It's Hard to Imagine…

As you all recall, the NAS panel let MBH off rather lightly in respect to disclosure and the House Energy and Commerce Committee couldn’t be bothered. So all in all, MBH dodged a bullet and you’d think that they’d have been wise enough to leave well enough alone. But no. In today’s Nature, Mann, Bradley and Hughes send an astonishing letter, in effect re-opening disclosure issues after everyone else had got bored with it. MBH write:

Your News story “Academy affirms hockey-stick graph”à (Nature 441, 1032; 2006) states that the US National Academy of Sciences (NAS) panel “concluded that systematic uncertainties in climate records from before 1600 were not communicated as clearly as they could have been”. This conclusion is not stated in the NAS report itself, but formed part of the remarks made by Gerald North, the NAS committee chair, at the press conference announcing the report.

The name of our paper is “Northern Hemisphere temperatures during the past millennium: inferences, uncertainties, and limitations” (Geophys. Res. Lett. 26, 759-762; 1999). In the abstract, we state: “We focus not just on the reconstructions, but on the uncertainties therein, and important caveats” and note that “expanded uncertainties prevent decisive conclusions for the period prior to AD 1400″. We conclude by stating: “more widespread high-resolution data are needed before more confident conclusions can be reached.” It is hard to imagine how much more explicit we could have been about the uncertainties in the reconstruction; indeed, that was the point of the article!

The subsequent confusion about uncertainties was the result of poor communication by others, who used our temperature reconstruction without the reservations that we had stated clearly.

Well, readers of this site can doubtless think of many ways in which they could have been more "explicit about the uncertainties".

Some of the "poor communication by others" is conveniently documented at Mann’s website for MBH98 and MBH99, he lists various press clippings. Not all the links still work, but some do. Contemporary examples of poor communications victimizing MBH include:

USA Today is one example of "poor communication by others", saying:

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.

And, of course, the CBC:

Researchers at the University of Massachusetts say the 1990s were the warmest decade of the millennium, and 1998 was the warmest year of the decade.

I’m sure that MBH took every conceivable step to try to redress these "poor communications by others" and were frustrated when their efforts to ensure uncertainties were emphasized by these publications were rebuffed.

The victimization was not just in the press, but even their own colleagues victimized poor MBH. At CRU, Phil Jones – and I’m sure they felt certain that they could rely on Phil – let them down by saying atthe CRU website:

Analyses of over 400 proxy climate series (from trees, corals, ice cores and historical records) show that the 1990s is the warmest decade of the millennium and the 20th century the warmest century.

No wonder they feel let down. But one of the worst offenders in victimizing poor MBH was the University of Massachusetts press office, which issued news releases for both MBH98 and MBH99, ( obviously over the vehement protests of Mann et al), claiming that "advanced statistical techniques" were used. The MBH98 news release stated:

Climatologists at the University of Massachusetts have reconstructed the global temperature over the past 600 years, determining that three recent years, 1997, 1995, and 1990, were the warmest years since at least AD 1400. …

The researchers were able to estimate temperatures over more than half the surface of the globe, pinpointing average yearly temperatures in the northern hemisphere to within a fraction of a degree, going back to AD 1400. The study places in a new context long-standing controversy over the relative roles of human and natural changes in the climate of past centuries, according to Mann….

Advanced statistical techniques were used to translate the proxy information into surface temperature patterns, so that past centuries could be compared with the 20th century.

The MBH99 news release stated:

1998 Was Warmest Year of Millennium, UMass Amherst Climate Researchers Report
March 3, 1999

AMHERST, Mass. – 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. …

Using proxy information gathered by scientists around the world during the past few decades, the team used sophisticated computer analysis and statistics to reconstruct yearly temperatures and their statistical uncertainties, going back to the year AD 1000…

FAQ for MBH99 can be retrieved from the Wayback Machine here.

How frustrating it must have been for Mann et al do be so frequently victimized by "poor communications by others" – even by their own university press office – with themselves helpless to do anything about it. It must have taken great personal fortitude and courage to survive such adversity.


  1. Ian Castles
    Posted Aug 10, 2006 at 6:40 PM | Permalink | Reply

    Another source of poor communication was the American Geophysical Union, which issued a news release on 3 March 1999 in identical terms to that of UMass Amherst. The AGU release provided contact details for each of the three researchers and referred journalists to a press kit and to the Q&A document. The University of Arizona was also involved in the poor communication by others: it issued a release in identical terms to the AGU and UMass releases on 5 March 1999.

    The news releases from the AGU and the two universities refer to a reconstruction of “GLOBAL surface temperature records going back 600 years” (CAPITALS added). They do not mention the title of GRL article, and do not even mention that the results of the study relate only to the Northern Hemisphere. On the contrary, the specific references to “tree rings from … Tasmania [and] Argentina” give a contrary impression.

    Attention should also be drawn to a report in “Science News”, March 20, 1999, headed “1998: Warmest Year of the Millennium”. The last two paragraphs of this report reads as follows:

    [Extract from "Science News" begins]
    Although there are large uncertainties in the temperature estimates for the earliest part of the record, the current warmth is unprecedented, says Mann. “The numbers for 1998 are so unusual. They push it up to the ballpark of 99 percent certainty that 1998 is the warmest year in the reconstruction,” says Mann. It’s also very lkely that the 1990s are the warmest decade of this millennium, he adds.

    Such strong statements, however, get a cool reception from tree-ring researcher Gordon Jacoby of Lamont-Doherty Earth Observatory in Palisades, N.Y. “There’s so much uncertainty in the chronology,”:says Jacoby. He calls the study “a good first effort, but there’s a lot more work to be done.”
    [Extract from ":Science News" ends. All quotation marks are in the original]

    The report is signed “R.M.” It was presumably open to Dr. Mann to ascertain the identity of R.M. and protest about the poor communication of the science in “Science News”.

  2. Ken Fritsch
    Posted Aug 10, 2006 at 6:48 PM | Permalink | Reply

    Was not Mann involved in the writing of the executive summary the year that the Hockey Stick was prominently displayed in an IPCC report? Were his uncertainties and reservations clearly displayed in that report or was the poor man misunderstood in that instance also?

  3. Pat Frank
    Posted Aug 10, 2006 at 7:03 PM | Permalink | Reply

    Sounds to me like a follow-up letter of sympathy to Nature is warranted.

  4. Barclay E. MacDonald
    Posted Aug 10, 2006 at 7:11 PM | Permalink | Reply

    But isn’t the real point, “expanded uncertainties prevent decisive conclusions for the period prior to AD 1400″, and therefore the MWP doesn’t exist or can’t be shown to exist, and moreover, I will not point out concerns raised by others regarding the period following 1400, because then in the eyes of the general public my HS survives.

  5. Ken Fritsch
    Posted Aug 10, 2006 at 7:51 PM | Permalink | Reply

    re: #4

    “expanded uncertainties prevent decisive conclusions for the period prior to AD 1400″

    Actually, if you look at the reputed 2 standard error limits for the HS, the uncertainties are nearly the same and huge up AD 1600 (that is probably why NAS rather begrudgingly limited their coldest decade to the last 400 years).

  6. Steve McIntyre
    Posted Aug 10, 2006 at 8:12 PM | Permalink | Reply

    #2. He said that he was not involved in writing the SPM, but was lead author of a chapter in which he was again victimized by the IPCC claim that the MBH model had statistical skill in cross-validation statistics. I feel confident that he protested against this incorrect language, but was over-ruled by his colleagues who inserted the phrase over his vehement protests,

  7. MarkR
    Posted Aug 10, 2006 at 8:40 PM | Permalink | Reply

    Perhaps they should change the name of their website to “Really Uncertain Climate, (but on the other hand we’re 99% sure, depends who we’re talking to)”


  8. JMS
    Posted Aug 10, 2006 at 9:39 PM | Permalink | Reply

    As I pointed out in a previous post — so long ago that I don’t remember the thread — MBH99 acknowledged almost all of the points you have made here (except for the statistical errors, which seem to be immaterial given the dataset).

    Steve M, you have made some points about the uncertainties of tree ring data, but I seriously doubt that the tree ring people are as ignorant of them as you seem to imply. Although you read a lot of papers, you never seem to cite textbooks, which probably means that you are not as well versed in these issues as you wish the acolytes on this site to think you are. Yes there are a lot of problems, that is why chronologies from trees at the limits of their ecological range are chosen — they are more likely to show climate (whether rainfall or temperature) as a signal, rather than competition with neighboring trees of similar or different species as a limiting factor. Many of the factors cited by the acolytes on this site (fires, instects, disease) show up in the rings — this may be one of the criteria for sorting out your mysterious “linear” and “non-linear” individuals, however, I haven’t read any texts on dendrochronology so I will admit that I don’t know how this distinction is made…

    The only thing I buy from you is the divergence problem, what causes it? As far as the Hannibal thing that people have been mentioning read this. This seems to imply that Hannibal went over one Alpine pass, the lowest he could have chosen. Oh, and it snowed while he was up there…

  9. Posted Aug 10, 2006 at 9:56 PM | Permalink | Reply

    Wasn’t Mann also forced to assert before the NAS committee that his estimates of uncertainty of knowledge of the temperature of the MWP was half of what everyone else in the room thought?

  10. JMS
    Posted Aug 10, 2006 at 10:07 PM | Permalink | Reply

    That’s his opinion.

  11. mark
    Posted Aug 10, 2006 at 10:38 PM | Permalink | Reply

    except for the statistical errors, which seem to be immaterial given the dataset

    Garbage into a garbage processor and you get… garbage out. The dataset is bad enough, the problems lie in the statistics, which are even worse. MBH99 acknowledged none of this. Had it, someone might have taken notice of how bad the data is as well and none of this whining would have ever occurred.

    Although you read a lot of papers, you never seem to cite textbooks, which probably means that you are not as well versed in these issues as you wish the acolytes on this site to think you are.

    OH.MY.GARAGE. You’ve single-handedly uncovered the dirty little secret of what it takes to be smart. Textbooks. Well, I DO read a lot of textbooks, as does Jean S., and I’m certain Dr. McKitrick does as well as Steve McIntyre. Guess what, they say the same things Steve has been posting on for over a year (and, believe it or not, publishing on as well). Would you like to know some of the citations we would use?


  12. fFreddy
    Posted Aug 11, 2006 at 1:08 AM | Permalink | Reply

    Re #8, JMS

    (except for the statistical errors, which seem to be immaterial given the dataset)

    How is the complete failure of the cross-validation R2 statistic “immaterial”, whatever the dataset ?

  13. The Knowing One
    Posted Aug 11, 2006 at 1:39 AM | Permalink | Reply

    Re #8, by JMS. The standard text on dendroclimatology is Tree Rings and Climate (by Fritts H.C.). It was published in 1976. There is also an edited book published in 1982: Climate From Tree Rings (by Hughes M.K., Kelly P.M., Pilcher J.R., and LaMarche V.C. Jr.).

    The only other books are edited volumes that contain chapters on dendroclimatology. See especially Methods of Dendrochronology (by Cook E.R. and Kairiukstis L.A.) in 1990 and Tree Rings and Environment (by Schweingruber F.H.) in 1996. (The latter contains no original dendroclimatological research.)

    Really, that’s about it. You can check at Classic References in Dendrochronology.

    Moreover, in general I would think that someone was almost always better off reading, and citing, the peer-reviewed literature.

  14. UC
    Posted Aug 11, 2006 at 3:26 AM | Permalink | Reply

    There are claims of great accuracy.. Criticisms are met by ad hoc excuses.. One more, and then bingo .

    A bit OT: can anyone explain me this sentence of MBH99?

    Spurious increases in variance back in time associated with decreasing sample sizes [see e.g. Jones et al, 1998] are not an issue with this series, owing to the high degree of replication in the underlying chronologies back to AD 1000.

  15. fFreddy
    Posted Aug 11, 2006 at 3:55 AM | Permalink | Reply

    Re #14, UC
    Mann is a post-modernist with a HumptyDumpty-like tendency to redefine standard mathematical terminology to mean whatever he wants it to mean.
    A Mannian “spurious” works out as something like “a serious mathematical problem which I choose to ignore”.

  16. jae
    Posted Aug 11, 2006 at 6:11 AM | Permalink | Reply

    Mann and the Team have also worked real hard over at RC to explain all the uncertainity in their work. LOL.

  17. Louis Hissink
    Posted Aug 11, 2006 at 6:57 AM | Permalink | Reply


    probably mission impossible, but have you thought of summarising everything to date and interpreting it?



  18. Posted Aug 11, 2006 at 7:07 AM | Permalink | Reply

    This is just another example of how the activist-scientists play the media. It’s always easy to blame the media for misreporting scientific issues, but when one examines the issue more closely, one finds that it is most often the scientists themselves who distort the message from their own publications.

    In a scientific paper, one has to be cautious to back the conclusions with solid evidence, and in any case state the error margins clearly, and not overstate the significance of the results. This is what you find in most climate-related papers (except perhaps James Hansen’s papers, but that’s another story). MBH99, with all its flaws, nevertheless seems to have followed these rules.

    But when the same scientist speaks outside of the so-called “peer-reviewed” literature, none of those rules apply (that, of course, includes blogs!). The science reporters who cannot be well versed in the technical details of every topic they cover will tend to trust the same researcher who has written the paper, and will rely on a verbal interview for their article. The scientist can then go well beyond what’s actually published, and express his/her opinions, but those pass as scientific evidence as well. And in climate science, those opinions are more often than not ideologically biased, not to mention the fact that expressing scary comments about future climate makes sure that you’ll get even more interviews in the future!

    Here’s another example reported by Penny Peiser today. A paper just came out in Science showing how snow fall in Antarctica hasn’t really varied over the past 50 years. This goes against what every climate model is predicting. The actual conclusion should be: the models get it wrong and we should figure out why before concluding anything else. But what does the author say in an interview? He “says the recent evidence supports the idea, not recognised in climate models, that there is a lag between global warming and Antarctica’s response to it.” Furthermore, “”If we were to rewrite this paper in say 10 years time the likelihood is that we will be actually be writing a paper that says ‘significant change in Antarctic snowfall over the last 10 to 15 years’,” says Goodwin.”

    In other words, the models get it wrong, we don’t really know why, but we are certain that things will get worse! Can that conclusion be trusted? Of course not, it’s just a hypothesis at this point. It wouldn’t pass any kind of peer review unless it’s accompanied by some kind of evidence. But to express it in a newspaper is OK.

    The NAS report is another example. By including, in its summary, the statement that the conclusions about the 90′s being the warmest decade was “plausible”, without the bulk of the report backing it in any way, the authors of the report knew full well that this could be transformed by the media into “likely”, and, why not, “quite certain”. That’s of course exactly what happened. Was it intentional from the NAS authors? You bet!

    This has become so typical of climate science it’s really annoying. If Mann’s 1999 reconstruction was so uncertain, why publish it in the first place? Had I been the reviewer, I would have sent the authors back to the lab: come back when you’ve got significant results!

  19. beng
    Posted Aug 11, 2006 at 7:19 AM | Permalink | Reply

    RE 8: JMS writes:

    Yes there are a lot of problems, that is why chronologies from trees at the limits of their ecological range are chosen “¢’‚¬? they are more likely to show climate (whether rainfall or temperature) as a signal, rather than competition with neighboring trees of similar or different species as a limiting factor.

    Sounds good. So why were Bristlecones on sites that obviously are arid & precip likely to be the major limit (or even CO2 because of the altitude), elevated by the Mannomatic method to the status of a global thermometer?

  20. Paul Penrose
    Posted Aug 11, 2006 at 7:42 AM | Permalink | Reply

    Mann likes to point out that they use the word “uncertainties” in the title of their paper, but what he does not mention is that there is almost no discussion in the paper itself on the various sources of error and uncertainty in using proxies in temperature reconstructions. In fact they even managed to botch the calculation of the confidence intervals and didn’t even bother to consult a statistician on their novel statistical methods to make sure they were valid. If the point of their paper, as Mann asserts, was to access the quantitative uncertianties of these types of reconstructions, then they failed utterly.

  21. L Nettles
    Posted Aug 11, 2006 at 7:59 AM | Permalink | Reply


    Although you read a lot of papers, you never seem to cite textbooks, which probably means that you are not as well versed in these issues as you wish the acolytes on this site to think you are.

    This post could be flaged for piling on, but in my opinion despite much competition the quote from #8 may be the stupidist thing ever posted on this site.

    You may not agree with Thomas Sowell’s politics but he articulates the point well link

  22. Dave Dardinger
    Posted Aug 11, 2006 at 8:03 AM | Permalink | Reply


    Ah, you beat me to the punch! I was just looking for a good thread to post a link to the same series of articles. Here’s the final paragraph of the third (last?) article in the series up today:

    Even when the taxpayers’ money is used to collect data or finance research, those who dispense that money and control that data often treat these things as if they were their own private property, to be used to promote research congenial to their own ideologies or interests.

  23. bender
    Posted Aug 11, 2006 at 8:10 AM | Permalink | Reply

    Re #8
    I personally am very impressed by the level of discussion on the CA blog on the matter of tree ring reconstructions. Steve M’s analysis and insight are on par with that of many of the world’s experts.

    You misunderstand the nature of the criticism probably because you haven’t looked at the more challenging quantitative aspects of the problem. You are entirely correct that dendrochronologists choose trees from sites that they believe to be at the limit of the tree’s tolerance levels. The problem is that temperatures, treelines, and other physical conditions surrounding that tree change. They are not static, and this undermines the tree-ringers’ “unformitarian principle”. (If you want to read about this in a textbook, get Cook & Kairiukstsis (1990), which I’ve cited in previous posts.) What that means is that the sensitivity coefficient is not a single parameter, it is a dynamic variable. That makes it very much harder to estimate.

    Response function analysis (the step that allows you to confirm that what you think is the limiting factor actually is the limiting) is also problematic for reasons I’ve described earlier (multiple hypothesis tests where confidence levels are not adjusted using a Boferroni correction factor). Why is this not described in the literature? (1) Because it’s understood by tree-ringers (but not the multi-proxy recosntructionisists) that response function analysis is exploratory analysis, not a priori hypothesis testing. (2) because it’s methodological; there’s no story to sell. (“Newsflash: Error erodes confidence in hypothesis test”)

    Given these problems, JMS, think what it means to reconstruct past temperatures knowing that the correlation between temperature and ring width in the calibration period is on the order of 0.3-0.5. I’m not sure if you’re experienced with time-series and statistics, but that’s very, very low.

    JMS, what happens when you take an already sketchy calibration based on a fixed x,y data range and extrapolate outside the x,y range? You know what happens. You don’t need a PhD dendrochronologist to tell you that the degree of confidence in that extrapolation drops.

    Add into that the other problems that dendroclimatologists prefer to dismiss (fire, insects, disease, survivorship bias) rather than disprove, and you have a pretty shaky foundation.

    All this, JMS, is fairly well-recognized many, but not all, tree-ringers. It is the major reason that multi-proxies were seen as the answer. But Steve M’s point is that there are, or may be, problems with each of the proxies.

    Now look at the ensemble. Look at what you have here. If the tree-ringers have only 30% confidence in their reconstructions, but are confident the ice-core people know what they’re doing; if the ice-core people have 50% confidence in their reconstructions, but are confident the bore-hole people know what they’re doing …

    I’m not saying these people are incompetent or dishonest. Not at all. I’m saying that multi-proxy studies, by their very interdisciplinary nature, are on shaky ground. This is exactly the sort of situation where you want an auditing process.

  24. bender
    Posted Aug 11, 2006 at 8:18 AM | Permalink | Reply

    Re #20:

    In fact they [MBH] even managed to botch the calculation of the confidence intervals and didn’t even bother to consult a statistician on their novel statistical methods to make sure they were valid.

    Honestly, people, they are just NOT INTERESTED in showing you the real uncertainty on these multi-proxy reconstructions. Of course they botched the calculation; they don’t take the subject seriously. How do I know? Because it is obvious that MBH99 was an encouraged follow-up to MBH98, most likely a direct invitation by the Editors of Nature! Uncertainty is NOT their expertise. They do NOT find it intellectually stimulating. It does NOT serve their agenda.

    Scientifically estimated statistically robust confidence intervals – that’s the lynchpin. and they bloody well know it.

  25. Steve McIntyre
    Posted Aug 11, 2006 at 9:28 AM | Permalink | Reply

    #9. David, I wouldn’t say that Mann was “forced” to say that. Cuffey asked all the other panelists whether anyone knew the temperature 1000 years ago to within half a degree. Everyone else said no. Mann said that he knew it within a couple of tenths.

  26. jae
    Posted Aug 11, 2006 at 9:34 AM | Permalink | Reply

    23, Bender: great post!

  27. Steve McIntyre
    Posted Aug 11, 2006 at 9:42 AM | Permalink | Reply

    #23. bender, the average correlation between temperature and ring width in the MBH98 North American network – the soure of all the trouble – is much less than 0.3 – it’s approximately 0, although many sites have a correlation in the range of 0.3-0.4 to precipitation and some have a correlation in the range of 0.5-0.7 to carbon dioxide (bristlecones). See the little diagram in our Reply to Von Storch.

  28. bender
    Posted Aug 11, 2006 at 9:50 AM | Permalink | Reply

    Steve M.,
    You are 100% correct. Whether we’re talking bristlecone pines or cedars, the correlations are very low. I was being VERY generous with my numbers so as not to irk my colleagues.

  29. bender
    Posted Aug 11, 2006 at 9:57 AM | Permalink | Reply

    I’ll tell you this too, Steve M, there are many scientists who approve of the audit, but are not willing to say so on record for fear of reprisal. Yes, dear reader, the debate is that heavily politicized.

  30. fFreddy
    Posted Aug 11, 2006 at 10:01 AM | Permalink | Reply

    Re #29, bender
    Given your clear expertise in an unusual combination of fields, I’ve been getting very curious as to what your background might be …

  31. bender
    Posted Aug 11, 2006 at 10:06 AM | Permalink | Reply

    Never mind credentials, look at the content of the posts, look at the bare facts.

  32. fFreddy
    Posted Aug 11, 2006 at 10:49 AM | Permalink | Reply

    Re #31
    Oh, absolutely. Not what I meant, but no problem.

  33. KevinUK
    Posted Aug 11, 2006 at 11:19 AM | Permalink | Reply

    #30 fFreddy

    People are entitled to anonymity if they choose it on the internet. Many choose not to post anonymous which can be a risky, perhaps even foolish thing to do particularly if they work ina given field and you are openly criticising that field and your work colleagues happen come across your posts on the internet. I have no problem with that, but others might so please respect their choice to remain anonymous.

    As bender points out is often very easy to work out whether certain posters have ‘credentials’ or not by the content of what they post particularly when you read their posts over a period of time on a variety of diffeent threads. This of course assumes that ‘credentials’ i.e. appeals to authority actually matter in this regard. Just look at Hansen and Mann in this regard. Both of them are full of credentials but do you for one minute, now that the ‘emperor’s clothes’ have all but disappeared, believe that they are credible any longer?

    JMS, am I carrying a (pre-Vatican II) candle for Steve M? Well no as I’m a respectfully married man with five kids. Do I support Steve M in what he is doing? Yes I do because as is the case with alot of people who visit this blog, we want to know the quality of the science that underpins this claimed AGW debate (OK, I’ve already read enough, found the science sadly lacking and have concluded that it is a myth for reasons I’ve already posted). Surely you are also interested in seeing the full rigor of the scientific method being applied to the ‘evidence’ that underpins AGW, the Kyoto protocol, carbon trading etc etc? That is exactly what is happening here on this blog.


  34. Richard deSousa
    Posted Aug 11, 2006 at 11:47 AM | Permalink | Reply

    Speaking of untruths, the bottom line is Al “I invented the Internet” Gore has a huge audience with his utterly stinkeroo of a movie “An Inconvenient Truth.” A (movie) picture is worth a thousand words and once these lying words get into peoples minds it difficult to dislodge!

  35. KevinUK
    Posted Aug 11, 2006 at 12:13 PM | Permalink | Reply


    Then who’s up for funding an alternative movie called ‘A Convenient Truth’ co-starring The ‘Two Macs’, Richard Lindzen, Fred Singer, Wille Soon, Sally Baliunas etc etc? Steve M, who would you like to play your part?

    And by the way Lee, PH etc Exxon (or Al Gore’s Oxy Petroleum) is not a valid reply as unlike Gore’s movie this will be an independently funded production.


  36. ET SidViscous
    Posted Aug 11, 2006 at 12:31 PM | Permalink | Reply

    Actually some Canadians did a decent one. Liindzen and such were interviewed. Was about an hour long if I recall. Wasn’t as polished as I assume The Penguin’s was, but was very informative.

    I’ll have to try and find it. I quite liked it.

  37. JMS
    Posted Aug 11, 2006 at 12:50 PM | Permalink | Reply

    I guess I did not make my criticism clear: Steve (and many others on this site) are basically saying that people working in dendro are all incompetent because they don’t take the confounding factors into account. I think that they do, to the best of their ability and that doing a little bit of reading to come up to an undergrad level of competency might reveal that many of the obvious confounding factors are taken into account — it’s the subtle ones which give problems.

  38. Barclay E. MacDonald
    Posted Aug 11, 2006 at 12:52 PM | Permalink | Reply

    It’s truly a pleasure and reassuring to my ultimate confidence in science to read this thread. Nice posts!

  39. UC
    Posted Aug 11, 2006 at 12:57 PM | Permalink | Reply

    #8:Maybe they acknowledged the problems, but why it doesn’t show up in the error error limits?

    #15: I agree. Rules for the distribution of the sample mean can be dodged by saying that they are not an issue here. And it can be emphasized by referring to Jones.

  40. jae
    Posted Aug 11, 2006 at 1:00 PM | Permalink | Reply

    37: It looks to me like they are certainly incompetent WRT statistics! Also, the use of bristlecones and other series that are known to NOT be temperature related certainly casts suspicion on their honesty, if not their competence. Plus refusal to share code and data. Plus no real discussion on just how they can identify a temperature signal in tree rings. Plus, they will not defend their work on this blog. Give me a break, JMS!

  41. ET SidViscous
    Posted Aug 11, 2006 at 1:00 PM | Permalink | Reply

    Found it.

    I thought it was longer, but [shrug] Could be useful for raising funds for a more flash movie.


    You think that they do, then can you please explain how they account for the upside down quadratic that is a representation of tree rings to temperature. i.e. that at high temperatures growth is retarded. Please explain how on this upside down quadratic they can place trees without having other information such as rainfall, local CO2 etc.

    Better info describing this can be found here: It gets into other issues, mainly survivorship. But the base curve that looks like a bell describes the relationship from tree rings to temperature. If it is not linear, how can applying a linear relationship to tree rings/temperature be taken into account. It’s not just a matter of Have they taken confounding factors into account, but Can they take confounding factors into account.

  42. KevinUK
    Posted Aug 11, 2006 at 1:03 PM | Permalink | Reply

    Just had some thoughts on the opening sequence for ‘A Convenient Truth’.

    I was thinking of something along the same lines as the opening sequence in Stars wars where the text come on at the bottom of the screen and recedes into the distance. The words could begin something along the lines of:

    “It is the 1970s and the Climate Model Empire have struggled with developing their models to predict why the earth warms up and cools down during inter-glacial periods. Some models have been predicting an impending ice age and there is much concern over anthropogenic global cooling (AGC). A decade has passed and the dire predictions have not come true – the Climte Model Empire may be wrong – that cannot be. Indeed the instrumented global temperatures are showing an upward trend and the Climate Model Empire are feeling pretty dis-illusioned. Fear not, as a saviour is at hand who understands the error of the Climate Model Empire ways and is 99% certain that the the solution is simple. We have the wrong feedback mechanisms in the models. We must claim that previous cooling was due to sulphate aerosols (which have been masking the underlying long term warming trend) and that recently observed warming is down to the evil Fossil Fuel Empire. To re-inforce this, we must change the feedback effects so that they are positive and involve the evil gas CO2 so that we can defeat the evil Fossil Fuel Empire. We must invent new statistical methods so that we can show that the warming is unprecedented. We must search and cherry pick the proxies so that we can remove any periods in the past when temperatures might have been as warm as before the start of the evil Fossil Fuel Empire. We must write computer programs (in an ancient computer language) least any Canadians should wish to try and independently review our reconstructions and if they do we must claim IPR so that the source code cannot be released…..”

    This should be enough to summarise the ‘Convenient Truth’ and still be able to scroll into the screen reasonably quickly at the start. What do you think?


  43. fFreddy
    Posted Aug 11, 2006 at 1:13 PM | Permalink | Reply

    Re #31 bender (and Kevin in 33)
    Eek. My #31 was meant only as a friendly nudge, from someone with an inquisitive nature. I’m not sure where the credentials bit came from – I am temperamentally disinclined to trust them at the best of times, and certainly in anything to do with climatology.
    More to the point, I explicitly referred to bender’s “clear expertise”. I also entirely agree with anyone’s right to privacy – after all, I too am using an alias.
    Most to the point, if I have offended you bender, please accept my unreserved apologies.

  44. KevinUK
    Posted Aug 11, 2006 at 1:15 PM | Permalink | Reply

    #41 Sid

    I’ve watched those video sequences and forgot the link so thanks for the reminder. I was think more along the lines of a parody/homage to the climate modellers/paleoclimatologists as the serious stuff has already been done by Big Al.


  45. Jonathan Schafer
    Posted Aug 11, 2006 at 1:17 PM | Permalink | Reply

    Related to the use of statistics and studies, I read this opinion piece today, written by Dr. Thomas Sowell. Not directly related to global warming, MBH, or anything else, but an interesting read none the less..

    Often we hear that “all the experts agree” that A is better than B or that “studies prove” A to be better than B. But one of the reasons for this can be that only people who favor A over B are likely to get the money to conduct studies or be given access to the data needed for a study.

    A few years ago, a book by William Bowen and Derek Bok paraded various statistics that they interpreted as proving the success of policies of preferential admission of blacks to colleges and universities.

    A chorus of praise for this study was heard throughout the media and echoed in academia and among liberal politicians. The study was later cited in a landmark Supreme Court decision on affirmative action.

    Not everyone thought this was a great study, however — or even an adequate study. But no one was allowed access to the raw data on which the Bowen and Bok study was based. So no one else could run the numbers for themselves and reach their own conclusions.

    Those who sought such data included Harvard professor Stephen Thernstrom, whose long and distinguished record of scholarship included being one of the creators of the Harvard Encyclopedia of American Ethnic Groups. He was refused access to the data.

    When only people with one set of views are allowed to do certain studies, do not be surprised if “studies prove” that set of views is right.

    Sound familiar to anyone?

  46. ET SidViscous
    Posted Aug 11, 2006 at 1:19 PM | Permalink | Reply

    Oh if it’s parody your looking for.

  47. KevinUK
    Posted Aug 11, 2006 at 1:37 PM | Permalink | Reply


    Do you know anyone who works for DCI Group? If you do then tell them from me, I like their work!

    Now is there also a hidden meaning in that video about people who use a certain open-source operating system? Where the real DCI clients a company who sell a non-open source operating system?


  48. ET SidViscous
    Posted Aug 11, 2006 at 1:51 PM | Permalink | Reply

    Me? I don’t know anyone there, never heard of them.

    I just like the image of Gore as the Penguin going Wanh wanh wanh. I’ll think of it every time I see him.

  49. John Hekman
    Posted Aug 11, 2006 at 2:16 PM | Permalink | Reply

    In an interview, Gore was asked:

    “There’s a lot of debate right now over the best way to communicate about global warming and get people motivated. Do you scare people or give them hope? What’s the right mix?”

    He answered:

    “I think the answer to that depends on where your audience’s head is. In the United States of America, unfortunately we still live in a bubble of unreality. And the Category 5 denial is an enormous obstacle to any discussion of solutions. Nobody is interested in solutions if they don’t think there’s a problem. Given that starting point, I believe it is appropriate to have an over-representation of factual presentations on how dangerous it is, as a predicate for opening up the audience to listen to what the solutions are, and how hopeful it is that we are going to solve this crisis.”

    There are many ironies in politics. It’s tiresome to hear over and over “isn’t it ironic that so-and-so said this given…” And so it is tiresome to hear myself say this: Al Gore, who accused the President of the United States of “betraying” the American people by misleading us [i.e. lying us] into Iraq, says with no trace of irony that it’s OK for him to lie about global warming, because people are in “denial.”

  50. jae
    Posted Aug 11, 2006 at 2:20 PM | Permalink | Reply

    Yup, one of the Democrat’s guiding principles is that the end justifies the means (some Republicans, too, of course).

  51. bruce
    Posted Aug 11, 2006 at 2:24 PM | Permalink | Reply

    Re #49: What is really amazing is that now Gore, like Stephen Schneider, acknowledges that it is OK to lie about the issues since the problem is so serious that they MUST do that to mobilise opinion to get things changed. The end justifies the means. So now we have the public spectacle of Mann et al being caught out effectively lying, Stephen Schneider acknowledging that it is OK to lie if the intentions are good, and now Al Gore!

    These guys are destroying their own credibility without any help from any of us.

  52. Ken Fritsch
    Posted Aug 11, 2006 at 4:37 PM | Permalink | Reply

    If the BCP issue becomes uncomfortable for Mann (and others), will his near perfect record on an avoidance of performing a mea culpa require him to note that the censored file showing the reconstruction without them was planted where he knew a sharp eyed critic would find it or might he suggest that a graduate student helper forgot to include it in the final write ups? There must be any number of alternative ways the poor man’s intentions about it were misconstrued because he just does not make mistakes.

    Seriously though, I must say that while I see Mann guided by an ego as big as all outdoors, I have less blame to place on him than I do on those who are in positions to evaluate his work.

    The little word games that some authors involved in climatology play when describing their conclusions and what the media does with that is more or less a given in today’s political climate, but still a discerning look at these articles and the reviews of them (with the help of Steve M’s blogging) can provide much insight into the state of the art.

  53. KevinUK
    Posted Aug 11, 2006 at 4:48 PM | Permalink | Reply

    #46 Sid

    After following you link to YouTube, I spotted some other video clips on Global warming and came across this one.


    which shows the reverred (in the UK at least) Sir David Attenborough explaining the climate change graph. On the basis of the explanation of how well the climate models (from the Hadley Centre) agree with the measurements he is now personally convinced of the existence of AGW. The explanation of the model fit to measurement is given by none other then Peter Cox, the man who has now linked in the carbon cycle with the Hadley A and O CGMs and is predicting (wait for it, surpise, surprise) a further positive feedback effect of CO2 from the ecosystem tipping from an absorber of CO2 to an emitter. The net effect of this new wonderful positve feedback mechanism is that the model predicts that Amazon rainforest will dry-out by 2050 and global mean surface temperature will increase by 10C by 2100.

    Here is a link were he is discussing ‘the science’ (NOT!!!!) of all this on the Climate Outreach &
    Information Network climate radio web site at



  54. jae
    Posted Aug 11, 2006 at 5:05 PM | Permalink | Reply

    KevinUK: these “scientists” have been exaggerating so much that even much of the public is beginning to see them as clowns. A large chunk of the US public already sees Gore as a clown (a deranged one, at that). It is no wonder that AGW is far down on the average person’s list of concerns, despite all this hype. It is becoming very common to hear someone say sarcastically, in connection with some disaster (even things unrelated to weather), “its due to that damn global warming.” And they say it with a laugh. The problem, of course, is that many of the climatologists are damaging the image of all scientists in the public’s eye. The average Joe/Jane is not as stupid as some think he/she is.

  55. jae
    Posted Aug 11, 2006 at 5:15 PM | Permalink | Reply

    I watched as much of the YouTube link as my stomach would stand. Attenborough comes across to me as one of the clowns.

  56. jae
    Posted Aug 11, 2006 at 5:41 PM | Permalink | Reply

    Here’s a new phrase: “climate porn.”

  57. ET SidViscous
    Posted Aug 11, 2006 at 8:18 PM | Permalink | Reply

    “which shows the reverred (in the UK at least) Sir David Attenborough explaining the climate change graph. On the basis of the explanation of how well the climate models ”

    I realize that they are trying to present this to the masses in an easily digestable version.

    But Sir David should take the director of that bit and feed him into a woodchipper. He already has a bit of dynamic talking with his hands kind of way about him, not a criticisim, nothing wrong with it.

    But then the director shoots him from slightly below magnifying such movements. Then uses a long lens, giving a false curvature to the image further magnifying such effects. Then uses a hand held camera instead of a stabilized one inserting more movement.

    During the introduction I was worried the poor man was having a siezure, if it wasn’t for the fact his elecution was fine I would have expected an ambulance to pull up.

    One of those cases where I think they are their own worse enemies. MTV camera work doesn’t work with everyone (meaning the person being filmed), and definitely didn’t work here. It doesn’t matter to the already converted, who just watching it nodding there head. “yes!, yes!, that’s right! yup!, wes!” For someone else lokking to see the information it is a poor presentation (keep in mind I’m not talking about the content, I’m talking about the presentation.).

    Fine by me.

    On another note. The wamrer crowd here was very recently talking about the heat wave of a week or so ago, and implied its evidence towards global warming.

    Well Last night I had to close all my windows and put on a sweater. Tonight, with no AC or fan running, it is 61 outside, and 66 inside. Bit chilly for August if I do say so myself. Glad the heater in my truck works. I think the high today was 74

    We have plans this winter to post sentires on fire towers to look for swiftly approaching glaciers.

  58. Posted Aug 11, 2006 at 8:22 PM | Permalink | Reply

    It occured to me that I too was guilty of relying too much on papers and not enough on text books. So I went to my bookcase and pulled down my copy of Terrestrial Ecosystems (Aber and Mellilo 2001).

    I find in Figure E.1 on page 533 a graph that shows human population and carbon dioxide in the atmoshere plotted from 1750 to 2000. Both have almost the same curve. Its quite drammatic. I got the point.

    Then I looked at the scale. The human population scale starts at zero but the carbon scale starts at 270 ppm. This is one I haven’t seen in a while. Not since I read How to Lie With Statistics in high school. In that classic book this technique was called the Truncated Bar Chart. If you restrict the vertical range relative magnitudes are distorted, or in this case the rate of change is manipulated to exactly mirror the population increase. Population grew nearly 600% while carbon increased a little more than 25%. They are plotted to look the same.

    This is the kind of math shenanigans that anyone can understand. I’m afraid my character is flawed. When I catch people trying to fool me like that, my mind closes just a little bit more. I know I should continue to listen to the eco-litany with an unprepared and receptive mind but there has been too just much deception. I’m on guard.

  59. JMS
    Posted Aug 11, 2006 at 9:22 PM | Permalink | Reply

    The problem is Pat that 270 is about right for a start of Holocene CO2 concentrations.

  60. bruce
    Posted Aug 11, 2006 at 9:36 PM | Permalink | Reply

    Re #59: Amazing isn’t it JMS! Just an itty bitty little bit of CO2 causing such havoc with the world climate. You realise, don’t you that 270 ppm is 0.027%, ie 2.7% of 1%, or one part in 3704 in the atmosphere. The increase to 380 pmm increases those numbers to 0.038%, 3.8% of 1%, or one part in 2613 in the atmosphere.

    Most people I ask haven’t got a clue how much CO2 is in the atmosphere. They give me numbers like 30%? 15%?

    Meanwhile the impact of the sun is considered minor. Go figure.

  61. Hans Erren
    Posted Aug 12, 2006 at 2:45 AM | Permalink | Reply

    bruce, it’s more complicated than your cartoonic summary suggests.
    It’s change in the sun and co2 that is the debate and sensitivity for these changes.
    The “itty bitty little bit” of CO2 is responsible for 18% absorption of the outgoing heat. So “most people” confuse absorption with concentration.

  62. Kevin
    Posted Aug 12, 2006 at 2:57 AM | Permalink | Reply

    Re #61: Climate sensitivity to CO2 is unknown, however, which is why it is an adjustable parameter in the GMCs. In fact if climate is a chaotic system, as admitted in TAR, it cannot be known.

  63. MarkR
    Posted Aug 12, 2006 at 4:22 AM | Permalink | Reply

    Re#61 The figure given of 18% implies the CO2 is between 473 and 666 times more absorbent to outgoing heat than other average atmospheric constituents.

    Is that really correct?

    CO2 molecules must get really hot!

  64. Louis Hissink
    Posted Aug 12, 2006 at 5:14 AM | Permalink | Reply

    Unless the assumptions are wrong.

    That minute changes in the chemical composition of air can affect such inferred physical changes.


  65. Steve McIntyre
    Posted Aug 12, 2006 at 5:45 AM | Permalink | Reply

    Some people have made some pretty silly comments above.

    If you look at the infrared spectra of the earth, the CO2 band is a distinctive and very important feature. TO say it’s just “itty bitty” is nonsense in the context of the earth’s radiation balance – it isn’t.

    In fact, the “itty bitty” argument totally backfires as it is expressed. If an “itty bitty” bit of CO2 can cause as much impact as it does, then doubling it can surely be expected to have a major impact.

    I trhink that there are some valid issues with the infrared calculations – but they pertain to the interaction of water vapor and CO2 and water vapor feedbacks, including clouds. I would urge people to cast the “itty bitty” argument firmly from their minds.

  66. ET SidViscous
    Posted Aug 12, 2006 at 11:23 AM | Permalink | Reply

    While at the same casting away the thought that the Sun has little effect, and that it’s output is constant.

  67. Steve McIntyre
    Posted Aug 12, 2006 at 11:59 AM | Permalink | Reply

    #66. Quite so. I’ll try to post up some notes on solar correlations next week.

  68. Posted Aug 12, 2006 at 3:00 PM | Permalink | Reply


    I would add that water vapor is the most important greenhouse gas. This is not “itty bitty”, it’s the truth. It’s water vapor that brings the earth temperature from the -18C to about 15C average temperature that we have. CO2 contributes but a fraction of it. That’s why doubling CO2 is thought to bring about only 1-2 deg.C of warming, without feedback. In itself, it’s far from catastrophic. We’ve gone through 0.6 deg.C of warming already over the last 150 years, and furthermore, we may not come to the point where CO2 is doubled. The alarmists assume all kinds of unproven feedback mechanisms to come to 4-11 deg.C warming. But that’s all based on models and models have, in my opinion, very weak points. I think all mainstream climatologists agree that clouds are poorly understood, and they can make a huge difference in the feedback mechanisms. But recently, there have been many instances where the models have failed to predict the observed behavior. There was the discovery in 2002 that the earth’s radiation budget showed annual to decadal variations that are much more important than what the models predict. I mentioned earlier the snowfalls in Antarctica. There was also a drop in the oceans temperature from 2003 to 2005 that is not accounted by any model (see Roger Pielke’s blog). And that’s not even mentioning the difference between surface and tropospheric warming. Given those shortfalls, how can we trust models to adequately represent unknown feedback mechanisms?

    What strikes me about the models is specifically that question of variability. They never seem to catch the actual amplitude of the climate dynamics. As a physicist, I would be much happier if the model would reproduce those variations, because they are the key to undertanding how the climate works. Just fitting the global temperature curve over the last 100 years is not enough. They get that simply by assuming a forcing that mimicks the curve in the first place. How they convince themselves that this is a great success is beyond me. But that can happen if you work with models for too long.

    Steve, about solar: there have been quite a few papers on correlations between the sun activity and climate in recent years. They’re very interesting, but I can’t make my own opinion on the statistics. I’ve recently figured out how the PC method works, but I don’t have much more time to dig into this. I can post a list of what I have if you want.

  69. Kevin
    Posted Aug 12, 2006 at 3:49 PM | Permalink | Reply

    Re #67: Having links to the raw data would be great too! Haven’t had much luck traking this down.

  70. Kevin
    Posted Aug 12, 2006 at 4:11 PM | Permalink | Reply

    Regarding what climate scientsts themselves believe about GW and the models, this link will take you to an actual survey, a profeesionally conducted survery of climate scientists:

  71. Hans Erren
    Posted Aug 12, 2006 at 4:23 PM | Permalink | Reply

    re 62:

    The Unknown
    As we know,
    There are known knowns.
    There are things we know we know.
    We also know
    There are known unknowns.
    That is to say
    We know there are some things
    We do not know.
    But there are also unknown unknowns,
    The ones we don’t know
    We don’t know.

    Donald Rumsfeld Feb. 12, 2002, Department of Defense news briefing

  72. Hans Erren
    Posted Aug 12, 2006 at 4:27 PM | Permalink | Reply

    re 66:

    hey it’s called the solar constant innit? :-D

  73. Posted Aug 12, 2006 at 4:36 PM | Permalink | Reply

    I regret that the “itty-bitty” argument was ever used (Crichton in “State of Fear” looked stupid for saying it). It is poor logic and is easy fodder for the hockey fans.

    However, two questions remain in my mind. 1) Is the causal link between CO2 levels and temperature clearly established, and, if so 2) are we looking at a linear relationship, or is there a point where additional CO2 doesn’t have as much impact? I admit I haven’t done much research on this, and would be interested if anyone would point me to relevant research / data.

    On a side note, Mann, at his presentation in Santa Cruz earlier this spring, stated that the cooling trend in the 50s – 70s was caused by an increase in the use of aerosols (overriding the warming properties of CO2). Is this a common position?

  74. Posted Aug 12, 2006 at 5:20 PM | Permalink | Reply

    An interesting paper on models and the different attitudes of modelers.

    More about the sun: the sun is fluctuating a little, and most likely has little effect by itself (although the UV part of the spectrum fluctuates more, and could have a larger effect). See a good review here. However, solar activity is directly related to cosmic ray flux (an active sun shields the earth from galactic cosmic rays), and cosmic rays MAY have a significant role in cloud formation (see this, and this, and this). The correlation is striking, even going back billions of years. We don’t have a good understanding of cloud formation, but there is a big project planned in Europe to use CERN’s facilities to study cloud formation in the lab and get a better understanding of it. In short, the high energy particles that hit microdust particles in the upper atmosphere tend to charge them electrically. This in turn attracts the water vapor molecules, and favors condensation, i.e. a cloud.

    Clouds have a very strong effect on the radiation budget of the earth, but it’s not clear how much, and what sign it has. A cloud will hide the sun, and thus have a cooling effect. At the same time it’s made of a greenhouse gas (water) and has a heating effect. The net effect is a balance between those two effects, but it’s probably different depending on the type of cloud, and their altitude. But the net forcing is easily larger than that of CO2. That’s why the solar effect (via cosmic rays) could turn out to be equal or larger than GHG over the past 50 years. The bottom line is we don’t know yet. A correct scientific attitude is: let’s figure it out. The warmer’s attitude is: I don’t want to hear about this!

  75. KevinUK
    Posted Aug 12, 2006 at 5:24 PM | Permalink | Reply

    #70 my namesake Kevin

    Thanks for the link but is that not one o fthe worst web sites you’ve ever visited. Uses frames so that you cant even see the bar charts and uses Javascript mouseover events on the links. Sorry but far too much ‘mysterious meat’.

    #73, Justin

    Well if we are to believe Peter Cox’s ‘Day of the Triffids’ model then eventually the ecosystem will stop absorbing CO2 and even start to emit it (see post #53 here.). Why the hell am I paying my taxes when they are getting spent on this complete and utter load of b*****ks!



  76. Hans Erren
    Posted Aug 12, 2006 at 5:26 PM | Permalink | Reply

    The simplified formula for CO2 forcing is:

    F= 5.3 ln(C/C0)

    so there is a logarithmic relationship, the forcing is constant for every doubling, the formula is tested for the range 300-1000 ppm.

    Myhre, G., E.J. Highwood, K. Shine and F. Stordal, 1998. New estimates of radiative forcing due to well mixed greenhouse gases. Geophys Res Letters 25 (14) 2715-2718

    The simplified formula for climate sensitivity is
    \Delta T_s / \Delta F = \lambda (6.1)

    The IPCC consensusus claims invariablity for lambda, but there are signs that is has different values for Co2 and solar forcing. My own idea is that lambda is even dependent on forcing frequency.

  77. Hans Erren
    Posted Aug 12, 2006 at 5:27 PM | Permalink | Reply

    does your latex renderer still work?

  78. Hans Erren
    Posted Aug 12, 2006 at 5:31 PM | Permalink | Reply

    \Delta T_s / \Delta F = \lambda (6.1)

  79. Kevin
    Posted Aug 12, 2006 at 5:35 PM | Permalink | Reply

    Re #75: Hey dude. It is awful and I don’t know why it was set up this way. (I believe there may have been some local IT issues beyond Bray’s control.) Nevertheless, the content is fascinating and enjoyed a near total media blackout in the U.S.

    Re #76: The solar forcing is an adjustable parameter in the models, though.

  80. Posted Aug 12, 2006 at 5:42 PM | Permalink | Reply


    The CO2-temperature link is only established because there is no other explanation. You can set a value for CO2 forcing in the models, add a negative forcing for aerosols, tweak their annual values and make the model temperature curve look a lot like the actual curve (a good example here). The aerosol hypothesis is just that: a hypothesis. There are no reliable values for aerosol concentrations and their actual forcing for the period concerned. On the other hand, solar activity clearly went down during that period. That’s one further argument for a stronger solar effect.

  81. Posted Aug 12, 2006 at 5:57 PM | Permalink | Reply

    #76 Hans, as I understand it, the forcing value is the one that makes the model best fit the observation. But that’s assuming a low value for other forcings, including solar. Solar is currently taken as less than 10% CO2. But if solar forcing is larger, then CO2 has to be smaller. The real question should be: how much of a better fit can you get with a larger solar forcing, and a correspondingly smaller CO2 forcing? This is also complicated by the fact that the solar correlation can change phase whenever a big volcanic event occurs, as was recently found out. The more we understand about the cosmic ray-cloud cover interaction, the more we should be able to assess the real value of the solar forcing.

  82. Kevin
    Posted Aug 12, 2006 at 6:27 PM | Permalink | Reply

    Re #79 (my own) Typo, I meant C02 forcing. Yikes.

  83. ET SidViscous
    Posted Aug 12, 2006 at 6:59 PM | Permalink | Reply



    Besides increasing Solar, and reducing CO2 I think you’ll get a better correlation if you add a third variable that increasing CO2 reduces the responce time to solar warming. i.e. Solar should be linear, and CO2 should be logarithmic, but Increasing CO2 will give Solar a more upturned slope rather than linear, somewhat the inverse of CO2, or close to Inverse.

    Sorry My math isn’t anywhere up to the level to describe what I’m saying well.

    Off to Montreal Tomorow. Whhheee Heeeee

  84. Phil B.
    Posted Aug 14, 2006 at 2:39 PM | Permalink | Reply

    Re #76 Hans, weren’t these plots generated by using a hitrans atmospheric model and not really “tested”? Hans is there an open source for this paper? I have read some of Myhre’s later papers but don’t have access to this particular paper.

  85. Geoff
    Posted Aug 14, 2006 at 6:04 PM | Permalink | Reply

    An abstract of a comment from a different field of study may have some relevance to one aspect of the MBH9X case, withholding of adverse results:

    “Underreporting research is scientific misconduct

    I. Chalmers

    National Perinatal Epidemiology Unit, Radcliffe Infirmary, Oxford, England.

    Substantial numbers of clinical trials are never reported in print, and among those that are, many are not reported in sufficient detail to enable judgments to be made about the validity of their results. Failure to publish an adequate account of a well-designed clinical trial is a form of scientific misconduct that can lead those caring for patients to make inappropriate treatment decisions. Investigators, research ethics committees, funding bodies, and scientific editors all have responsibilities to reduce underreporting of clinical trials. An extended use of prospective registration of trials at inception, as well as benefiting clinical research in other ways, could help people to play their respective roles in reducing underreporting of clinical trials”.

    Ref: The Journal of the American Medical Association, Vol. 263 No. 10, March 9, 1990

  86. Paul Williams
    Posted Aug 14, 2006 at 9:59 PM | Permalink | Reply

    #73, Justin, I too am curious about the aerosol forcings being blamed for the 1940 to 1976 cooling trend, but then apparently being overpowered by greenhouse gas emissions. For that to happen, it seems logical that aerosol forcings should decrease, or at least level off a bit, after 1976, but according to this graph, they don’t do that.

    I’ve asked about this over at realclimate, but no answer so far.

  87. MrPete
    Posted Aug 15, 2006 at 6:34 AM | Permalink | Reply

    These graph links have prompted me to speak up on something that’s been bothering me (this is one of my areas of professional expertise):

    There’s a simple yet very significant misrepresentation of the data in almost every SST map I’ve seen: significant magnification of polar area, which leads to serious visual interpretation errors.

    It would not be difficult to correct this. Equal Area projection algorithms are widely available. I recommend taking a look at this (and specifically this or perhaps this)
    A very interesting projection from Snyder is discussed here, including source code etc.

  88. brent
    Posted Aug 15, 2006 at 4:50 PM | Permalink | Reply

    October 29, 2003 2:30 p.m.
    Editor, USA Today
    We write to address false statements in the piece "Researchers question key global-warming study" (USA Today, October 29, 2003), by Nick Schulz of TechCentralStation. We also wish to inform your readers that late 20th century warming is unprecedented not only in the past six centuries (as shown by Mann and colleagues in 1998), but at least the past two millennia (see attached graph, which we request that you publish).

    Sure makes interesting reading now

  89. Michael Jankowski
    Posted Aug 15, 2006 at 4:56 PM | Permalink | Reply

    Re#89, can’t you see all the caveats and uncertainties thoroughly detailed? :)

  90. Ken Fritsch
    Posted Aug 15, 2006 at 8:27 PM | Permalink | Reply

    re: #90

    Re#89, can’t you see all the caveats and uncertainties thoroughly detailed?

    Mann, Bradely, Hughes, Briffa and Jones can say

    We also wish to inform your readers that late 20th century warming is unprecedented not only in the past six centuries (as shown by Mann and colleagues in 1998), but at least the past two millennia (see attached graph, which we request that you publish).

    without mentioning those error bars and uncertainties (in their graph), R2s that were near zero and lack of robustness without the BCPs. They showed the uncertainties for MBH’s reconstructions in the graphs but do not mention them in their unequivocal claim. They can then write to Nature and claim their position has been misrepresented. They really have to think that readers of this material are either naive, gullible or constantly winking at one another when these claims and complaints are made.

  91. bender
    Posted Oct 3, 2006 at 11:31 AM | Permalink | Reply

    Re #13
    The following quote is from the p. vii preface to Fritts (1976) Tree Rings and Climate.

    “It is recognized, however, that future studies of the growth-climate system will undoubtedly lead to new possibilities, and refinements in which factors originally thought to be irrelevant will turn out to have a measurable effect. When this occurs, the newly dsicovered fators must be added to the list of others already considered important.

    In addition, I would like to emphasize that this particular text is essentially a progress report on a rapidly developing subject. I hope no reader will consider these pages as unquestionable statements of fact. Rather, they should be viewed as a treatment of best inferences of dendroclimatology as we know it, including applications, conclusions, and principles that are reasonable deductions from the accumulated facts.”

    Of course the field has progressed in 30 years. My point is Fritts sounds like the kind of guy that wouldn’t be impressed by an appeal to authority (least of all himself) when appeal to logic and data are available as alternatives.

  92. Steve McIntyre
    Posted Oct 3, 2006 at 12:19 PM | Permalink | Reply

    Fritts was one of the coauthors of Lamarche et al 1984, which originally posited CO2 fertilization in connection with the Sheep Mountain site. Graybill was another coauthor.

  93. Steve McIntyre
    Posted Oct 22, 2006 at 10:08 PM | Permalink | Reply

    In the 1990s, Hughes was one of many researchers who adopted the so-called multiproxy approach. (” “Multiproxy’ sounds too much like a Chicago election,” he grouses, in his still-strong English accent. “I’m not too fond of that word.”)

    link here

    Didn’t just sound like a Chicago election.

  94. bender
    Posted Oct 22, 2006 at 10:26 PM | Permalink | Reply

    I’m probably too young to undesrstand the Chicago reference. Care to clarify, or post a link to a clarification? Sounds interesting.

  95. Steve McIntyre
    Posted Oct 22, 2006 at 11:06 PM | Permalink | Reply

    Wikipedia under "Electoral fraud" mentions:

    Some notorious examples of electoral fraud in the United States of America include the widespread election manipulation committed by the Daley Machine in 20th century Chicago and Tammany Hall in 19th century New York.

    The most famous example was the 1960 presidential election where the Daley machine delivered Illinois to Kennedy in an election that was as close as 2000. Joseph Kennedy was said by opponents to have purchased the delivery.

    It seems like a curious way for one of the MBH coauthors to describe the study, but some would say it was an apt description.

  96. Paul Linsay
    Posted Oct 23, 2006 at 6:52 AM | Permalink | Reply

    Having lived in Chicago during the apogee of the Daley machine, I’m reminded of their motto, “Vote early, vote often.”

  97. Ken Fritsch
    Posted Oct 23, 2006 at 12:27 PM | Permalink | Reply

    In the 1990s, Hughes was one of many researchers who adopted the so-called multiproxy approach. (” “Multiproxy’ sounds too much like a Chicago election,” he grouses, in his still-strong English accent. “I’m not too fond of that word.”)

    For someone there in 1964, I would have to say that while leading to similar results, the Chicago elections were nowhere near as subtle as the multiproxies — they did not have to be.

  98. Steve Sadlov
    Posted Oct 23, 2006 at 1:44 PM | Permalink | Reply

    RE: #98 – “Alright, youse guys…. let me play yah a tune on my violin….” LOL!

  99. Posted Jun 8, 2008 at 5:16 AM | Permalink | Reply


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