a decline in forest clearance”

    This is unlikely to be possible except when complaring many years of data on many countries. Confounding factors include that a) a country with a growing economy is likely to also have a growing demand for both wood and food and therefore increases both in clearing and in wood plantations. b) there’s an interaction between government laws and attitude toward private ownership of resources and what combination of methods are likely to be used in production of forest products. c) related to the last point, tax laws and depreciation and the like will increase or decrease the incentives for business to take a long view when it comes to resourses they own or control.

    3. A) Sorry you don’t get irony. B) the last two references you provide would have come out after Lomborg’s book. C) You still seem not to be getting the point that we’re comparing converting some land into plantations and that this prevents larger areas of older forests from being disrupted. If you can show the damages to the land being more frequently logged vs converting some land to tree farms is in favor of some other system, go ahead. But no matter what the articles you point to show, they don’t address Lomborg’s point.

  58. Klaus Flemloese
    Posted Jul 22, 2005 at 2:11 PM | Permalink

    I will be pleased to draw your attention to the following website:http://www.lomborg-errors.dk/ written by biologist Kaare Fog, Denmark.

    This website gives a good overview of facts about Lomborg and point out errors, flaws and mistakes.

    Lomborg is to my understanding not a scientist, but very good in marketing he points of views. He is in writing style and in points of views close to most of the sceptical organisations like American Petroleum Institute,The Marshall Institutet etc.

  59. Jeff Norman
    Posted Jul 22, 2005 at 2:27 PM | Permalink

    Re#59 Klaus, when you say:

    “Lomborg is to my understanding not a scientist, but very good in marketing he points of views. He is in writing style and in points of views close to most of the sceptical organisations like American Petroleum Institute,The Marshall Institutet etc.”

    Did you mean that to be so ironic?


  60. Dave Dardinger
    Posted Jul 22, 2005 at 5:34 PM | Permalink

    re: #59
    I looked at the site and there is indeed a lot there, but I don’t know that it proves much. From what I can tell with a quick look, the vast majority of the complaints fall into either disagreements on policy or attempts to use Lomborg’s refs as cudgels by basically saying that since he cited a particular work, he must accept everything in that work as correct. If you’d care to pick one or two particular complaints I’ll look at them but there’s no sense having me cherry pick complaints I think are unfounded.

  61. Klaus Flemloese
    Posted Jul 23, 2005 at 11:47 AM | Permalink

    Re 59/Jeff Normann

    I am not joking. Lomborg is a politician and a very smart, but his is not a scientist. You can agree or not with his point of views, that’s OK for me. He political point of views are similar to the sceptical persons and organisations and against the NGO’s.

  62. Klaus Flemloese
    Posted Jul 23, 2005 at 11:54 AM | Permalink

    Re 60/Dave Dardinger

    Please look into example 2:


    This example deals with: “Historical trends in global forest area (chapter 10)”

  63. Dave Dardinger
    Posted Jul 23, 2005 at 1:11 PM | Permalink

    Re #63

    Well, I don’t know that the writer is anymore onto the truth than Lomborg. I decided to try a test and did a google search on Forests +Satellite and came up with this site: http://www.gsfc.nasa.gov/topstory/20011204carbonsink.html There they say,

    “NASA-funded Earth Science researchers, using high-resolution maps of carbon storage derived from NASA-developed satellite data sets, suggest that forests in the United States, Europe and Russia have been storing nearly 700 million metric tons of carbon a year during the 1980s and 1990s.”

    I suppose the NH may be anomalous, but it’s definitely an offset to any .2% per year or more decrease in forests in the SH.

  64. Paul Gosling
    Posted Jul 25, 2005 at 4:07 AM | Permalink

    Dave D

    RE 57 – Well if as you say, there is no way of knowing that plantations reduce pressure on natural forests, Lomborg should not have used this as an example of how natural forests are being protected. If plantations are being established to substitute for imported wood which itself comes from plantations then the plantations make no difference. Similarly if plantations are there to supply an increased internal demand for wood while clearance of natural forests continues at the same rate, then they are only protecting the natural forest from extra exploitation, the natural forests will still be cut down. Lomborg implies that plantations protect natural forest while giving no evidence, spectulation at best, I would call it misrepresentation.

    The references I gave were in response to a specific point you made in 53, that I was just speculating about the effect of plantations in the UK. I answered it by providing, unlike Lomborg, facts to back up my point, it had nothing to do with Lomborgs book, so the dates of the references are irrelevant.

  65. hans kelp
    Posted Jul 25, 2005 at 3:38 PM | Permalink

    re: #59

    Just a short remark to all these nice people who are so busy claiming Bjàƒⷲn Lomborg a non scientist and that a danish biologist ( Kàƒ⤲e Fog ) has proved him wrong on several points.
    Regarding being a non scientist I will leave to others to judge, but… Theres a book written by Bjàƒⷲn Lomborg and Ulrik Larsen especially to take care of all of the so- called complaints regarding the Skeptical Environmentalist . The book can be downloaded from here http://www.lomborg.com/GodhedensPris.pdf . The book is in danish and I´m not sure if it has been translated yet. I also just wanted to point to the fact that people seem to forget that
    the claims to a great part succesfully has been rejected by Bjàƒⷲn Lomborg, which makes the Skeptical Environmentalist thrustworthy!

    Hans Kelp

  66. Paul Gosling
    Posted Jul 26, 2005 at 1:36 AM | Permalink

    Hans RE 66

    Like the controversy over MBH98, whether you believe that Lomborg has succesfully refuted his critics or not depends on which side of the fence you are sitting.

  67. Paul Gosling
    Posted Jul 26, 2005 at 4:49 AM | Permalink

    Dave D

    Re 64.

    You seem to be confusing forest area with carbon storage. The two are not the same

  68. Dave Dardinger
    Posted Jul 26, 2005 at 12:10 PM | Permalink


    It’s true that forest area vs carbon storage isn’t the same, but I bet it’s a better proxy than bristle-cone pines are temperature proxies.

  69. Paul Gosling
    Posted Jul 27, 2005 at 1:57 AM | Permalink

    Dave D Re 69

    A quick scan of any undergrad ecology text will show you that the amount of C stored in different forest types varies by a large amount. As a result it is possible to have falling total forest area and increasing carbon storage and vice versa.

  70. Dave Dardinger
    Posted Jul 27, 2005 at 4:25 PM | Permalink

    re #70 Yeah, sure. And it’s possible to have rising CO2 levels and no little rise in average temperatures too. You better be careful what sort of possibilities you accept.

  71. Paul Gosling
    Posted Jul 28, 2005 at 1:51 AM | Permalink

    So you accept my point then?

  72. hans kelp
    Posted Jul 31, 2005 at 7:39 AM | Permalink

    Paul re 67

    Paul, I hope youré still watching this thread. Other things has distracted me for a while but I would like to come back to your answer to my posting #66.

    You say;

    ” Like the controversy over MBH98, whether you believe that Lomborg has succesfully refuted his critics or not depends on which side of the fence you are sitting”

    Now, first, I do not hold that all of what BjàƒÆ’à‚ⷲn Lomborg is telling us in the Skeptical Environmentalist is the divine thruth, as also must be understood from my posting, where I specifically and intentionally use the phrasing ” to a great part succesfully rejected”. I do not expect a book that expound primarily on results and statistics from others research and fields to be without certain caveats. But I also have to say that the uproar the book caused in both scientific circles all over the world, as well as in the lay population ( at least in Denmark where I live), made the book become very very thoroughly scrutinized , and as it is still very much debated I think at least it has proven its value in engaging people in “combat”.

    Well from the above you might come to the conclusion that I agree with you on the ” side of the fence ” philosophy you present. I dont , because it ain´t that simple!. First, truth ( scientific facts ) is not a question of whether you like or admire a person or not , which your posting seems to imply (maybe that´s the reason why you seem to defend Michael Mann in trying to persuade Steve Mcintyre to stop raising questions in that regard ?!)., or whether you like or not some fancy scientific theory . Your remark make you actually trying to push me to the one side of an imaginary fence which obviously exist in your world but certainly not in mine. To me there are so to speak only one side, – the skeptics side. I´m a so to speak learned skeptic to all that I see and hear because things in my way of life has taught me so, and scientifically speaking I can´t imagine not being a skeptic at all times and in all cases. With being skeptic I mean both being curious because you hear or see things which just dosen´t seem to fit into your personal view and experiences and also being curious because issues or things just happen to catch your attention in a ” raising your curiosity ” way . How else could mankind have been progressing if they had not reached the states of curiosity that made them start asking questions which then lead them to answers as they gained the necessary tools to solve the questions whatever they were.
    Now , I consider myself a lay person in climatological science even though I held a Masters Degree at Sea from Svendborg Navigation School in 1978. Also, later I was very close to obtain a traffic pilots license ( which I had to drop in the end thanks to Saddam Hussein who made the prospects for pilots rather pitty at the time). But in both of these two studies meteorology is essential and has at least made it easier for me to capture and understand some of the threads encountered both on this site ( ClimatAudit ) as well as the threads on Realclimate, where I find especially Gavin Schmidt rather impressing. I also now am running my own small dry cleaning business rather succesfully, so my way has proved me to be a what I call a “common sense man” who have been able to make the right decisions at the right times and also have learned to accept things for being what they were without knowing what they contained or concisted of.
    But I have to admit to myself that I don´t have the academic tools ( and I don´t want to spend the time to obtain them) necessary to get into detailed scientific argumentation, but that dosen´t make me being unable to see or sense if something dosen´t fit. Not to say that things then actually might be wrong.
    But then to my great relief, and certainly to a lot of others I´m sure , I can say that I´m lucky to have both a Steve Mcintyre , Ross Mckitrick and a BjàƒÆ’à‚ⷲn Lomborg who all posesses some of the academic tools I myself is in great need of. They do just what curious people do, they ask questions. The most natural thing to do for skilled intelligent people if things makes them wonder. And aren´t they obliged to?- I think so!
    To all of these guy´s credits I have to say that they certainly have caused a justified stir in the climate science community with a lot of unanswered relevant questions that in itself indicates that something is not quite as it should be in the field of climate science and in environmental issues as well. AND I really don´t see that not everybody at this point should´nt be interessested in f.ex. having the MBH98-99 laid bare for all to see so that every single tiny little bit of detail in it can be dissected and thereafter be accepted or refuted. After all, thats the way science ought to work, and I really think it´s sad to see the way people on your side of your imaginary “fence” is trying to desperately and by all means ( even by a proffessors slimy spitballs and a danish mudsuckers outright lies ( BjàƒÆ’à‚ⷲn Lomborg is not a politician and has never been, but he has been a member of Greenpeace) is trying to block and discredit honest and deliberate questioning with a lot of opposing questions and insults which mainly consists of emptyheaded blaa. blaa. blaa… YOU DON´T TEASE MY HERO,- DO YOU HEAR ME?!.

    So , to clarify my position I just have to support the questioning part, then I´m sure that in due time the right answers will emerge and getting accepted ( also by me of course ) never mind the name of the “man” of origin. I therefore have to dismiss your philosophy as a pure mental artifact, that in this very case has no meaning.

    Hans Kelp

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