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Followup to the ‘Hockeystick’ Hearings

Filed under: — group @ 31 August 2006

The House Energy and Commerce committee held two hearings on the “Hockey Stick” and associated “Wegman Report” in July. We commented on the first of the two hearings previously. The hearings, while ostensibly concerning the studies of Mann and coworkers, were actually most remarkable for the (near) unanimity of the participating scientists on critical key points, such as the importance of confronting the issue of climate change, and the apparent acceptance of those points by the majority of congresspersons present.

The committee subsequently provided followup opportunities to participants to clarify issues that were discussed at the hearings. Mike Mann (Penn State Professor and RealClimate blogger) participated in the second (July 27 2006) of the two hearings, “Questions Surrounding the ‘Hockey Stick’ Temperature Studies: Implications for Climate Change Assessments”. He has posted his responses to five follow-up questions, along with supporting documents. Among the more interesting of these documents are a letter and a series of email requests from emeritus Stanford Physics Professor David Ritson who has identified significant apparent problems with the calculations contained in the Wegman report, but curiously has been unable to obtain any clarification from Dr. Wegman or his co-authors in response to his inquiries. We hope that Dr. Wegman and his co-authors will soon display a willingness to practice the principle of ‘openness’ that they so recommend in their report….

Update: There is an interesting discussion of the Wegman and North reports by Gerald North (talking at TAMU) available through Andrew Dessler’s site….

94 Responses to “Followup to the ‘Hockeystick’ Hearings”

  1. 1
    John Dziak says:

    I’ve been kind of blown away by a recent comment by physicist Stephen Hawking: “The danger is that global warming may become self-sustaining, if it has not done so already. The melting of the Arctic and Antarctic ice caps reduces the fraction of solar energy reflected back into space, and so increases the temperature further. Climate change may kill off the Amazon and other rain forests, and so eliminate once one of the main ways in which carbon dioxide is removed from the atmosphere. The rise in sea temperature may trigger the release of large quantities of carbon dioxide, trapped as hydrides on the ocean floor. Both these phenomena would increase the greenhouse effect, and so global warming further. We have to reverse global warming urgently, if we still can.” — ABC News interview, August 16, 2006.
    I really respect Dr. Hawking and I wish more people were hearing about this sort of thing and taking it seriously.

  2. 2
    C. DeLise says:

    I’m a bit awed by the text of question #5:

    Question No. 5. Should all scientific papers be withheld from publication until the results are independently replicated?

    Correct me if I’m wrong, but isn’t peer review a major ultimate aim of publishing? If replication is difficult (let’s say because the evidence has melted, etc) or because proving a theory is beyond current technology (i.e., special relativity) should publishing be denied?

  3. 3
    Margaret M says:

    Relying on Hawking for your climate information is like getting your dentist to do brain surgery.

    [Response: Actually it’s more like getting a brain surgeon to floss your teeth. However, in this instance, Hawking is mistaken – there is no danger a Venusian runaway greenhouse effect on Earth – at least not before the sun becomes a red giant, but it’s a relatively subtle point as to why – David Archer has a good discussion in his book ( , figure 7.2). – gavin]

  4. 4

    Re: #3

    I have to agree. With all due respect to S. Hawking’s accomplishments in his field, he does not seem to understand that melting “hydrides” (hydrates?) would release methane, not CO2. It IS a problem, and I appreciate he is trying to lend his credibility to a serious issue, but mistakes like this can cause as many problems as they solve.

  5. 5
    Chris Rijk says:

    Reading the responses to the 5 questions is certainly interesting.

    I tend to see science as a “survival of the fittest” applied to ideas/theories trying to explain the real world. These ideas are tested to destruction – those that aren’t “killed” become stronger. Advances in tools (whether sensors, or mathmatical tools) to measure and understand the real world can sometimes prove a theory wrong – and there’s some famous “negative results” for when this happens. Since scientific theories can be proven wrong, attempting to push a theory you know is wrong will only end in failure.

  6. 6
    caerbannog says:

    When I looked through the Wegman report (convenient link:, I found figure 4.1 to be rather curious.

    The top panel of fig 4.1 shows a “hockey-stick” PC1 that M&M generated from red noise. The bottom panel shows MBH’s “hockey-stick” PC1. What I couldn’t help but notice is that the two hockey-sticks were plotted with wildly different Y-axis ranges. The Y-axis range of MBH’s hockey-stick plot was approx: -0.5 to +0.3 C. M&M’s “red-noise hockey-stick” was plotted with a Y-axis range of -0.08 to +0.025 C. or so.

    Now, it would seem to me that a fair comparison of the hockey-sticks’ significance would require that they be plotted with the same Y-axis scale. But in this case, the Y-axis ranges of the two plots differed by nearly an order of magnitude! Were Wegman and Co. trying to pull a fast one here, or am I missing something?

  7. 7
  8. 8
    Chris says:

    Re #2

    Peer review isn’t a “major ultimate aim” of publishing. Rather it’s part of the process. An anonymous reviewer (or referee) taking part in the peer review process assess the suitability of the manuscript (MS) for the specific journal, determines (as best s/he can) whether the data is sound and adequately analysed and the interpretations valid, whether the MS correctly cites previous work etc. S/he makes recommendations about the figures and tables that are presented (whether these are all necessary, whether other data should be highlighted in figures/tables). The reviewer may suggest (or insist) that other data be included including further work that should be done etc. etc. S/he might take the trouble to point out typos, minor errors, correct grammar etc.

    But that’s more or less it. There isn’t really any means for the reviewer to assess wether the work is reproducible other than to assess whether sufficient experimental details are included to allow for a reproduction of the experiments/analyses.

    The point of publishing combined with peer review is to ensure that studies are “sent” into the scientific/public domain, and that the description of the studies conforms to certain standards (these have a certain degree of subjectivity, but generally a paper must satisfy the scientific perusal of anywhere from 2 to 7 or more referees).

    Questions of the absolute validity of the work, its importance, its reproducibility and impact, at that point (passing peer review and being published) remain to be determined! One assumes that published work is valid and inherently reproducible. But this is only specifically addressed through the scientific process. If the work is important enough it will almost certainly be “tested” either directly (others may do the same experiments) or indirectly (its explicit or implicit conclusions/predictions will be shown to be satisfied or not).

    It’s a process that works pretty well. The idea that one can completely determine the reproducibility of a piece of work independently falls down when one considers what would be involved (a vast pool of technicians whose job it would be to redo every study that was submitted for publication!). Of course one generally reproduces the work oneself before publishing, and depending on the nature of the work, the reproducibility is likely to be explicitly described in terms of a statistical analysis.

  9. 9 says:

    @John Dizak
    Thx, for the info id just like to add the source containing a 3 page interview with the master.

  10. 10
    Hank Roberts says:

    Hey, let’s talk about the topic – the documents linked at the top post are interesting enough.

    And I hope Dr. Wegman does participate. The problem is bigger than we are, we need to inspect it from all possible angles — as the blind men said about the elephant.

    He did say it’s time to lay the old research issues down and address what’s happening now, expressed concern about the oceans, and has worked with the Navy. And the Navy through their Grad School is doing some interesting work that’s public.

  11. 11
    Vern Johnson says:

    For those two entries critical of Hawking, they should be reminded that methane could have much the same effect as CO2 in aggravating and prolonging global warming. The point Hawking is trying to make is that we do not fully understand the climate of Venus where any water that might have existed is long gone let alone any signs of organisms. It is not a foolish comment by Hawking at all. It was a well-informed one. Vern

  12. 12
    Hank Roberts says:

    P.S. — Dr. Wegman also has astronomical interests (I believe his chair is in physics and astronomy at GMU). This one is interesting at least for contrast:

    “Statistical Software, Siftware and Astronomy


    This paper discusses statistical, data analytic and related software that is useful in the realm of astronomy and spaces sciences. ….

    1. Introduction

    It seems somewhat presumptuous for a group of statisticians (and one astronomer) to tell a group of astronomers what manner of statistical software they need. …. Fortunately, there are a few guides to the type of statistical methods perceived by astronomers as being required. …”

  13. 13
    ike solem says:

    Re#4, and other comments on Hawking’s statement:

    Methane is CH4 and does have a place in the infrared window, but it’s lifetime in the atmopshere is ~10 years, compared to the residence time of CO2, ~100 years. However, methane + oxygen in the presence of sunlight eventually produces CO2, so the atmospheric flux of methane results in increased atmospheric CO2 as well.

    For a description of the atmospheric infrared window and the absorption spectrum of all the atmospheric components, see

    Stephen Hawking probably took a look at all the processes, and noticed that they have a positve feed-forward effect on carbon dioxide and temperature, from the albedo effect to the melting permafrost effect to the wildfire effect to the relation between ocean temperatures and dissolved gas concentrations – there are very few negative feedbacks. Cloud formation in a wetter, warmer atmosphere was once thought to be a strong negative feedback, but break-even seems more realistic after years of research on the topic.

    At some point, certain processes must limit atmospheric CO2 concentrations as well as surface temperature. Venus has an atmosphere of 97% CO2, Earth was at 280 parts per million and will almost certainly get up to 560 ppm, if not 840 ppm. That’s a big difference. Still, sea level rise might be far faster and higher than current estimates.

    Whatever the long-term result is, it seems that the rate of change is accelerating. It is possible to monitor sources of CO2 using methods such as carbon isotope analysis (see realclimate: If the ‘natural system’ starts releasing massive amounts of CO2 as a ‘tipping point’ is reached then one might be able to detect this.

    So, are CO2 emmissions to the atmosphere set to increase? Look at the original Hawaiian record compiled By Dr. Keeling:

    The slope at the bottom left is not as steep as the slope at the upper right; what this record shows is a slightly accelerating rate of total CO2 emissions, and due to the above-described positive feed-forward effects, that rate looks set to continue to increase unless large steps are made to reduce human CO2 emissions.

  14. 14
    Hank Roberts says:

    But let’s not let ourselves be distracted, when it’s so hard to focus on the topic, eh?

  15. 15
    Leonard Evens says:

    Reading Mann’s responses to the five questions, I am amazed at his patience. He goes to pains to explain the most elementary aspects of scientific research. It is hard to see how Wegman and colleagues could not be aware of such matters.

    One misconception which seems to underlie the criticisms of Wegman, et. al. is that there is a vast pool of experts available so that it is possible to choose truly independent people to either referee a paper or to try to independently verify the results before publication—a silly idea if I ever heard of one. In fact, in many active fields of research, the number of specialists who are knowledgeable enough to say something sensible is usually pretty small. All these people attend the same conferences, and they all tend to know one another. I know that in mathematics, when I’ve been asked to referee a paper even just slightly outside what I do, I find it very difficult, and when I’m done, I’m not at all sure I caught all potential errors. In addition, I’m unaware of some implicit background information which is necessary to put the work in perspective. So, instead of relying on lack of social interaction among peers, we rely on their scientific integrity. Such integrity is not purely based on altruism. If you publish things you know are false or you collude in such publication, you are bound to be found out in the fullness of time, at least if your results are important enough to draw attention. Some new person entering the field will make his or her reputation by destroying yours. Since Wegman et. al. must be aware of this as it applies to their own field, I can’t believe they are serious about such assertions.

  16. 16
    Dano says:

    In fact, in many active fields of research, the number of specialists who are knowledgeable enough to say something sensible is usually pretty small. All these people attend the same conferences, and they all tend to know one another.

    I was surprised at the amateurish tactic for the network analysis. What sort of campaign uses a tactic that can so easily be turned back on them, what with the same 3 dozen usual suspects appearing at every turn? What kind of manager thinks this will resonate with a wide audience (no one dared pick that up, BTW, folks)? Mind-boggling, yet calming as well – this is the best they could do. They had their shot and took it, and it hit the side of the backboard (the .jpg of the physicists was a nice touch).



    [Response: Indeed – as I pointed out in a response (here, in German) to some of the more weird media reporting on the Barton hearing, almost any internationally successful scientist like Mike has a similar network of co-authors. I have not counted them, but if you go to my publication list you will also find a number somewhere between 50 and 100. The surprising thing actually is that Mike’s network was so small at the time of the groundbreaking 1998 MBH publication, as Mike was a young scientist then and not yet very established in the field (sorry Mike, of course you are still young now). -stefan]

  17. 17
    Jeff Weffer says:

    Regarding the comments about Venus:

    Venus has 250,000 times as much CO2 in its atmosphere as Earth. Solar irradiance is 2,614 w/m2 versus Earth of 1,368 w/m2. Average surface temperature is 464C on Venus versus Earth’s 15C. Someone can do the math to see how much Earth would have to change to reach a run-away greenhouse.

    [Response: No, you can’t from the numbers you gave.

    First, you need to be aware that Venus absorbs less solar radiation per unit area than Earth, namely 130 Watt/m2 on Venus versus 242 Watt/m2 on Earth. These numbers are the ones you gave above, divided by the geometric factor 4 so that they refer to surface area of the planet, and substracting the amount that is reflected back to space and therefore does not affect climate (the albedo of Venus is much higher than that of Earth). Therefore, without its huge carbon dioxide greenhouse effect, the climate of Venus would be much colder than that of Earth.

    Second, from the knowledge that the huge amount of carbon dioxide on Venus is enough to fry the surface, you can’t derive any information on where a critical threshold for a runaway effect on Earth would be (or even whether such a threshold even exists). All you can conclude is that the carbon dioxide greenhouse effect obviously does not “saturate” (in the sense that adding more does not warm the climate any more) before the surface is at a searing temperature. – stefan]

  18. 18
    Lynn Vincentnathan says:

    Re #1 & 3, okay, let’s make a distinction between hysteresis & permanent runaway (which would be the total end of life on earth or any possibility of life in the future).

    We may not get permanent runaway, but even with limited runaway or hysteresis, as happened in the end Permian extinction, up to 95% of life died — and that’s bad enough. They say life is more resilient now, I guess having gone thru several such limited runaway GW episodes and other extinction level eras, so who knows, maybe only 50% of life will die….if we keep releasing GHGs like maniacs & nature starts responding to the warming with her own GHGs & warming through lowered albedo, etc.

    I don’t think there’s anyone who thinks this is an OK situation, just because it’s not so bad as permanent runaway, and just because eventually we would get back to normal, say, in several hundred or thousand years.

  19. 19
    Rob Miller says:

    well, i must say that i am severely disappointed in the myopic set of comments that i have read thus far. this whole “hockey stick” and “hawking adventure” is completely out of hand. a casual observation of “climate”, as it were, and population, and build of environmental toxins, and depletion of natural resources, and degradation of life sustaining resources (expressed positive with respect to an asymtote), and increased decrease of the biome quanta, and spiritual and social deterioration of our species in relationship to itself and the universe, and the planet wide increase in senses of entitlement, and a growing sernse among the fundamentalists and old hippies that we are getting toward a nadir…of what? that nadir might just need to be named. otherwise, get prepared to be the chosen one that can make a hockey stick from a tree and a sharp rock. and be dressed well and built strong to play the game, as it was played in the Pleistocene.

  20. 20
    Rob Miller says:

    something more or less like the Paleolithic awaits those of us who survive, and that right quick. our individual heartfelt desires and our scientific characterizations have almost no effect on the way in which our planet and the rest of its life continues. it will in fact be an extremely viable skill if one has the ability to create a hockey stick with nothing more than a sharp rock and a dead-fall tree limb. one will even trade that skill for a few days food, just like it used to be for our species for the recent last and mostly 200,000 years. this will not in any way be a “bad” thing, but it will entail what some call “giga-death”, and a re-organization of the life of our species to again recognize our intrinsic relationship with all life. sorry for me and you, but truth is we stepped out way too far, and now we’re all gonna pay.

  21. 21
    Rob Miller says:

    and anyway besides, there was never a writ that we were entitled to this earth, we were only allowed here to see if we could find a way to sustain ourselves; the fact that we have, in a very short and recent history, come up fell-short in this regard should be taken for the admonishment that it is: we blew our last chance to change our new-found evil ways. bye-bye.

  22. 22
    Mark A. York says:

    I watched both hearings and it had the atmosphere of a hanging with Judge Roy Barton struggling with reality, and choosing political fantasy. Non atmospheric scientists are qualified to judge those who are. It showed.

  23. 23
    mark schneeweiss says:

    The unstable ‘house of cards’ that contrarianistas now rely on, to try and keep the AGW issue ‘foggy’, now seems to be reduced to going on holiday, to avoid the difficult questions!This would be laughable, if the situation wasn’t so serious.

    It would be surprising if Wegman’s report (which seems to be helping to keep things ‘foggy’), can retain any credibility, if he doesn’t pull his finger out pretty sharpish.

    At least it is nice to see that relatively (ha ha!)big-name physicists now appear prepared to wade in to emphasise the climatologists increasingly strident warnings. I think that the support of scientists outside the climatological community is hugely important now, as they cannot be accused of crying wolf to increase their level of funding.

    The average person knows very few individual scientists, and Hawking (despite his well documented faults) is probably the most famous one, who is actually living. Its a real pity that we dont have a real star name, who can really explain things to the US public. I wish Carl Sagen or Richard Feynman were still around, as credibilty, combined with charisma, would help tremendously. Al Gore is trying hard, but he is seen as a politician, and therefore is not really trusted.

    The BBC are carrying the first broadcast interview (since his appointment) by the new president of the AAAS, John Holdren. He appears to be emphasising the acceleration of this crisis, in no uncertain terms. He echoes Jim Hansens line, of highlighting just how risky our present, woeful efforts to tackle AGW are.

    I find the possibility of a 4m sea-level rise by 2100 pretty alarming- 400cm over 90 years, works out at nearly 5cm/year! That is a undoubtably a Lovelock-ian rate.

    Recent evidence from polynesia (Professor Atholl Anderson-ABC Science Online, 30 Aug 2006 and the current issue of Antiquity) reminds us that societies with overused and/or diminishing rescources almost always end up fighting over what is left.

    IMHO, I cant see us being mature enough to avoid the nightmare scenario, the way the evidence seems to be heading. Of course, i’m just a layman, but i am now (in some ways) better informed than any scientist of 2 or 3 years ago.

    This is thanks (at least partly), to Realclimate. I therefore have a better chance to give my family and friends a useful ‘heads up’, on the challenges we all face.

    I am deeply grateful to Coby and Gavin et al, and also to the regular posters on this site. You have helped prepare me for our uncertain future. Thank you

    All the best, Mark

  24. 24
    pete best says:

    We do not require a runaway greenhouse effect in order to be in trouble, just a partial melting of the land bound ice caps in greenland and antartica to give us major problems. James Hansen appears to have stated that the simulations/models of future climate are behind the real data in terms of -ve climate change. Whilst people argue about the science of a very complex system (the earth itself and in realtion to the Sun etc) the world is warming it would seem.

    Humankind has emitted some 200 billion ton(ne)s of CO2 into the atmosphere since 1850 making 800 billion ton(ne)s at present with some 4.5 billion tonnes added annually (7 billion ton(ne)s actually emitted but some is absorbed by the oceans) and that number is growing due to world economic growth. I believe that the world has already signed up to some 1 to 2 Deg C of warming and that by 2050 that will have become some 2 to 4 deg C and perhaps by 2100 around 4 to 6 deg C if we continue to release as much Co2 as we is projected.

    The physics of Co2 in realtion to trapping heat is well known and well documented, it is good physics. As good a scientific doctrine as any other quantitative science at the level of physics and chemistry I would say.

    The only reason why people are arguing of all of this is because we stand to lose all of our progress and current wealth and systems in the modern age (an age that has allowed humankind to cheat nature in many ways and increase standards of living dramatically) and that no current or planned new energy making technology is on the horizon to help us out in a way that allows us all to drive our massive SUV’s, gain increased wealth and increase prosperity etc.

    People just refuse to get real about the possible implications of climate change, the word doom does spring to mind at times.

  25. 25
    Leonard Evens says:

    Re 25: “Most ‘scientists’ are bottle washers and button sorters.” — Robert A. Heinlein

    Heinlein was an important science fiction author, not a scientist. He did have some background in science and engineering, and his stories are based on plausible scientific ideas to a greater extent than some other science fiction authors. But he was hardly qualified to tell us anything about “most scientists”, even at the time, and certainly not today. I suppose quoting Heinlein is a couple of steps above quoting Crichton, but I wouldn’t personally use him as a source of authority in the matter.

    [Response: That wouldn’t stop Congress of course. Curiously, Heinlein and Crichton appear to be the only science fiction authors to have testified on scientific matters….. – gavin]

  26. 26
    Grant says:

    I’m afraid there is no supremely charismatic scientist whose name is a household word, and for whom the public (and politicians) will sit up and take notice. Only two I can think of ever fit that description: Newton and Einstein. Carl Sagan had the charisma — but not the rep. Feynmann had the rep — among scientists, but was surprising little known among non-. Hawking is the closest we’ve got, he has the rep and good name recognition, but he doesn’t have the charisma or notoriety.

    So don’t expect super-scientist to come to the rescue. We ordinary foot-scientists are gonna have to do the job. Maybe we can elist the aid of Samuel L. Jackson: “I’m sick of these m*****f***** greenhouses gases in this m*****f****** atmosphere!”

  27. 27
    Bill Morlan says:

    re: @#24 “The only reason why people are arguing of all of this is because we stand to lose all of our progress and current wealth and systems in the modern age …” SO NOT TRUE…and this spurious argument is used to fan the flames of resistance to making changes to our current lifestyle model. We do not have to return to pre-industrialization lifestyles to mitigate climate change. Intelligent choices are available that allow comfort and reduction. Let’s not allow the discussion to be framed as an either/or choice: As things stand now, we wouldn’t win hearts and minds in that battle.

  28. 28
    John L. McCormick says:

    Sorry to also get off thread but some comments, of late, are needing a poke.

    RE #26,

    I am neither a scientist nor a Republican.

    That said, I challenge Grant’s comment:

    [We ordinary foot-scientists are gonna have to do the job.]

    Scientists do not come to the rescue. I hope they can tell us which door not to open or when to abandon the building.

    It is politicians who will begin to put our future into some form of rescue mode (too late for recovery).

    Has anyone noticed what Governor Schwartzenneger and the bi-partisan legislators in Sacramento accomplished yesterday? Spend a moment and read up on California’s enactment of AB32 and the Governor’s agreement to sign that bill.

    This is no small, and inconsequential moment for the world’s 9th largest economy and 12th largest CO2 emitter.

    No disrespect intended, but the American public cares nothing about who wins the “hockey stick war”.

    California put its cards on the table as have a group of Northeastern States. They are gambling billions of dollars and millions of votes to get our comatose Congress to realize the time to act is now. And, lets all agree that Pat Michaels, Lindzen, Sen. Inhofe, Fred smith and Fred Singer are (and have been from the outset) irrelevant.

    Would someone from the California Legislature please inform us what you have accomplished?

  29. 29
    Terry Miesle says:

    E.O. Wilson has waded into the pond, too.

    His is not a fringe opinion. Hopefully his effort will lend momentum.

    At some point political propoganda must be seen for what it is. This is too big an issue to maintain substantial denial. Many industries are embracing greener building – for cost-savings as well as better corporate citizenship.

    Many vehicle purchasers are opting for more efficient options.
    But I fear nothing short of $6/gal gasoline in the US will really prompt serious change. Most of us are not taught the basics of conservation and certianly we’re not reminded of it on a daily basis. Even the “crying Indian” anti-litter commercials are gone….

    Following the spirit of the topic, perhaps we will see a growing number of prominant scientists inform Congress and the people.

  30. 30
    John L. McCormick says:

    Sorry to also get off thread but some comments, of late, are needing a poke.

    RE #26,

    I am neither a scientist nor a Republican.

    That said, I challenge Grant’s comment:

    [We ordinary foot-scientists are gonna have to do the job.]

    Scientists do not come to the rescue. I hope they can tell us which door not to open or when to abandon the building.

    It is politicians who will begin to put our future into some form of rescue mode(too late for recovery).

    Has anyone noticed what Governor Schwartzenneger and the bi-partisan legislators in Sacramento accomplished yesterday? Spend a moment and read up on California’s enactment of AB32 and the Governor’s agreement to sign that bill.

    This is no small, and inconsequential moment for the world’s 9th largest economy and 12th largest CO2 emitter.

    No disrespect intended, but the American public cares nothing about who wins the “hockey stick war”.

    California put its cards on the table as have a group of Northeastern States governors. They are gambling billions of dollars and millions of votes to get our comatose Congress to realize the time to act is now.

    And, lets all agree that Pat Michaels, Lindzen, Sen. Inhofe, Fred Smith and Fred Singer are (and have been from the outset) irrelevant.

    Would someone from the California Legislature please inform us what you have accomplished?

  31. 31
    Hank Roberts says:

    California’s page for this information, here, has not been updated yet:

  32. 32
    Hank Roberts says:

    This may deserve a thread of its own, but meanwhile, California businesses should look into the current system for tracking emissions, here:

    Once the legislation is passed and text is available look for the details.

  33. 33
    John L. McCormick says:

    Again, my apology for getting off the thread.

    Hank, the text of the enacted California Climate Change legislation ( AB32) is provided at the following link: (courtey of Tiny URL — a most welcome friend)

  34. 34
    Yartrebo says:

    I’m afraid that expensive oil and natural gas will lead to a massive switch to coal, coal-to-liquids, tar sands, oil shales, peat, and other fossil fuels or processes that are even larger emitters of GHGs per unit energy than oil and natural gas.

    We’re already seeing a rash of new coal-fired plants being built in China and the USA, with plans calling for about 1 new GW-sized coal power plant a week for China, and a pretty hefty amount for the USA (maybe 1 every 2 weeks?).

    Tar sands are about 3x more GHG-intensive than conventional oil (2 units of GHG from the mine/refinery + 1 from the vehicle burning the fuel), and they’re a booming and highly profitable industry right now. Coal-to-liquids isn’t a big source of emissions yet, but if it does take off in any substantial fashion, it will also double or triple the emissions caused by the vehicles that burn the fuel they make.

  35. 35
    Eli Rabett says:

    Minor point, but a trap I fell into a while ago. While under current conditions the atmospheric lifetime of CH4 is ten years or so as it is oxidized by OH radicals, if there is a major release of CH4 from clatherates the lifetime goes to hundreds of years of more, because the release saturates the ability of the system to oxidize the methane and other VOCs in the atmosphere.

    That would be a very nasty place to live.

    [Response: We did a number of simulations of this effect in a 2003 paper, and although it’s clear, it is not as strong as you suggest (we estimated CH4 lifteime would maybe get to 40 years or so) (see , table 1) – gavin]

  36. 36
    Don Baccus says:

    E.O. Wilson has waded into the pond, too.

    His is not a fringe opinion. Hopefully his effort will lend momentum.

    Well, except the anti-science Right already dislike him because of his work on species extinction. Remember, Lomborg devoted a whole chapter to “debunking” (in his own mind) E.O. Wilson’s estimates of modern extinction rates.

    In reactionary circles, Wilson’s just another “Chicken Little” proclaiming that the sky’s falling. “real science” not only “debunks” global warming, but “proves” that the intensive development and exploitation of natural resources doesn’t lead to an increased species extinction rate, but rather increases diversity!

  37. 37
    Dano says:

    RE 36 (Baccus):

    I believe, Don, the term ‘chicken little’ has fallen into disuse and has been replaced by ‘alarmist’ over the past few months. ;o)

    Nonetheless, the term ‘religion’ is also used wrt to marginalizing climate science, to the effect that the tactic is to paint ‘believers’ or ‘warmers’ as they must believe in AGW due to (fill in blank, use of ‘Gaia’ preferred).

    I think one should tread very carefully when choosing allies, but it is best to have a ‘big tent’ approach, but also to have an answer in advance for your critics – and keep it close at hand.



  38. 38
    ike solem says:

    For those interested, here is the temperature reconstruction record (below), though I believe a recent issue of Science? Nature? has a breakdown of the individual temperature proxies (boreholes, delta O-18, tree rings, etc.). Each of these data types is a ‘specialty’ and if I understand correctly the ‘skeptics’ are questioning the statistical methods whereby those individual records were combined to get a single record. What’s amusing is that they don’t dare attack the original individual data trends, because they’d expose their lack of knowledge of the science if they did that.
    (Science, Vol 297, Issue 5586, 1481-1482 , 30 August 2002):

    The political aspects of all this are well-described in this article:

    “Several independent studies have come to conclusions similar to theirs. But the work of Mr. Mann and his colleagues has served as a lightning rod for attacks by skeptics of greenhouse warming, in part because the researchers’ early studies, in 1998 and 1999, figured prominently in a 2001 report by the Intergovernmental Panel on Climate Change, a U.N.-sponsored group known as the IPCC….

    Rep. Henry A. Waxman, a California Democrat who is a member of Mr. Barton’s committee, issued a statement describing the requests as “extraordinary demands” that are “burdensome and intrusive” in their nature.

    Mr. Waxman also questioned the motivation for the inquiries. He observed that Mr. Barton had not held any hearings on global warming in his 11 years as chairman of the panel, and had “vociferously opposed all legislative efforts in the committee to address global warming.”

    When science meets govenrmental politics… but why stop there, let’s review some of the legal (oh no!) ramifications of all this – particulary as related to California’s AB32, and proposition 87. Rules on interstate commerce mean that states have limited abilities to tax or control energy imports from other states or from other countries, if I understand this correctly:

    Supreme Court carbon-dioxide case (and if you thought the science was confusing, wait till you read this)

    Legal thinking and scientific thinking – are these mutually exclusive?

  39. 39

    Re #3;


    In your “debunking” of Hawking’s nightmare scenario, you pointed to figure 7.2 of Archer’s book. I found the discussion there not only confusing, but largely irrelevant to the points at issue, as it really only addresses the water feedback issue.

    Incidentally, I note that Archer’s 7.2 is essentially a slightly modified redrawing of Richard P. Wayne’s figure 2.7, as found in his book Chemistry of Atmospheres (1991). In my opinion, Wayne’s discussion is far clearer – maybe Archer should draw on that as well. The point, I guess, is that you get rainout when you get saturation at the mean radiating temperature, which depends on the insolation and the albedo. The albedos assumed in the diagram are fake, however. Venus has a very high albedo and consequently a lower mean radiating temperature than Earth.

    So why is it so hot? Because water vapor is not the only GHG in the atmosphere, and most of the radiating is done by CO2.

    Methane hydrates contain perhaps several hundred times as much carbon as the atmosphere, and methane is a more potent GHG. Sudden release could potentially raise the temperature of the planet dramatically, and in a much shorter time span than the 10 – 50 years needed to remove it from the atmosphere – or even convert it to CO2.

  40. 40
    Pete Best says:

    Re #27, politicians are unable to get to grips with the scope and scale of climate change. We are not going to replace fossil fuels with anything soon because the technology does not exist yet, and even if it did it would take a long time to roll it out across the globe (governments willing of course). Sure we can mitigate CO2 release but not eliminate it but I am unsure as to the 65 % reductions that scientists say is required in order to stay off serious climate change.

    If the powers that be are resiting change based on the skeptics claims and ignoring the very scientists that they are funding then you must try to reason why they are doing that. Here in the UK the government realise that AGW is going to be serious, however we are having trouble getting other governments on board including the USA in regard to even attempting to reduce CO2 via government interference. FOr some reason president bush seems to think that capatalism will come in some miraculous time span and elimiate CO2 and methane from our energy production. I can see his point really, after all in order to eliminate CO2 etc you are going to require trillions in investment, the USA needs a new grid etc.

    At present if we look at porjected world economic growth and energy requirements then we are going to require 50% more energy by 2020 then we use now and where is it going to come from? Only one infrastructure can provide this level of growth really, sure wind and wave, solar and the like can mitigate it but not fulfill it. Maybe energy efficiency can play a large scale role but I am doubtful it can in the time scales provided.

    Nope, it looks like we are headed for 1 trillion tonnes of free CO2 in the atmosphere by 2070 or so, maybe even sooner. The FF companies hold massive financial and real influence and power over Governments and the masse do not care enough about it.

    The USA burns some 5 tonnes per head of capita, Europe 3 tonnes, China 1 tonne and India half a tonne, this is all set yo grow and nature itself is releasing more overall CO2 from bogs and forests etc to.

  41. 41
    John L. McCormick says:

    Peter, I agree with all you said.

    When I really stop and think about the challenge to convince the few US politicians over whom I have some clout (my elected representatives) and recognize their many competing issues that come before global warming mitigation, I too succumb to that feeling of hopelessness.

    Then, I read about the Chinese government and its citizens awakening to the real economic and environmental price being paid to become a superpower. There is a slow evolving and cautious measurement of those costs because a majority of its 1.3 billion population are closely tied to the land and those village dwellers and farmers are losing their meager standards of living as drought creeps deeper into their land.

    Melting glaciers in the Andes and Himalayan mountains are threatening the existence of whole nations and major metropolitan areas because the melt runoff is rapidly diminishing and farmers are the first to feel the effects. Local governments are beginning to speak out to their central government leaders.

    Global warming impacts, over time, will be small at first and be seen as not unusual events (Cat 5 hurricanes, massive flooding, add your impacts) but the accumulative impacts of a warming planet will visit misery on the down river populations and farmers unable to grow crops. Populations will migrate; militaries will be activated and the world will see the handwriting on the wall. Will we wake up in time? Probably not. Will the industrial world begin to take action? Likely the corporate world will demand relief.

    Remember, the reinsurance industry has taken a stand even if it was to cut policy holders from their accounts and raise rates to the rest of us. But, it is a recognition of climate change, nonetheless. Chinese and Indian farmers may be insignificant to the power elites but their crops in the market place are the means by which nations survive. Keep the faith.

  42. 42
    Yartrebo says:

    Maybe in the long run the Chinese can worry about how clean their power is, but in the short run they have to deal with the chronic power shortages that stem from their sustained 10% GDP growth and reliance on heavy industry. From what I’ve been reading, they’re building coal mines and coal power plants as fast as they possibly can, with production and consumption growing by about 100 MT/year (about 5% given a base of 2.1 GT/year) of coal, and they still have electricity, coal, and railroad capacity shortages. Considering that the Chinese have planned a new coal power plant a week for the next decade and that their existing plants have to deal with coal shortages, I really doubt their GHG emissions will be contained any time soon.

    They’re also building steel mills, aluminum smelters, and cement factories like crazy. In the case of cement they’re consuming around 4x or 5x the amount the USA consumes (roughly at parity on a per capita basis).

    As far as the peasants go – the Chinese government is relying on rapid industrialization to bring them material benefits and city jobs to keep them content. So far it seems to be working.

  43. 43
    John L. McCormick says:


    Keeping hungry, thirsty people content is a non sequitor.

    I am not arguing the Chinese leaders are coming to their senses and rescue. I am reading how the Chinese government is beginning to tally the cost of rapid industrialization and the cost of polluted rivers and desertification.

    Will the price be high enough that China will cut back on its energy growth path? Most of China’s coal mining is underground and new mines will have to go deeper into thinner seams to get the coal. And, steam generators need access to huge volumes of once-thru water. China knows there are limiting factors that will eventually cause it to revise its growth projections or be forced to sieze resources from neighboring nations.

    Bottom line: China is waiting for the US to take the big step and will then make adjustments based upon its internal politics of keeping 1.3+ billion people content.

  44. 44
    Gar Lipow says:

    >We are not going to replace fossil fuels with anything soon because the technology does not exist yet, and even if it did it would take a long time to roll it out across the globe (governments willing of course).

    Yes the technology does exist. And we can roll it out in time to prevent the worst harms. Not that we don’t have to adapt to harm that is already done plus the harm locked in that has not yet happened. but we can phase out emissions before we get to the point where we can no longer adapt.

  45. 45
    Mark Shapiro says:

    Re: 44 – friendly technologies to reduce fossil fuel use: efficiency and renewable sources.

    Yes, those technologies exist. We should deploy them faster and improve them continuously. Gar L., our economist friend, makes this excellent point in nearly every post. And how often has Lynn V., friend to all, noted how easy it is to enrich oneself with simple efficiency and conservation measures?

    Is this relevant to the Energy and Commerce Committee hearings? Absolutely, positively, screamingly, yes.
    Because Rep. Barton and the others are so concerned about the economic “costs” of lowering CO2 emissions that they seem blind to the many benefits, including the economic ones.

    And perhaps we could teach the Chinese to practice better economic science, namely by desubsidizing fossil fuels. IIRC China subsidizes electricity and gasoline more than the US does.

  46. 46
    ike solem says:

    Re#35 and comments,

    Thanks for the clarification of the lifetime of methane in the atmosphere – I now recall that atmospheric chemistry is dominated by the kinetics, not the thermodynamics. That does represent yet another positive feed-forward effect. Rather like saturating a buffer?

    It is worth noting that in anoxic sediments, much of the methane, ammonia, and hydrogen sulfide that such systems generate is oxidized by microbes who live at the oxic-anoxic interface; these microbes can be overwhelmed by high concentrations of methane, etc, as they generally have slowish metabolic rates (then you get fish kills and hypoxia). Increased temperature will also speed up other microbial decomposition processes that will result in increased fluxes of CO2 and also N2O to the atmosphere.

    I hope no one tries to use these concepts to claim that methane release in the Artic won’t be a problem! The site is an example of this kind of thing; the heading describes it as a site “On effects of increasing atmospheric CO2 levels on the biosphere, with emphasis on studies that suggest a beneficial impact from rising C02”. RealClimate has a short rebuttal to this at

    The biochemical point is this: plants (unlike non-biological processes) are capable of regulating their responses, and if you put more food on their plate they just end up eating a smaller % of food (why go to all that work if you don’t have to?). This was undestood in 1990; since then people have been studying the underlying biochemical and genetic mechanisms. The biosphere does buffer many physical processes (consider the effects that mangrove swamps and coastal wetlands have on hurricane energy dissipation), but all buffers can be exhausted.

    (For example, see
    The Greenhouse Effect: Acclimation of Tomato Plants Growing in High CO2, Photosynthesis and Ribulose-1, 5-Bisphosphate Carboxylase Protein (1990) R. T. BESFORD, L. J. LUDWIG and A. C. WITHERS, Journal Exp. Bot. Vol. 41, Number 8 Pp. 925-931)

    Processes in trees are less well understood (hard to do the tree lifetime experiments) but see the above realclimate link.

    The “CO2 Science” website is run by the “Center for the Study of Carbon Dioxide and Global Change”; see if you can find them in this interesting chart:

  47. 47
    Robin Johnson says:

    While I thoroughly enjoyed reading Dr Mann’s stinging rebuke of Dr Wegman – I couldn’t help but laugh at this statement:

    Our decision to make our code public comes at a time when there is increased
    standardization in codes, and the need to tailor codes to accommodate the various and
    often idiosyncratic computer systems that were used in the 1990s has diminished. But
    even today, many, perhaps most, climate scientists do not share their codes.

    Being a professional software engineer*, in 25+ years of writing software I’ve never heard anyone refer to software code as “codes”. Code is a plural in every software sense except cryptography and error correction. It really should be read as “lines of code” or source code. Secondly, I am perplexed and dismayed that climate scientists do not routinely publish their source code for scientific review and simply sharing of techniques common to the particular specialty of writing climate model software. I’m quite frankly shocked that scientists would not share their library and function source code with each other on a routine basis. It would seem that efficient code (ie fast in both time and space) would be an important premium in the computer models.

    Dr Mann is quite right, however, that source code is not necessary for replication – in fact from a scientific replication point of view – you would necessarily want to write at least the algorithmic level code from ‘scratch’ to reduce the chance of a software bug influencing the outcome in an undetected manner.

    External and internal review of source code [called code review] is standard practice throughout the software industry. Most computer models could benefit substantially I suspect by external review. It could get done for free in many cases if they published the source code (on a website obviously) where it could be reviewed by software professionals with interest and time. I gotta think it would save the climate scientists a lot of wasted time wrangling with screwed up results from common coding errors.

    Please tell me that climate scientists actually consult with software professionals (and hire them) in addition to statisticians. Basic, simple things like “random” numbers and rounding errors routinely trip up the inadequately trained code writers. I’m not accusing anyone without evidence – but then if we can’t see source code – how do we know your not using rand() to generate random numbers?

    * – Software Engineer. I know. I know. I know perfectly well that bonafide “licensed” engineers get annoyed by the term. But it is the term used in the industry to distinguish between “programmers” and folks who can design and write whole systems and actually understand computer science. And its certainly better than that bastard term “software architect” which means management likes you but you can’t write code and can’t manage coders… But honestly, I think software engineers SHOULD be licensed. Everything has software intimately involved these days. And basically anyone is allowed to write and sell code with virtually no liability attached. Its freaking crazy actually.

  48. 48
    Thomas Shrack says:

    Regarding the release of computer code: Wouldn’t one reason not release specific computer code be to keep from influencing the outcome of subsequent studies which attempt to replicate results? I understand that those who demand the release of code want to examine it for logical errors and subjective assumptions, but usually, don’t errors become clear when subsequent studies arrive at different results, and aren’t the assumptions made clear in a description of the process of the code? Should code be made available before attempts to refute or confirm have had a chance to survive?

  49. 49
    Eli Rabett says:

    Gavin, I was thinking of this with regard to the Late Paleocene Thermal Maximum:

    The models used in the new study show that when you greatly increase methane amounts, the OH quickly gets used up, and the extra methane lingers for hundreds of years, producing enough global warming to explain the LTPM climate.

    [Response: This is not quite true. Methane levels can be maintained at a high level for many hundreds of years, yes, but that is a combination of the decreased sink and continual fluxes. The reason why the sink doesn’t drop to near zero is that there are (at least) two other sinks which today are small fractions of the sink, but as tropospheric OH gets ‘used up’ they will become more important – and the time scales for methane will asymptote to values associated with these other sinks. Specifically, stratospheric oxidation and soil bacteria which have different chemical pathways to tropospheric oxidation. We did address this more carefully in the paper… ;) but this quote from the news write up is not ideal. Since I probably proof read this, I’ll just have to take my lumps…. ;( – gavin]

  50. 50
    S Molnar says:

    Re #47: I say “computer codes” all the time, but then my background is in maths, so there may be a cultural difference.