IPCC and treatment of uncertainties

by Judith Curry

A new review paper on the IPCC and treatment of uncertainties.

IPCC and treatment of uncertainties: topics and sources of dissensus

Carolina Adler and Gertrude Hirsch Hadorn

Abstract. Characterizing uncertainty in the assessment of evidence is common practice when communicating science to users, a prominent example being the Intergovernmental Panel on Climate Change (IPCC) Assessment Reports (ARs). The IPCC guidance note is designed to assist authors in the assessment process by assuring consistent treatment of uncertainties across working groups (WGs). However, debate on this approach has surfaced among scholars on whether applying the guidance note indeed yields the desired consistent treatment of uncertainties thus facilitating effective communication of findings to users. The IPCC guidance note is therefore a paradigmatic case for reviewing concerns regarding treatment of uncertainties for policy. We reviewed published literature that outline disagreement or dissensus on the guidance note in the IPCC assessment process, structured as three distinct topics. First, whether the procedure is reliable and leads to robust results. Second, whether the broad scope of diverse problems, epistemic approaches, and user perspectives allow for consistent and appropriate application. Third, whether the guidance note is adequate for the purpose of communicating clear and relevant information to users.Overall,we find greater emphasis placed on problems arising from the procedure and purpose of the assessment, rather than the scope of application. Since a procedure needs to be appropriate for its purpose and scope, a way forward entails not onlymaking deliberative processesmore transparent to control biases. It also entails developing differentiated instruments to account for diversity and complexity of problems, approaches, and perspectives, treating sources of uncertainty as relevant information to users.

The paper is published as an Advanced Review in WIREs, it is publicly available online for one month [link].

This is a very interesting paper, and it refers to some relevant papers that I haven’t come across previously  (see esp Table 2; my papers Uncertainty Monster and Reasoning about climate uncertainty and No consensus on consensus are referenced.)   The review is framed in the following context:

Two questions guided our appraisal of concerns raised: What are the topics of dissensus? and what reasons are given for dissensus?

A paper on the IPCC that focuses on dissensus rather than consensus – gotta love it.

From Debate on Topics and Related Sources of Dissensus:

The idea of a systematic treatment of uncertainty consists of assembling and aggregating relevant information and related uncertainties, then translating the aggregated result into a degree of certainty about this result.

First, the position that a degree of certainty is precise if it is attributable on a quantitative basis, as in the case of the likelihood scale, has been criticized. The basis for this criticism stems from lack of traceability as to what evidence is included or left out. Furthermore, given the inevitable role of value judgment, the understanding of terms such as ‘very likely’ is ambiguous. In addition, the attribution of a certain degree of likelihood or confidence is not without doubt, thus giving rise to inconsistent characterization of uncertainties. Degree of certainty may differ depending on whether or not probabilistic methods were used, types of methods used to calculate consistency of ensemble modeling results, or on the choice of spatial aggregation scale.Biases or inconsistencies in expert judgments may relate to characteristics of the events described, or they may be due to group dynamics and heterogeneity of contributing authors.

Second, criticism has been raised on how both the quantitative likelihood scale and the qualitative confidence scale are constructed and expected to be used. The construction of the qualitative scale is a source of dissensus, given that it is not clear whether and how to conceptually distinguish between agreement, evidence and consistency, or whether these concepts are appropriate for the purpose. Furthermore, both scales are criticized for being incomplete, since they do not systematically circumscribe areas of ignorance or controversy. Ignorance may be due, for instance, to a lack of resolution on relevant scales or to controversy on hypotheses among experts who build on different assumptions or theoretical perspectives. If no degree of certainty can be attributed, information that is nevertheless relevant may be excluded or given minor attention. However, ignoring information which does not meet the conditions for attributing a degree of certainty may further lead to overestimation or underestimation of events

Third, arguments have been put forward to show that explicit distinctions between different sorts of uncertainties are important to avoid misinterpretations of uncertainty characterizations. This is exemplified with regard to structural model uncertainty, i.e., assumptions that enter modeling and scenarios. In this context, it is worth noting that robust results, i.e., if different models or methods lead to similar results, do not provide a sufficient basis for high probability because robustness might be due to models which are not independent from each other or do not account for important variables or parameters.

Purpose deals with a general contention toward the linear model of expertise enshrined in the IPCC process. In this linear model, the IPCC is said to privilege scientific knowledge as the authority on climate change, thereby constraining political deliberation on whether to react to this information and address problems on the ground. In this context, the contested issue rests on how adequate the linear model of communication is at delivering perceived relevant knowledge, versus how the receiver understands this information. Reaffirming this point, Hulme and Mahoney state that knowledge ‘claimed by its producers to have universal authority is received and interpreted very differently in different political and cultural settings. [Therefore], revealing the local and situated characteristics of climate change knowledge … becomes central for understanding both the acceptance and resistance that is shown towards the knowledge claims of the IPCC’. The content of information that is communicated, and how it is interpreted by users, manifest as sources of dissensus.

Interpretation of information refers to users’ perception and understanding of the assessment findings in IPCC ARs. The assumption here is that simplified communication of facts, highlighting consensus, raises confidence in users that they have suitable and unambiguous information for policies formulation. However, arguments presented in the papers reviewed disagree with this assumption on two fronts.

First, simplification of complex information on degrees of certainty masks and down-plays the importance of nuanced and fine-grained reporting of diverse value judgements on evidence, a point also raised by users who support reporting on dissensus to better interpret evidence presented. Vasileiadou et al. affirm that the logic of reasoning that underpins assessment of evidence, including where and how disagreements manifest, is not sufficiently transparent in the IPCC assessment process. Improving this transparency would better serve deliberation, interpretation, and reflexivity on evidence presented—among scientists and users alike, improving confidence in the quality of the IPCC ARs. According to van der Sluijs assessment findings that lack details on deliberation make policies vulnerable to scientific errors, insisting that robust and flexible policy strategies should take into account uncertainty and plurality in science.

From the concluding Future Directions:

 Any procedure for assessing uncertainty should be appropriate for its purpose. So, what can be learned from dissensus on whether communicating findings with a degree of certainty is what is relevant for and is clear to users? To the extent that WGs have to assess information on wicked problems with persisting deep uncertainty, there are good reasons for different judgments on which information is relevant and how certain findings are. As a way forward, we suggest to go beyond Hulme’s position that ‘[action on] climate change can only be understood from a position of dissensus’. We propose to proceed from dissensus on a singular position toward consensus on a plurality of relevant, even controversial positions or findings, as assessment results for users. This accounts on the one hand for the purpose of consensus, which is to reach inter-subjectivity, and on the other hand for its limits, since any consensus may be mistaken, especially when it comes to problems with deep uncertainty. A consequence for the science-policy interface would be to interact on a different assumption, namely within frameworks such as adaptive governance. Learning from dissensus on procedures for attributing a degree of certainty to findings serves several purposes: not only to make deliberative processes more transparent and consequently enabling control of bias, but also to develop more differentiated instruments that treat sources of uncertainty as relevant information to users. Last but not least, a broader understanding of relevant information for policy, together with fostering a culture of learning about uncertainty in the policy process, better accommodates for plurality in uncertainty assessment to account for diverse problems, approaches, and perspectives.

JC reflections

This paper hits on a lot of the same points that have concerned me regarding the IPCC, treatment of uncertainties, and consensus-seeking approach.

At the heart of the problem is the linear model of expertise, e.g. ‘speaking consensus to power.’  As discussed in my No consensus on consensus paper, this approach simply does not work when you are dealing with a wicked problem and conditions of deep uncertainty.

I am not sure where the IPCC will go from here, but a more mature approach to dealing with uncertainty, disagreement, dissensus and ignorance is badly needed.  This review paper by Adler and Hadorn points the arrow in the right direction.



135 responses to “IPCC and treatment of uncertainties

  1. “I am not sure where the IPCC will go from here, but a more mature approach to dealing with uncertainty, disagreement, dissensus and ignorance is badly needed. ”

    “Mature” is a careful and as always, polite word choice Judith. I think a more accurate phrase would be “a more honest approach.” Although on second thought, that implies a level of honesty that can be improved upon. Their 95 percent certainty is many things, but “honest” is not one of them.

    • Lack of humility is our problem.

      Humility was sacrificed at the end of the Second World War:


      Humility and honesty are basic ingredients of democratic governments, science and religion.

      False intellectual pride kept the scientific community from seeing that loss of humility is the problem and restoration of humility is the obvious solution to society’s current spiritual, political and intellectual demise !

      Standard Models, Watergate, Fusion Reactors, Climategate, Big Bang, Dark Energy, Oscillating Solar Neutrinos, AGW, etc are manifestations of this one, same problem:

  2. I have not seen dissensus used in a long time! It should get more usage as it is a more accurate term to describe even the Warmist camp.

    • It might even be a paradigmatic epistemic dissensus. Should JC’s work have been called “Dissensus on Consensus”. Seriously though, this paper is a nice addition to the voices of reason. It calls for “treating sources of uncertainty as relevant information to users”. Yes indeed.

    • Likewise, except for me it was a new and useful word entirely. Live and learn. Plus, much food for thought in this post and the paper.

  3. The Left chose Al Gore over the scientific method. Government science now stands for unnatural catastrophic global warming which is a view of reality that helps facilitate the politicization of science and in turn has caused catastrophic public policy–e.g., “The cost of having that desalination plant there [in Melbourne] – producing no water at all – is $384 for every single household… And that is $384 every year single year — for 30 years. If it were to produce any water, the cost would increase,” says George Christensen, representative in AU’s Parliament. “Australian policy-makers were threatened and cajoled into undertaking farcical desalination projects on the back of menacing doomsday climate prophecies.”

  4. Time For An Ob

    Oreskes had that title ‘Merchants of Doubt’ which was supposed to be about overstating the doubts in AGW theory.

    But the IPCC are their own merchants of doubt – it could be a little or it could be a LOT of global warming – egregiously overstating the observed and recent sensitivity.

    • Ah but now you are trying ot have it both ways, as climate skeptics often try.

      By claiming you can constrain climate sensitivity to be low while simultaneously complaining that the IPCC would claim to constrain anything.

    • A fan of *MORE* discourse

      Oreskes speaks eloquently:

      Scientific Consensus
      and the Role and Character of Scientific Dissent

      I would argue that something has been lost, over the last fifty or sixty years; something that Bohr and Einstein knew how to articulate. And that, I would argue, is a sense of moral gravity, a sense of what is at stake.

      And so we miss the opportunity to communicate what Bohr and Einstein recognized, in a different context: that scientists, by virtue of our expertise, at least in some cases have a uniquely vivid appreciation of the risks that we face, and in the case we’ve studied most closely, the damage that climate-change can wreak.

      Climate Etc readers are invited to verify for themselves that Oreskes’ analysis is *FAR* more science-respecting *AND* history-respecting than Adler and Hirsch-Hadorn!

      \scriptstyle\rule[2.25ex]{0.01pt}{0.01pt}\,\boldsymbol{\overset{\scriptstyle\circ\wedge\circ}{\smile}\,\heartsuit\,{\displaystyle\text{\bfseries!!!}}\,\heartsuit\,\overset{\scriptstyle\circ\wedge\circ}{\smile}}\ \rule[-0.25ex]{0.01pt}{0.01pt}

      • Curious George

        Speaking eloquently puts Oreskes in a distinguished company of Holdren, Ehrlich, Gore, and Barack Hussein Obama.

      • One should advise the Consensus to find their own Bohr and Einstein, then. Parading people like Mann, Gleick and Lewandowsky speaks to the shortcomings of the Consensus, not their critics.

  5. David Wojick

    The underlying assumption here seems to be that the weight of evidence (or degree of uncertainty, etc.) is independent of the observer and that is false. There is no known function for taking a body of documents, or expert statements, and generating a weight of evidence for a given hypothesis, nor can there be. On the contrary, the weight of evidence is a matter of individual judgement, based on all one knows and believes. It may well be an objective function of this knowledge and belief, but it is different for every person, because no two people have the same knowledge and beliefs. Thus the weight of evidence is relative to the observer.

    • Danley Wolfe

      “Thus the weight of evidence is relative to the observer.” For a scientist the weight of the evidence is not relative to the observer. The weight of the evidence is dependent on the science and the interpretation of the science. The IPCC has approached this from the beginning to influence the audience in IT’S interpretation cum presentation or “spin” of the science. The general public is not capable of interpreting the science and generally the policy makers don’t care, they have predetermined agendas. The IPCC has had a mission, and its periodic reports are written, with the purpose to present the science in a way that pushes its predisposed policy positions – “it’s” meaning the advocacy positions of SOME GOVERNMENTS WHO BY THE WAY HAVE STRONG INFLUENCE AND FINAL EDITORIAL APPROVAL ON THE FINAL IPCC REPORTS.

      Compare this with the historic debate in the early 1900s on wave vs. particle theory of statistical mechanics – an open and honest debate of the science but very much epistemological in nature. What we have seen in the climate change debate can also be called shaping (using la bunch of propaganda techniques) the opinions of primarily nonscientists especially policy makers who would decide the structure of the activity of mankind on the planet. Examples are Mann’s infamous “hide the decline” and others (including “some IPCC lead scientists” – those who are following the recent discussions know who I am talking about) who present GISS / NASA temperature results to average out the hiatus or say that the hiatus is just a short term deviance and tell you to draw a trend line from 1959 to the present which makes the hiatus invisible. Of course if you do 5 year running averages of monthly temperature data it’s true – you can’t see the current hiatus, but that is like trying to fool mother nature. The current hiatus 17 years in running comes at the end of the data set and begs the question “since we have this total lack of response and are in the middle of this thing, why should we not wait another 5-10 years to see how this plays out – we might gain enormously valuable information to inform our policy decisions. The reason why we have to “act now” is because if we do wait the empirical data just might not support the case. And if we do “act now” and the temperature continues to pause or grow more slowly they can say “see, we told you so, our policies saved mankind.”

      • @ Danley Wolfe

        ” The reason why we have to “act now” is because if we do wait the empirical data just might not support the case. And if we do “act now” and the temperature continues to pause or grow more slowly they can say “see, we told you so, our policies saved mankind.”

        A little editorial revision, and you will be spot on:

        ” The reason why we have to “act now” is because if we do wait the empirical data just might not support the case. And if we do “act now” and the temperature continues to pause or grow more slowly they can say “see, we told you so, our initial, weak policies ARE SAVING mankind but we have to expand and strengthen them to fully avoid the disaster that, thanks to the obstinate opposition by the anti-science shills of the fossil fuel industry that ensured that fully effective policies could not be implemented, we have only managed to delay temporarily.”

      • Danley Wolfe

        @Ludwick says – “…A little editorial revision, and you will be spot on: …temperature continues to pause or grow more slowly they can say “see, we told you so, our initial, weak policies ARE SAVING mankind but we have to expand and strengthen them…” This misses or should we say obfuscates my point, which is actually his intent. To take credit based on the absence of the event / evidence is a logical fallacy. The change could be caused by natural causes unrelated to policy measures taken. And then what – means we spent a lot of money and effort on the wrong policy. But progressives use these propaganda tricks all the time. This one is an example from the top five propaganda tricks – demagogue by “name-calling” or other personal slurs – castigation of unnamed persons as anti-science shills of the fossil fuel industry. Used extensively by ideologue liberals lacking fundamental knowledge of the topic. Such propaganda tactics were refined by Dr. Goebbels and Willi Münzenberg and embraced by Sol Alinsky and his disciples. In addition, to say that a pause or permanent change in trajectory is the result of policy measures before a policy measure has been implemented is a logical fallacy and circular reasoning. The change could have just as well been caused by other e.g., natural factors. Is all global warming attributable to AGHG? No. What part is attributable to AGHG? We don’t know and can’t quantify but we wish we could – but we like to tell people it is primarily due to AGHG. Would eliminating fossil fuels eliminate global warming? Absolutely not. Does the current hiatus support the theory of AGHG causing global warming? No. Does it refute it? Maybe, but we will know a lot more in the next 5-10 years (why would we not want to take the opportunity to gain valuable information before we take policy measures that may not address the issue either. Some would say there is no pause, it’s just a statistical artifact. That is just nonsense talking and actually funny to listen to because it is a sign of scientific illiteracy. For example, make an x-y plot of Mauna Loa CO2 vs. GISS NASA 1emperature since 1998. Slope = 0.001 (which implies 0.002 oC increase for a doubling of CO2). Looks like a triple aught shotgun practice target. R squared = 0.0007. If you manipulate the numbers, e.g., by taking 2 or 3 or 5 year averages the hiatus indeed disappears. But that is trying to fool mother nature and she doesn’t like being fooled…llke Michael Mann’s ‘hide the decline” trick.

      • @ Danley Wolfe

        From your reply to my revision : “To take credit based on the absence of the event / evidence is a logical fallacy. The change could be caused by natural causes unrelated to policy measures taken. And then what – means we spent a lot of money and effort on the wrong policy. But progressives use these propaganda tricks all the time.”

        It appears that we are in violent agreement.

        But you will have to admit, the policies have succeeded and continue to succeed in two VERY important areas: increasing and the power of progressives enormously and making a large number of the ‘connected progressives’ VERY wealthy.

    • One of the ongoing issues with this debate is the failure to distinguish the term “weight of evidence” from the term “weight of opinion”. The weight of evidence is, ideally, independent of the observer while the weight of opinion is not. The confusion of these two concepts lies at the heart of the alarmist-sceptic controversy. Weight of evidence concerns objective facts which can be agreed on by everyone. The predictions of computer models are not facts they are opinions in numerical form. Proxy temperatures determined from isotope ratios in ice-cores are accepted as facts. Only the computer models give any cause for concern that the climate is presently changing, the ice-core data do not. Climate change is a matter of opinion which is being presented to the lay public as if it were a scientific fact.

  6. Curious George

    How is uncertainty in climate “science” determined? Mostly subjectively; I asked for the exact mechanism a number of times, never got an answer. A “model spread” might seem objective, until you realize that it never asks Mother Nature for her opinion.

    • David Wojick

      There is no “exact mechanism” for determining uncertainty in inductive logic. What would such a thing look like?

  7. WRT any scientific prediction:

    1. What is the uncertainty according to the paradigmatic definition of uncertainty in this particular area?

    2. How well does the paradigm characterize the calculation of its uncertainty?

    3. What is the uncertainty regarding the paradigm? That is, how likely is it that the paradigm is obsolete and that conclusions reached according to that paradigm are, or should be, deprecated?

    It’s that last question that’s the kicker. Conflicts over paradigms are fought out in a highly political arena, and the lack of funding for research into alternatives can result in greater uncertainty over the entire paradigm. The same is true of documented skullduggery involving gatekeeping for high-impact journals, or attempts to “redefine” “peer-reviewed”.

    • David Wojick

      Uncertainty is cannot be calculated, except in the case of pure sampling error. Uncertainty is not a measurement.

      • ,
        “Uncertainty is not a measurement.”

        Uncertainty is a part of every scientific measurement and should be given as a part of the calibration of the instrument used. Reasoning with such uncertain data should always provide the uncertainty of results from the data. If you can’t propagate uncertainty, you aren’t doing science. More likely, you are doing politics.

    • Curious George

      Please list five most important paradigms in climate science.

      • There isn’t any. Climate science is still in its infancy and seems destined to be replaced by an extension of the more mature science of meteorolgy.

      • Please list five most important paradigms in climate science.

        AFAIK there is only one, starting early last century, and based on (roughly) linear assumptions regarding the thermodynamics and evolution of complex systems.

        Most (valid, IMO) challenges to that paradigm are based on more recent work in “chaos theory”, which show that even the tiniest changes in initial conditions (“butterfly effect”) or boundary conditions (“hawkmoth effect”) can produce differences in the behavior of the system in question far out of proportion to the scale of the changes.

        These challenges to the existing paradigm are being fought out in ways far removed from normal science, using political methods to control funding and access to high-impact journals. Not unlike paradigm challenges in other fields (e.g. over the nature of the common ancestor of humans/chimps/bonobos, or the existence or not of a dark age separating the Mediterranean Early Iron Age from the Late Bronze). The primary difference is that the conclusions based on this possibly (probably IMO) obsolete paradigm in Climate Science are being used to justify demands for major interventions and changes in political and economic policy world-wide.

  8. Climate ‘science’ hasn’t grasped the fact that number of interacting climate parameters run on either solar or oceans tidal clocks. Mutual interaction assures that neither of two frequencies are clearly identifiable in any of the global, hemispheric or regional temperatures indices.

  9. Of course, if the IPCC were just dead wrong because largely in ignorance of climate then it wouldn’t just be a matter of “facilitating effective communication of findings to users”, would it?

  10. It is now too late for the IPCC to regain credibility. Because if it cools – they will be laughed at, if it carries on with the pause – they will be laighed at. And even if it warms, they will be laughed at because they will have no explanation at all for why the pause happened nor why it ended.

    • There is no pause. It’s a statistical artifact that is lost in the ever warming world. Sea temperatures are currently at record levels for example. how did that happen?

      • catweazle666


      • John Carpenter

        “Sea temperatures are currently at record levels for example. how did that happen?”

        You seem very confident. Source?

      • Danley Wolfe

        “There is no pause…it’s a statistical artifact.” Is nonsense talking. Plot Mauna Loa CO2 vs. GISS NASA 1emperature since 1989. Slope = 0.001 (that means .002 oC increase for doubling of CO2). Looks like shotgun target practice Rsq = 0.0007

      • Danley Wolfe

        Jim D. the data you refer to appear to be annual data. As I said elsewhere on this page, if you plot the raw monthly data for Mauna Loa CO2 (indep var) vs. GISS NASA Temperature, deg C (dep variable) you see a wonderful chart that is a) flat from 1959 (start of the data set) to mid 1970, b) rises monotonically (with noise) but appears linear with noise from mid 1970s to mid 1990 (or so) and c) is “flat as fens of Holland” from the mid- to late-1990s to the present. The IPCC models are tuned on these data and do not go back before 1959 said to be due to the data availability. Using time averages “hides” this pattern (such as annual or biannual or 5 year averages). The giant question in the sky is how will this play out in 3-5-10 years from now. But the man said …. We must act now! We must act now ! (I think it was chicken little said this?.

  11. “The scientific theorist is not to be envied. For nature, or more precisely experiment, is an exorable and not a very friendly judge of his work. It never says “Yes” to a theory. In the most favorable cases it says “Maybe” and in the great majority of cases simply “No.” If an experiment agrees with a theory it means for the latter “Maybe” and if it does not agree it means “No.” – most theroies soon after conception.”
    — Entry into my memory book for Professor Kammerling Onnes, November 11, 1922; quoted in Dukes and Hoffman, Albert Einstein, the human side page 18

    If only ‘the science is settled’ legions were so humble today. The language of the IPCC is at best that of scientists opinions not of science itself. They should get back to presenting the scientific evidence in it’s raw form and stop prognosticating. The idea that one can accurately predict what amount of CO2 will cause what amount of temperature rise is on such shakey ground I personally believe it’s a “No.”

  12. I don’t know about other readers but I find these discussions without visual aids and cartoons to be quite confusing. Maybe that’s my handicap because I see everything as color graphics in my head. But I’m sure more normal readers would like a sketch once in a while. Hell, I may try sketching and scanning this tomorrow and then I’ll scan it and post it if something comes out.

    I’ve given this topic a lot of thought over the years because the oil industry is a constant gamble and we also have to deal with simple minded management full of individuals who don’t understand risk concepts, nor probabilities nor when some of us were just dancing and playing guitar to get their blessing and go spend more money.

  13. Matthew R Marler

    Here is another quote: Another principal obstacle comes from diverse
    and variable contexts and causes, creating a problem for general statements across regions on spatial and temporal scales. 42 Although this problem is rarely mentioned among the sample of papers reviewed, it
    seems to be an ubiquitous issue given how statements from WGIII in the AR4 Summary for Policymakers state possibilities, e.g., that ‘changes in lifestyle and behaviour patterns can contribute to climate change
    mitigation across all sectors. Management practices can also have a positive role (high agreement, medium evidence) ’ (Ref 59, p. 12). Attributing a degree of uncertainty to generalized statements of a possibility
    is unclear and of not much value to policymakers in negotiating appropriate actions. 60

    I can’t tell whether the paper is useful or meaningful or not.

  14. David L. Hagen

    Mistaken consensus
    Re: ” since any consensus may be mistaken, especially when it comes to problems with deep uncertainty”
    Armstrong’s No Change forecast is more accurate than Gore/IPCC

    • A site premised on the lie that Gore has entered a bet. Hiding the fact that Gore turned down the bet.

      Probably because Gore doesn’t gamble with clowns. Especially when the bet is scientifically flawed.

      • David L. Hagen

        Reality check: Armstrong offered Gore bore both a bet and a scientific challenge, and explicitly states he still awaits Gore’s response:

        1. Why are you unwilling to back your forecasts in a challenge intended to promote scientific forecasting of climate change?
        2. Under what conditions would you be willing to back your forecasts in a challenge against my forecasts from a simple scientific method that is appropriate in situations of high uncertainty: the naïve “no change” method?” . . .
        “Mr. Gore simply does not wish to participate in a financial wager.” Armstrong responded that it was fine by him and that we could “merely do it for its scientific value.” The spokesperson said that she would ask Mr. Gore. Armstrong asked if Mr. Gore would also respond to question #2.

        The second question is of particular importance given that we have not been able to find any scientific forecasts to support global warming –or any that would support negative effects from global warming –or any to support the notion that efforts to reduce man-made CO2 would have a favorable impact on the climate. See Green & Armstrong’s paper “Global Warming: Forecasts By Scientists Versus Scientific Forecasts,” Energy & Environment 18 (2007), 995-1019.

        Armstrong said that this is a scientific issue, not a political issue. Opinion polls do not provide a scientific approach in this situation, even when some of the respondents are climate experts. However, procedures do exist that would allow us to make scientific forecasts.

        Meanwhile, Professor Armstrong awaits Mr. Gore’s response to the revised challenge.

        Gore is unwilling to be accountable. My statement stands: Armstrong’s “No change” / “naive” forecast is more accurate than Gore/IPCC’s 0.03C/year.

      • “Gore doesn’t gamble with clowns.”

        Throw in some cheesecake and Big Al might take the bet.


      • Matthew R Marler

        lolwot: Probably because Gore doesn’t gamble with clowns. Especially when the bet is scientifically flawed.

        He has earned a handsome income betting with other people’s money.

      • Years ago I bet Armstrong that the world wouldn’t cool because of the solar minimum.

        Looks like he’s losing that bet.

      • Most people do not bet with themselves. Why would you think algore was different?

  15. Abandoning climate science as a so-called field and just doing the bits of science you can do as real science might be a mature approach.

    There used to be articles in the JGR etc in the 70s like that.

    Somehow certainty never came up then. It has to be patched on now. Why?

    Climate science is not science, and is not a field, is why.

    It’s a grant opportunity.

    • Yep, make things unsexy and admit to the mountain of stuff you just don’t know. Don’t call it uncertainty, call it dunno. We live on a hot, plasticky ball with water inside and out. Let’s find out more about it. Then there’s that other hot ball…

  16. Ingvar Warnholtz

    If you are not sure about uncertainty, please look at nature. Nature doesn’t forgive, nor does it reads scientific papers. I am not a scientists, but having been subject to its forces, I can assure you that the AGW is very subjective as it does not account for natural CO2 emissions. For example, in a year my wife and I exhaled as much CO2 as my VW 2 litre engine driven to 15,000 km in the year. How do you make a difference between ‘natural’ and ‘industrial’ emissions?
    The CO2 measuring devices are exact in targeting atmospheric CO2 at 400ppm, but the clever things cannot differentiate between what is natural and what is industrial. Second, we never get an account of what makes up the remaining 999,600ppm.
    And people tell me I am a sceptic.
    I have more questions on this subject and you know where to reach me.

    • Some people who are called skeptics just genuinely don’t understand when they ask these types of questions. It shows more a shortage of knowledge than skepticism, but it can look like skepticism to some.

      • You are right, I don’t know the exact answer. You have the right to demand proper accounting when an exact part number appears. But what is so undisciplined in this field is that the main players do not know the difference between weather and climate. The latter is a mere statistic exercise with the former as the input.

  17. According to Monckton, there is 100% consensus on these questions, that he tested out at Heartland.
    1. Does climate change?
    2. Has the atmospheric concentration of CO2 increased since the late 1950s?
    3. Is Man likely to have contributed to the measured increase in CO2 concentration since the late 1950s?
    4. Other things being equal, is it likely that adding CO2 to the atmosphere will cause some global warming?
    5. Is it likely that there has been some global warming since the late 1950s?
    6. Is it likely that Man’s emissions of CO2 and other greenhouse gases have contributed to the measured global warming since 1950?

    I have no doubt about that (except the dragonslayers who apparently don’t even show up at Heartland, it seems). What he should have asked while he had that audience

    7. Is it likely that Man’s emissions of CO2 and other greenhouse gases have contributed most to the global warming since 1950?

    8. Is it even possible that Man’s emissions of CO2 and other greenhouse gases have contributed most to the global warming since 1950?

    These would have actually been more interesting poll questions.

    • and
      9. Has most of the CO2 increase since 1950 been due to Man.
      This would have sorted out the Salbyite faction.

  18. A fan of *MORE* discourse

    Observation  The article by Carolina Adler and Gertrude Hirsch Hadorn contains *zero* mathematics, *zero* theory, *zero* observations, and *zero* history … and so it is nugatory.

    Postulate  Scientists learn from history, as follows:

    Public sanitation  Scientists adamantly opposed far-right fundamentalists fundamentalists … and won.

    Vaccination  Scientists adamantly opposed far-right fundamentalists … and won.

    Creationism  Scientists adamantly opposed far-right fundamentalists … and won (mostly!).

    Ozone depletion  Scientists adamantly opposed far-right fundamentalists … and won.

    Atmospheric H-bombs  Scientists adamantly opposed far-right fundamentalists … and won.

    Persistent pesticides  Scientists adamantly opposed far-right fundamentalists … and won.

    Nuclear disarmament  Scientists adamantly opposed far-right fundamentalists … and won.

    Tobacco/cancer  Scientists adamantly opposed far-right fundamentalists … and won.

    Healthcare reform  Scientists adamantly opposed far-right fundamentalists … and won.

    Conclusion  Scientists are adamantly opposing far-right fundamentalists on climate-change … and will win.

    Scientists aren’t likely to abandon a winning hand, eh Climate Etc readers?

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  19. Pingback: Timmy’s failed scientific predictions … ‘timfoolery’ | pindanpost

  20. This is off subject, but I heard this on the radio on the way to the store:

    JPL: El Nino the weak getting weaker


    • Opps that’s from 2005.

    • A fan of *MORE* discourse

      WUWT prediction  Arctic sea-ice minimum of 6.1×10^6 km^2.
      Consensus prediction  4.7×10^6 km^2 (median).
      Cryosphere Today  smashing the WUWT prediction … whereas the consensus scientific prediction is looking pretty good.

      Question  Why do skeptical predictions so very often prove to be so very wrong? Shouldn’t skepticism be right *MORE* often (not less?).

      The world wonders!

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      • FOMD,
        I don’t get what your trying to point out? I was pointing out what I heard on the radio regarding El Nino. I realize my link discussed sea level but it was not about artic sea ice. Further I don’t follow WUWT and neither his nor the consensus predictions mean much to me since it is so small it has little meaning to me. Perhaps you could elaborate. I’m simple folks lol.

  21. The fundamental problem which the IPCC must address going forward is the common bottom line for all of its models: to date, the noise, error, and uncertainty exceed the claimed signals.

    Many years, many dollars, and much valuable manpower have been consumed. A huge opportunity cost expended, but with no real product to show for it. Meanwhile an equally vast and costly marketing confederacy has spun its wheels in self-destructive fashion while waiting for an appearance of a convincing correlation between computational cycles and weather cycles. But as each day passes, its appeal to authority and consensus slowly depreciates.

    “Tomorrow, and tomorrow, and tomorrow,
    Creeps in this petty pace from day to day,
    To the last syllable of recorded time;
    And all our yesterdays have lighted fools
    The way to dusty death. Out, out, brief candle!
    Life’s but a walking shadow, a poor player
    That struts and frets his hour upon the stage
    And then is heard no more. It is a tale
    Told by an idiot, full of sound and fury
    Signifying nothing.”

  22. Brilliant paper;

    Bottom line- we need to work towards consensus.


  23. Learn to say no; it will be of more use to you than to be able to read Latin. – Charles Haddon Spurgeon

    What is time but others’ expectations of us? That game we can refuse to play. – Joyce Carol Oates (“Blonde” 2000)

    What is a rebel? A man who says no. – Albert Camus (“The Rebel” 1953)

    The average American cannot say no. This is why he is average. – Roy H. Williams (“The Wizard of Ads” 1999)

    If you keep your mind sufficiently open, people will throw a lot of rubbish into it. – William A. Orton

    The eye of the painter is a battle field, and at the same time an idyllic prairie. Certain images, in fact, shock the eye while others caress it, some nourish it and others denutrify it, and so on. Consequently, if you wish to make your eye vibrate happily, remembering that your eye will be ceaselessly engaged in choosing, in struggling for holy unity, which is your holy unity, you must treat it with very special care…. You should surround yourself with a prison for your eye. For nothing is more harmful to it than the freedom to see everything, to attempt to embrace everything, to want to admire everything all at once. But the prison which I advise for you eye must be mobile, transparent, and its flying bars aerial and tiny. – Salvador Dali (“50 Secrets Of Magic Craftsmanship” 1948)

    He who controls your eyes controls your mind. – Timothy Leary

    The light of the body is the eye: if therefore thine eye be single, thy whole body shall be full of light. But if thy eye be evil, they whole body shall be full of darkness. If therefore the light that is in thee be darkness, how great isthat darkness. – Jesus of Nazareth (“The Bible”)

  24. David in Cal

    I have dealt with this sort of thing as a casualty actuary. In the case of climate, I see the following sources of uncertainty:

    1. The original data may be somewhat inaccurate.
    2. Adjustments made to the original data may be inaccurate.
    3. The model may be wrong.
    4. Parameters for the model may be wrong.
    5. Just by randomness, the actual results for a future period may differ from the model.
    6. Conditions in the future may be different from what they were in the past. Thus a model based on the past may not be right for the future.

    Numbers (4) and (5) might be subject to mathematical calculation. The others would be purely judgmental. I think a reasonable assessment combining each of these sources of uncertainty or error would produce an enormous error range.

    • nottawa rafter

      Thanks. You have put some structured thought to my instinctive reaction to the issue. Very rarely do my instincts let me down.

    • David, since both of us are outsiders, maybe we can discuss an issue which has bothered me for years.

      As you know, these models have to be fed a “scenario”. I don´t know if in your mind this is called a “parameter”. I tend to think of parameters as the parameterizations we use when we have to upscale physical phenomena as well as other basic parameters such as the energy exchange into deepwater or cloud formation.

      So, the scenario requires inputs computed outside the climate model. From what I can observe, sometimes these inputs aren´t estimated as such, they seem drawn with a pencil on graph paper (for example the methane concentration seems to be a joke).

      But the key issue which worries me is that as time goes by we do observe changes. And as things change we tend to make decisions, which tend to change outcomes. This is the basic philosophy behind the use of dynamic system models versus simple spreadsheets.

      So now let´s assume we have a dynamic model which takes the climate data and other inputs, cranks up, and delivers a view of the world as it may exist. The problem I have had is that as time moves forward we have nodes…decision points. And these decisions are made using the observations of what is, as well as predictions of what may happen in the future. What makes this more vexing is that, based on my experience, those making the decisions don´t behave rationally (ie they don´t use the information we have provided).

      So here we have another factor which throws everything to hell. We have those uncertainties associated with the items on your list, but we also have the uncertainties associated with irrational decision making and behaviour which take place as time goes by. This means the definition of risk perception is lost in the noise of the irrationality of the decisions we will make.

      Does this make any sense at all?

      • David in Cal

        That’s a nice point, Fernando. I agree that a big source of error is that the decisions often will not follow the models. Or, decision-makers may use the models as an excuse to promote policies that they liked in the first place, whether or not the models really support those policies.

        Perhaps an example of your point would be the President’s announcement of the recent EPA conservation plan. I have seen a calculation that this approach, if fully implemented, would decrease global temperature in 2100 by only .018 deg. C. (Of course, that prediction depends on which model one believes.) Sacrificing so much for a negligible effect is irrational. It’s like having the passengers bail the Titanic with tea spoons, rather than head for the lifeboats.

    • David said:

      “Sacrificing so much for a negligible effect is irrational. It’s like having the passengers bail the Titanic with tea spoons, rather than head for the lifeboats.”

      Its like taking your IRA and investing in a stock with a zero or negative growth, then having no “dry powder” available when an excellent investment opportunity comes your way.

      We do it all the time in the US of late. For example, we will soon invest somewhere between 170 and 500 million in auto backup cameras (17 M/yr production x 10 yrs x $10-30 each vehicle), plus 17-50 million annually thereafter, plus maintenance, plus opportunity costs in order to save an estimated 15 or so lives annually. How many starving people could be saved by the same investment? How many bright but poor kids could receive a free Ga Tech education for those sums? How might those kids be able to improve the world going forward? The confiscation of private wealth for the purpose of promoting no-benefit, low-benefit, or unproven-benefit schemes must end at some point.

      • David in Cal

        Sciguy — IMHO a backup camera is more than just saving lives. I use mine every time I parallel park. When I drive a rental car without that feature, I sorely miss it. In fact, I had a minor accident while backing a rental car in a tight parking lot. The body damage I caused cost more than a backup camera.

      • David

        And you should have the option to chose between a vehicle with a backup camera, learning to be more careful (even if you have a backup camera), or backing into things which are sitting there behind you and paying more for insurance. You get to determine how you will handle your risk based on your experience.

        As someone who has had a license since 1969, without backing into anything hard enough to do damage, I would suggest that a moment spent looking at your car from some distance before you enter and after you get out will do more to eliminate more kinds of risk than will ever be prevented by adding backup cameras and sensors.

  25. More reinforcement that climate science is in its infancy. Too bad we spent all that money under faulty assumptions. Perhaps we will see new approaches to modeling and a new respect for the study of natural forces and feedbacks.
    This study opens up the entire subject to creativity. Will the leaders of the controlling “social network” of scientists allow climate science to rise out of the dark and dank cellar into the fresh air of new ideas!

  26. Reading this article, I am amazed by the abundance of the literature triggered by the IPCC way of dealing with uncertainties. To me the most important comment is by Judith Curry who states that “when working with policymakers and communicators, it is essential not to fall into the trap of acceding to inappropriate demands for certainty”. IPCC obviously fell into this trap and their way to quote as 95% certain events for which we are not even able to define a probability is sufficient, for a physicist used to deal with handling uncertainties, to throw discredit on the totality of their conclusions. This is probably too strong a bias against them, I agree. It seems to me that if one had chosen a scientist as chair of IPCC, rather than a man making declarations such as “it is five minutes before midnight” one could have avoided falling in such a trap. No serious scientist would accept to quantify uncertainties mostly due to our ignorance of the underlying physics the way IPCC has done. Yet, I understand that deciders want to have some idea of the likelihood that this or this may happen and when. I understand that the problem of communicating honestly to them the state of our knowledge and ignorance is not easy. But the masquerade used by IPCC to give the illusion of our ability to quantify our ignorance with high precision is shocking and not acceptable.

    • Excellent comment. When facing this problem in the past, I´ve tried to give them a simple color code, something like red yellow green.

      However, higher ups seem to love getting “solid” numbers from us. So we run 50 realizations and show them the whole set of results (which reminds me, why would anybody average a realization family when it makes for better visual learning to see the spread?).

    • “No serious scientist would accept to quantify uncertainties”


      To assess the threat climate change we have to address how likely things are. Eg how likely is it that we will see 4C warming by 2100? How likely is it that Greenland will completely melt by 2300? Etc.

      In the real world scientists can assess these things and provide likelihoods. Hell even climate deniers when they are not busy being utter hypocrites recognize this when they blandly state catastrophe from the ongoing human carbon volcano “isn’t likely” (or even “impossible”).

      But you see in a respectable international report such as AR5, where lots of non-english speaking people will read it, people want clarification on exactly what the word “likely” means.

      So some definition has to be found. Expressing it as a % is the only way. “Very likely” is defined as 95% or more certainty.

      And yes there is a consensus among expert scientists that humans very likely caused most of the warming since 1950. Get over it.

      • “Wrong.”

        Now re-read that passage in it’s proper context.

      • I guess one can provide numbers, like that 95 %. I tend to see that as “1 in 20 chance”, or the inverse, “19 out of 20 times”. However, when I see the data, the models, and they workflows they use, that 19 out of 20 does look a bit goofy.

      • You take half of my sentence, which has lost the meaning of the full sentence, and say that it is wrong. You are not serious.

      • bacpierre, you make a compelling comment and lolwot distorts. That is what we are dealing with. lolwot is really no different than Pachuri.

    • A fan of *MORE* discourse

      bacpierre claims [utterly wrongly]  No serious scientist  thousands of serious scientists would accept to quantify uncertainties”

      Denialist error by bacpierre, science-respecting correction by FOMD.

      Conclusion  The reality of uncertainties — even the most “wicked” uncertainties — has *NEVER* obstructed the scientific community’s construction of consensus.

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      • The question in my mind is whether, under these circumstances, with the available data and models, anybody with a bit of common sense would extend their neck and express that 19 out of 20 figure.

      • A fan of *MORE* discourse

        Fernando Leanme wonders [sensibly!] “The question in my mind is whether, under these circumstances, with the available data and models, anybody with a bit of common sense, and a solid appreciation of radiation transport theory and thermodynamics, would extend their neck and express that 19 out of 20 figure.”

        Question by Fernando Leanme, extension by FOMD.

        That is a sensible question Fernando Leanme! To which the answer is “yes”.

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      • The extension is inappropriate. And the presumption that I don´t understand thermodynamics is pretty funny.

      • see my comment above

      • A fan of *MORE* discourse

        Fernando Leanme  “The presumption that I don´t understand thermodynamics is pretty funny.”

        Do not underestimate the challenges, Fernando Leanme!

        Vladimir Arnol’d  “Every mathematician knows that it is impossible to understand any elementary course in thermodynamics.”

        Perhaps general circulation models *ARE* a path to understanding?

        Donald Knuth  “Science is what we understand well enough to explain to a computer. Art is everything else we do. [\ldots] Science advances whenever an Art becomes a Science. And the state of the Art advances too, because people always leap into new territory once they have understood more about the old.”

        Thermodynamical guidance by Vladimir Arnol’d and Donald Knuth, climate-science links by FOMD!

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      • Fernando, Climate Science demands that a tilted rotating body in an elliptical orbit around a star is treated as an equilibrium system. One cannot argue with the equilibrium approximation or they pull the ‘antiscience denier’ card on you.

      • A fan of *MORE* discourse

        DocMartyn asserts [imprecisely] “Climate Science demands that a tilted rotating body in an elliptical orbit around a star is  treated as an equilibrium system  appreciated as a dynamical cascade.”

        Concept by DocMartyn, mathematics by FOMD!

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      • Fan of More Discourse, you don’t understand the skeptics enough to say what they do or do not believe, understand or want. That is because you react rather than listening.

        I don’t understand what skeptics believe, understand or want and I’m on considerably better terms with many of them than you. I suspect there is very little they all agree on, other than pointed criticisms of the behavior of those advocating the Consensus view. Even as a non-skeptic, I agree with them on that. So should you.

        You should take to heart Ygritte’s gentle words of wisdom to John Snow:

        “You know nothing, John Snow.”

      • stevefitzpatrick

        Tom Fuller,
        “I don’t understand what skeptics believe, understand or want and I’m on considerably better terms with many of them than you. I suspect there is very little they all agree on, other than pointed criticisms of the behavior of those advocating the Consensus view. ”

        Interesting comment. I think you are correct that there is a broad range of views. But there may be a lot more that the majority of skeptics have in common than you seem to think. It would be an interesting subject for discussion… and maybe even (dare I say it?) scholarly research. Any serious effort would be a lot more informative than Lewandowsky’s idiotic declaration of skeptics being crazy.

        BTW, I think it is ‘Jon Snow’….. but the quote is indeed appropriate.

      • Well, you could have congratulated me on spelling Ygritte correctly, but yes, it probably is Jon…

  27. The real problem climate skeptics have with consensus is simply that the consensus has reached a position they don’t like.

    If the consensus was that man wasn’t warming the climate, you can bet climate skeptics wouldn’t have a problem with appealing to the consensus at all. We see this in miniature every time some loony such as an ex-astronaut or washing machine engineer touts themselves a climate skeptic, the climate skeptics go loopy at promoting their faux authority all over the news.

    It’s the same with creationists who also surprisingly enough have a real problem with consensus.

    The fact is if you take a bunch of experts and shut them in a room with all the climate data we have to date, they will come out convinced that man was warming the planet. That’s just how it is. And lay people recognize that is a powerful reason to accept man is warming the planet. Climate skeptics really don’t like that.

    • You mean the ‘loony’ ex-astronaut who was lumped together with those who claim that the moon landings were faked, even though he actually stood on the moon?
      There are loonies, conspiracy theorists, wild claims and unsubstantiated theories, half-truths, beliefs, opinions and generalisations on both sides of the fence, so harping on about that and pretending those are exclusively sceptic failings does you no favours at all.
      Oh, and do drop the pretentiousness – there’s a perfectly good English word for ‘faux’

    • A fan of *MORE* discourse

      The Slashdot consensus understands these matters perfectly

      The oil companies/Heartland Institute don’t have to create spin anymore, because they’ve had the most important success possible: making denialism an important part of the identity of a lot of people.

      In some ways, it [climate-change denialism] is very cult-like in the way that it forms identity.

      Denialism gives you victim/threatened status (those evildoers are attacking our beliefs, we need to be warriors), enough victories to think of oneself as a winner but maintain the communal aspects of thinking oneself under threat, charismatic leaders, the companionship of shared beliefs, a sense of superiority to those who disbelieve, and, in the most cult-like aspect, the assurance of being above mere facts, of living in a world where your personal beliefs trump mere objective facts.

      Consequence  It’s no wonder that the world’s STEM community is unalterably opposed to willfully ignorant anti-science denialism!

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      • FOMbs continues to sprinkle threads with the confetti of irrelevant and strawman assertions, to knock down imaginary positions.

        As Mark Twain is supposed to have said (quote also attributed to Will Rogers by some),

        “It ain’t what you don’t know that hurts you, it’s what you know for sure that just ain’t so.”

        *EVERYONE* on Climate Etc. can see that Fan rarely knows wth he is talking about. We do enjoy the entertainment, though — Good on ya, FOMbs!!

    • lolwot | July 12, 2014 at 6:50 am |
      “The real problem climate skeptics have with consensus is simply that the consensus has reached a position they don’t like.
      If the consensus was that man wasn’t warming the climate, you can bet climate skeptics wouldn’t have a problem with appealing to the consensus at all”

      The ‘skeptics’ have no problem with the old consensus; that man could have no impact on such a vast system as the atmosphere climate.

      But there was a paradigm shift that many of them are still struggling with.

      • The ‘skeptics’ have no problem with the old consensus; that man could have no impact on such a vast system as the atmosphere climate.

        And when exactly did this “old consensus” actually exist?
        If you want to know why there’s such a level of scepticism, you need look no further than your own antics

      • A fan of *MORE* discourse

        Rush Limbaugh asserts [bizarrely] If You Believe In God, Then Intellectually You Cannot Believe In Manmade Global Warming

        See, in my humble opinion, folks, if you believe in God, then intellectually you cannot believe in manmade global warming … You must be either agnostic or atheistic to believe that man controls something that he can’t create.

        Question  Is it any wonder that the world’s STEM professionals *OVERWHELMINGLY* reject the science-denying ignorance of Limbaugh-style faux-conservatism?

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      • Not from what I have read and it talks about your rejection and why it was going to happen. We are still faithfully trying to bring everyone into consensus. You all seem to have put your faith in a lot of numbers. Still no paradigm shift but we are holding on. Also, you two are correct we don’t have any problem with that man.

      • I started looking into this topic around 24 years ago, and I never had any doubts the climate sure looked like it was getting warmer. I also had no problem with the physical process called the greenhouse effect. Nor did I object when it was pointed out we were cutting down forests, raising cattle, burning fossil fuels, and growing rice in prodigious quantities. Even if I only used intuition, it sure seemed that we were making a mess out of things.

        My specialty is to understand the architecture of deception, how propaganda is used to drive people in a given direction, and what can be done to discern the nature of “truth”. And the global warming “movement” sure looks like a good study subject.

      • Look how far we brought them through the ages. They leave their mark all over the world.

      • Joe 2:10 The earth shall quake before them; the heavens shall tremble: the sun and the moon shall be dark, and the stars shall withdraw their shining:

      • catweazle666

        “The ‘skeptics’ have no problem with the old consensus; that man could have no impact on such a vast system as the atmosphere climate.”


        I doubt you’ll find a single sceptic who believes any such thing.

        All we are sceptical of is the degree by which man can affect the climate,

        I suspect that you are in fact aware of that, i and many others have repeated it times without number.

        Stop making stuff up.

      • Ah yes, Dr Inofe, the great scientist.
        At least we don’t believe what he says, can you warmists say the same thing about Gore?

      • The difference is that Gore listens to the scientists and attempts to reflect what they say. Inhofe casts them all as hoaxers in his own mind and has closed much of the science out as a result.

      • So what? I, and many others, don’t give a fig leaf for what either of them think or say, so why do people like lowlot attempt to make it an issue?

    • John Carpenter

      Cept it’s no longer just the skeptics questioning the ‘consensus’. I think that’s the problem you are having.

      • wait…what consensus? oops!

      • John Carpenter

        Good catch lolwot, let me rephrase… It’s no longer just skeptics questioning the ‘idea’ of a consensus. Glad you helped me clarify that.

    • lolwot: The real problem climate skeptics have with consensus is simply that the consensus has reached a position they don’t like.

      Maybe for some; certainly not for me or, from what I read, of Dr. Curry.

      My real issue with the whole “consensus” thing is that it is misleadingly attached to conclusions quite separate from the actual statements. I would certainly agree with the consensus that human activities are causing the climate to warm. But that doesn’t mean I endorse your catastrophism or the idea that we need to immediately take steps that will kill millions of people to prevent potential problems later on.

      Hmm, now that I thin about it, it’s remarkable that you do exactly the same thing in your post — you twist the view of so-called “skeptics” to be something that is actually only endorsed by a fringe, and then act as if it were representative.

      Maybe intellectual dishonesty such as you have demonstrated cannot help itself.

    • stevefitzpatrick

      “The real problem climate skeptics have with consensus is simply that the consensus has reached a position they don’t like.”

      Unlike you, I make no claim to being able to read people’s minds. I can’t speak for all skeptics, of course, but I can certainly speak for myself: you are mistaken. The problem I have with ‘the consensus’ in climate science is NOT that rising GHG’s will warm the surface (they have to). The problem is that it seems to me the influence of GHG’s has been clearly exaggerated in the consensus view, and this could lead to very bad and very costly public policies. It has nothing to do with what I like or don’t like about the consensus, it has to do with me not liking bad public policy. If climate science had the same magnitude of policy influence as string theory, then I would not care at all about climate science, no matter the accuracy of the consensus view.

    • As you have no clue about skeptics, talking authoritatively about them merely reflects your own actions and beliefs.

  28. From the Twitterati above: “The process of peer review used in the scientific press is often held up as a mark of quality,,, But the peer review process is also open to abuse. Just as the social sciences became infected by political correctness 20 years ago, climate science has become governed by climatic correctness.”

    Kristen Barnes (Ponder the Maunder) was a victim of climatic correctness. At 15 years old Barnes figure it all out. Instead of celebrating her perspicacity, here we are 7 years later and still, no apology from academia for just standing by and allowing Barnes to be smeared by the self-proclaimed government experts of global warming. When Al Gore claimed there was a scientific consensus of opinion that humanity was causing global warming, he was being dishonest. All of academia that stood by quietly was being dishonest.

    • A fan of *MORE* discourse

      wagathon’s suspicions prove correct
      Scientists Reject What Denialists Stand For

      What denialists stand for …

      “The schoolteachers that peddle climate p*** in the nations’ classrooms are ****ing about their underlying motives and don’t know **** from **** about global warming or what it takes to earn a living in the real world.”

      Conclusion  Wagathon is entirely correct: scientists overwhelming reject the demagogic ignorance and hateful smears of ideology-driven climate-change denialism.

      That’s obvious to *EVERYONE*, eh Climate Etc readers?

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      • I would like to call your attention to an egregious case of “citation out of context” appearing in the comment/rebut by Mora et al. today on your journal website. Their use of Tebaldi and Knutti (2007) to support their projections … is laughable, since our paper actually presents arguments against it. ~Roz Pidcock, Overconfident predictions risk damaging trust in climate science, prominent scientists warn)

  29. catweazle666


    The science isn’t settled?

    Anyone remember this, courtesy of Roger Harrabin, BBC climate correspondent??

    I remember Lord May leaning over and assuring me: “I am the President of the Royal Society, and I am telling you the debate on climate change is over.”

  30. David in Cal

    What is the meaning of a probability assigned to something that’s actually a fixed “Yes” or “No”? E.g., consider the IPCC 5’s conclusion that it’s “highly likely” that climate sensitivity is between 1.5 and 4.5 deg. C?

    Leonard Savage has assigned one possible meaning in his classic book, Foundations of Statistics. It involves the odds that would be required for one to take either side of a bet. However, I don’t think anyone is basing their confidence intervals are Savage’s concepts. His concept is of a personal probability — a figure that would differ for each person.

    I think the assignment of a confidence interval to, say, climate sensitivity, is not only judgmental, but so undefined as to be almost meaningless.

  31. Where IPCC is wrong is that NO ONE can categorically state that there must be a glazier on Greenland and that the Arctic Ocean should have an annual ice cover of 100%. Thus we are not dealing with facts, but uncertainties in our assumptions. As a non-scientist I fail to see that at any time the glaziers will ever disappear, despite the models. If we had the most potential computer available, know all the natural forces known to man (and woman), we would not be able to create a program that will make the true predictions. Thus, any future predictions on temperature is futile, because we cannot even predict next week’s weather. Unfortunately, for the scientists, and this is for you, If you cannot nail the the true amount of water vapor in the air at any time, any temperature, then you don’t understand why we have a thermometer, that records the temperature of the air and the composition of that air. (Ever been in a sauna?)
    As a rough guide, if the sun burns off 1/10 of ocean and sea surfaces you end up with some 30 billions (give or take a billion) tonnes of water vapor. Think of your thermodynamics and when that vapor condenses in the form of rain, where does the heat/energy do? Into space, my friends.
    i know that your rain gauge is a scale-down from a meter square box where one millimeter yields one liter of water. I live on an average block of land, a bit over 1,000 sq meter. Each millimeter of rain is one tonne of water. I made a comparison with the energy released from the Hiroshima bomb and came to the astounding result that 10 mm of rain over 25 of my neighbors’ land would cover that energy release. I may be wrong, I don’t trust Excel s/s for my calculations, I use pencil, and 5mm grid-paper with on number i each square.
    What I am really saying is that water vapor is the greenhouse gas that warns the earth, carbon dioxide is inert and can never influence the earth’s temperature. Refer to Goode’s theory of 1949: add water vapor to the air and it tens to warm it, whereas adding carbon dioxide to the air it tends to cool it.
    Thank you.

  32. “Purpose deals with a general contention toward the linear model of expertise enshrined in the IPCC process. In this linear model, the IPCC is said to privilege scientific knowledge as the authority on climate change, thereby constraining political deliberation on whether to react to this information and address problems on the ground.”

    This seems to deal with the question of the linear communication of results, not the linearity of the physics of climate. Perhaps the authors of this article were closer to the truth than they thought. The 1940 singularity shows how misleading a linear model can be. In1940 the rate of change of atmospheric temperature changed from + 0.15C/decade to -0.15C/decade in a single year despite an ever increasing concentration of CO2. It is hard to imagine how a linear model could do that.

  33. What is the “Linear Model of Expertise”?
    What the heck is linear about political power?
    Politics and political influence is a very non-linear, chaotic process.

    In fact, I wonder if “Linear Model of Expertise” isn’t really a disinformation ploy to disguise what really goes on.

  34. Considering last topics paper, how to acknowledge the ever present ‘tacit assumptions’. Seems like an endless supply of papers with strong statements of conclusion with unstated assumptions about linearity, computability, etc. This seems not to be included, forgotten or swept under the rug….

  35. Pingback: Weekly Climate and Energy News Roundup | Watts Up With That?

  36. The ISO Guide to the expression of uncertainty in measurement http://www.bipm.org/en/publications/guides/gum.html
    Identifies two determinations of uncertainty and provides a framework with which to combine them: type A from measurement and type B from other methods. The approach is Bayesian and wrestles with the same issues in a general context that can shed light on this debate.