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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. 1

    Can we all get on with something more interesting now?

    Sure, like when the United States will become one nation under science again?

  2. 2
    Dano says:

    Can we all get on with something more interesting now?

    Yes, let’s examine the multitudinous alternative hypotheses and testable results by the handful of skeptical climate scientists out there.

    All their results that explain the warming as natural. All their data. Let’s audit it.

    Lets begin.

    Any time now.

    Discuss all the data they collected.





  3. 3
    Joel McDade says:

    I would appreciate it if you would post larger chart images, or link to larger versions.

    These are unreadable. I cannot evaluate your point, therefore.

    Thank you,

    [Response:Sorry. Should be ok now. -gavin]

  4. 4
    pat neuman says:

    I’d like to put that on my resume, i.e. that I’m … “part of a tight-knit social network of climate scientists,”
    … along with other things I’ve done: prairie landscaping, paleontology studies, parenting, hydrologic modeler, bird/butterfly watching, EX-river forecaster, environmentalist, troublemaker, …

  5. 5
    Mark Shapiro says:

    Wegman et al did look at both MBH 98 and MBH 99. But I recall that MBH 99 specifically warned about added uncertainty going back beyond 1400 because of sparse data. That caveat is rarely mentioned.

    A couple other minor observations: Wegman mentioned (offhandedly) something about CO2 sinking because it is heavier, and when asked if he thought GW was important, acknowledged that we had warmed about 2 degrees F since 1850 but offered that most people couldn’t notice the difference between 72 and 74 degrees. North responded well to both points.

  6. 6
    George A. Gonzalez says:

    From a political point of view it is extremely unfortunate, one might say pathetic, that with the signs of global warming all around us (e.g., persistent heat waves, melting polar ice caps, rapidly retreating glaciers, etc.) the Congress is still stuck debating the merits of the global warming science. Given the emergency we are facing as a species, we need to be on square #15: discussing how high should a carbon tax be, how to save the rainforest, how to save the oceans, how to get those SUVs off the road, what are the merits of geoengineering, how to ensure that people get the income they need in a low carbon economy, etc. The hearing amounted to Nero playing the violin while Rome burned. But the hearing was worse, because at least Nero did not play while humanity was the verge of extinction.

  7. 7
    Hank Roberts says:

    Here’s what Wegman said about CO2 density, I typed that as I heard it.

    Didn’t North’s “Blockhead” method result — a chart simply averaging all the proxies without any treatment — also confirm the published pattern?

    I didn’t manage to type any of that, but I remember he said they did that to find out which proxies contributed any odd bumps, and noticed that the Medieval period bump disappeared — because some areas of the world were warmer and others were colder during that period. He made the point that climatologists look at overall climate because CO2 is well mixed.

    It was fascinating to hear the chairman reiterate he represents a coal mining state several times. Yo, voters!

  8. 8
    Armand MacMurray says:

    Do you have any graphs showing the results of following the North et al NAS committee’s recommendations on proxies, such as not using bristlecones?

    [Response: Read Wahl and Ammann (2006)… – gavin]

  9. 9
    Ender says:

    We all know it but are completely helpless to stop it. The AGW debate is being effectively swiftboated. Rep Barton can trot out endless rounds of these studies and people such as yourself can refute them until the cows come home but the fact remains that to the general public that knows anything about global warming, Hockey Stick = AGW. The main problem is that the contrary data does not have to be true. Lies and innuendo are good enough.

    Refute the Hockey Stick and you refute AGW plain and simple in classic swiftboat style. I still maintian that nothing effective, trancending economic issues, will ever be done until/if something destructive and disasterous that is clearly and irrefutably linked to AGW occurs to the US or some other first world country. Until then nothing, other than the research that builds our knowledge, will be done while money is the primary focus.

    BTW Nero did not poor accelerant on the flames of Rome while he fiddled so actually he is one up on us.

  10. 10
    Glen Raphael says:

    I had the impression the most interesting part of the MBH “hockey stick” was the part before the charts presented in this post – years 1000-1400. Does a version of these charts exist that shows the impact of fixing the centering and other issues on perception of the Medieval Warming Period?

    [Response: I’ll try and find one… – gavin]

  11. 11
    Ernestine Gross says:

    This is a quick thank-you note addressed to the RealClimate people for your efforts to dissiminate your knowledge to the wider public.

  12. 12

    From Mr Wegman’s printed testimony:

    “Because of this apparent isolation, we decided to attempt to understand the paleoclimate community by exploring the social network of authorships in temperature reconstruction.”

    “Because of these close connections, independent studies may not be as independent as they might appear on the surface. Although we have no direct data on the functioning of peer review within the paleoclimate community, but with 35 years of experience with peer review in both journals as well as evaluation of research proposals, peer review may not have been as independent as would generally be desirable.”

    “The MBH98/99 work has been sufficiently politicized that this community can hardly reassess their public positions without losing credibility.”

    –Now here, we have genuine exhibits of bad methodology and unsupported conjecture.

    Where did these non sequiturs come from, and who ordered them to be in there? In a report that begins by “circumscribing the substance” to “an independent verification by statisticians of the critiques of the statistical methodology…”?

    Anyway, as it was foretold, here it is: Our lobbied House Representatives are going after an old study that is already superseded, and they are ignoring all the other data. You scientists are being slandered, dissed, and dismissed.

    –Report by Lee A. Arnold, Society for the Long-Term Modeling of the Anti-Science Crooks in Congress, and Their “Social Network”

  13. 13
    Max says:

    Re #1:

    Do you know what happened last time, when a whole nation was put at sciences hands: Soviet Union.
    It was one of the biggest social engineering projects available and brought great loss to all of the people living in it. The last thing I want is politics and science to merge, it would be disasterous for science and a new religion for politics.
    Natural Science must be an open independent field to evaluate nature and not a thing to influence governments to base their policies on.
    Instead, you should focus to persuade people to follow your belief of an environmental-friendly lifestyle. If you cannot, then perhaps your ideas aren’t so good as you thought.

    For the rest, I have still to see a warming that is unprecedent. Why are there even different numbers for past data. A warming of 2C down to a warming of +0.24 °C per century. Which is true, the first or the latter? Why are there even such vague expressions on past warming?

  14. 14
    Juola (Joe) A. Haga says:

    I suggest petitioning Congress for a bill. Although tradition encrusts the Brits, their Parliament now allows journalists, to cope with global warming’s heat wave, attendance in shirtsleeves. Our 535 rule-makers, surely more forward-looking, ought to allow jpurnalists in the coming heat waves to appear bare-assed nekkid. Or how will one lighten up the fog-bank on the Potomac? John Quincy Adams regularly introduced a petiion to discuss slavery every session for years. Regularly the House tabled it. But the topic was by thius and other means kept alive. Congress’s refusal to discuss led to the ultimate violence. Belts of arable land will shrink. Either with forethought and discussion the world’s population will also shrink humanely or some very real nastiness and naughtiness will ensue in a generation or two.

  15. 15

    The Center for American Progress has kicked off a campaign for American energy independence called Kick the Oil Habit. Find out more and take the pledge at and watch Mark Pike and his buddies try to drive across the US using only ethanol – their video blog is available on You Tube. We need your help – you can make a difference – contribute to the collective genius (and bring a friend). Thanks!

  16. 16
    teacher ocean says:


    You need to educate yourself in science. “I have still to see a warming that is unprecedent”? First, this sentence is grammatically incorrect. Second, what do you base your precedent on? Relying on your personal experience alone to evaluate nature is naive. I have relatives who smoked like a chimney and who lived to be 90 something, then died in a car accident. Does this discount medical findings that smoking causes lung cancer? And, by the way if you have yet to feel global warming, you haven’t been very observant. I am 37 years old and the winters I experienced in my childhood were far colder than those I’ve experienced in the last 10 years. And the death, en masse, of coral reefs from waters that are now TOO warm for them [which you can learn about from just watching TV] is again warming you can experience in your life time from just paying attention.

  17. 17
    Dan says:

    After reading about the methods for compositing proxy networks ad infinitum, the reader might be left with the impression that the compositing methods justify the result. However, one must be reminded that traditional dendroclimatology methods are not very good at all for reconstructing the magnitude of climate variation at the centennial time scale. In my opinion, what we need are more novel ways to develop (i.e., detrend, such as RCS methods) and interpret (i.e., what climate variables have the most functional relationship with growth?) tree-ring chronologies. Lets move the discussion from the uncertainity in compositing methods to the uncertainty in the underlying proxies.

  18. 18
    Ron Taylor says:

    Things may not be as grim as some of the above posts would indicate. Besides the oil and coal companies, there are other important financial interests in play on the issue of AGW. Business Week has had a number of articles in recent months on how the insurance industry and the electrical power industry have accepted the reality of global warming and are adjusting plans accordingly. I recall one report from a meeting of electrical power company executives in which they were virtually unanimous in their opintion that some form of carbon tax would be imposed within the next few years. They simply cannot afford to ignore the reality described by the data before them.

  19. 19
    Joel Shore says:

    Does anybody know if there is a way to watch the hearing now that it is over? I know that they had a “webcast” up while it was going on and I had hoped they would have the full file online to watch once it was finished. However, this does not seem to be the case.

  20. 20

    Re: #13: “Do you know what happened last time, when a whole nation was put at sciences hands: Soviet Union.
    It was one of the biggest social engineering projects available and brought great loss to all of the people living in it. The last thing I want is politics and science to merge, it would be disasterous for science and a new religion for politics.”

    Something I actually know of, because I obtained and published a document in 1991, originating from the Soviet Academy of Sciences, summarizing research carried out by that institution. The research was led by KGB Gen. Anatolii Kuntsevich. It described in general terms the profound damage to public health in the USSR caused by the use of chlor-organic compounds such as dioxins and furans. The document was signed by three notables, including the Chairman of the KGB, Kryuchkov. It was adddressed to Gorbachev.

    If anyone here reads Russian and has access to a Slavic languages periodicals library see Nezavisimaya Gazeta for November 11, 1991.

    The situation in the USSR was completely different from the one that obtains in the West, and yet strangely similar. The SU was run not by scientists but by the Central Committee of the CPSU, with a parallel power source in the KGB. The country was environmentally ravaged, since the Party was all-powerful and could do what it liked with the environment in most cases (there were exceptions, notably in the plan to divert the courses of Siberian rivers).

    In the West we have representative government, not the dictatorship of one party, and yet the controlling group here is most certainly not scientists, as you’re finding out when you try to think up practical political strategies for stopping the onrush of climate change.

    Do many scientists think that all that is necessary to change fundamental social and economic behavior is to present rational evidence and conclusions? Something more basic is required. The Montreal Protocol of 1987 suggests what that might be.

  21. 21
    pat neuman says:

    re 18. Ron wrote … They simply cannot afford to ignore the reality described by the data before them. …

    Then I read:

    “The four-day heat wave, caused by a high-pressure system to the south pumping in hot air from Mexico, resulted in heat advisories being posted in the South, Midwest and Northeast United States.

    Record temperatures were also set in Stockton, California (110 degrees) and Salt Lake City, Utah (103 degrees).

    “A heatwave like this usually comes about once a year,” said a spokesman for the National Weather Service. …

    Does anyone believe that a heatwave like this usually comes about once a year in the US, besides the spokesman for the National Weather Service?

  22. 22
    Tom Fiddaman says:

    Wegman’s Figure 4 appears to disagree with Wahl & Amman’s 5d, reproduced above, over the period from ~1800 on. Any speculation as to why? Presumably it involves non-exclusion of M&M criticisms deemed invalid, but which and why do they matter?

    [Response: Wegman’s graph is mislabelled. It is PC1 of the N. American network, not the full MBH reconstruction. See here. – gavin]

    [Response: Update: I should have been clearer. The figure is from the earlier posting and shows the PC1 (and PC4 with centered PCA). Actually, I should have linked to figure 4.3 in the full Wegman report which is correctly described. – gavin]

  23. 23
    Lynn Vincentnathan says:

    “…but still, the public recognition is nice.” Yeah!

    In my college poli sci course the prof told us (re candidates): positive publicity is best; negative publicity, 2nd best; and no publicity, the worst.

    So now that more people have been made aware of RC, let them come here & see for themselves, & come to their own intelligent conclusions about “is GW real.” Please leave contrarian biases and motives at the door for a brief moment.

  24. 24
    Lynn Vincentnathan says:

    Also, I say: Don’t miss the forest for the tree rings. It’s hot today!

  25. 25
    Hank Roberts says:

    22 — Wegman’s Figure 4 … is mislabelled. It is PC1 of the N. American network, not the full MBH reconstruction…

    That’s a rather devastating mistake. I wonder if they’ll try to correct it.

  26. 26
    Peter says:

    “Response to #22: Wegman’s graph is mislabelled. It is PC1 of the N. American network, not the full MBH reconstruction. See here. – gavin”

    would it be possible to ask that the testimony document be corrected ?
    I can see this figure picked up by the “contrarians” and trotted out
    as the definitive shoot-down of MBH98.

  27. 27
    Mark Shapiro says:

    Re 1, 13, and 20, and the role of science and scientists in government policy.

    Many of us who read this site would like scientists to have more influence on our government’s policies. We should recognize two things: 1) they don’t; 2) the very idea terrifies many people and clearly provokes all kinds of attacks. The Wegman hearings, even if you don’t see them as an attack, is clearly the vehicle of attacks, like the WSJ editorials that some Congressman read, so quickly, into the record.

    So use the first fact to counter the second. Please. How does one scientific paper, actually just one graph from one paper, get to be the subject of a hearing in the United States Congress? Folks are afraid of Mann + MBH99 + IPCC + RC + its audience, that this “clique” is going to influence energy policy. They certainly haven’t yet. They won’t get close to influencing it, because they don’t have power. Congressman Barton does. The President of the United States and the United States Congress (and their social networks) do.

  28. 28

    Re #22,


    Wegman explicitely says for Fig 4.3 in his report that the graph showing the difference between decentered/centered methods is about the PC1 of the N.American network.
    He also comments on the relevance of bristlecone pines in the N.American PC1, with and without the methodological differences, on page 81.

  29. 29
    Jan Rooth says:

    You’ve got to admire the power of the imagery in Figure 7 of Wegman’s testimony. Dr. Mann lurking menacingly like a spider at the heart of the web.

    Do we know who proposed the idea of tacking the social network analysis to this investigation? The testimony is vague, only saying “we decided” to do it. It seems rather an odd thing to just independently decide to do, when your task is otherwise so carefully circumscribed (as noted, they abstained from examining what effect the PC centering changes would have had on the final reconstruction, presumably because they were not tasked to do that).

  30. 30
    Terry Miesle says:

    But I thought President Bush said we’d base policy on ‘sound science.’
    Or did he mean “sounds like science?”

    Thanks for the site guys, it’s a great resource.

  31. 31
    George Landis says:

    According to your policy here you do this: “The discussion here is restricted to scientific topics and will not get involved in any political or economic implications of the science.”

    So why are there so many political and policy oriented statements and discussions going on here? One would think this to be a political blog, as most do.

    [Response: We try to keep politics out of it, but we are not always successful… – gavin]

  32. 32
    Mark Shapiro says:

    Re 29, from George Landis: ” . . . So why are there so many political and policy oriented statements and discussions going on here?”

    A valid question, and as a faithful reader and sometime commenter I readily admit to writing on the politics and policy of climate. My excuse is that it is difficult not to when a piece of the science is investigated by two congressional committees.

    But note that the eight contributors restrict themselves pretty well (I would say amazingly well) to questions of the science. It is commenters like me who can’t help edging into policy questions.

  33. 33
    Doug Percival says:

    George Landis pondered: “So why are there so many political and policy oriented statements and discussions going on here? One would think this to be a political blog, as most do.”

    Wealthy and powerful individuals and corporations who stand to become astronomically more wealthy and powerful from the use of fossil fuels — particularly in the “peak oil” era of increasing demand and declining supply — do not want humanity to reduce the use of fossil fuels in response to anthropogenic global warming, so they politicize the subject and attack the science, for example by recruiting United States Senators to proclaim that global warming is a “hoax” and recruiting United States Congressmen to attack the work of climate scientists.

    Ideally, there would be nothing “political” about dealing with anthropogenic global warming, no more than there would be anything “political” about dealing with a large asteroid or comet heading directly for a collision with the Earth. But unfortunately those who seek to forestall any significant reduction in the use of fossil fuels, in the interest of their own enormous financial gain, have thoroughly politicized the issue, and made it difficult to discuss it without some reference to the hostile political environment that they have deliberately created around it.

  34. 34
    Armand MacMurray says:

    Now that’s a nice science post! :)

  35. 35
    cat black says:

    Business is become the New Religion. And just as rational science once fell afoul of the Old Religion, so now. These modern hierophants simply will not abide discussion of their superior position as thought-leaders. But business was born in ancient times of rationalism, and science is its parent; I can’t see this “I Am The Word” posturing from Washington and General Motors to continue for very long. It’s just silly and thinking people will see that ere the end. Hopefully well before the entire Greenland ice sheet makes its way to the sea.

  36. 36
    Mark A. York says:

    More ad hominem for the WSJ and Peggy Noonan. In her world it’s the scientists who are guilty of politics:

    The Heat Is On
    On global warming, the media’s continuing power, Ralph Reed–and revisiting last week’s column.

    Thursday, July 20, 2006 12:01 a.m. EDT

    During the past week’s heat wave–it hit 100 degrees in New York City Monday–I got thinking, again, of how sad and frustrating it is that the world’s greatest scientists cannot gather, discuss the question of global warming, pore over all the data from every angle, study meteorological patterns and temperature histories, and come to a believable conclusion on these questions: Is global warming real or not? If it is real, is it necessarily dangerous? What exactly are the dangers? Is global warming as dangerous as, say, global cooling would be? Are we better off with an Earth that is getting hotter or, what with the modern realities of heating homes and offices, and the world energy crisis, and the need to conserve, does global heating have, in fact, some potential side benefits, and can those benefits be broadened and deepened? Also, if global warning is real, what must–must–the inhabitants of the Earth do to meet its challenges? And then what should they do to meet them?

    You would think the world’s greatest scientists could do this, in good faith and with complete honesty and a rigorous desire to discover the truth. And yet they can’t. Because science too, like other great institutions, is poisoned by politics. Scientists have ideologies. They are politicized.

    All too many of them could be expected to enter this work not as seekers for truth but agents for a point of view who are eager to use whatever data can be agreed upon to buttress their point of view.

    And so, in the end, every report from every group of scientists is treated as a political document. And no one knows what to believe. So no consensus on what to do can emerge.

    If global warming is real, and if it is new, and if it is caused not by nature and her cycles but man and his rapacity, and if it in fact endangers mankind, scientists will probably one day blame The People for doing nothing.

    But I think The People will have a greater claim to blame the scientists, for refusing to be honest, for operating in cliques and holding to ideologies. For failing to be trustworthy.

  37. 37
    mark says:

    That’s a bunch of nonsense. The scientific community has come to a consensus, you just don’t want to believe it, so you and people on the right resort to making up garbage about how science has been taken over by politics, liberals, etc. The fault lies mainly with the people spreading disinformation, like republican politicians and the oil industry. However, it’s not the scientists’ fault if dumb people listen to the propaganda instead of investigating the facts. If you believe Rush Limbaugh over real scientists, it’s no one’s fault but your own.

  38. 38
    cwmagee says:

    Interesting timing. This has nothing to do with the cngressional hearings, but today I found out that a world-class, white, western geoscientist has decided to move to China, because it offers him less political interference, more reliable funding, and better instrumentation than working in the US, Europe, or Australia.

  39. 39
    Robin Johnson says:

    I always found that “Environmentalists/scientists are just a bunch of Communists” accusation highly amusing. My response is always: “Have you EVER seen pictures of Eastern Europe from when the Soviets [Communists] were in charge?”

    Communism wasn’t based on science, it was based on “economic science” and very typical utopian political thought processes of the kind that has often led to political and social disasters. Without impugning the honor and valuable work of economists, equating the work of economists with “traditional” scientists is clearly a logical fallacy and a misplaced insult.

    State of the art [18th century] theories in natural science, economic science and poltical science known to scientists and thinkers like Tom Jefferson and Ben Franklin were critical to the formulation of the US Constitution and helped guide early American principles of governance.

    Scientists have been conducting their side of the debate using “the unwritten rules of scientific discussion and argument.” While there are skeptics who adhere to those rules of the “debate”, many others are conducting their side of the debate using “the unwritten rules of legal argument”. The purpose of scientific argument is to establish what is likely true. The purpose of legal argument is to establish who gets the money or power. In a legal debate, “truth” can be decided by a “vote”. In science, “truth” is always provisional. In legal debate, precendent is revered and protected where discovery of error is a matter of great shame. In a science debate, everything “known” is open for ridicule and actually showing previous belief to be erroneous is often greeted with laughter – as in “wow – we were STUPID to think THAT”.

    So, for a Congressional Committee to use “legal” arguments to undermine a scientific finding is not really a surprise. And refuting “legal” arguments using the rules of scientific argument is time consuming, tedious and highly frustrating. That’s why maintaining “scientific” discipline in the face of such tactics is very important.

    It also is important to focus the discussion into the REAL political realm. Legitimate political debate focuses on what policies will lead to “success” [as defined by the electorate]. Finding the right policy can be a challenging, highly complicated process even when everyone is playing on the same “team”. Policies that advance the long term goals of the electorate require “good” political, economic and natural scientific theory and information. The natural tendency in the face of uncertainty is to maintain the status quo or make simple tweaks. Forging a consensus for a radical departure in policy based on complicated theory and data is hard, slow work especially when the costs and consequences are seemingly or actually high.

  40. 40
    pat neuman says:

    re 37.


    I was warned by my supervisors and directors for National Weather Service (NWS) that climate change science was too political, liberal, etc. Maybe attitudes toward research on climate change and hydrologic modeling changed after I left the NWS North Center River Forecast Center in 2005. I don’t know anyone close enough in NWS anymore to talk to in order to find that out. While I worked there, no one would say anything about climate change or global warming. I couldn’t help speaking up about how climate change affects hydrology so they got rid of me. It was not just my supervisor and NWS directors that wanted me out, as I was told later by my supervisor, but also John Mahoney, a NOAA administrator and head of the US Climate Change Science Program.
    My supervisor carried that out in July, 2005. As I see things now, the reason for an absence of will by the public to slow greenhouse gas emissions lies with government officials allowing disinformation on global warming to continue to be accepted by the public. Agencies in the US have failed in seeing to it that accurate information and education on global warming reaches the public. Otherwise it would have been well known by the public that the scientific community reached consensus on global warming many years ago.

  41. 41
    Tim D says:

    The last line of the Wegman report caught my eye. I quote it below in full:

    “The most conclusive finding is that the 20th century is the most anomalous interval in the entire period of analysis, including significant positive extremes in the proxy records.”

    I’m just joe public but I’d interpret that as meaning:
    More ‘anomolous’ [Deviating from the normal or common order, form, or rule] than the ‘significant positive extremes in the proxy records’ [i.e. the medieval warming period and Little Ice Age period].

    My reading of that is the Wegman report is saying:
    a) There is Climate Change/warming
    b) It is more significant than the other unusually significant periods of climate change that we have seen before, in the past thousand years.

    If anything, I see that line as backing the central notion of the Mann report.

    [Response: Wegman is just paraphrasing Osborn and Briffa (2006) (which we discussed ) – gavin]

  42. 42
    George Landis says:

    I notice in the press today that a new congressional hearing by another House Committee (Mr. Davis’)is happening next week. It also quoted one of the invitee scientists as saying that today is 8-10 degrees warmer than 1000s of years ago. I cannot see that in even Mann’s extreme scenarios, anyone know what that is about?

    [Response: That happened yesterday, and the 8 to 10 degrees (F) remark was in relation to the ice ages (20,000 years ago) – which is an interesting number of course – but not relevant to the temperature reconstructions of the last millennium. – gavin]

  43. 43
    George Landis says:

    OK, thanks, I thought perhaps Jim Hansen made that comment, since he used to think extreme climate scenarios are useful in provoking political action.

    [Response: No he didn’t. I suggest you actually read Hansen’s actual remarks, rather than someone else’s partisan pseudo-interpretation: – gavin]

  44. 44
    tom root says:

    Can someone give me link to some theories as to what was happening in the tropics during the glacial epochs. (Either here at RC or elsewhere) Thanks!

  45. 45
    John Donohue says:

    re: 42
    I can almost bet you that “8-10 degrees 20,000 years ago” was a result of pulling an alarm point from the Discovery Channel show “Global Warming all you need to Know” which aired Monday. Right in the first segment of that show there was a cynical moment. As an illustration of the ‘terrible melting’ now taking place, the speaker was standing in melt water of a glacier. He said “things are a LOT warmer here than they were 20,000 years ago.” No context was supplied! I screamed at the TV: “Yes, the Earth was in full glaciation then; this is the interglacial!” That was a dishonest moment for that show.

  46. 46
    Ron Taylor says:

    RE #36

    Mark, I assume your post is a quote of Peggy Noonan, right? In any case, I cannot tell you how sad it makes me. It illustrates perfectly the chasm of world view between the scientific community and today’s political conservatives. It calls to mind John Deanâ??s quote of Barry Goldwater from a conversation they had in 1994. Goldwater asked, “John, where in the h**l is the conservative movement headed in this country?” Dean replied, “Barry, I don’t know, but I’m going to try and find out.” The result was Dean’s recent book, “Conservatives Without Conscience.” (Having been a Goldwater precinct captain in 1964, I sympathize with his question.)

    First, ask yourself why someone would become a scientist. Is it because of a lust for power? For money? Nonsense! For most, it is because of a deep curiosity about some aspect of the world and how it works. They are driven by the need to understand and explain things. Getting to that point requires intellectual discipline to master their field and to avoid having their work distorted by personal bias. But personal discipline alone won’t suffice, so a second level of discipline is imposed by peer review. If you have an idea or have achieved some result, you have to write it up in the most rigorous way you can, then submit it for publication. If it passes the initial screening and is published, then hundreds of highly competent people in your field will go through it carefully, trying to pick it apart, to find where you may have erred. To be effective at all in science requires both intelligence and intellectual honesty in seeking a description of provisional truth.

    By contrast, political conservatives represented by Imhof, Barton, Noonan, Limbaugh, et al, see the world entirely through ideological lenses, with power and money as dominant core values. So when an idea or a scientific result surfaces that is in conflict with their ideological goals, they assume it must have emerged from a conflicting ideology, i.e., “liberalism!” They cannot comprehend the possibility of non-ideological, objective truth (albeit, for the scientist, provisional.) Everything is reduced to politics and “inconvenient truths”, whatever their merits, are countered by political attack. What better illustration than the attempt to blame the whole AGW issue on a “small, in-bred group of paleo-climatologists.” The scientific consensus, of course, extends vastly further than paleo-climatologists, even if the description were accurate.

    Global warming will continue its relentless march, so eventually the chasm of understanding will be bridged, perhaps by the business community, which cannot base its decisions on ideology.

  47. 47
    Lynn Vincentnathan says:

    Re #31, AGW by definition includes a human element, which brings in the need for human scientific inquiry (both on the cause & effect side). I know the social/behavioral sciences are not as scientifically “hard” as the physical sciences, mainly because people/societies/cultures are a lot more complex & there’s this self-reflexivity about them (sort of like an endless hall of mirrors).

    So, that means that perspectives from poli sci, econ, sociol, anthro, psych should all be considered when studying AGW holistically. And I think you could bring in the humanities, since AGW is also a moral issue.

    Many who contribute to this site (such as myself) are not physical scientists, though we want to learn more about the physical science side of AGW. We can only offer other comments & ideas, and for the most part these are not even rigorously within the human sciences domain either. So, just take them as hypotheses. RC & scientists did not bring politics into AGW — AGW is political/economic/cultural/social/psychological, as well as physical, by its very nature.

    The issue of AGW is important enough that we must thrash it around and hammer out ideas about it, no matter how “unscientific” they may seem. We need to grasp AGW at a level that includes, but goes beyond the physical sciences.

    As for the above critiques on “communism,” I would add that the Marxian conflict or critical perspective in the social sciences asks, “Who benefits?” I personally don’t follow that perspective because it is economic (social) deterministic. But the question is a good one to keep in mind.

    BTW, I personally find fault with both communism & capitalism — both of which are concomitants of industrialization. We need to move on to a better world for all. By refusing to address & solve AGW we are not only risking our material support system, but political & economic freedoms & stability, as well. Think of solutions (such as the idea in the UK of carbon rationing — see ) as innoculations against possible social chaos and material degradation.

  48. 48
    Lynn Vincentnathan says:

    Good hypothesis, Ron (#45). It’s important to understand mindsets, as well as motivations (for one, because mindsets can even block people’s realization of their ultimate goals). You are right. People do have a tendency to think in binary oppositions (check out Levi-Strauss’s structuralism), which can help us think, but also can obfusticate deeper, more complex thinking & knowledge.

    That’s why I would suggest keeping the mind as open as possible. So I tend to fall back on: supposing the scientists are right & we do address AGW (or fail to address it). Supposing the denialists are right and we do address AGW (or fail to address it). Since my own experience has been economic improvement through efficiency & conservation (with an increased standard of living), I would say, even if the denialists are right, we should act as if they are not & address AGW. And in so doing ameliorate many other problems.

    Unfortunately, it seems economists are dead wrong — there are no soley economically motivated, rational, Spock-like people to heed this message. There’s other stuff going on in our psyches – like these limiting mindsets, and tangled up motivations & (who knows) subconscious horror stories.

  49. 49
    James L.Young says:

    Year by year we are marching forward onto ‘thin ice’ while the politicians protect their special interests. The endless debating of Global Warming (GW) or not will put us in a position where we have passed the point of no return. When the Arctic Tundra Methane stock releases reach a high rate, it will probably precede Ocean releases of Methane by a few years. When the oceans warming trend continues to the point the vast deposits of Methane Ice stored in the cold waters reverts to gas, we will see a REAL spike in GW and as the saying goes, “Games over over Man”.

  50. 50
    Ron Taylor says:

    Re 45

    John, I found the comment to be more stupid than dishonest. Whether it is warmer today than 20,000 years ago is really irrelevant. I took it to be a minor glitch that should have been caught in editing. Overall, I thought the program was good.