Stalking the uncertainty monster

by Judith Curry

Its time to check in with the Climate Uncertainty Monster.

The occasion for this post is an invitation to present a keynote talk at the 2nd International Workshop on Econometric Applications in Climatology.  The Workshop website is [here.]

To those of you that are new to Climate Etc., the concept of the ‘climate uncertainty monster’ seeded my inaugural posts at Climate Etc. in 2010 (Tag Uncertainty for entire series, see especially the earlier posts).

New presentation

My new ppt presentation can be downloaded here [uncertainty].  Check out the presentation; lots of good monster cartoons. Below is the text of my prepared remarks (I rambled on at the end including some material from my recent testimony that isn’t included in these remarks):

I’ve long been concerned about how the IPCC treats uncertainty, and in 2003 I started gathering my thoughts on this. A seminal event in my thinking on this subject occurred in 2010, when I attended the Royal Society Meeting on Scientific Uncertainty.

Let me start by describing the uncertainty monster, in context of the debate on climate change.  The “monster” is a metaphor used in analysis of the response of the scientific community to uncertainties at the climate science-policy interface. Confusion and ambiguity is associated with:

  • knowledge versus ignorance
  • objectivity versus subjectivity
  • facts versus values
  • prediction versus speculation
  • science versus policy

The climate uncertainty monster has its roots in philosophy and sociology.  Monster theory regards monsters as symbolic expressions of cultural unease that pervade a society and shape its collective behavior.  Dutch philosopher Martijntje Smits articulated the monster as co-existence of public fascination and discomfort with newer technologies.  Dutch social scientists Jeroen van der Sluijs articulated the ‘uncertainty monster’ as related to ways in which the scientific community responds to the monstrous uncertainties associated with environmental problems.

By way of introduction to this topic, I’m going to go through some uncertainty monster coping strategies, that are in evidence at the interface between climate science and policy.

Uncertainty monster hiding or the “never admit error” strategy can be motivated by a political agenda or because of fear that uncertain science will be judged as poor science by the outside world.  Apart from the ethical issues of monster hiding, the monster may be too big to hide and uncertainty hiding enrages the monster.

Ignoring the monster is typified by this statement from President Obama’s web page:  Call out the Climate Deniers – 97% of scientists agree.  A dubious paper that found a 97% consensus on fairly trivial aspects of climate change is then morphed into 97% of scientists agree that human-caused climate change is dangerous.

Monster simplifiers attempt to transform the monster by subjectively quantifying and simplifying the assessment of uncertainty. Monster simplification is formalized in the IPCC  by guidelines for characterizing uncertainty in a consensus approach consisting of expert judgment in the context of a subjective Bayesian analysis.

The uncertainty monster exorcist focuses on reducing the uncertainty through advocating for more research. In the 1990’s, a growing sense of the infeasibility of reducing uncertainties in global climate modeling emerged in response to the continued emergence of unforeseen complexities and sources of uncertainties.  For each head climate science chops off the uncertainty monster, several new monster heads tend to pop up.

The first type of uncertainty monster detective is the scientist who challenges existing theses and works to extend knowledge frontiers.  A second type is the watchdog auditor, whose main concern is accountability, quality control and transparency of the science. A third type distorts and magnifies uncertainties as an excuse for inaction for financial or ideological reasons.

Monster assimilation is about learning to live with the monster and giving uncertainty an explicit place in the contemplation and management of environmental risks.  Assessment and communication of uncertainty and ignorance, along with extended peer communities, are essential in monster assimilation. The challenge to monster assimilation is the ever-changing nature of the monster and the birth of new monsters.

The IPCC faces a daunting challenge with regards to characterizing and reasoning about uncertainty, assessing the quality of evidence, linking the evidence into arguments, identifying areas of ignorance, and assessing confidence levels. The IPCC uses a common vocabulary to express quantitative levels of confidence based on the amount of evidence (number of sources of information) and the degree of agreement (consensus) among experts.   Because of the difficulties of objective uncertainty assessments, the IPCC relies primarily on expert judgment in the context of a subjective Bayesian analysis.  A quantitative likelihood scale represents ‘a probabilistic assessment of some well-defined outcome having occurred or occurring in the future.’

The IPCC characterization of uncertainty is based upon a consensus building process that is an exercise in collective judgment in areas of uncertain knowledge. The general reasoning underlying the IPCC’s arguments for anthropogenic climate change combines a compilation of evidence with subjective Bayesian reasoning. A ‘consilience of evidence’ argument consists of independent lines of evidence that are explained by the same theoretical account.

In my assessment, the IPCC has institutionalized overconfidence. Scientists disagree because:

  • Insufficient observational evidence
  • Disagreement about the value of different classes of evidence (e.g. models)
  • Disagreement about the appropriate logical framework for linking and assessing the evidence
  • Assessments of areas of ambiguity and ignorance
  • Belief polarization as a result of politicization of the science

The climate debate is unfortunately characterized by competing certainties, characterized by the two guys hitting each other over the head. If uncertainty and ignorance are acknowledged adequately, then the competing certainties disappear. Disagreement then becomes the basis for focusing research in a certain area, and so moves the science forward.

About 5 years ago, following Climategate in fact, I became acutely concerned that climate scientists were focused on uncertainty hiding and simplification, which I regarded as a very unhealthy state of affairs for climate science. I began writing about this problem from multiple perspectives, including mathematics, philosophy, engineering applications, regulatory science, and even social psychology. I was seeking some new ideas for overcoming scientists’ bias about this topic and for employing more objective methods for understanding, characterizing and communicating uncertainty.

  • Curry, JA 2011: Reasoning about climate uncertainty. Climatic Change
  • Curry, JA and Webster PJ 2011: Climate science and the uncertainty monster. Bull Amer Meteorol. Soc.
  • Curry, JA 2011: Nullifying the climate null hypothesis. WIRES Climate Change
  • Curry JA, 2013: Climate change: No consensus on consensus. CAB Review


My main concern has been the overconfident conclusions put forward by the IPCC:

  • Consensus building process introduces biases
  • Ignorance and ambiguity is unaccounted for
  • Politicization acts to marginalize skeptical perspectives
  • Leads to overconfident conclusions

Symptoms of an enraged uncertainty monster include increased levels of confusion, ambiguity, discomfort and doubt.

Politicization of the issue of climate change has introduced huge biases into the science. However, when a scientific issue becomes politicized, and scientists attempt to speak consensus to power, then a scientific discussion of uncertainties is regarded as a political act.  There is an ideology that many climate scientists subscribe to, which I’ve termed the UNFCCC/IPCC ideology:

  1. Anthropogenic climate change is real
  2. Anthropogenic climate change is dangerous
  3. Action is needed to prevent dangerous climate change
  4. Deniers are attacking climate science and scientists
  5. Deniers and fossil fuel industry are delaying UNFCCC CO2 stabilization policies

The problem with scientists subscribing to this ideology is that there is a tendency for absence of doubt,
 intolerance of debate
, appeal to authority
, a desire to convince others of the ideological truth, and a willingness to punish those that don’t concur.

Given the enormous biases that ‘expert judment’ and ideology introduce into climate science, I have been pondering the feasibility of some more objective ways of understanding, characterizing and communicating uncertainty.

The bar on the bottom provides a good illustration of the different levels of uncertainty, starting on the left with determinism (implying no uncertainty). Statistical uncertainty Is when we have formulated a robust well defended PDF. The next level of uncertainty is when we don’t know the full PDF,, but we have some well defended percentile bounds. Scenario uncertainty means that we have some estimate of likelihood. The next level of uncertainty is that we have confidence in the sign or trend. With greater uncertainty than that, we head into the territory of ignorance. Personally, I would assess the 20th century climate attribution and 21st century climate projections at the 4.2 level (encompassing elements of scenario uncertainty and recognized ignorance).

In the previous slide, we discussed the uncertainty level. This diagram illustates also the nature of uncertainty. Epistemic uncertainty means that we have limited knowledge or information – this is the uncertainty type that in principle can be reduced. Ontic or aleatory uncertainty is irreducible; this relates to unavoidable predictability.

Another key factor to include in uncertainty assessments is quality of evidence.

  • High quality –  Further research is very unlikely to change our confidence in the estimate of effect
  • Moderate quality – Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
  • Low quality – Further research is very likely to have an important impact on our confidence in the estimate of effect and may change the estimate
  • Very low quality –  Any estimate of effect is very uncertain.

As an example, I would argue that the quality of the historical surface temperature record is moderate to high quality. I suspect that paleoclimate estimates of global surface temperature are very low to low quality.

One of my biggest concerns about reasoning about climate uncertainty is that Bayesian methods have trouble dealing with true ignorance. In classical two valued logic, unknowns are undifferentiated which may lead to false assertions. Evidence based 3 valued logic, or the so-called italian flag, is more honest about unknowns and allows for a better analysis of uncertainty.

So here is the problem as I see it.  The drive to reduce scientific uncertainty in support of precautionary and optimal decision making strategies regarding CO2 mitigation has arguably resulted in:

  • unwarranted high confidence in assessments of climate change attribution, sensitivity and projections
  • relative neglect of black swans and dragon kings
  • relative neglect of decadal and longer scale modes of natural climate variability
  • conflicting “certainties” and policy inaction

The current focus on the precautionary principle and optimal decision making is driving climate policy to a position between a rock and hard place.  Motivated by the precautionary principle, emissions targets are being set based on highly uncertain climate model simulations.  Classical decision analysis can suggest statistically optimal strategies for decision makers when uncertainty is well characterized and model structure is well known.  Optimal decision making is  a poor fit for the climate change problem.

The reason that we find ourselves between a rock and a hard place on the climate change issue is that policy makers have mistaken climate change for a tame problem. Climate change is better viewed as a ‘wicked mess’. A wicked problem is complex with dimensions that are difficult to define and changing with time. A mess is characterized by the complexity of interrelated issues, with suboptimal solutions that create additional problems.

When confronted with deep uncertainties surrounding a complex wicked problem, better decision analytic frameworks include:

  • Enlarge the knowledge base for decisions
  • Adaptive management
  • Build a resilient society

In closing, I leave you with this quotation by Bruce Beck:

“Being open about uncertainty should be celebrated: in illuminating where our explanations and predictions can be trusted and in proceeding, then, in the cycle of things, to amending their flaws and blemishes.”

JC reflections

In the 5 years since I started stalking the uncertainty monster, we’ve seen a lot of intellectual progress on how to frame and approach this issue.  It is becoming easier for scientists to do and publish research that challenges the consensus.  That’s the good news.

The bad news is that the interface between climate science and policy remains badly broken.  Many politicians seem to have become uncertainty deniers, with President Obama leading the pack.  The UNFCCC/IPCC is on a collision course with reality; it will be interesting to see how the Paris meeting goes next Dec, and how the IPCC AR6 will proceed.  But science seems less and less relevant to what is going on in the policy arena.  Which is fine; please get out of our way and let us do our science so that we can try to figure all this out by exploring the knowledge frontiers, rather than pledging allegiance to the consensus.

166 responses to “Stalking the uncertainty monster

  1. I ran across a paper a while back (IIRC it was linked here) about how the early evolution of intelligence (primitive brains) may have included innate strategies for “keeping one’s options open”; i.e. choosing options in decision-making that will avoid closing off paths of response to future developments.

    Seems very relevant here. I’ll post a link when/if I find it. Unless somebody else does first.

    • Well, this isn’t the one I was thinking of, but it looks interesting:

      The Origins of Options by Paul E. Smaldino and Peter J. Richerson Front Neurosci. 2012; 6: 50.

      Most research on decision making has focused on how human or animal decision makers choose between two or more options, posed in advance by the researchers. The mechanisms by which options are generated for most decisions, however, are not well understood. Models of sequential search have examined the trade-off between continued exploration and choosing one’s current best option, but still cannot explain the processes by which new options are generated. We argue that understanding the origins of options is a crucial but untapped area for decision making research. We explore a number of factors which influence the generation of options, which fall broadly into two categories: psycho-biological and socio-cultural. The former category includes factors such as perceptual biases and associative memory networks. The latter category relies on the incredible human capacity for culture and social learning, which doubtless shape not only our choices but the options available for choice. Our intention is to start a discussion that brings us closer toward understanding the origins of options.

      • “psycho-biological” = derived from internal processes or just plain internal
        “socio-cultural” = derived from the external world or just plain external

    • This also looks interesting:

      Why good solutions make us oblivious to better ones

      “Our brain generally prefers a familiar, trusted solution, rather than exploring alternatives,” Merim Bilalić (Department of Psychology) explains. This phenomenon has been known since 1942, when the American psychologist Abraham Luchins conducted experiments with water jugs, each with a different capacity. Participants in the experiments were asked to work out how to transfer liquid between the jugs so that they would end up with 100 units of water in one container. The solution to this task involved three steps. When they were subsequently given simpler tasks to solve, they continued to apply the more complicated three-step solution.

    • Keeping options open… Dan Ariely and Jiwoon Shin…

      • Thanks. Not the one I was thinking of, but still very interesting.

        The last experiment provides initial evidence that the mechanism underlying the tendency to keep doors open is a type of aversion to loss rather than a desire for flexibility.

        This is a very interesting statement. It displays, IMO, a pre-conceived notion regarding how the brain works, on a hardware level. Why shouldn’t a tendency to regard flexibility as a value subject to “loss” be hardwired into the brain? In fact, why shouldn’t it have been hardwired into our earliest bilaterian ancestors?

        In this scenario, conscious, explicit intent to preserve flexibility would be like foam on the sea, over the deep waves of innate values. Losing flexibility, even if it’s not consciously recognized, would be perceived as a “loss” because that’s the way the brain is wired. Because individuals whose brains weren’t wired that way had lower survival/reproductive chances.

      • thx for link, interesting article

    • Curious George

      I had this problem many years ago when programming a chess player: What move to select in a hopeless situation? Answer: One that keeps most of your options open – one that makes it most difficult for your opponent to win. Wissner-Gross and Freer generalized that principle nicely,

      • Thanks. This may be the paper I was thinking of, although IIRC there was actual mention of chess in what I read, and I don’t find it here. But this paper is interesting, because it suggests that hyper-complex non-linear dispersive systems like weather/climate may actually be able to behave adaptively.

        Don’t have a lot of time right now, but you might enjoy the outcome of this search in Google Scholar.

  2. Pingback: Stalking the uncertainty monster | Enjeux énergies et environnement

  3. Danny Thomas

    This presentation and discussion is a logical step in the hunt for certainty and the stalking of the monster. Given all the unknowns in the climate discussion, there are certainly known (or knowable) economic impacts towards addressing those unknowns. I look forward to a post soon after the event to gain your perspectives.

  4. “I’ve long been concerned about how the IPCC treats uncertainty”

    They treat it by denying it. Nice trick.

    • No, they are smarter than that. They use Rachel Carson’s trick of stating that there is uncertainty but presenting their information in a way that leads in one direction only. That way, they can deflect criticism by saying that they have been transparent about the uncertainty. (Not that any criticism comes from those predisposed to swallowing the message).

    • aneipris, EPA, IPCC are creating uncertainties, intentionally, intention of the propaganda is; to confuse, not to inform! because: if the public knows the truth – most of those ”advisers” to EPA, IPCC would end up in jail

  5. “Many politicians seem to have become uncertainty deniers, with President Obama leading the pack.”

    Obama desperately needs global warming to distract our attention from all the real problems in the world, many of which he’s significantly worsened in his 6+ years.

  6. “Many politicians seem to have become uncertainty deniers,…

    By her frequent and continued use of the term, it seems that Judith has given up taking offense to the term “denier.”

    • Joshua, I’m proud to be a ”GLOBAL WARMING DENIER” not what you are trying to con the public and call it ”climate denier” – if you succeed to con somebody who thinks that ”climate doesn’t exist” – that’s not a success, because with person who believes that climate doesn’t exist = must be something wrong mentally… proof that: the brainwashing / aggressive propaganda created mentally deform people…

    • It’s called irony, Josh.

      • Ironically comparing people to holocaust deniers?


        Personally, I don’t like the term, but you’d think that if “skeptics” are going to drama-queen and be outraged, outraged I say about its usage, then they wouldn’t turn right around and use it themselves.

    • Nothing of substance on the topic to add (again), Joshua returns to his creepy Curry stalking…

      If someone repeatedly uses offensive language at me I tend to lose my inhibitions over time at returning slurs in kind. Most adults know where I’m coming from, even if it’s not the most noble response. Before you can admonish Dr. Curry you’d need to hit at the originating side, and we know you have no interest in such objectivity. You’re here to pester, and since you can’t argue the science or the topic at hand you’re left to the inane.

    • Joshua makes a fair point[*]. But I’m not sure about Judith using the term frequently and continually. The word certainly crops up a lot, but that’s normally because other people’s use is being quoted.
      [*] A rare event.

      • I use the word ‘denier’ in this post for a ‘shoe on the other foot effect’.

      • =======>”I use the word ‘denier’ in this post for a ‘shoe on the other foot effect’.”

        You think I don’t know that? Huh! I’m still mad because you told on me for bragging on ATTP (he’s my friend) that I am incessantly trolling CE. So there.

      • “I use the word ‘denier’ in this post for a ‘shoe on the other foot effect’.” – JC

        It’s the ‘they-did-it-first’ defence.

        Very sophisticated.

      • Danny Thomas

        Read more, comment less.
        This looks to me like “misframing of one’s argument, no matter from which side, is misframing one’s argument”. (see how that works?)

      • Judith –

        So let’s break this down a bit:

        ==> “I use the word ‘denier’ in this post for a ‘shoe on the other foot effect’.”

        But we see so much outrage, outrage I say about the use of “denier” because “skeptics” are so offended by an epithet where they are “compared to holocaust deniers”

        1). If I tried to make a list of other epithets that you would never consider using to a put the “shoe on the other foot effect,” they would never get past the filter you use for moderating comments.

        2) It is interesting that when you use the term “denier,” you mean it not as a comparison to holocaust deniers, but to describe people that you think are “denying” a scientific reality.

        So it’s an OK and “ironic” usage of a horrible epithet on your part but a deeply, deeply offensive comparison to holocaust deniers when “realists” use it.

        So again, it’s double-standard-apalooza around here.

        If someone is offended by the use of the term “denier,” we certainly would expect them to absolutely not use the term to describe others. Hence, indeed your use of the term is ironic (something that happens in a way opposite to what we’d expect), but unintentionally so.

        I’ll also note the even more amusing aspect of the outrage, outrage I say about the political incorrectness of the horribly offensive term “denier” coming from a group who (as a group) frequently whine about the horrible effects of political correctness.

        This is just more of the exploitation of victimhood that is so common (on both sides) in the climate wars. Just more of the identity-aggressive and identity-offensive behaviors associated with tribalism.

        Again, it’s not a good term – because its use is a sign of poor reasoning (how do you know what someone else is or is not “in denial” about?) – but can’t we get past all the drama-queening?

      • “but can’t we get past all the drama-queening?” – Joshua

        How horrible ‘they’ are is vital to tribal politics.

      • =======>This has got nothing to do with what I am yammering about. I am calling her a drama queen cause I’m still mad cause she put me in moderation and tattled on me for bragging on my friend ATTP’s blog that I am the main troll at CE. So there.

    • Nothing says “intellectual” like the ability to recognize irony.

    • Note all that wordpress has an idiot blocker feature, but you have to install the greasemonkey add-in first. Idiot blockers may be seen as somewhat unethical, but I work on the principle that trolls should be given three chances and then they’re blocked.

  7. J.C.wrote:
    “Uncertainty monster hiding or the “never admit error” strategy can be motivated by a political agenda or because of fear that uncertain science will be judged as poor science by the outside world. Apart from the ethical issues of monster hiding, the monster may be too big to hide and uncertainty hiding enrages the monster.”

    I suggest that which is hidden, is not a monster, and it is what removes the uncertainty. And few are knowingly hiding it, because they see no need to question whether natural variability is internal or not.

    • The classic example of uncertainty hiding (see my presentation) is the hockey stick saga

      • Or I could put it another way. All the uncertainty monsters are created out a single bad assumption about the nature and cause of natural variability..

    • fear that uncertain science will be judged as poor science by the outside world.

      It really is poor science if it is uncertain and it is presented as certain.
      The outside would get it right if they saw it as uncertain science that is poor.

  8. Read the presention. Learned a different style back in the day. Never the less, persuasive. Well done.
    A suggestion, as I trained undergrad as an economist back when. More facts, more statistics, go down easily and well. Do notmheaitate to use them. Economists are by and large not politicians.

  9. Or I could put it another way. All the uncertainty monsters are created out a single bad assumption about the nature and cause of natural variability.

  10. ”knowledge versus ignorance” YES, confusing the Urban Sheep -> then their ignorance creates in them fear from the truth / knowledge… common tactic… accompanied by ”silencing the truth”.

    There is NO uncertainty, only fear from facing the truth; for political expediency AND guillotining democracy in democratic west… Every leading ”CARBON molester” is a Marxist, top-coated in green colour – which gave them the appropriate name: ”the Chameleons”

  11. My dad used to observe degreed people doing stupid things that would not occur to the less educated with better judgment and more common sense.

    My dad called this educated stupidity. Giving a diploma to the stupid does not make them smart or improve their judgment – they just have better paperwork.

    Which leads us to global warmers and environmentalists. We have spent 10’s of billions planning for climate change, estimating harm to the environment, spent somewhere between 1/2 trillion and a trillion dollars reworking our energy systems etc.

    35 years ago in 1979 a committee guessed, guessed mind you, ECS = 3°C +/-50% and the answer hasn’t changed substantially in 35 years. We can’t get a straight answer on CO2 forcing, how much CO2 will go up, or how much the temperature is going to rise. We are relying on someone’s 35 year old guess. WTF.

    Spending over 1/2 trillion dollars on badly defined problem could only make sense to a government bureaucrat with a degree in one of the soft-headed subjects. ANYONE WITH HALF A BRAIN KNOWS THE FIRST THING YOU DO IS DEFINE AND BOUND THE PROBLEM.

    Which leads us to the precautionary principle. The precautionary principle is used to allow activists to use scaremongering based on uncertainty to drive public policy. There is no incentive to define the problem – because defining the problem could reduce or eliminate funding that is going toward the activist agenda.

    The real precautionary principle is that you don’t spend hard earned tax dollars to appease people who have the credibility of nigerian internet scammers. If we allow activists to drive public policy with scaremongering based on uncertainty, activists will be driving public policy with scaremongering based on uncertainty until the end of the Republic – which won’t take long.

    • PA +100

      I believe that Indhar Golkany concluded, in his book on the precautionary principle, that in the case of climate change an aggressive all out approach to mitigation was not warranted.

    • PA “35 years ago in 1979 a committee guessed, guessed mind you, ECS = 3°C +/-50% and the answer hasn’t changed substantially in 35 years. We can’t get a straight answer on CO2 forcing, how much CO2 will go up, or how much the temperature is going to rise. We are relying on someone’s 35 year old guess. WTF”.

      Polemic aside, I find that a darn good questtion.

      Can anybody here state a really good reason for the failure to pin down that number?

      • KenW, “Can anybody here state a really good reason for the failure to pin down that number?”

        What failure? The number came from a compromise, Hansenites at 4 C dangerous impact and Manabeans at 2 C unlikely to be very dangerous, take the average and you have a coalition, at 3 C, probably dangerous with a large enough range to include most scientists. Ta dah, you have a consensus. That is a political solution, no scientist left behind.

        Another approach would have been Hansenites versus Manabeans, both cannot be right, let’s see who is more right. That though would inspire competition, someone would end up being wrong. That is bad for science, you just cannot have a potentially large percentage of the climate elite being WRONG. That’s bad for biz.

        The compromise should really have created a Monte Hall problem. Climate science picked the Charney door, now after the commercial break you get to change to Hansen, or Manabe, or stick with your first guess. What to do?

      • But Capt’n, that would mean that all those studies based on models which are based on some assumed values of TCS and ECS are no better than the original guess?

      • KenW, “But Capt’n, that would mean that all those studies based on models which are based on some assumed values of TCS and ECS are no better than the original guess?”

        Pretty much. Maintaining the range has its advantages. James Annan mentioned that some would intentionally produce high estimates just to keep the range alive. There isn’t really any advantage in a low range there is an advantage in “we don’t know fur sur but it could be bad”. The advantages are not the same for everyone of course.

      • “Maintaining the range has its advantages…”

        Capt’n, you suggest there is an institutional aversion to reducing the uncertainty surrounding ECS. Now that sounds a bit conspiratorial, but, on the other hand, yours seems to be the only explanation around here.

      • Can anybody here state a really good reason for the failure to pin down that number?

        Yep! They use climate model output and ignore real data.

        The climate model output does not match real data.

        To pin down a number, you would need a climate model that could match real data.

        That is a really good reason for the failure to pin down a number, their model output does not match real data.

        They publish their number. Mother Nature publishes her Number.
        The numbers are different. Mother Nature has the real number. You cannot pin down a number that disagrees with Mother Nature.

      • Enjoying your wit Cap’n Dallas. Nice blogspot too.

    • David Springer

      Comparing global warming nutcases to Nigerian internet scammers is an insult to Nigerian internet scammers.

    • ECS is Equilibrium Climate Sensitivity, which is untestable.
      Much more accessible is ‘Effective Climate Sensitivity’ – what’s actually occurred.
      1.6K per CO2 doubling:

  12. The climate warmists demand changes that have severe economic consequences. They should therefore be judged in part by the standards that governmental agencies such as the FEC require of any public offering of securities and be subject to the penalties assessed for false or misleading information.

    Too few folks realize that Steve McIntyre’s background is in that sort of work, where being scrupulous and open is essential to not only being employed and successful, but staying out of jail. Those who believe that McIntyre sets the bar to high obviously have no knowledge of the standards he’s spent his career following.

    • It’s SEC, not FEC. So off with your head.

    • “The climate warmists demand changes that have severe economic consequences. ”
      And, besides, achieve absolutely nothing by way of actually reducing emissions i.e. the desired end.

  13. Possibility assessments:

    “Expert judgment”

    There in lies the rub. Everybody believes their own expert judgement is correct with exclusionary favorable evidence. What was missing from the Guelph lecture: the willingness to say: “I don’t know.” Fundamentally, the inability to say to one’s self as well as to others: “I don’t know” places scientists into the dilemma of external believability and one’s own self awareness. Which is most important? Look around at the activists, all eyes are focused upon the externality. For me, this is the measure of their integrity. Can one look in the mirror and say, what I said today to the outside world, I believe as I stand in front of this mirror. There is not a: “Yes, but”.

    This all goes back to my learning about climate science and whose information I would believe. I learned not to believe a number of people, not because they were not smart or prominent, but, I didn’t believe them because they lied to me; either by inclusion or exclusion as I learned only after some time. Whatever they said subsequently, I did not believe.

    The Uncertainty Monster really has many qualities and believability is but one, and a necessarily important one. Scientist who approach uncertainty without that caveat: “I don’t know”, appear to me to be without shame, and hence, are unbelievable and untrustworthy and are to be dismissed in their uttering.

    • Danny Thomas


      This, in a nutshell, is my biggest issue: ” or exclusion”.
      Ignoring the “uncertainty monster” and framing the discussion as catastrophic led me to distrust the ends based on those means.

    • My judgement is not “expert judgment”, I don’t have the credentials. My judgment is based on seven years of studying climate. I could not have gotten any degree from any college because I do disagree with consensus. To be qualified to provide “expert judgment”, you must submit to the consensus. You cannot have an opinion that does disagree. You are not counted in the 97% if you disagree.

      Consensus is evil. Consensus is not science. Consensus prevents knowledge advancement. Consensus is really Stupid.

  14. Clearly with a current forcing between 2 and 3 W/m2 on its way to 6 W/m2 by the end of the century we are hitting the climate with a big hammer, and there is a lot of uncertainty as to what happens when the hammer is that big. Maybe all the ice melts, for example. A reasonable solution is to ease off with the hitting as fast as possible until we have a better idea of all the consequences. An unreasonable solution is to say I don’t know what all this hitting is doing, but I will keep doing it regardless and just keep an eye on all the consequences as we go along.

    • A reasonable solution is to ease off with the hitting as fast as possible until we have a better idea of all the consequences.

      Nope. Just as “unreasonable” as:

      to say I don’t know what all this hitting is doing, but I will keep doing it regardless and just keep an eye on all the consequences as we go along.

      Just because it might be a good idea to “ease off with the hitting” doesn’t mean it’s a good idea to throw every other value overboard in pursuing it.

      Think about the actual meaning of your term “as fast as possible”.

    • Maybe all the ice melts, for example.

      As long as you realize that scenario is just something you’ve made up or seen in a movie – not even the IPCC, mother of agenda – projects ‘all the ice melts’.

      In fact, of course, the record is quite the opposite:

      higher temperatures = greater snow accumulation on Greenland

    • Jim D | April 23, 2015 at 10:48 pm | Reply
      Clearly with a current forcing between 2 and 3 W/m2 on its way to 6 W/m2 by the end of the century we are hitting the climate with a big hammer, and there is a lot of uncertainty as to what happens when the hammer is that big. Maybe all the ice melts, for example. A reasonable solution is to ease off with the hitting as fast as possible until we have a better idea of all the consequences. An unreasonable solution is to say I don’t know what all this hitting is doing, but I will keep doing it regardless and just keep an eye on all the consequences as we go along.

      Well, gee let’s bring some reality to this discussion.

      1. What were the sources of post 1900 warming.
      a. AGW: 0.24°C
      We have the only study of IR that says 0.2W for 22 PPM or about 2/3rds of the famous IPCC F=5.35*ln(C/C0), or 3.49 * ln(C/C0). The TSR (from the IPCC site) is 2X the CO2 forcing or 0.61W for 22 PPM, more that 3 times higher than the observed forcing..

      F = 3.49 * ln (400/310) / 3.7 = 0.24°C
      This is 0.24°C for the post 1900 CO2 change.

      b. CGAGW: 0.23°C
      It should be noted that despite what is claimed by people who should know better CGAGW is not real and is an electronic artifice.

      c. Post 1900 warming: 1°C

      d. SOTGG Warming (all the non-greenhouse warming) 0.53°C
      This is the difference between adjusted warming, the greenhouse gas component and the computer component.

      The bottom line is the natural warming in the 20th century was more than twice the CO2 induced warming 0.5°C vs 0.24°C.

      2. Warming the ocean to 2000 meters takes roughly 130 W-Years/K-m2 for each unit (1mx1m) section of ocean.
      The ocean has lagged the land at least 0.3°C, and the ocean is warming at a rate of only 0.2-0.3W/m2 it . It will take about 130 years to catch up to the last century warming – which was less than 1/3 related to CO2.

      3. All things being equal, since the CO2 level isn’t going to exceed 500 PPM, 2100 will be about 1/2 a degree celsius warmer than it would be otherwise.

      What scientists have completely failed to simulate is “what it would be otherwise”. Unless the 2100 temperature sans GHG forcing is accurately simulated the IPCC pretty model graphs have no meaning or value.

      The performance of the models during the hiatus makes it pretty clear IPCC pretty model graphs have no meaning or value.

      To illustrate the problem: If the natural temperature in 2100 is going to be 1°C colder we should be aggressively looking for new fossil fuel sources to help mitigate the damage the cold will do to society and try to reduce the drop in temperature by enhancing GHG warming.

      • If you are saying CO2 won’t exceed 500 ppm in 2100 you are setting the same goals as the IPCC. That would be great, but currently the forcing is increasing by nearly 0.4 W/m2 per decade for a more realistic value of 6 W/m2 by 2100. If you want to reduce the forcing increase you should be supporting the IPCC targets. Only significant reductions in burning rates keep us anywhere near 500 ppm in 2100 which is about 3 W/m2, a fairly solid mitigation scenario.

    • Curious George

      “forcing between 2 and 3 W/m2 on its way to 6 W/m2 by the end of the century.” How accurate are your numbers? What is the accuracy of a 1-hr step in the best GCM?

      • Currently the forcing is increasing by nearly 0.4 W/m2 per decade. It is a BAU extrapolation of the forcing change, but allows for population growth and development.

    • We have actual data. The “hitting” is hitting in the same bounds as in the Roman and Medieval Warm Periods. There is no uncertainty about this, The real data shows us this. A reasonable solution is to say the hitting is going down the exact same way it did in the Roman and Medieval Warming Periods and it is most likely going to go down just the same way again. Keep an eye on it and we are looking at a lot of real data in normal bounds and flag a problem when real data gets outside the bounds of past data. That has not happened. In warm times, it always snows more and it always gets cold. This will happen again, it always does. You only know this if you look at real data.

    • Jim D | April 23, 2015 at 10:48 pm | Reply
      Clearly with a current forcing between 2 and 3 W/m2 on its way to 6 W/m2 by the end of the century we are hitting the climate with a big hammer, and there is a lot of uncertainty as to what happens when the hammer is that big.

      Say what?

      The “2 and 3 W/m2” is 2/3rds unrelated to GHG. Unless you are going to go after mother nature with a slave collar and a whip (geoengineering is a cure of dubious value that may be worse than the disease) there isn’t much you can do about current or future warming.

      CO2 is icing on a very thick cake. If the earth cools it will cool, if the earth warms it will warm. The move to 500 PPM will add about 1/4°C on top of the 20th century 1/4°C caused by the increase from 310 to 400 PPM.

      So far the 55% increase in plant growth since 1900 says this is a thumbs up situation. That it will be a bonus not a calamity.

      • According to some skeptics like Lewis, anthropogenic forcing adds up to 2.8 W/m2 already (with their low aerosol estimate). The IPCC has a more reasonable 2.3 W/m2. Where does your 2/3 come from, and precisely what do you think the IPCC and Lewis are doing wrong? Their values are almost all GHGs with some aerosol offset.

  15. Where’s the Mark Twain “expert” ppt? I wanted to be able to cite/quote it. :)

    • Steven Mosher

      “While we may quarrel about the construction of the first sentence, it does not say that human-caused climate change is dangerous.”

      Ah yes Obama says climate change is the greatest threat, but it’s no danger. I get it.
      It’s not catastrophic. It’s not dangerous.

  16. > Ignoring the monster is typified by this statement from President Obama’s web page: Call out the Climate Deniers – 97% of scientists agree. A dubious paper that found a 97% consensus on fairly trivial aspects of climate change is then morphed into 97% of scientists agree that human-caused climate change is dangerous.

    See for yourself:

    97% OF CLIMATE SCIENTISTS AGREE that climate change is real and man-made, and affecting communities in every part of the country.

    Yet too many of our elected officials deny the science of climate change. Along with their polluter allies, they are blocking progress in the fight against climate change.

    Find the deniers near you—and call them out today.

    While we may quarrel about the construction of the first sentence, it does not say that human-caused climate change is dangerous.

    Also note, for the nth time, that this is the web page of Organizing For Action, not “President Obama’s web page”:

    Here’s President Obama’s web page:


    Mr. T frowns upon misrepresentation.

    • Uhhh, who precisely is denying that climate change (ie. changes in climate regardless of cause or degree) is “affecting communities in every part of the country?”

      If you take the statement at face value, it is a tautology. Of course changing climate affects communities. But his statement is more than that. He goes on to lament that ” they are blocking progress in the fight against climate change.”

      Who cares if anyone is “blocking progress in the fight against climate change” if that change is not dangerous.

      This bait and switch use of the term ‘climate change’ is the oldest PR trick in the alarmists’ tool bag. But they return to it every time. ‘Climate change’ to Barack Obama, in the context of accusing others of blocking government efforts to fight against it, only makes sense in the case of dangerous, aka Catastrophic Anthropogenic Global Warming.

      To a degree, Willard has a point. Obama does not claim that AGW will be dangerous. He claims it is going to be catastrophic, as does every other warmist.

      • > If you take the statement at face value, it is a tautology. Of course changing climate affects communities. But his statement is more than that. He goes on to lament that ” they are blocking progress in the fight against climate change.”

        GaryM has a point: there’s a party that is filibustering action against consequences that trivially follow from a fact some of its representatives deny or minimize.


        > Obama does not claim that AGW will be dangerous. He claims it is going to be catastrophic […]

        A quote might be nice.

      • “Climate scientists say we need to avert an additional 2-degree temperature increase to avoid the most catastrophic impacts of climate change.”

        Now Willard can tell us why the webpage which is titled ” Climate Change And President Obama’s Action Plan” is not really Obama.

        “We can choose to believe that Superstorm Sandy, and the most severe drought in decades, and the worst wildfires some states have ever seen were all just a freak coincidence. Or we can choose to believe in the overwhelming judgment of science — and act before it’s too late.”
        – President Obama”

        Then he can tell us that Obama does not attribute “Superstorm Sandy”. the California/southwestern US drought and wild fires in various states to CAGW.

        Who ya gonna believe, Willard or your lyin’ eyes?

      • GaryM –

        Thought you might find this interesting:

        I figure some history on the roots of your ideology couldn’t hurt.

      • But then, Willard believed that if he liked his insurance plan, he could keep his insurance plan.

      • =========”A quote might be nice.”

        Very nice work, willy. Say, have you managed to remove all my comments on ATTP, wherein I bragged about incessantly trolling CE? You promised, willy.

      • > Climate scientists say we need to avert an additional 2-degree temperature increase to avoid the most catastrophic impacts of climate change.

        That’s better: if we’re to attack the President’s action plan, we might as well cite it.

        Here’s the lead, BTW:


        No C word over there. A threat is not always something that is going to happen.

        Then there’s a joint announcement with China. No C word there either.


        Then there’s the inconvenient fact that:

        2014 was the hottest year on record globally, and temperatures from 2001 to 2012 were warmer than any previous decade in every region of the United States.


        Then there’s this other inconvenient fact:



        Some might argue that more than $100 billion is somewhat catastrophic. Some might disagree. Mr. T’s waiting for the river card before raising.


        Then we get to GaryM’s quote.

        That’s how important the C word is.

        Yet, “we need to avert an additional 2-degree temperature increase to avoid the most catastrophic impacts of climate change” is not exactly the same claim as “it is going to be catastrophic.” Nor is it made by “every other warmist.”

      • Willard,

        Brilliant response. Here let me help you. Count all the words, and tell us how many are NOT “catastrophic”, so everybody will ignore his actual words.

        “Yet, ‘we need to avert an additional 2-degree temperature increase to avoid the most catastrophic impacts of climate change’ is not exactly the same claim as ‘it is going to be catastrophic.’ Nor is it made by “every other warmist.”

        Actually, for anyone with a 6th grade level of reading comprehension, that is exactly what it says.

        His statement is “we need to avert an additional 2-degree temperature increase”, or we will experience “the most catastrophic impacts of climate change.”

        That tells us 2 things, for those who can read.

        1. If we don’t “avert” the 2-degree rise in temperature, we will experience “the most catastrophic” effects of CAGW.

        2. It clearly implies that even avoiding a 2-degree rise will prevent only the “most catastrophic” effects.

        Somebody take the shovel away from Willard, before he hits magma.

      • The United States is leading global efforts to address the threat of climate change. Wind power has tripled, and energy from the sun has increased tenfold. U.S. carbon emissions have fallen by 10 percent from 2007 to 2013 – the largest absolute emissions reduction of any country in the world. To build on that progress, President Obama has taken a series of ambitious steps to combat climate change.

        energy from the sun has increased tenfold.

        What kind of stupid is that? Does any honest person believe that? The energy from the sun has been almost the same for thousands and millions of years. The energy from solar cells is a tiny percent of the energy we get from the sun and it is still tiny. A tenfold increase is still just in the noise.

    • And oh yeah, OFA is Obama’s 2012 campaign apparatus renamed.

      ” Later, it became the grassroots arm of Obama for America. After Obama’s second inauguration, it was reorganized as Organizing for Action and returned to its previous mission of organizing around the President’s agenda.”

      Next Willard will assure us that the Clinton Family Foundation, which received hundreds of millions of dollars from foreign governments who received preferential treatment from the State Department while Hillary was secretary of State, is not Bill and Hillary Clinton.

      • > OFA is Obama’s 2012 campaign apparatus renamed.

        Not quite. GaryM’s own quote mentions that OFA became the grassroot arm of Obama for America. Which means that Judy’s targeting a grassroot movement with her incorrect claim.

        Here’s what happens when you don’t have a grassroot arm, BTW:

      • Willard,

        You should go back to pseudo-cryptic one liners. When you try to talk about reality, it’s embarrassing.

        “CNN has confirmed that Obama for America will transform into a non-profit, tax-exempt group, that will attempt to leverage the re-election campaign’s powerful grassroots organization and social media operation, as well as its rich voter database and vast email distribution list, to build up public support for the president as he pushes for agreements over the debt ceiling and the federal budget, gun control legislation, immigration reform, and other objectives.

        A senior Democratic official with knowledge of the plans confirms to CNN that name of the new organization will be ‘Organizing for Action.’ The formal announcement will come Sunday, at an Obama campaign legacy conference being held in the nation’s capital.”

    • So, Willard and Jim D. – if we stop burning fossil fuels tomorrow, can you promise that we will stop all climate change, have no more hurricanes, tornadoes, droughts, floods, etc. so that we can all rest assured that our children and grand children will live in a state of climate utopia?

    • rogerknights

      On May 16, 2014, Obama tweeted:
      “97% of scientists agree climate change is real, manmade and dangerous.”
      Google for it.

      • > On May 16, 2014, Obama tweeted: […]

        Incorrect. This was discussed almost one year before that:

        Note: revisions have been made to the original post.

        Almost two years now.


        Again, if you want to attack Obama’s action plan, you quote and cite the action plan or its website. Only one “small” (H/T Koonin) problem: there’s no hit for “97%” on that website. This might explain why Judy hangs to this tweet.

        Lest we forget:

        Well, I am not going to play the propaganda game here; I don’t care which phrase is more effective at mobilizing ‘action.’ What concerns me is accuracy.

        Mr. T thrives on accuracy.

      • patmcguinness

        First, if anyone is trying to argue that the Obama administration has NOT been using the 97% ‘factoid’, they have the inconvenient truth that SoS John Kerry has used it in multiple speeches, on top of the Obama tweet on it.

        “97% of scientists agree climate change is real, manmade and dangerous.”

        This debunked junk science phony ‘statistic’ of 97 percent is a statistic created for political purposes by activists (Cook et al) for the cause. it was intended for a PR purpose and is used as such. It’s use here by a politician to create an intended but false impression NOT based on the actual data. Is this the climate change that has gone on continuously since earth was born?

        Is this ‘fight against climate change’ those legal efforts that do very little to change the trajectory of actual temperature trends? Prof Judith Curry pointed out in her April testimoney that these bills don’t actually change much.

        Assertinga consensus that is a faked up trumped up statistic to assert a claim that is contrary to the actual science and data (ie it’s not proven to be ‘dangerous’ ) highlights how corrupted the ‘science’ has become around climate change. This 97% stat should be in the junkpile.

  17. Judith wrote, “…please get out of our way and let us do our science so that we can try to figure all this out by exploring the knowledge frontiers, rather than pledging allegiance to the consensus.”

    Hoo aahhh!

  18. “But science seems less and less relevant to what is going on in the policy arena. Which is fine; please get out of our way and let us do our science so that we can try to figure all this out by exploring the knowledge frontiers, rather than pledging allegiance to the consensus.”

    I’m not quite sure how to frame this, but if AGW is so slight as to not warrant major disruption of the lives of ordinary people, it’s not OK. Scientists brought this to the fore. Scientists engaged politicians, political apparatus, gave fodder to people who would control the lives of others using convenient sticks provided by scientists. Having done that, and then to let the political forces wreak havoc on the lives of ordinary Americans, then I say Scientists are ethically bound to undo the damage.

    On the other hand, if AGW is on the other extreme, CAGW, then all bets are off. The politicians need to look at available options to protect the peoples of the world. I personally think that’s an engineering problem, best solved by planning engineer and friends.

  19. David L. Hagen

    IPCC Policy vs Scientific Method
    Obama’s policy is to coerce worship of the goddess Gaia at all costs – forcing the poor into greater poverty by denying them the cheapest coal fired power.
    Isaiah raised the issues:

    Woe to those who call evil good and good evil, who put darkness for light and light for darkness, who put bitter for sweet and sweet for bitter.

    Back to the scientific method addressing ALL the uncertainties
    Build for resiliance while caring for the poor.

  20. JC,

    This is great. But one day too late. I’ve just posted my submission to the Australian Government on how Australia’s GHG emissions abatement targets should be stated. I’f I had this a day ago, I could have referenced this. I did include the complete summary from your Senate testimony, however, and it is ideal:

    • Likewise. Cited statements by Judith and Karen Harbert
      in their representations to the Hearing on “The President’s
      U.N. Climate pledge.”

  21. Pingback: Negacionistas de la incertidumbre |

  22. John Costigane


    Mark Levin is a very good contact for us skeptics. Your recent contact with him has opened his eyes further to the politico-science cabal. His focus on young Conservatives should inform you, and us, of the value of reaching out to this third generation (grandchildren approx), who, by their natural inclination , will reject the middle generation ‘s pessimism.

    • Interesting thought John. Maybe our generation IS unduly pessimistic, if so I wonder why?

      • I don’t this our generation is pessimistic. I think it is the young who are gullible. We all were when we were younger and had less experience of real world realities.

      • John Costigane


        I am a baby-boomer. That generation was in the best situation,and optimism naturally flourished. About 1970, pessimism arose unchallenged, as part of the new generation’s focus and has persisted to this day. There is a chance to overturn it since it has now been driven to excess.

      • I am a boomer as well (1940) but agree that it seems to be the next generation (1950’s and 1960’s) that seem to be generally pessimistic. Peter Lang you could be right that the !970’s and 1980’s are more gullible. We should perhaps ask Lewandowsky to do another survey re pessimism and AGW idealogy? :)

      • John Costigane


        The 70s-80s were a time of lower education standards (UK). This could have lowered skepticism by itself. There were also the Cold War and Ice Age Scare where propaganda flourished, instead of enlightenment.

      • The ice age scare? You people will believe anything. Nobody, and I mean nobody, was, even in the slightest, walking around worrying about an ice age in the 1970s. I’ve forgotten the exact year, but probably 1971 – 1973 when I was in college… there was a nasty Dakota winter and the temperature did rise above some insanely low number for a couple of months. At the time we buried water pipes at about 6 foot, and they were freezing, including city water pipes. I had to work almost full-time crawling under my Dad’s rental houses thawing and repairing water pipes. Also had a partially frozen battery array explode on his huge snowplow. That was neat. You are flippin’ gullible, nobody was worrying about a freakin’ ice age. We were all wondering why anybody would want to live in that frozen hellhole, but then, Canada? Those knuckleheads probably wanted an ice age. They’re crazy.

      • did not rise above.

        The blogger named Sou was in college in Canada straight north of the Dakotas that year and remembers the winter from hell.

      • John Costigane

        JCH (What is your name?),

        I lived through the period in the UK. It did happen but not to the same extent as the AGW fraud.

      • The global cooling scare was real, but nobody is claiming the climate botherers of the day were as frenzied as this modern lot. And nobody back then had figured out a way to make money selling a fraction of thin air. (That only came after the marketers of bottled tap water showed how you can sell absolutely anything.)

      • JCH

        You are right, no one was walking around obsessing about the next ice age. That does not mean there were no articles about it. I remember them well. What most people were thinking was that the Leftist MSM was off dreaming up some dumb way to increase circulation. So what has changed except for the topic.

      • >>> The ice age scare?
        >>> You people will believe anything.
        >>> Nobody, and I mean nobody, was, even in the slightest, walking around
        >>> worrying about an ice age in the 1970s.

        If by nobody, you mean Stephen Schneider, then…

        “An increase by only a factor of 4 in global aerosol background concentration may be sufficient to reduce the surface temperature by as much as 3.5 deg.K. If sustained over a period of several years, such a temperature decrease over the whole globe is believed to be sufficient to trigger an ice age.”

        Schneider S. & Rasool S., “Atmospheric Carbon Dioxide and Aerosols – Effects of Large Increases on Global Climate”, Science, vol.173, 9 July 1971, p.138-141

      • Danny Thomas

        Turbulent Eddie,
        Reading your post made me think………..Hmmmm, I wonder if catastrophe sells?

    • Probl’y it’s eve-o -lu -shun at work.

  23. – I don’t see how probability assessments will help us any. The problem is that you have only one event to observe. What meaning has a probability assignment to that event? No matter what the outcome is, you never know how probable it was. You can only exclude pdfs with a 0-probability assignment as invalid retrospectively. The warming pause (or not) isn’t that informative e.g. in respect to judging model validity.
    – an interesting question is how far is C02 the cause of something or just an indicator (of human influence on the planet). In the economy the idea of manipulating indicators (inflation rate, unemployment rate) has led to terrible imbalances in other places.
    – if the problem is human influence on the climate, you cannot forecast climate without forecasting human history. A lot of the coupled human subsystems are currently approaching critical points. The future may be much more interesting as commonly believed.
    Can C02 reduction policies precipitate a major breakdown in human systems by reducing the resources available for consumption (which in the past regularly lead to state breakdowns and warfare)? What would be the effect on climate?
    Will we be able to innovate us out of our presumed C02 problems as currently seems to be the central idea? What if not?
    – talking about probabilities: if your final event is dependent on n premises you have to multiply the probabilities of the premises to get the final one. If you have n=10 and p=0.95 you’re down to 0.6. Except errors can cancel out.

  24. Prof. Curry:

    In addition to addressing the “knowledge risks” arising from scientific uncertainty, your presentation also mentions (e.g., slide 30) the economic risks arising from bad climate policies. Although I believe many of those economic risks are exaggerated (compared to, say, the recent financial crisis) it does seem reasonable that the burden of proof should be placed on those advocates who favor decarbonization.

    What if that were not the case? Perhaps the precautionary principle compels you to flip the null hypothesis in their favor (null = “without action the climate will become significantly worse with dire human/environmental consequences”). Even if we all agreed with this statement of the problem decarbonization advocates cannot show that any specific action will reduce climate risk by X amount within a reasonably predictable time-frame.

    Given the uncertain science, any policy’s benefits are also uncertain. So, once again, let us concede that the scientific uncertainties are small or unimportant. The remaining “consensus” view of the science suggests that the United States could rapidly and completely decarbonize its economy and it would not be enough to reverse or even stabilize this century’s warming rate.

    As unlikely as it is that we could get everyone to agree to the above concessions about the science, it is far less likely that we could get anything close to the economic policy concessions necessary to produce the near-global decarbonization required to prevent/stall catastrophic warming. Barring significant improvements in technology — and a significant lowering of the costs to implement them — humanity is going to experience whatever climate change is coming over the next 50 to 100 years. In that sense, it really doesn’t matter whether we agree on the science, or not.

  25. David Wojick

    When it comes to false certainty in climate econometrics the best case by far is the so-called Social Cost of Carbon modeling that is spreading through the US federal agencies. It makes detailed global economic damage predictions for today’s CO2 emissions, going out 300 years, on a ton by ton basis. Most of the damages are in the 100-300 year period.

    How can something so patently uncertain (I would say insane) be so widely accepted? Policy decisions based on 300 year climate+economic projections. This is the ultimate measure of the monster being ignored.

  26. Geoff Sherrington

    Dr Curry,
    We should all be thankful that some severe climate problems are recognised, partly understood, being subjected to improved analysis etc as your words describe. I had been mournful that the climate change dictionary did not seem to mention important aspects of the conduct of science that are well known to the experienced hard scientist. Thank you for confirming that climate science does not work unchallenged in a paradigm world of its own, where anything goes.
    You note “◾High quality – Further research is very unlikely to change our confidence in the estimate of effect”. There is a minor quibble here. There are many cases – the Australian helicobacter/ulcer work epitomises – where that description of ‘high quality’ would dissuade investigators. Science progresses in one of several streams. Challenging the orthodoxy is one. I would prefer high quality to be defined more by the lack of room for the existence of unknown unknowns, that is, current knowledge answers virtually all questions that can be put and tests/rejects the input of further speculation. This ‘ticks all the boxes’ approach might not dissuade further research nearly as much.

    Somewhere in the philosophy, someone has to admit the concept of motivation. As a private industry person doing things like making new mines, our motivation was to succeed at science because that generated $ profit, part of which was fed back to fund us for future years. We were also accountable to others for the best use of the available dollar. So often when I read academic papers and related blogs about climate, I am struck by the separation of accountability from the work. In climate work, an ‘expert’ seems to be able to say wild things with no punishment. In my career world, if you said stupid things in public, you would get sacked or even be taken to a civil or criminal court.

  27. Thanks for the interesting and lucid post Dr. Curry. I see that I didn’t really understand the Uncertainty Monster references properly before, this has helped clarify.

  28. Thanks for the ppt.

    Did you leave a copy of this with Lamar Smith when you were in Washington?

    In any event, it looks like he got the message.

    See this:

    in today’s WSJ

    Way to go Judith!

  29. And all this hubbub because certain tribes can’t accept nuclear power. Tsk tsk.

  30. Uncertainty or blatant lies
    disguised as empirical facts?

  31. Seems to me the IPCC appeals to certainty – warming and other things will happen.

    At the same time, the IPCC appeals to uncertainty – ‘the temperature range could be 1.4C to 4.5C or whatever – ‘it could be much worse’.

    No one can know what will happen by 2100.

    But we do have some repeatable measurements about what has happened in a third of a century and that indicates warming at the low end.

    Classical uncertainty presupposes there are things we can know whereas quantum uncertainty recognizes that the more we know of one thing the less we know of other things –e.g., the the more precise we can be about one thing the less precise we can be about another thing.

    That is to say, we can at best know one or the other but we cannot at the same time know both. Quantum uncertainty explains the paradox of global warming, as follows:

    It is impossible to know both the average and trend of the average global temperature (GW).

    So, that is why, for example, global warming can simultaneously be going both up and down –e.g., the overall GW trend over the last 10,000 years can be down, as in reality we know that is the case. GW can, however, also be going up as we know it has over the last 100,000 years; and, still overall as we also know to be true GW can be going down for the last 4,000 and 2,000 and 16 years as well as going up prior to the aforesaid epochs.

  33. Another monster of uncertainty – the one under the bed.

    When a child calls out because there’s a ‘monster under the bed’, they are certain that an unlikely event is occurring.

    The comforting adult is certain the unlikely event is NOT occurring.

    Eventually, the repeated experience of turning on the lights reduces the child’s
    ‘monster probability density function’ and they become more certain that the 99.9% of their experience holds and there is no monster.

    Can those terrified of global warming monsters be comforted by our rather benign observed experience? Unfortunately, politicians will try to spin towards motivating fear which enables political power.

  34. A “Wicked Mess” is a great problem. You never really know that you are dealing with a wicked mess until you try something “sub-optimal” and what is a wicked mess for some isn’t so wicked for others. What is really fun is most wicked messes are self inflicted.

    Nibbling around the edges, low regret action, can help reduce wickedness, provided you leave options open. Even a low regret action can end up being sub-optimal, like the ethanol mandate. It should not have caused increased grain prices according to some, but it did. It should not damage engines, but it does. Cellulose ethanol should have been available, but it wasn’t. Since there was a “mandate” it literally requires an act of congress to allow for exceptions. It should be obvious with any potential wicked problem you try things you don’t mandate things. The IPCC approach pretty much guarantees that the problem will be wicked.

  35. Something to consider when reading overly- certain bashing of peer- review:–Peer-Review-Predicts-Success/

  36. Reasons US posturing about CO2 is both wrong and irrelevant.

    1. US emissions and indeed emissions from nearly all developed economies are declining.
    2. That’s largely because of a migration to cheaper natural gas from more expensive coal which appears to be a worldwide phenomenon.
    3. It’s also a representation of demographics which are also a global phenomenon.
    4. The emergence of the AIIB ( Asian Infrastructure Investment Bank ) was largely to fund energy projects in the developing world. The US opposed this bank for competitive reasons, but it’s a reflection that the emerging markets, which are the ones with increasing emissions, need energy to rise out of poverty ( which improves the environment ). They will do so on their own. Should the US stop them? How? Go to war over CO2?
    5. Pope Francis might want to consider the morality of stifling economic development and keeping nations in poverty in the name of CO2.
    6. Arguably, and ironically, the country that made the biggest effort to move to renewable energy has been Germany. They have achieved something remarkable – sky high electricity rates AND increasing CO2 emissions.

  37. Kevin Williamson has an interesting piece in NRO today titled; “Global Warming Guacamole”. A few excerpts:

    “California presents the global-warming dispute in miniature. The Left, with the prominent advocacy of President Barack Obama, has argued that the challenge of global warming necessitates a new form of economic organization under political discipline. Never mind, for the moment, that the Left has been arguing for a new form of economic organization under political discipline for more than a century (the crisis changes every generation, but the identical solution endures); consider the actual choice presented by Sternbergh’s avocado. We could embark on a sprawling, unfocused, and unmanageable crusade to cajole and coerce the world — including the not-especially-cajolable gentlemen in Beijing — into reorganizing the entire human race’s means of sustenance in accordance with not especially well-defined atmospheric metrics. Or we could insist that California get its act together on the matter of water infrastructure.”

    “California not only is effectively a single-party state operating under Democratic monopoly, its Democrats are impeccably progressive, almost spotlessly so. The progressives are forever insisting that they are the ones who know how to handle infrastructure projects, that they are the ones who care about them, and that their broader understanding of public goods will contribute to general prosperity. In reality, California has the worst water infrastructure situation in the country, with the EPA in 2013 calculating that the state requires nearly $45 billion in improvements. A more liberal view of California’s real possibilities would identify an even larger deficit. California’s recent lack of precipitation is nature’s doing; its inability to weather the ordinary variations of life on Earth is entirely man-made.”

    Read more at:

    • Not surprising – the IPCC was a political creation by the Club of Rome with a political agenda from the get go.

      Maurice Strong, a member, enlisted COR in the creation of the IPCC.

      And the Club of Rome includes this member that has given a lot of money to the UNEP:

      Does he entertain any uncertainty in his beliefs?

      The unending irony is how wrong they all were. Not about radiative forcing, a verifiable concept they were trying to leverage for politics. But about how they thought reining in capitalism would improve the environment – just the opposite has proven true. Economic development has nations with better education, welfare, health and ironically better environment. And perhaps even more ironically, lowering CO2 emissions because capitalism improved the efficiency of energy use and allowed for improved alternatives. And more irony, birth rates fall as nations develop. Were these ideologues successful they would have worsened the very things ( population and environment ) they claimed motivated them.

      Many with an interest in science ( climatology, meteorology, and otherwise ) engage in various scientific questions regarding theories of change.

      But in some ways this effort is irrelevant because the political motivation for study already has an agenda.

      The Club of Rome wrote “The common enemy of humanity is man.”
      They may be correct, but also ironically, as it applies to themselves.

      • These things come off as conspiratorial, but it is a matter of record
        that Maurice Strong was the first UNEP director, was a member of the Club of Rome, and enlisted the CoR in the forming of the IPCC, and that the Club of Rome writings explicitly stated their desire to use ‘global warming’ as a causus belie to advance a political agenda.


        I used to cringe when the politically minded would bring up socialism in the context of global warming discussions, but it’s in the political agenda of the ostensible trusted source.

        Does that disprove radiative effects of CO2? of course not! Lots of academic study pre-dates the IPCC, some by a century or more.

        Does that mean no well meaning, hard working, mostly objective scientists work on the IPCC reports? of course not!

        However, when the organization is born of a political movement, it does cast a long shadow on the culture, motivations, and findings of the IPCC.

        Fortunately, evidence wins out and human population is on the path to shrinking soon ( thank you, capitalism ) and CO2 emisisons are on the path to falling soon ( thank you, capitalism ). A hundred years from now, nobody ( or no robot ) will care about any of this.

      • Turbulent Eddie

        The Club of Rome wrote “The common enemy of humanity is man.”

        The Club of Rome’s agenda lead to the creation of a political entity, the IPCC with a purpose to provide science cover for the Club’s political machinations. To counter such force, a political push-back is needed to right the Ship of State.

        Today in the Wall Street Journal on the editorial page, Lamar Smith, Chair of the House Committee on Science, Space and Technology wrote an article: The Climate-Science Religion. In the article, Smith pointed out that in spite of the uncertainty within the science of climate change, our POTUS spoke on Earth Day regarding worsening severe weather, rapidly warming globe, the need to act immediately, the “dharma” behind this belief system, as well as the futility of the efforts to alter climate of the future by destroying the economy of the present. Judith Curry’s Uncertainty Monster paid a visit; i.e. the 0.003C temperature forestalled by economy wrecking as well as the 1/2 the thickness of a dime of sea level rise expected with business as usual CO2 emissions through to the end of the 21st Century was prominently mentioned.

        This was a very public push-back to a recent House Member from New Mexico who should remain nameless, advocating investigation of so called skeptical scientists’ funding sources, to discredit their work using a conflict of interest theme. The advocacy position to inquire went to government and academic employers of named skeptical scientists. Frankly, this political inquisition made me an alarmist! just not of the CO2 variety.

        The push-back by political entities is needed, somewhat like changing rudder direction to eventually alter the course of the Ship of State. Navigating a future course hopefully will change the impact of the hot wind direction and speed. Judith Curry’s courage to inform is a breath of fresh air.

        Ahhh. Yes thank you, I WILL have a second cup of coffee.

  38. Some prophets say the world will end in fire-as factory carbon dioxide fills the atmosphere, swathing the globe in a greenhouse mantle. Some say it is lee that coal in the eir reflect back the sun s warmth and Initiate a new Ice Age…. – Paul Samuelson column, 1976

    • Pro(fits)phets of doom tend to be wrong?

    • Well, you would know a lot about that. I bow to your vast experience.

    • The report warns that man’s activities are already altering the world’s climate in ways that could bring on a catastrophe.

      So little is about this, however, that the Council was undecided whether it might emerge as a man-made ice age or – just the opposite effect – a melting of the polar ice caps and flooding of large land areas. – President Nixon’s Council on Environmental Quality, 1970

  39. The bad news is that the interface between climate science and policy remains badly broken. Many politicians seem to have become uncertainty deniers, with President Obama leading the pack.

    But isn’t this how public policy has always worked? Suppose the question is whether we need to urge people to be immunized against X. If most scientists respond with a confident ‘yes’ then the public authority takes the position that the science has been settled and advises the public to be immunized. Why shouldn’t they? If in fact there is no need for the public to be immunized then it would seem that the problem does not concern the interface between science and policy but rather the problem is within science. (Unless we are saying that public policy is no longer justified in assuming that science and not politics drives scientific conclusions.)

  40. Any half decent memeplex worth its salt encourages* an environment in which fear and doubt flourish. Ironically, this can sometimes be done by suppressing (genuine) uncertainties, which block the route to consensus and common action. In their place fantasy uncertainties may be substituted, which are so extreme as to demand consensus and immediate action, and yet also so wide as to promote the kind of constant worry and speculation via which co-evolving memes in the overall narrative can enjoy enormous replication rates.

    This happens in many domains not just the current one of environment and CAGW, and has happened throughout history (religions also do this). The underlying mechanisms are simple and elegant, relying on the fact of basics like emotional bias and the differential selection of narratives (replicative power is rewarded more than veracity). There has to be sufficient uncertainty in the first place to kick the process off and start the evolution of the perceptions of particular uncertainties. As they part company with the real ones and consensus coalesces around an arbitrary position, that’s when genuine uncertainties undermining that position begin to be suppressed.

    ‘The CAGW Memeplex’ essay featured here about 18 months back, has a section (8) on uncertainties, expanding the above. Of course as noted within this essay, money and over-lapping motivations and activist politics etc will all align to (and amplify) a successful memeplex, but they are not a root explanation regarding the social mechanisms, rather, this is how such things are fueled.

    * Despite the use of agential language, a memeplex is not sentient nor agential. Our language is just not geared up to describe things which are not alive but have some of the properties of life, and so it is common practice to use agential language (even though caveats like this one are often assumed in the literature to be obvious, and so aren’t always explicitly stated). It’s just too clumsy to do otherwise. The same language problem and convention occurs in biology, e.g. regarding diseases caused by viruses or prions, which are not generally considered alive (especially prions) and yet have some of the properties of life (e.g. replication, via hi-jacking machinery for such from living entities).

    • Are memplexes immune to the supposed ability of the scientific method to get at the truth?

      • Not immune, but highly resistant to. Flat fact tends to short-circuit the doubts, fears, hopes etc. via which so many memes prosper. But scientists are humans like anyone else, and just as subject to highly coherent narratives that evolve over many narrative generations to target our psychological hot-buttons.

        Religious memeplexes have frequently gotten in the way of scientific endeavor, and one could hardly say these are a thing of the past, considering the current level of religious belief still. Secular memeplexes can also resist or even hi-jack science.

    • Secular memeplexes can also resist or even hi-jack science.

      Presumably it would not be the scientific findings themselves but rather the conclusions or generalizations drawn from them? Do you think that a memeplex can infect the findings themselves in a situation in which all the appropriate scientific procedures were in place?

  41. Newspaper headline:

    New Ice Age Coming – – In 10,000 Years, 1972

    Cites a British climatologist named Lamb.

    I remember that day. Several panicked people jumped from their office windows. They intended for it to be to their deaths, but most buildings in South Dakota are one story. Many felt silly when the EMTs informed they 10,000 years was a long time.

    • Danny Thomas

      And the moral of this story is falling on one’s sword (literally or proverbially) may not be the best course of action.

    • Well, it is nice that South Dakota has a “passive-safe” technology against defenestration.

  42. New Ice Age Coming – – In 10,000 Years, 1972

    That may well be wrong, too.

    Summer insolation at 65N appears to be headed higher for most of the next 100,000 years ( and not reach the low levels which started the last glacial for another 620,000 years! ).

    So those in panic state about the Arctic will have to fight Mother Nature for a l-o-o-o-o-n-n-n-n-g-g-g time:

  43. Dr. Curry,

    Thanks for what you do.

    I have one point about your Uncertainty presentation. On slide 14, the second bullet states:

    “Disagreement about the value of different classes
    of evidence (e.g. models)”

    I should like to point out that models or their outputs are not evidence. Models produce predictions that are either accurate when compared with measured data, or not accurate. In engineering, we call these tools simulators, and the outputs simulations.

    Referring to a model (or simulator) as evidence confers status that it does not own. I have used many modelling tools, and very few of them are good, although a few are excellent- within certain defined limits.

    Certainly, we never accept the output without some verification of the Real World via measurement, of course, we are not climate scientists…


  44. Danny – I do not trust people like you to make decisions. You’re like my father’s Admiral, and he damn near got everybody killed: two cruisers lost their bows; one sank; one set on fire; one unharmed.

    3rd worst defeat in the US Navy in WW2.

    His reason? He did not trust radar. Decision making under deep uncertainty or some such no-action jackson bullcrap. After that night they handed the right to shoot to the young studs on the destroyers, and shoot they did. Money out the kazoo. The freakin’ egghead Admirals had that job taken away from them.

    Dad wrote to my mother that he knew the first and last names of all ~190 boys who died that night on his cruiser:

    • Danny Thomas

      While I would not compare myself to any of the war hero’s of WWII (including my own father), I’m not clear on what you’d base this “I do not trust people like you to make decisions”
      The early evidence of the 70’s was “a coming ice age” no matter how it’s portrayed today. HIndsight is a wonderful thing. I’ve asked repeatedly for evidence (in MSM where folks of the day got their information…….internet didn’t exist) that “global warming” was even on the “radar”.
      Even today, in case you’ve missed it, there is a huge debate raging on how much warming is likely, will it cause damage, and what to do about it. I don’t recall that debate around radar, but that was before my time so I lack that very personal experience.
      Comparing my thought process of accepting warming (plenty of evidence for that) to some WWII admiral’s decision to not trust radar is a reach at best and certainly apples and fig newtons.
      Many thanks to your father for serving and it’s sad to hear of the unfortunate loss of life surrounding those circumstances.

      • Curious George

        Danny, you have misplaced your trust. You should not trust unreliable thermometers or satellite observations; you should trust reliable models and an always reliable Al Gore.

  45. JCH “Nobody, and I mean nobody, was, even in the slightest, walking around worrying about an ice age in the 1970s.”

    I was. I have a strong memory of being a kid sitting with my best friend in his back yard talking about the coming ice age. It seemed pretty scary to us at the time. The fact that it never came played an important part (though by no means the only part) in making me suspicious of the both the press and scientists.

    • Danny Thomas

      Well, I’m pretty certain JCH isn’t gonna trust you to make decisions any more than he does me. Guess we’ll just have to leave it up to him to make those decisions as those of us who use our experiences to filter future decision making are just way out of line. (Wonder how many times JCH has stuck his hand in a burning flame?)

    • The cycle is a thousand years, plus or minus a few hundred.

      The next ice age will come, but it will be in a few hundred years.

      Look at actual real data for the past ten thousand years.

      It does get warmer, then colder, then warmer, then colder, then warmer, then colder, etc.

  46. Judith, great discussion about the climate “uncertainty monster”, but I think you may be overconfident in stating: “I would argue that the quality of the historical surface temperature record is moderate to high quality”.

    I believe the new USCRN data qualifies as “high quality”, but only represents a tiny portion of the globe. We really need a GCRN including oceanic buoys to have high confidence in assessing global surface temperature anomalies, and that would take many decades to implement and even longer to generate a 30-year climate baseline – if there was even an effort to do so (of which I am not aware).

    As far as historical measurements, my experience in working with temperature measurements and forecasts for decades leads me to believe using our historical surface temperature measurements to estimate global surface temperature anomalies is fraught with many pitfalls. I would rate these estimates as “moderate” for only the last few decades and that is through using all the measurements going into weather forecast models via the CFSR approach as opposed to using the GHCN. The recently corrupted GHCN with so much infilled missing data does not qualify as “moderate” and I would rate it “low quality”. Prior to the CFSR analyses, the GHCN global temperature anomaly estimates are also “low quality” back several decades and “very low quality” in the 1800’s because of terrible spatial coverage and poorer methodologies.

    I believe the GHCN based estimates of global temperature anomalies do not have enough accuracy to clearly and confidently resolve trends in the historical data set for the temperature anomaly ranges that have occurred so far. At best, they provide only a somewhat uncertain hint at possible trends over periods of many decades to a century or more. Most of the year-to-year variation is easily in the noise range.

    More detailed reasoning for my view of GHCN uncertainties here:

    BTW, I thought you did a great job in testifying to Congress. Keep up the good work and thanks for sponsoring this forum.

  47. stevefitzpatrick

    An excellent essay, and one I which Mr Obama would take the time to read.

  48. Don’t know how relevant here, but in many contexts I think confusions between “probability” and “plausibility” arise.

    Say Person A tells you a story about a bridge game in which a well-shuffled deck was dealt to four players, resulting in a “normal-looking” bridge deal, which Person A describes exactly.

    Say Person B tells you a similar story, except in this case the first player ends up with all the spades, the second player with all the hearts, third player with all the clubs, last player obviously with all the diamonds.

    I think most people would find Person A’s story very plausible and Person B’s story not at all plausible. But the *probabilities* of the dealt hands in each story are of course exactly the same,

    Unless we’re operating in mathematician-mode I think we usually use plausibility rather than probability as a guide. And outside of highly-constrained situations, probability seems pretty useless – how would you calculate it; what does it actually mean; every “real-world enough” scenario has arbitrarily small probability until it actually happens, at which point its probability suddenly becomes 100%.

    But then the interesting question is how do we arrive at plausibility assessments sufficiently aligned with reality to get us safely through the day? Given that they’re based on *stories* rather than reality.

    Hmmmm … that’s probably enough of that :)

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  52. The IPPC has promoted the “certainty” that all the rise in atmospheric CO2 is the result of anthropogenic emissions and none is natural. I have attempted to quantify the relative contributions of each and estimate confidence limits. I would appreciate your readers critically reviewing my efforts.

  53. Pingback: Judith ja epävarmuushirviö | Roskasaitti