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The missing piece at the Wegman hearing

Filed under: — group @ 19 July 2006

It’s not often that blogs come up in congressional hearings, but RealClimate was mentioned yesterday in the Energy and Commerce hearings on the ‘Hockey Stick’ affair. Of course, it was only to accuse us of being part of tight-knit social network of climate scientists, but still, the public recognition is nice.

There is much that could be said about the hearings (and no doubt will be) and many of the participants (Tom Karl, Tom Crowley, Hans von Storch, Gerry North) did a good job in articulating the big picture on climate change independently of the ‘hockey stick’ study as we’ve highlighted before. But it seems to us that there was a missing element in the discussions. That element was the direct implication of the critique that was the principal focus of Wegman’s testimony and that was mentioned periodically throughout the day.

Wegman had been tasked solely to evaluate whether the McIntyre and McKitrick (2005) (MM05) criticism of Mann, Bradley and Hughes (1998) (MBH) had statistical merit. That is, was their narrow point on the impacts of centering on the first principal component (PC) correct? He was pointedly not asked whether it made any difference to the final MBH reconstruction and so he did not attempt to evaluate that. Since no one has ever disputed MM05′s arithmetic (only their inferences), he along with the everyone else found that, yes, centering conventions make a difference to the first PC. This was acknowledged way back when and so should not come as a surprise. From this, Wegman concluded that more statisticians should be consulted in paleo-climate work. Actually, on this point most people would agree – both fields benefit from examining the different kinds of problems that arise in climate data than in standard statistical problems and coming up with novel solutions, and like most good ideas it has already been thought of. For instance, NCAR has run a program on statistical climatology for years and the head of that program (Doug Nychka) was directly consulted for the Wahl and Ammann (2006) paper for instance.

But, and this is where the missing piece comes in, no-one (with sole and impressive exception of Hans von Storch during the Q&A) went on to mention what the effect of the PC centering changes would have had on the final reconstruction – that is, after all the N. American PCs had been put in with the other data and used to make the hemispheric mean temperature estimate. Beacuse, let’s face it, it was the final reconstruction that got everyone’s attention.Von Storch got it absolutely right – it would make no practical difference at all.

This is what MBH would have looked like using centered PC analysis:


Red is the original MBH emulation and green is the calculation using centered PC analysis (and additionally removing one of the less well replicated tree ring series). (Calculations are from Wahl and Amman (2006), after their fig. 5d). Pretty much the same variability and the same ‘hockey stick’. We’d be very surprised if anyone thought that this would have made any difference to either the conclusions or the subsequent use of the MBH results.

In fact, it’s even more simple, Throw out that PC analysis step completely, what do you get?


Again, red is the original MBH98 multiproxy+PC analysis, green is if the raw data are used directly (with no PC analysis at all). (This comes from Rutherford et al (2005) and uses a different methodology – RegEM – to calibrate paleoclimate proxy data against the modern instrumental record, but that doesn’t make any difference for this point).

Why doesn’t it make any difference? It’s because the PC analysis was used to encapsulate all of the statistically relevant information in the N. American tree ring network and so whatever patterns are in there they will always influence the final reconstruction.

So what would have happened to the MBH results if Wegman and his colleagues had been consulted on PC centering conventions at the time? Absolutely nothing.

Can we all get on with something more interesting now?


185 Responses to “The missing piece at the Wegman hearing”

  1. 101
    Lynn Vincentnathan says:

    #98, James, I like your point about a non-significant result not ruling out any effect.

    As an environmentalist, I would even take it further. I’d like to see the denialsts prove to me at 95% confidence that GW is not happening. But that would only be out of curiosity, since I would still continue to rake in money & savings from energy/resource efficience/conservation & even plow back some or that money into reducing actions that cause GHG emissions, since those GHG emitting actions also usually cause a host of other problems, as well.

  2. 102
    Lynn Vincentnathan says:

    Re mention of the FDA (#84), I consider the agency a total joke. It has a dual mandate to help the F&D business communities, as well as the customers, and it tends to err on the side of helping business. E.g., the toxins fed to farm-raised salmon, certain drugs, and (my big peeve) inadequate labeling for MSG (much less control over it). MSG comes under 50+ different names, including “natural flavor” (40% MSG) and pervades our food supply; see http://www.truthinlabeling.org . But the FDA refuses to recognize this or require adequate labeling of this neuro-excito-toxin that does great harm to some people, and has no benefits. It does not give flavor, but just excites brain cells (& kills them) making one think the food tastes better. Since it is cheaper than real spices, such as cumin, and is additive (making people eat more product), it’s a great deal for the food industry. So if the gov is involved in allowing this additive drug & poison on the market, no wonder they don’t care about harms from AGW.

    Furthermore, if Congress were following the ideal FDA model of protecting the people, then they would require 95% or 99% certainty that GHGs are not causing GW, before allowing us to emit additional GHGs much beyond what nature emits. Or, since GHGs have already been allowed on the market, they should be banning or curbing them!…according to the ideal FDA model, assuming the main mandate were to protect the people.

  3. 103
    Craig Butcher says:

    I have a dumb question. I don’t understand the thrust of the argument made by ‘hockey stick’ critics.

    Do they claim that choice of statistical methods determines how much if any of a Medieval Warm Period temperature “bump” shows up on a graph of temperatures plotted against time? And that the Mann ‘hockey stick’ minimizes the plotted Medieval bump? Yet the more recent warming is not disputed?

    Or is it that, presumptively, there could have been no greenhouse forcing during the Medieval period? And that no greenhouse forcing before industrialization necessarily means no greenhouse forcing now? I don’t understand how this follows. Even if solar variability accounts for the medieval warming (which would have to be world-wide, in that case, not just regional), I don’t see why solar + greehouse would not both be factors today.

    Or are they arguing that there has been no recent warming?

    Some climate expert please clarify this. Thanks.

  4. 104
    caerbannog says:


    An amazing (to me as a mere reader) comment’s recently posted in the Scientific American blog — this link:

    Find this one:
    Comment from: cearbannog [Visitor]
    dated
    July 22, 2006 @ 20:23

    Yeah, that was my post… I should follow up here and fess up to some sloppy terminology, as I probably should have used the terms “singular value” and “singular vector” instead of “eigenvalue” and “eigenvector”. (But singular values/vectors are similar enough to eigenvalues/vectors that it doesn’t matter too much in an “arm-waving”, non-technical discussion.) Hopefully, the more mathematically inclined folks here won’t cringe too much!

  5. 105
    MIKE says:

    We are the only pollution makers!!!

    We live on the earth. We must treasure our earth all the time. A good living environment is very important to the people but the pollution problem is influencing our lives and other’s lives as well!!!.

    The air pollution and water pollution are global problems.

    Air pollution can cause health problems including burning eyes and nose, itchy irritated throat and breathing problems. The effects of water pollution are varied. They include poisonous drinking water, poisonous food. Unbalanced river and lake ecosystems that can no longer support full biological diversity deforestation from acid rain.

    I think people should take some measures to minimize it. We can use the new energy as the power to minimize the air pollution. We must stop to throw the rubbish in to the river.

  6. 106
    metaskeptic says:

    Re: 95
    I think it’s pretty clear that the 20kyr statement was true but misleading. But I don’t follow your logic that 8kyr is an appropriate comparison; indeed, comparing today to the interglacial peak seems equally misleading. The point is not to cherry-pick a single date of comparison to fit a predetermined point (as both you and the offending documentary have apparently done). The point is to look at overall trends and to see where we fit into that picture. M&M’s criticism is that MBH’s technique overstated recent warming in relation to previous, non-anthropogenically-forced variations. The counterargument, which caerbannog and others have made to my satisfaction, is that if MBH did underestimate previous variability, they did so to such a small degree that M&M’s critique boils down to an insignificant technicalilty, and that the previous assessment of the overall trend — that anthropogenic forcing is causing warming outside the range of natural variability _for this point in the interglacial_ — still stands. This is essentially how the NAS panel presented their conclusion as well.

    Re: 104, I’m not a climate expert, but my understanding is that they’re not trying to argue that recent warming isn’t real (it is instrumentally measured, after all). They’re trying to say that MBH’s reconstruction of previous temperatures is flawed because it understates natural variability… and they’re trying to _imply_ that that means that current warming is within a natural range, and therefore AGW is insignificant. M&M, Wegman, et al. are not making any explicit points about anthropogenic forcing (greenhouse gases, etc.), but they are stating facts selectively and leaving big gaps to fill in. Someone who knows more what they’re talking about, please correct me if I’m mistaken.

    What gets my proverbial goat is those big gaps. It seems so transparent — they state just a few outlying facts, then present those to politicians (who are scientific laypeople), who then make some inferences and pass it on to the public (who are generally both scientific and political laypeople). It gets repeated by the talk show minah birds, and by the time the “facts” are drilled into the public’s minds, they’re so distorted that no semblance of science is left in them. Joe Public is left to believe that climatologists aren’t really scientists, but just tools of the left-wing alarmist propaganda machine. It’s like a giant game of telephone, where one person is deliberately altering the message… only the stakes in this case are rather high.

  7. 107
    John Donohue says:

    Yes, you don’t follow my logic or my ironic method, but I am not going to try again.

    The reason you think it is in “gaps” and outlying is that the Consensus is presenting the ‘pro’ case; they are making the contention. Therefore, the burden is on them to prove the affirmative for a very unnatural hypothosis. The opposition’s job is to address first one part, than another issue, etc. and they do not have to make a continuous case. They are the obnoxious nitpickers. That’s par for the course when you declare a monumental, culture-shaking theory not only true, but irrefutable, settled, beyond doubt with no wiggle room. People will challenge you on a ‘but what about this’ basis.

    “This is essentially how the NAS panel presented their conclusion as well.” But not the Barton/Wegman panel.

  8. 108
    John Donohue says:

    re: 104 Craig,

    I am a critic and not a climate expert, but I can respond with civility.

    Many object because we feel the statistical method used to generate the hockey stick artificially exaggerates the spike and diminishes both the Medieval Warm period and the Little Ice Age. Just contrast it with the IPCC 1990 graph included with the Wegman report, available as a PDF.

    We do not hold the Medieval Warming Period to be a isolated one-time bump or happenstance. Going back beyond 1000 years, we contend there is a fluctuation around a mean for 8000 years in 400 year loops, all within less than 1 degree C (but that is enough to be very noticeable), and that the Medieval Warming Period was an upside half of a full loop-around. It is true that Mr. Mann and others have stated that even without his data and graphs, other proxy series do not show this fluctuation, or show if to be very slight, especially in contrast to the spike since, say, 1940. Challenge accepted.

    However, there are data series to the contrary, as well, and they do show the fluctuation, including the final upswing since 1850 (but far less abruptly), and non-contradictory with the cycle I am describing. These series indicate temperature today reaching that of 1000 years ago, roughly. Our contention is that this upswing will assume the usual curve and flatten for a few hundred years, then cycle down to below the mean, and so on until the next glaciation. On its own, several hundred years at current or very slightly higher temperature definitely will get the world’s attention! That’s a lot of time for ice to slowly melt, as it certainly did 1000 -1400.

    All of the above is a priori consideration of human-driven greenhouse effect. We contend that, yes, mankind is contributing to warming through CO2 concentration, but not in even the remote neighborhood of the dire warnings of Mr. Gore or Mr. Brokaw, etc. Many also believe human attribution is not proven; that CO2 concentration is caused by warming, not that it drives warming, but that there still is human-contributed warming due to other factors. Few believe in runaway or tipping-point scenarios, or that there is evidence that the ~30 million year old Ice House has been trumped by industrial development over a few decades, and the world is about to return to 22 degrees C, and all the ice will melt over the next hundreds of years.

    There are two aspects that I personally subscribe to that bode strongly for higher than usual temperatures this time through the 400 year expected warm sequence:
    1) The slope up to today since 1850 may have been steeper than other upswings in this 8000 year period. It’s got momentum.
    2) Because of human loading of greenhouse gases, but more importantly because of land use changes and other factors, the 400 year upswing might last longer or be somewhat higher.

    Looks like we might be in for warm times next few hundred years. It might not be all bad. But what evidence is there anywhere that the next glaciation, expected between now and 10,000 years hence, will not commence right on schedule?

    I am describing the above contrarian stance as ‘beliefs’ or ‘contentions’, but that does not mean they are just invented. It is just not the place in this post to do any actual grounding or substantiation. Also, while I used “we” because I have associates who hold the same outlook, I speak for no one but myself.

  9. 109
    caerbannog says:


    The opposition’s job is to address first one part, than another issue, etc. and they do not have to make a continuous case. They are the obnoxious nitpickers..

    But the proper forum for such obnoxious nitpicking is in peer-reviewed scientific journals, not in popular publications whose readership wouldn’t know a singular value from a Cingular cell-phone.

  10. 110
    Grant says:

    Re: #109

    However, there are data series to the contrary, as well, and they do show the fluctuation, including the final upswing since 1850 (but far less abruptly), and non-contradictory with the cycle I am describing. These series indicate temperature today reaching that of 1000 years ago, roughly.

    Exactly what series are you referring to? Reference(s), please.

  11. 111
    Brian Gordon says:

    Why RC sometimes unavoidably strays into political territory:
    “The MBH98/99 work has been sufficiently politicized that this community can hardly reassess their public positions without losing credibility.”

    Re: John Donahue:
    “I am describing the above contrarian stance as ‘beliefs’ or ‘contentions’, but that does not mean they are just invented. It is just not the place in this post to do any actual grounding or substantiation.”
    ???This is NOT the place for substantiation??? What makes you think this is the place to propound unsupported views – some of which are not only unsupported, but actually proven wrong?

  12. 112
    John Donohue says:

    ok, i’ll change this:

    It is just not the place in this post to do any actual grounding or substantiation.”

    To this:

    I elect not to defend a position or statement at this time in this place. Craig asked for an explanation/description/clarification of what critics of the hockey stick think; that’s what I provided. Since I elect not to defend at this time, you can just state I am wrong, as you did, since the burden indeed would be on me if I insisted on proving my case instead of just describing my position. Meanwhile Craig hopefully got his answer.

  13. 113
    John Donohue says:

    “Exactly what series are you referring to? Reference(s), please”

    Once again, I do not elect to argue this case, I am just describing a position. However, I will say that when this thread specifically asked (see above) for more proxy studies on the millenium, and especially the Medeival Warm Period, I DID post links to two fantastic pages which in turn link a panoply of studies, some of which more or less support the hockey stick, some which show a non-flat millenium.

    The post was not put online, but in retrospect that was to be expected as the page was at a site highly critical of the MBH and IPCC position.

  14. 114
    David says:

    Two questions… one on science and one on the report.

    First is how can one really apply a “traditional” mean centred PC analysis when the proxies have different start and end dates? Unless I am missing something, it seems to be just plain impossible.

    Second one is anyone providing a reponse to the Wegman report highlighting the huge number of errors of fact it contains. For example, take chapter 6, para 10 (last part) – my comments in brackets.

    …it is clear that average global temperature increase are not the real focus (wrong, and what does this mean anyway?). It is the temperature increase at the poles that matter (wrong – most people live away from the poles and will and are feeling the impacts far before the polar icecaps roll into the oceans) and average global or Northern Hemisphere increases do not address the issue (wrong… what about spatial correlation). We note that according to experts at NASA’s JPL, the average ocean height is increasing by approxiately 1mm per year (wrong, the number is 3mm/year based on satellite altimeters), half of which is due to melting of polar ice (wrong, at least based on TAR the total polar contribution over the century was probably a slight reduction in sea level) and the other half due to thermal expansion.

  15. 115
    metaskeptic says:

    John, please do repost, if you still have those links. Given that your rather harsh criticism of RC in #104 went through, I’m sure the mods would allow a simple reference (right, guys?). Perhaps there was some other reason the auto-moderating system rejected it before. Even an oblique reference to where this information exists might be helpful.

    If the information you’re mentioning constitutes a valid complaint about the state of the science, then it can only benefit the scientific community to see it. If it exposes holes in the scientific consensus, it gives the scientific community a chance to reexamine their arguments, and either strengthen their position or reevaluate their conclusions. M&M (and the Barton/Wegman “panel”, whose report was a brilliant exercise in circular logic, using M&M to support M&M) simply haven’t done that. They’ve picked a few nits off the gorilla, but the gorilla’s still there.

  16. 116

    re #109 and “We contend that, yes, mankind is contributing to warming through CO2 concentration, but not in even the remote neighborhood of the dire warnings of Mr. Gore or Mr. Brokaw, etc. Many also believe human attribution is not proven; that CO2 concentration is caused by warming, not that it drives warming, but that there still is human-contributed warming due to other factors.”

    If the greenhouse gases aren’t driving the warming, what is? Elves? The Sun sure isn’t, because I’ve run that regression myself and it doesn’t hold up.

    -BPL

  17. 117
    Mark A. York says:

    “For all its protocol, Wikipedia’s bureaucracy doesn’t necessarily favor truth. In March, 2005, William Connolley, a climate modeller at the British Antarctic Survey, in Cambridge, was briefly a victim of an edit war over the entry on global warming, to which he had contributed. After a particularly nasty confrontation with a skeptic, who had repeatedly watered down language pertaining to the greenhouse effect, the case went into arbitration. “User William M. Connolley strongly pushes his POV with systematic removal of any POV which does not match his own,” his accuser charged in a written deposition. “His views on climate science are singular and narrow.” A decision from the arbitration committee was three months in coming, after which Connolley was placed on a humiliating one-revert-a-day parole. The punishment was later revoked, and Connolley is now an admin, with two thousand pages on his watchlist – a feature that enables users to compile a list of entries and to be notified when changes are made to them. He says that Wikipedia’s entry on global warming may be the best page on the subject anywhere on the Web. Nevertheless, Wales admits that in this case the system failed. It can still seem as though the user who spends the most time on the site – or who yells the loudest – wins.”

    From a New Yorker story on Wikipedia. Unfortunately it leaves the impression that W. Connolley has pulled a fast one and the skeptic had a valid view. That’s not right.

  18. 118
    Armand MacMurray says:

    Re:#103
    Lynn, MSG does have a flavor. It was created precisely to stimulate the fifth type of taste receptor (after sweet, sour, salty, and bitter), “umami.” This receptor was only discovered in the last 5 years, but the taste was described (and MSG created) by a Japanese chemistry professor 100 years ago. A nice example of the difficulties caused by a premature “consensus.”

  19. 119
    John Donohue says:

    re 117 BPL,

    “If the greenhouse gases aren’t driving the warming, what is? Elves? The Sun sure isn’t, because I’ve run that regression myself and it doesn’t hold up.”

    For the context of your reply, please define “the warming” (what time frame and range) and ‘greenhouse gases’ (which ones?)

    Thank you

  20. 120
    John Donohue says:

    here are two links which respond to a request on this thread for more and various proxy studies, and especially for the Medieval Warm Period.

    http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/mwpp.jsp

    http://www.junkscience.com/MSU_Temps/Warming_Proxies.htm

  21. 121

    #109 : But what evidence is there anywhere that the next glaciation, expected between now and 10,000 years hence, will not commence right on schedule?

    You might take the time every once and a while to actually look at the best available schedules :

    http://www.glaciology.gfy.ku.dk/papers/pdfs/197.pdf

    The glaciation train has definitely broken down.

  22. 122
  23. 123
    Ender says:

    John – “here are two links which respond to a request on this thread for more and various proxy studies, and especially for the Medieval Warm Period.”

    I found a lot of the papers that are referenced from link you posted from CO2Science to be badly misrepresented. Some of the papers actually said nothing like the CO2 science description.

    I listed some of them here:
    http://stevegloor.typepad.com/sgloor/2006/02/bogus_descripti.html

    I actually now have all the papers mentioned in this ‘project’. I have not had a chance to go through them all however this now might be the time.

  24. 124
    Hank Roberts says:

    Did you all listen to the House Energy hearings about the Wegman report? North, describing what he called his ‘bonehead’ approach to charting, showed and described how the ‘bump’ in the Medieval temperature period disappeared when he combined all the sources, and said it was because at that time some areas were warmer and some were cooler and they averaged out to disappear.

    The coal industry’s PR people are desperate to convince the public that warming happened worldwide in the Medieval, it’s one of the key foundation claims for their story. But the evidence is otherwise.

    It was one of the stronger points made in the hearings. I eagerly await the transcripts.

    If anyone (with Windows) is able to turn the RealAudio stream of the video into a downloadable file — oh, please, please do. I want to check the official transcript when it comes out and see if it’s accurate.

    Especially about the places that were so embarassing for the denial lobby, like this issue.

  25. 125
    John Donohue says:

    I am always curious about that ‘follow the money’ refutation attempt. Those calling upon it think
    1) they are somehow exempt from the logical fallacy poisoning the well
    2) they are somehow exempt from having the tables turned on them with the same charges, due to them taking billions of tax money and being beholden to their own brand of special interests.

    How about a different paradigm, that a climate scientist, or an entire peer group of them, is capable of detachment and objectivity despite possible pressure or obligation from the source of his/her livelihood, and a critic of the Consensus is also so capable, even if they have received money from the oil industry? The work of any and all should be judged on its objective merits.

    The links at jscience are stronger. You’ll notice that even though some of the studies reveal a non-flat 1000-1900, many also reveal a shape closer to the Mann/IPCC shape.

    The first study cited, Moberg, A., et al. 2005, would be a good one for analysis. Both the graph and the raw data are provided; anyone who thinks the data was improperly graphed could issue their own graph. The evaluation of the statistical technique, “combining low-resolution proxies with tree-ring data, using a wavelet transform technique to achieve timescale-dependent processing of the data” is above my head personally. The data only goes to 1979, so any drastic upswing in the last 25 years would not be revealed. This study is one, however, which returns a non-flat millennium. This is a Northern Hemisphere study.

  26. 126
    John Donohue says:

    re 122:

    I was not aware that part of the consensus on Global Warming is that the “The glaciation train has definitely broken down.”

    Is that actually true? That from analysis of climate, oceans and atmosphere, and regarding the human loading of greenhouse gases over the last century, that it is considered settled, irrefutatble science that the glaciation/interglacial cycle is terminated, the current ~ 30 million-year ice house has ended, we are about to return to 22 C, all the ice is about to melt?

    Frankly, it is hard for us critics to determine how far the consensus claim of settled and irrefutable goes.

    I am looking into the paper cited and looking for similar claims elsewhere. It might take me a while to respond

  27. 127
    Lynn Vincentnathan says:

    Re #119, Armand, that is not the main point re MSG (tho they say if you taste it plain, there is no flavor, but only when added to food). But even if you’re right, it is still harmful to some people, and extremely harmful to a tiny number. That’s the point.

    I think this discussion highlights the topic here. Pointing out some small problem or inaccuracy that has nothing to do with the main point, so as to make it look like the main point has been discredited. You may also tell me that MSG occurs naturally in some foods to various extents, and that’s true. So I can’t eat kidney beans & coconuts — but at least labels have to tell whether ingredients include those particular foods, whereas they don’t have to (or simply don’t) tell about MSG content when disguised under different names.

    So if anyone from the food industry is listening — I just avoid all foods that have “natural flavor” (artificial is fine), “broth,” “spices,” “hydorlyzed xxx,” “autolyzed xxx,” “yeast xxx,” “malted xxx,” etc. Sometimes when I give in, I’m really sorry, and out of comission with a terrible migraine. I think the food industry would do better insisting that the FDA require labeling of MSG content, and amount (I can take a little).

  28. 128
    John Sully says:

    John, note that there are two different Mann, et al, papers. The MBH98 paper showed a hockey stick with a basically flat handle — the “canonical” hockey stick graph. This recon only went back to 1400, a point in time when the NH was cooling down and headed into the LIA. Of course, this study would show no MWP because there was no MWP to show!

    MBH99 was a northern hemisphere study and did show a MWP and an LIA! In fact MBH99 stated that temps in the MWP approached 20th century means. So far from doing away with the MWP, MBH99 confirmed its existence, but only as a NH event.

  29. 129
    Ron Taylor says:

    Re 126

    Ah, if only the ideal of universal objectivity you describe was possible! I even accept that you are probably trying to practice it yourself. But, unfortunately, history does not give us much reason for optimism.

    When nobody’s ox is threatened, grants are made for scientific research, which, like all honest research, tries to find the best possible description of provisional truth. But, ever now and then, the scientific consensus moves toward a conclusion that threatens a major financial interest. Then another kind of research money often surfaces. It claims to be scientific, but everyone understands (wink, wink) that it is expected to provide plausible results that counter the emerging consensus. There is nothing scientific about trying to construct a rationale in support of a predetermined result. It poses as scientific, it is clothed in scientific language, but it is not scientific. That is not to say that all contrarians fit this mold, but so much garbage (think of the M&M effort to demonstrate a random data hockey stick) filters into the information stream that trust gets pretty much destroyed.

    I am sure that RC readers could cite many examples of the above. I am old enough to remember Ford’s cover up of their exploding gas tanks; I took Vioxx for years even though the manufacturer knew full well that it was dangerous; then, of course, there is the classic case of the tobacco companies funding studies to show that smoking does no harm, while their own secret internal studies showed that it did.

  30. 130
    Chuck Booth says:

    Re #126 John Donohue seems to be suggesting that in order to find the truth about anthropogenic global warming (AGW), one should pretty much ignore the scientists actually studying global climate and oceanography, and instead look to skeptics like Steve Milloy. I don’t think anyone can argue that academic and government scientists are infallible and 100% free of bias, but their professional reputation is built on producing original and creative work that is published in the peer-reviewed literature. There is no apparent reason to think that, collectively, climatologists and oceanographers have a vested interest in promoting theories about AGW for any reason other than that the data suggest to them that the phenomenon is real and the consequences could be detrimental to society.

    On the other hand, Steve Milloy has ties to think tanks and industry groups that raise serious questions about his impartiality (some links provided below), not to mention a lack of forthrightness in disclosing relevant information about potential biases. Moreover, his academic background suggests that he lacks the qualifiations to comment with much authority on many of the topics discussed on his website. If I have form a judgment about the dangers of second-hand smoke, I am much more inclined to look to the National Institutes of Health and the National Academies of Science than to Steve Milloy. Likewise, when it comes to AGW and the reliability of the “hockey stick” model for temperature trends, I will defer to the the researchers actively publishing on the topic in top quality, inernational, peer-reviewed journals, and distinguished scientific bodies such as the U.S. National Academies of Science and the Royal Society (UK), rather than Steve Milloy (or John Stossel, Tom Brokaw, and Al Gore, for that matter).
    http://www.trwnews.net/Documents/Dow/junkscicom.htm
    http://skepdic.com/refuge/junkscience.html
    http://en.wikipedia.org/wiki/Steven_Milloy

  31. 131
    Leonard Evens says:

    Re # 98:

    James Annan objects to my statement about statistical significance in the context of a study desiged to see if the use of nutritional supplements is justified in order to prevent bone fractures in older women. I’ve spent some time at his blog looking at his arguments, and I think they have quite a lot of merit. I must admit though that statistics has always given me a headache just because of such issues. In the past, I was smart enough and had enough understanding of probability theory that I could eventually figure it all out, but it never came easy. I’m not sure I have the patience today. So let me just make one additional clarification. When applying probability and statistics, one must adopt some conceptual model for what one is doing. This will involve the mathematical concept of a sample space and also some philosphical assumptions about the relation of reality to any model you come up with. Having done that, you can draw relatively precise conclusions, stating probabilities, and it is clear what they mean in terms of your conceptual model. But often, that meaning isn’t what a naive interpretation might suggest. James Annan’s discussion gives examples of just how that can happen. My point was that in a typical biomedical study, the conceptual model is fairly straightforward, but there are still disagreements about how to interpret the results. The situation in observational climatology is much more complex, and getting agreement on a plausible conceptual model may not be so easy. I wanted to emphasize that treating it as a problem in pure statistics independent of the subtance may beg the question about what an appropriate conceptual model might be. That is why any statistician collaborating in such a study should have a thorough understanding of the science.

  32. 132

    Is that actually true?

    Yes it is.

    That from analysis of climate, oceans and atmosphere, and regarding the human loading of greenhouse gases over the last century, that it is considered settled, irrefutatble science that the glaciation/interglacial cycle is terminated, the current ~ 30 million-year ice house has ended, we are about to return to 22 C, all the ice is about to melt?

    You got it. We apologize for the inconvenience. I don’t know what you mean by 22 C, but complete melting of all the remaining polar ice caps within roughly 1000 years, is now guaranteed, if we don’t stop pumping carbon dioxide into the atmosphere. Methane feedback effects will do it. Even if we burn all that methane, it’s still going to happen.

    Back to the PETM we go. It’s a very simple conclusion, just extrapolate a 3-5 ppm/y carbon dioxide rise for the next few centuries. It’s over John, all you are doing is wasting my valuable time that I could be using to do the condensed matter physics necessary to change the obvious result of continued carbon and hydrocarbon combustion on this planet. That is, if we don’t destroy ourselves with nuclear fission first.

  33. 133
    Joseph O'Sullivan says:

    #126 (John Donohue) “I am always curious about that ‘follow the money’ refutation attempt”

    I have used this arguement myself. It does sometimes need a little explaination.

    The sources, like junk science, are financially supported by regulated industries and groups philosophically and politically aligned with them. They are giving these groups money to spread a political message, not to do any scientific research. The political message is consistant: there should be no government regulation. They try to cast doubt on the science to cast doubt on the regulations.

    Getting involved in a public discussion to influence political decisions is an admirable thing to do. However intentionally misleading is not. The groups that junk science and others work for have a long history of dishonest behavior in the public debates.

    The point is to show who is behind behind the arguments and remind people that they can not be trusted.

  34. 134
    Hank Roberts says:

    John Donohue — you’re asking for “settled, irrefutatble science”

    “Irrefutable” isn’t science. Science isn’t irrefutable.

    You seem to be reading advertising/PR sites, that publish puffery for the Western Coal Association, and quoting their talking points here.

    Why do you trust these people for your information?

  35. 135
    John Donohue says:

    134, Joseph Oâ??Sullivan

    Amazingly, rather than refute my point, you gave a textbook example of ‘poisioning the well’ and then offered it as a good thing! It’s a fallacy.

    Let me give you an example:
    If someone who works for Exxon whose job it is to find holes in the arguments that claim gobal warming is caused by burning their oil actually DOES find a data, logic or methods problem with that argument, it should be discarded because they work for Exxon?

  36. 136
    John Donohue says:

    In #135 Hank Roberts objects to my question being put in the form of the extreme “irrefutable” but in #133 not only are my terms “Irrefutable” and “settled” and “fact” reflected back in the affirmative, but “guaranteed” is thrown into the bargain.

    Certainly each poster here speaks for himself, but perhaps 135 ought to make a trip to the mound to settle down 133. That is, unless others reading this thread concur with Mr. Elifritz’ level and syntax of certainty.

    I checked a little deeper, and can find no member of the AGW consensus who is quoted (at least as visible to the google spider) as having used the word “irrefutable.” I retract any implication in my question that any scientist has made a claim of certainty using that word.

    What level of certainty is implied (or what term is appropriate) when the AGW community presses for government and international restrictions and actions, as well as calling for voluntary life-style changes? Proven? Probable?

    Additionally, if ‘irrefutable’ is not a term members of the AGW consensus allow for themselves, maybe some cautionary words are needed for the media-types who are running the message to the public. I do not hold you responsible for their rhetoric, but they are characterizing the Consensus conclusions.

    David Suzuki
    http://www.davidsuzuki.org/Climate_Change/Science/Skeptics.asp

    Tom Brokaw,
    Quoted as having said Al Gore was using the same science he was, “and that it was irrefutable.”
    Many many links found, just google it, no denials or apologies found. If he was misquoted by hundreds of journalists, he does not seem to have objected.

  37. 137
    John Donohue says:

    129 John Sully,
    Thank you for that clarification. I’m going to look at both studies/graphs and also ponder a good question I can put back to you on the significance of NH vs Global studies for a few days. Appreciated.

  38. 138
    Dan says:

    re:136. Except that the person who works for Exxon is either a. usually unqualified scientifically to make such comments, and/or b. cherry-picking irrelevant or trivial points to make them sound like *the* “proof” that every major scientific organization in the world (yes, the world) is wrong, and/or c. hardly ever publishes such comments in peer-reviewed journals.

  39. 139
    Jeff Weffer says:

    junkscience did nothing but post real data streams (from NOAA etc.) and studies by other climate scientists (with track-back links to the sources so one could actually check the data from the studies.) There are 100 times more climate studies linked in the website than there are at this website.

    Unfortunately, the website’s author, John Daly, passed away and there are only a few people posting the occasional update on the site.

    The Exxon link above is rather ridiculous because it shows Exxon donated only $40,000 to the website whereas maintaining a site like that over many years, including the 24/7 time that John Daly put into it, would have cost substantially more. It was strictly his personal mission to add fact to the debate rather than belief.

  40. 140

    < <"If the greenhouse gases aren't driving the warming, what is? Elves? The Sun sure isn't, because I've run that regression myself and it doesn't hold up."

    For the context of your reply, please define "the warming" (what time frame and range) and 'greenhouse gases' (which ones?)>>

    I regressed temperature (temperature anomalies + 287 K to find absolute temperatures) on Mauna Loa CO2 fraction, a trend, and the sunspot number. The period covered was 1959-2004 (N = 46). CO2 and the time trend were both highly significant (p > 99.9%), sunspot number wasn’t even significant at the 95% level. If you have another solar time series you’d like me to use, I’d be glad to run it through. CO2 all by itself accounts for 74% of the variance, so even if there is a Solar effect it’s most likely trivial.

  41. 141

    Re: #140

    That should have had the quote from earlier where the denialist guy asked me for the time period and which greenhouse gas(es) I was talking about. Here it is again, with my original phrase and his reply:

    [[["If the greenhouse gases aren't driving the warming, what is? Elves? The Sun sure isn't, because I've run that regression myself and it doesn't hold up."

    For the context of your reply, please define "the warming" (what time frame and range) and 'greenhouse gases' (which ones?)]]]

    Guys, never use double angle brackets to quote stuff — browser HTML interpreters take it as a tag!

    -BPL

  42. 142
    PHEaston says:

    RE 133. Thomas Lee Elifritz
    Given your very pessimistic view of our future, I’m interested to know which period in history you would prefer to have lived. When were things better?

    Regards

  43. 143
    caerbannog says:

    re: 117

    re #109 and “We contend that, yes, mankind is contributing to warming through CO2 concentration, but not in even the remote neighborhood of the dire warnings of Mr. Gore or Mr. Brokaw, etc. Many also believe human attribution is not proven; that CO2 concentration is caused by warming, not that it drives warming, but that there still is human-contributed warming due to other factors.”

    If the greenhouse gases aren’t driving the warming, what is? Elves? The Sun sure isn’t, because I’ve run that regression myself and it doesn’t hold up.

    Obviously, you are talking about the same elves who are responsible for stratospheric cooling. ;)

    But more seriously, the observed stratospheric cooling is the most obvious nail in the coffin for the denialists’ solar-forcing claims. Unless, of course, they can come up with a plausible mechanism that would explain how an increase in solar output would cool the stratosphere.

    Perhaps Mr. Donahue could provide a non-greenhouse-gas explanation as to why the stratosphere his been cooling while the troposphere has been warming. I suspect that such an explanation will involve a *lot* of arm-waving, though…

  44. 144
    caerbannog says:

    re: 142 (I must have forgotten to close a #$@! tag.)

    My response to the quoted material starts with:

    Obviously, you are talking about the same elves who are responsible for stratospheric cooling…..

  45. 145
    Robin Johnson says:

    Slightly off-thread – Peter Doran (Antarctic cooling) has an interesting op-ed in the New York Times (free registration required).

    http://www.nytimes.com/2006/07/27/opinion/27doran.html

  46. 146

    Even if you assume a continued linear rise of carbon dioxide concentration at the observed level of 2 ppm/y, complete melting of the ice caps is ‘certain’. I can’t speak for anyone else, but I consider that ‘irrefutable’.

    However, in the greater scheme of things, thermodynamics, quantum mechanics and general relativity is certainly ‘refutable’.

    Give it your best shot, we’re counting on you.

  47. 147
    Hank Roberts says:

    John Donahue:

    If it’s “irrefutable” it isn’t science.
    I don’t mean just climatology or atmospheric chemistry.

    You’re mixing rhetoric and research and they don’t mix well in discourse.

    Science is by definition refutable. Falsifiable is another word for how science works with the world.

    Again, you are taking your material from the public relations sites that offer puffery in the service of paying clients, primarily the Western Fuels Association.

    Why do you trust these people for your information?

  48. 148
    Mark Shapiro says:

    Re 144: The Peter Doran op-ed on his antarctic temperature studies, and how he feels they have been misrepresented, is exactly on the topic of the difficulty of keeping claims and counterclaims in context.

    Re John Donohue’s several comments – I especially liked “Certainly each poster here speaks for himself, but perhaps 135 ought to make a trip to the mound to settle down 133.”

    Many of us are trying to sort wheat from chaff, signal from noise. If you want reasoned, low-temperature discussions of the issues, comments on blogs are not the place to go. But there are signals even here, as you have seen. Some are about the science, some about the politics and money, some about emotions. Good luck sorting them out.

    Should you look at oil companies’ scientists? Sure, but cross-check all the assertions and conclusions ASAP.

    BTW, commenters often use works like truth, certainty, proof, irrefutable, so just discount them. Look at MBH 99, which provoked the Barton investigation and Wegman report. The subtitle is “Inferences, Uncertainties, and Limitations”. Sounds appropriately cautious and measured to me.

  49. 149
    savegaia.de says:

    Here is another little off-thread from ABCnews about paid lies from a company
    “Making Money by Feeding Confusion Over Global Warming”
    http://abcnews.go.com/Technology/GlobalWarming/story?id=2242565&page=3

  50. 150
    John Donohue says:

    re: 139 Dan,

    a) No rational person is unqualified to question the logic and methods of any scientific paper on the grounds of errors in those papers. The objection does not have to be about the subject matter per se, it can about the logic. A sharp, rational MBA, statistician or mathematician is qualified to spot holes in the structure and method of a study in another field, should they exist. They can also spot holes in the general interpretation/conclusions of a tendered proof. They can also call into question, with authority, the level of certainty attributed by the Consensus with regard to models that predict a completely radical departure from natural cycles. A journalist can offer contrary studies that contradict the consensus that stand unchallenged. Hell, Matt Damon mopping up the corridor of a building at MIT is qualified to challenge, if his brains and logic are good enough.
    b) if the points are trivial or irrelevant, the consensus response would be devastating, correct? If thus refuted, how could they have any traction?
    c) right now, the issue of the particular peer review system upon which the AGW Consensus counts so heavily, is itself the subject of fresh focus by the contrarian community. You can count on more of that, indefinitely.


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