Proc. Roy. Soc. Special Issue on ‘Handling Uncertainty in Science’

by Judith Curry

The Royal Society Discussion Meeting on Handling Uncertainty in Science, held 22/23 March 2010, played a seminal role in motivating me to investigate uncertainty in the climate debate.

The Proceedings of the Royal Society has a special issue for papers from the Meeting.  The list of papers, abstracts and full text links (for a few of the papers) are found [here].

Table of Contents

TN Palmer and PJ Hardaker: Introduction Handling Uncertainty in Science [full text]

RM May:  Science as organized scepticism [abstract]

HR Brown:  Curious and sublime: the connection between uncertainty and probability in physics [abstract]

I Stewart:  Sources of uncertainty in deterministic dynamics: an informal overview [abstract]

DJ Spiegelhalter and H. Riesch: Don’t know, can’t know: embracing deeper uncertainties when analyzing risks.  [abstract]

J Slingo and T Palmer:  Uncertainty in weather and climate prediction. [full text]

PJ Webster and J Jian:  Environmental prediction, risk assessment and extreme events:  adaptation strategies for the developing world. [full text]

D Aikman et al: Uncertainty in macroeconomic policy-making: art or science? [abstract]

LA Smith and N Stern:  Uncertainty in science and its role in climate policy [abstract] [full text]

JR Krebs:  Risk, uncertainty and regulation [abstract]

G Wells, S Williams, SC Davies:  The Department of Health perspective on handling uncerties in health sciences [abstract]

R Penrose:  Uncertainty in quantum mechanics: faith or fantasy? [abstract]

P Campbell:  Understanding the receivers and the recepton of science’s uncertain messages. [abstract]

O Peters:  The time resolution of the St Petersburg paradox [full text]

Palmer and Hardaker

Some gems from Palmer and Hardaker’s Introduction:

However, we can go further than this. Let us accept that we cannot be certain whether or not anthropogenic emissions of greenhouse gases will lead to unquestionably dangerous changes to climate in the next century. However, consider the question: how probable would such dangerous climate change have to be for it to warrant some mitigating action now, to limit anthropogenic emissions? By ‘unquestionably dangerous’, we could mean the complete loss of the Amazonian rainforest owing to shifting rain patterns, or of large parts of Bangladesh becoming uninhabitable owing to persistently intense monsoons, storm surges and substantial sea-level rise, or of permanent Sahelian drought of the type seen in the 1980s? How probable before taking mitigating action can be justified: 50, 10, 1 or 0.1 per cent?

This brings us to the second part of the problem: making decisions in the light of uncertain scientific input. Better decisions can be made using predictions that have a properly quantified estimate of uncertainty, than using over-confident predictions with no estimate of uncertainty. But decisions can only be made easily if one can value the different probabilistic alternatives. In many situations, this may be a relatively simple economic matter. If wind speed exceeds 20 m s−1, a wind turbine typically cannot operate safely and therefore must be shut down. A probabilistic forecast of wind, including the probability that the wind speed will exceed 20 m s−1, can be converted into a rational and objective decision into how much electricity a wind farm should contract to produce (bearing in mind that the costs of buying electricity on the spot market should wind speeds exceed 20 m s−1, can be substantial compared with profits when wind speeds are within the operating range). But how do we value the loss of the Amazonian rainforest, or of large parts of Bangladesh, or of prolonged Sahelian drought? Clearly, it is not a purely economic calculation, but involves issues more directly related to human suffering and the destruction of things that we hold intrinsically dear to us. Estimating value in this generalized sense, including the thorny (and ultimately ethical) issue of whether the suffering of future generations should be somehow discounted, is clearly an extremely challenging issue for all of us. Nevertheless, these challenges should not deflect scientists and governments alike from ensuring that we are doing all that is humanly possible; firstly, to estimate uncertainties in future climate change as accurately as possible, and secondly to reduce these uncertainties—a large element of which lies in improving the computational representations of the equations of climate—wherever we can.

Slingo and Palmer

This paper provides an excellent overview of uncertainty in weather and climate predictions.  From the concluding remarks:

This paper has considered how Lorenz’s theory of the atmosphere (and ocean) as a chaotic, nonlinear system pervades all of weather and climate prediction and how this has influenced the development of probabilistic ensemble prediction systems on all forecast lead times. It has also shown that the sources of uncertainty are not confined to the initial conditions, the basis of the Lorenz model, but that model uncertainty plays a critical role on all time scales.

It is important, however, to distinguish between model uncertainty that arises from imperfect knowledge of the real system, such as the representation of the carbon cycle, and uncertainty that comes from sub-gridscale phenomena that are understood quite well, but are inadequately represented because of the resolution of the model. In weather forecasting, there has been a continuous drive to higher-and-higher resolution with substantial benefits in terms of model performance and forecast skill. Furthermore, recent studies with ultra-high-resolution (approx. 3 km) global models, the so-called cloud system-resolving models, have shown a remarkable ability to capture the multi-scale nature of tropical convection of the type seen in figure 4 [28]. However, the resolution of climate models, still typically 100 km or more, has been constrained fundamentally by a lack of computing resources [29], even though there is compelling evidence to suggest significant improvements in climate model performance with higher horizontal and vertical resolution in both the atmosphere and ocean [27].

Finally, Lorenz’s theory of the atmosphere (and ocean) as a chaotic system raises fundamental, but unanswered questions about how much the uncertainties in climate-change projections can be reduced. In 1969, Lorenz [30] wrote: ‘Perhaps we can visualize the day when all of the relevant physical principles will be perfectly known. It may then still not be possible to express these principles as mathematical equations which can be solved by digital computers. We may believe, for example, that the motion of the unsaturated portion of the atmosphere is governed by the Navier–Stokes equations, but to use these equations properly we should have to describe each turbulent eddy—a task far beyond the capacity of the largest computer. We must therefore express the pertinent statistical properties of turbulent eddies as functions of the larger-scale motions. We do not yet know how to do this, nor have we proven that the desired functions exist’. Thirty years later, this problem remains unsolved, and may possibly be unsolvable.

So how much will uncertainties in climate-change predictions of the large-scale reduce if models are run at 20, 2 or even 0.2 km resolution rather than say 100 km resolution? Equally, we may ask whether there is a certain resolution (e.g. 20 km), where it might be feasible to represent small-scale motions using stochastic equations, rather than trying to resolve them? These questions urgently need answering as the pressures grow on the climate science community to estimate, and if possible reduce uncertainties, and provide more reliable and confident predictions of regional climate change, hazardous weather and extremes.

Nevertheless, however much models improve, there will always be an irreducible level of uncertainty—‘flap of the seagull’s wings’—because of the chaotic nature of the system. Even the climate we have observed over the past century or so is only one realization of what the real system might produce.

Figure 12 shows 2000 years of El Nino behaviour simulated by a state-of-the-art climate model forced with present day solar irradiance and greenhouse gas concentrations. The richness of the El Nino behaviour, decade by decade and century by century, testifies to the fundamentally chaotic nature of the system that we are attempting to predict. It challenges the way in which we evaluate models and emphasizes the importance of continuing to focus on observing and understanding processes and phenomena in the climate system. It is also a classic demonstration of the need for ensemble prediction systems on all time scales in order to sample the range of possible outcomes that even the real world could produce. Nothing is certain.

Webster and Jian

Webster and Jian address applications of weather and climate projections to adaptation.  From the abstract:

The uncertainty associated with predicting extreme weather events has serious implications for the developing world, owing to the greater societal vulnerability to such events. Continual exposure to unanticipated extreme events is a contributing factor for the descent into perpetual and structural rural poverty. We provide two examples of how probabilistic environmental prediction of extreme weather events can support dynamic adaptation. In the current climate era, we describe how short-term flood forecasts have been developed and implemented in Bangladesh. Forecasts of impending floods with horizons of 10 days are used to change agricultural practices and planning, store food and household items and evacuate those in peril. For the first time in Bangladesh, floods were anticipated in 2007 and 2008, with broad actions taking place in advance of the floods, grossing agricultural and household savings measured in units of annual income. We argue that probabilistic environmental forecasts disseminated to an informed user community can reduce poverty caused by exposure to unanticipated extreme events. Second, it is also realized that not all decisions in the future can be made at the village level and that grand plans for water resource management require extensive planning and funding. Based on imperfect models and scenarios of economic and population growth, we further suggest that flood frequency and intensity will increase in the Ganges, Brahmaputra and Yangtze catchments as greenhouse-gas concentrations increase. However, irrespective of the climate-change scenario chosen, the availability of fresh water in the latter half of the twenty-first century seems to be dominated by population increases that far outweigh climate-change effects. Paradoxically, fresh water availability may become more critical if there is no climate change.

Moderation note:  this thread will be moderated for relevance.  Relevant comments will discuss the papers referred to, and any other broader issues associated with uncertainty ignorance.  Technical debates about the sun, surface temperature, or whatever should be on the older threads that discuss a topic relevant to your comment.

161 responses to “Proc. Roy. Soc. Special Issue on ‘Handling Uncertainty in Science’

  1. “secondly to reduce these uncertainties—a large element of which lies in improving the computational representations of the equations of climate—wherever we can.”

    Exactly

  2. ["Let us accept that we cannot be certain whether or not anthropogenic emissions of greenhouse gases will lead to unquestionably dangerous changes to climate in the next century. However, consider the question: how probable would such dangerous climate change have to be for it to warrant some mitigating action now, to limit anthropogenic emissions?"]
    .
    The ‘probability’ of dangerous climate change due to anthropogenic emissions was based initially on the assumption that the radiative forcing theory had some veracity in a larger-than-negligible quantitative sense. As the years have progressed, the observed data has shown us that the ‘probability’ was over-estimated and is decreasing inexorably. There will – IMO – come a point when the mitigation action taken will be shown to have been inept and unnecessary.
    .
    ‘Climate science’ is going to have a lot of explaining to do…

    • Arfur Bryant

      “The ‘probability’ of dangerous climate change due to anthropogenic emissions was based initially on the assumption that the radiative forcing theory had some veracity in a larger-than-negligible quantitative sense.”

      What an odd claim. I’ve never used the assumption you state in any of my own considerations of Risk of human actions. Indeed, until BEST reduced the Uncertainty of the instrumental record so dramatically (pending review), I disdained the claim of temperature rise as no better than 10:1 the likeliest explanation of the observations (beginning at 2:1 in the 1980′s and rising steadily, though now with BEST, inclusive of Uncertainty, it’s 1000:3 or so likely that the global temperature is rising on a multidecadal scale).

      “As the years have progressed, the observed data has shown us that the ‘probability’ was over-estimated and is decreasing inexorably.”

      This bears no resemblance to observed data I am familiar with. Indeed, it is the opposite of the testimony we heard in the recent congressional climate briefing, and even the current Ludecke threads here don’t support your claim, unless one is willing to tolerate extraordinary levels of Uncertainty.

      The ‘decreasing acceleration’ argument about the global temperature curve brings us to probabilistic mechanics of third order differential equations, an extraordinarily messy level of maths which no one making the claims of change in jerkiness of the temperature graphs has ever on Climate Etc. provided scholarly discussion about.

      It’s such a wooly thing to discuss the probability of the rate of change of the probability of the rate of change of the probability of the rate of change of a curve, and what that may or may not mean given the curve convolves several dynamically related elements from the Hale cycle to AMO to PDO to three (at least) types of albedo to GHEs that I’m Uncertain such a discussion could shed any light on your claims one way or the other.

      One might as well be saying “As the years have progressed, the observed data has shown us that the magic is decreasing inexorably,” for all the verifiability of such a claim.

      On the other hand, if you’re still just talking about subdecadal trends, shame on you.

      Everyone in the world who isn’t a child of three years old or less can understand the tide rising even while the troughs in waves are lower than their crests.

    • Bart R,

      I’ll keep this really simple so you won’t need to deflect the main thread of my post and start bringing in sanctimonious snarky remarks about “a child of three years or less…”.

      If you don’t think the claim of the probability of ‘dangerous’ climate change was made on the assumption that the absorption and re-emission qualities of CO2 and other ‘dry’ GHGs are likely to have a significant impact (ie increase) on the global temperature then shame on you. If you don’t consider it was an assumption, then please provide any real-world proof that CO2 et al either have, are, or ever will cause such a dangerous change.
      .
      While you are at it, show me that you have any real-world proof that you – or any one else – knows for sure how much CO2 et al contributes to the Greenhouse Effect.
      .
      Then show me why you disagree that the ‘probability’ of dangerous climate change has not been over-estimated and then gradually reduced. For example, Arrhenius initially postulated a climate sensitivity of over 4.5 deg C. What is the common estimate today? Well, the IPCC may repeat their claim of ‘best guess 3 deg’ but most observers – it seems to me – are revising their estimates downward. Either way a global temperature rise appx 0.9 C in 160 years – which may or may not be in part due to CO2 – when the CO2 emissions have accelerated slightly does not support that. Of course the troughs are higher since the start of accurate data observations. That’s what happens when the temperature warms. Who says it hasn’t? Do you think an average warming of 0.0056 per annum since 1850 and not accelerating is really a problem?
      .
      What observed data do you use? The HADCrut dataset goes back to 1850 and gives us a trend of less than 0.06 per decade. This ‘overall trend’ today is FAR lower than it was in 1878 (0.17 deg pd) and is lower than any other peak since then (1944 = 0.06 and 1998 = 0.07). Want to use another dataset? ok, the overall GISS trend since start of data is 0.07Cpd. NCDC is 0.04Cpd. If you want to believe that the global temperature rise is accelerating then, quite frankly, I pity you.
      .
      Why do you think I want to use subdecadal trends? No. This is why I only use the overall trend. Any trend shorter than the overall trend in any dataset is pretty much irrelevant. If the global temperature rise is accelerating, the overall trend will have to increase.
      .
      It should have been obvious that the probability to which I was referring was the question quoted in my first post above.
      .
      Finally, if you think that ANY of the observed data gives you a sense of catastrophic impact due to anthropogenic GHG emissions then you are, in my opinion, being overly sensitive. Unlike the atmosphere.

    • Arfur Bryant

      I’ll keep this really simple so you won’t need to deflect the main thread of my post and start bringing in sanctimonious snarky remarks about “a child of three years or less…”.

      Given your reply, I stand by my statement, with no fear of sanctimony nor, yet, snark.

      If you don’t think the claim of the probability of ‘dangerous’ climate change was made on the assumption that the absorption and re-emission qualities of CO2 and other ‘dry’ GHGs are likely to have a significant impact (ie increase) on the global temperature then shame on you. If you don’t consider it was an assumption, then please provide any real-world proof that CO2 et al either have, are, or ever will cause such a dangerous change.

      How did you read my reply and not see that I didn’t rely on any of the premises you’ve supplied, and hence need not have made assumptions about them.

      The premise for objecting to the rise in CO2 is that there is a rise in CO2.

      Period.

      No more is needed.

      Let’s consider the story of Joe.

      Joe’s an ordinary homeowner who one night heard a noise, saw a shadowy stranger standing inside the front door of his house with a suspicious and threatening-looking object in one hand and a big sack of loot — Joe’s silverware and tv — in the other.

      Joe called 911, called out in a loud voice demanding repeatedly that the intruder leave, said he’d called the police, demanded the intruder stop advancing and stop taking Joe’s things, and finally swung his fist, causing the intruder to fall backwards and be knocked out.

      The intruder upon waking up hires a lawyer who accuses Joe, “if you thought that ANY of the observed data gave you a sense of catastrophic impact due to my client, then you were being overly sensitive,” and went on to demand, “please provide any real-world proof that my client either had, was, or ever will cause a danger.”

      Do you see how audacious your demands for proof that this trespass upon those who do not cause excessive emission of CO2 — the vast majority, by the way — by those plundering free riders who do emit excessive CO2 is dangerous?

      Under what system of justice must the trespassed-against prove within their own recognized rights that the trespasser has produced a harm?

      Every generation of humanity until the Industrial Revolution has known CO2 levels well under 300 ppmv.

      Every generation before our own has known that polluters who dump their waste into the common village well are trespassers against all.

      What is the exact nature of the threat — whether Joe’s intruder carried a knife or club or gun or just a harmful-seeming imitation of one of those weapons — never matters in such cases. It’s enough the threat is perceived by the victim of the trespass.

      It is not necessary for the burglar to escape Joe’s house with Joe’s goods in hand for the trespass to be a crime.

      It isn’t even necessary for Joe to show that his front door wasn’t pushed open by the wind or other natural variation allowing the intruder to walk into Joe’s home by mere coincidence.

      All traditional and customary conditions for offense are met by the present conditions.

      While you are at it, show me that you have any real-world proof that you – or any one else – knows for sure how much CO2 et al contributes to the Greenhouse Effect.

      So no, for a quarter of a century I did not feel the least need to answer such insolent demands for proof from defenders of the trespass, which does not mean I did not go about skeptically furnishing myself with such to my own satisfaction by the usual measure of 95% CI 19 times in 20 while alternative hypotheses failed, or by generally accepted principles where they are applicable.

      Then show me why you disagree that the ‘probability’ of dangerous climate change has not been over-estimated and then gradually reduced. For example, Arrhenius initially postulated a climate sensitivity of over 4.5 deg C. What is the common estimate today? Well, the IPCC may repeat their claim of ‘best guess 3 deg’ but most observers – it seems to me – are revising their estimates downward. Either way a global temperature rise appx 0.9 C in 160 years – which may or may not be in part due to CO2 – when the CO2 emissions have accelerated slightly does not support that. Of course the troughs are higher since the start of accurate data observations. That’s what happens when the temperature warms. Who says it hasn’t? Do you think an average warming of 0.0056 per annum since 1850 and not accelerating is really a problem?

      See, that passage was clearer. 4.5 deg C +/- 50% is indeed higher than 3.4 deg C +/- 50%, so could be called a (slight) overestimate, if one knew nothing of the conventions of estimation.

      Considering Arrhenius was working with only what a gentleman of moderate means might use over a century ago and mainly independently, and the latest figures have been confirmed repeatedly (within a large Uncertainty that still overlaps Arrhenius’ figure substantially) by such means as ice cores and satellite observations, I find your sophisms unsatisfying in this regard.

      Small wonder I couldn’t guess what you might have meant by overestimated and gradually reduced.

      You mean the accuracy and precision of Arrhenius’ hypothesis is improving, and in ways that mean that Risks increase on a timespan of three centuries instead of two and a quarter centuries.

      I’m not overly impressed, nor do I see the ‘trend’ of reducing the sensitivity estimate as proof it will one day disappear, as there’s no logic to such a line at all.

      The ‘steadily accelerated CO2 vs wildly swinging temperature’ claim is laughable. Anyone who looks at the unmodified CO2 graphs sees that CO2 wildly swings too — merely on a shorter timescale than temperature. If you can accept smoothing of the CO2 trend to show its acceleration on a suitable timespan, then you ought accept smoothing of temperature trend too to show its suitable timespan.

      When you do this, CO2 trend and global temperature trend appear highly correlated.

      And while correlation is not proof of causation, it’s terrible disproof of causation, too.

      What observed data do you use? The HADCrut dataset goes back to 1850 and gives us a trend of less than 0.06 per decade. This ‘overall trend’ today is FAR lower than it was in 1878 (0.17 deg pd) and is lower than any other peak since then (1944 = 0.06 and 1998 = 0.07). Want to use another dataset? ok, the overall GISS trend since start of data is 0.07Cpd. NCDC is 0.04Cpd. If you want to believe that the global temperature rise is accelerating then, quite frankly, I pity you.

      *squint*

      Why do you think I want to use subdecadal trends? No. This is why I only use the overall trend. Any trend shorter than the overall trend in any dataset is pretty much irrelevant. If the global temperature rise is accelerating, the overall trend will have to increase.

      You’ve really convinced yourself that there’s a value to using decadal trends from the start of the instrumental record, but none at all to using anything less than the full instrumental dataset (chosen from 20% or less of the instrumental observations available) for later time?

      Arfur, how did your reasoning get so convoluted? Did it get stuck in a paint-mixing machine? Trapped in some horrific rollercoaster accident? Left in a blender, or a spindle laundry machine, or a rotary lawnmower? This line of thinking you present is not even plausible illogic.

      It should have been obvious that the probability to which I was referring was the question quoted in my first post above.

      Yeah. Amazing the power of using actual words and sentences on clarifying a claim.

    • I apologise for interrupting you’re conversation with Arfur Bryant, but I have to say I’ve read your “Joe” analogy three times now and can see no relationship between the certainty/uncertainty of Joe being assaulted by someone who’s just robbed him and the certainties/uncertainties in climate change and associated policies.

      I believe what you’re doing is expecting everyone to be as frightened of global warming and its outcomes as you, in which case you’ll do pretty much anything to avert it. But the out come of our evasive actions is pretty much as uncertain as you can get. Even if you’re right in your nightmares, you have to overcome the problems of reducing CO2 emissions in the real world as a first step, and I don’t believe you’ll do that anytime soon. China, India, Brazil, Mexico and South Africa are not about to reduce their emissions without some clear empirical evidence. Then there is the uncertainties of the outcomes of the mitigation activities. I’m pretty certain that we cannot possibly reduce CO2 emissions to any meaningful levels in the next century, but in our attempts to do so we are definitely going to cause fuel poverty for the poor and put back the developments needed to alleviate poverty in Africa, whereas the dubious claims for drought/floods/pestilence/famine and disease put forward by the environmentalists are based on what people feel will happen and no legitimate empirical evidence at all, but are the outputs of models of a non-linear chaotic system. Which must be the longest oxymoron in history.

    • Bart R,

      Well, GerryM siad it pretty accurately. Way to go on the useless contrived analogy thing…

      You’re post was a veritable tour de force of consensus dogma and your personal adherence to the Precautionary Principle (PP). The trouble with using the PP as an argument is that there has to be a threat in the first place.

      So I’m going to have to make it even simpler…

      1. Upon what basis do you believe (nb) that an increase in CO2 has, is, or is ever likely to cause dangerous climate change? That’s fairly simple, isn’t it?

      2. What actualevidence do you have to support your belief?

      3. Do you have ANY idea how much of the Earth’s Greenhouse Effect is contributed by CO2? If you can’t answer this, how can you possibly think a rise in CO2 will cause the postulated ‘danger’? If you can, please show your actual evidence.

      4. How can you accept shorter, interim trends and yet dismiss the overall trend in a dataset?

      5. Please state what, if any, of the details I gave you are incorrect.

      BartR, how did your dogma become so entrenched? Are you not capable of rational thought? Look at the evidence and try to rationalise it to the cGAW theory that was ‘sold’ to the public in the late 20th century.

      I really don’t mind you disagreeing with me. I really don’t mind you having a belief. When you can provide some ‘real’ evidence, as opposed to consensus model predictions disgracefully posing as scientific truth, then we can argue on even terms. Until then, I maintain that the observed data in no way validates the theory that increasing CO2 will cause catastrophic climate change. Get a grip.
      .
      Now, as you like analogies, here’s one for you…
      .
      Let us take a large sports stadium such as the Melbourne Cricket Ground. Capacity 100,000 seats. Although the atmospheric concentrations of radiative ghgs are by ppm or ppb by volume, let us approximate to 10.000 molecules per percentage volume (1 million divided by 100). This means that of the 100,000 spectators in the MCG, only 40 (wearing red for rGHGs) are able to both hear the tannoy (LW radiation) and re-transmit what it says. Another 250 spectators (wearing blue for water vapour) can hear the tannoy but cannot re-transmit the message (because they are mute). The rest (wearing white) are deaf-mute. Let us now pretend the tannoy message was a very funny joke. The only way that the 99,710 spectators in white can even realise something funny has been said is by ‘conduction’ with the 290 people, who are shaking with laughter (vibration). If they are touching the laughing people, they may well laugh in sympathy – but maybe with less conviction. As most of the ‘water’ spectators are in the lower stand, that is where most of the shaking is done. Back in 1850, the number of emitting spectators was only 28 (probably 29 if you include all the other rGHGs apart from CO2). Therefore, according to the radiative forcing theory, the addition of 12 spectators (of any type of rGHG) has increased the degree of overall shaking by 2.5% (0.8 C = 2.5% of 33 C). According to the IPCC, doubling the number of emitters to 56 will lead to a ‘best estimate’ increase of appx 10% (3 C).
      Do you think the original 28 red spectators could have had a significant effect on the 99710 white spectators, and will the addition of another 12 (in 2011), or even doubling the original figure, be likely to incur catastrophic warming (laughter)?

      If your answer is ‘Yes’… why?
      .
      Aren’t analogies fun?:)

    • Bryent, I have all the proofs you need. Contribution of CO2 / H2O on GLOBAL warming is ZERO! http://globalwarmingdenier.wordpress.com When is more of those gases in the atmosphere – upper atmosphere a bit warmer – day temperature on the ground milder / less extreme. Overall, same warmth units in the troposphere. Talking about cricket = you are Australian… It’s your obligation, to peer review what’s on my blog (it’s not much) do it for your country. From first sentence / page, to the last. One solid proof is worth 1000 theories. I have all the proofs / proven all now! Challenge to everybody: I have proven you all wrong; if you can’t find mistake in my proofs = your antique theories are all wrong!

      To avoid the blame for the phony Nuclear Winter for year 2000; in advance they went in the opposite direction. The phony GLOBAL warming is as real as their nuclear winter. 98 wasn’t warmer – warming didn’t stop, because wasn’t any warming to stop. CO2 has nothing to do with any warming – climate is in constant change, H2O controls / changes the climate, without any GLOBAL warming.

    • stefanthedenier,

      Thanks for your input. I am not Australian. I’m British. I agree with some of what you say and I will look at your blog. I have to say that I agree with the bit about the climate changing and the fact that water vapour plays a FAR greater role than any radiative GHG. However, I would still say that CO2 (and the other rGHGs) do play a small role – the role of CO2 is not zero. It is the size of the contribution that warmists refuse to debate. I do not deny there has been warming, I am just extremely sceptical as to the postulated cause being CO2. Until the warmists can come up with some corroborating evidence, they are essentially guessing – or assuming, if you prefer. Most of their arguments revolve around ways of trying to make excuses why the facts don’t fit their theory instead of getting to grips with the basic assumption.

      Anyway, thanks for your input. Best of luck with your blog.

    • GerryM

      No worries about interrupting, and I’m glad you asked. My analogy was terribly obscure in so many ways.

      However, you misattribute fear in the decision process. A fearless person guided by principle will come to the same conclusion as a fearful one.

      Joe may have been a bold and steely-jawed hero or a frail and quavering weakling, and the story would have been the same, wouldn’t it?

      Why ought the brave or the meek either be burdened by intrusions on their rights?

      Let’s remove both fear and expectations from the table entirely.

      CO2 is higher now than it had been for the lifespan of the human species until the Industrial Revolution.

      We cannot sustain the argument that waste products of global industry has nothing to do with this rise.

      That rise in and of itself is a trespass on the inherent and inalienable rights of every human to breath the same air as their ancestors.

      This is self-evident, without reference to fear or expectation.

      And yet Arfur and his ilk demand proof of harm from this trespass before in their gracious charity they deign consent to hear arguments to stop it.

      What is that other than arrogance and tyranny, when consent was not asked nor obtained and compensation was not tendered nor accepted?

      Nightmares indeed. Where do people come up with such ideas?

      Further, all the countries you name have taken substantial CO2 limiting steps in one way or another that throw into sharp contrast the humiliatingly feeble record of America.

      China, sure, has on one hand started down a path of burning coal in a disastrous manner. It also has had generations of the nightmarish One Child Policy to limit its population. Pollution going up net, but lower per capita than the USA by a huge margin.

      If America emitted only per capita what China does today — which is well withing the technology available and at zero additional long term cost — then we wouldn’t need China to shut down a single one of its new coal plants to meet the targets being discussed in advance of Durban.

      Why are you so certain we cannot lower emissions meaningfully?

      The average vehicle on the road in America today gets one third the fuel economy and emission performance as the best vehicle in its class and price range. Not hybrid. Not electric. Not more expensive. Just better engineered.

      And that performance has been available for longer than the average age of vehicles on the road today.

      So, what’s the obstacle, Gerry?

      Try a more fuel-efficient car. What are you afraid of?

      Why are you pushing ‘fuel poverty’ alarmism, when it has no basis in fact?

      Do you expect everyone to be as frightened as you are of a world where fossil energy must compete on a level playing field with alternatives without subsidy from taxes coerced out of the poor?

    • Arfur Bryant| November 16, 2011 at 3:12 pm |

      Dogma? Consensus? @@

      PP? Which one? There are as many versions of the Precautionary Principle as there are Mortal Sins (maybe more, I’m terrible at dogma).

      I tend to favor — when a PP is applicable — the version that is most mathematically suited to the situation. I suppose that makes me a situational ethicist. I wonder if that leads me to the slippery slope of consensus that the ends always justify the means?

      1. Since you persist in demanding proof of harm of trespass as if there could ever be justification for such an appalling tyranny, perhaps I should humor your belief (cf) that you deserve one, just to see if we can get you past this entrenched sticking point of yours.

      Let’s look at your stadium analogy and go one better. We can put it into a spreadsheet — Excel will do, or Opensource Calc — of 250 rows by 400 columns, populate the whole with formulae and (with appropriate programming) generate a slap-dash model of known concentrations and temperature dependencies that will at some point reach a tipping point or run away.

      This is an inevitable conclusion of Chaos Theory on dynamical iterative processes of the type represented in our climate. Perhaps the actual levels where such runaways, collisions of attractors, collapses, bifurcations or other ‘catastrophic’ events happen can’t be estimated with such simple tools.

      They can, however, easily be produced in rough as proof of concept.

      Though not using spreadsheets, nor the exact math I’d use if I reproduced it today, I did such programming as an undergrad three decades (almost) ago, for several years. Simulations of chaos approximating the complexity of climate (though not identical to climate) can be validated and verified in ways true GCMs cannot, due their greater simplicity. My original purpose hadn’t even been climate-related, however the relationships are very generalizable.

      I can’t tell you if your 40 Red spectators, or the 250 Blue ones, or the additional Red and Blue ones analogically drawn into the stadium by the laughter they hear (GHG’s driven out of solution or ice or evaporated or shifted from water droplets to water vapor as dew point changes with temperature rise) themselves are enough, or the additional 12 Red, or if some peak or spike of natural variability coinciding with the effects of these additional GHGs will do it.

      However, the basis for absolute mathematical certainty of dangerous climate change in the abstract given enough time at expected rates of rise is a very compelling case for the likelihood of dangerous climate change in the physical world at some unknown time that becomes more probable with continued GHG rise.

      It is as reliable as the mathematics of coin tosses and handicapping sporting events. For any one coin toss or molecule of CO2, not reliable; for the size of the whole world, inescapable.

      Does this address your question?

      2. Actual evidence? Given a week or two, I could likely reconstruct a simplified dynamic iterative model of GHGs and temperatures to simulate a complex climate using only known, established relationships of concentration to temperature and temperature to concentration, and then perturb the GHG levels in the model until bifurcation or collapse. If I still programmed or did math, which I’m pretty rusty at now. This model could be audited and independently validated and verified as equivalent in complexity and likelihood of outcome to known physical components of climate.

      Evidence that this is ‘real?’ That the physical world operates in ways that are more like Chaos Theory than like your own unproven hypothesis of a world where nothing ever goes wrong no matter how much we perturb complex systems?

      Well, I could find a hornet nest and poke it with a sharp stick, I suppose.

      3. I once calculated an estimate of the energy impact of 390 ppmv compared to 280 ppmv CO2E as one million times the energy released by all known nuclear test and wartime explosions every 27 years, based on absorbtivity in the nonoverlapping wavelengths and insolation. You can do the same calculations yourself, if you like. Though I’m not entirely sure of the point.

      4. Interrim trends? Dude, almost everything that has numbers on it can be crunched through statistics and checked for whether there’s meaning to the process.

      For instance, one fifteen year trend on HadCRU (or any of the temperature datasets except the last half century of BEST, which is meaningful at 15 years for land, I think, per Santer’s signal:noise argument) is meaningless by itself.

      Take a hundred such trends, even overlapping, so long as their total span exceeds 30 years and their distribution is relatively homogenous, and you produce quite reliable statistics. This would allow you to apply Bayes’ Theorem if you have one 10-year trend and predict the probability it is consistent with other longer trends.

      5. Uh whut?

      As for what you feel others have sold, or their evidence? *shrug*

      I have issues with some things that have been said on both sides in the past quarter century. The world can’t go decades without some disagreeable statement being perceived somewhere in it associated with any large enough issue.

      I try to look past that and judge on principle, logic, evidence and willingly change my mind when new evidence and better logic indicate.

      Look at how BEST changes so much, for example.

    • Bart R,

      I almost missed your response – this nesting takes some getting used to!

      Firstly, something you said to GerryM:
      ["We cannot sustain the argument that waste products of global industry has nothing to do with this rise."]

      But who is saying that? I don’t personally know any sceptic who believes there is NO anthropogenic effect! I have no problem accepting the fact that a single CO2 molecule has properties that should – theoretically – enable it to become a GHG. It is the scale of the contribution, that assumption made by pro cAGW commenters that is what grates with me. Trying to make out (as many warmists do) that sceptics deny global warming is misleading and incorrect (IMO).

      OK, back to us…

      1. “Since you persist in demanding proof of harm of trespass…”
      Please desist from using the analogy again, Bart. I did not ask for proof of trespass, I asked for proof that CO2 has, is, or is ever likely to cause dangerous (catastrophic) climate change. It was a simple question.

      Instead of giving me evidential proof, you gave me… more models! If you don’t want to answer, just say so.

      Mathematical certainty? ["However, the basis for absolute mathematical certainty of dangerous climate change in the abstract given enough time at expected rates of rise is a very compelling case for the likelihood of dangerous climate change in the physical world at some unknown time that becomes more probable with continued GHG rise."]
      So you think that because there is a mathematical chance (certainty?) that a planet-destroying asteroid will hit the Earth means the governments of the world should now start mitigation policies – at whatever cost – to build underground nuclear shelters for the whole of mankind? Good luck with that one.

      2. “Actual evidence? Given a week or two, I could likely reconstruct a simplified dynamic iterative model…
      There you go again – no evidence supplied, just a promise that you can make another model to explain your theory! Do I really need to say more?

      3. I once calculated an estimate…
      Totally fascinating (and I’m truly not being sarcastic here…) but irrelevant.

      4. Dude, almost everything that has numbers on it …
      Well, I agree with that! However, that is why interim trends are of curiosity interest only. It is the overall trend that matters. The trouble is, where do we start? I use the HADCrut dataset as it is the dataset the IPCC used to state that ‘accurate temperature measurements started in 1850, in case you were wondering…)

      5. … I try to look past that and judge on principle, logic, evidence and willingly change my mind when new evidence and better logic indicate.
      OK! So, look at the principles involved with the basic theory. Then apply logic based on evidence (real, not models) and willingly change your mind when you have figured it out! :)

      Finally:
      Look at how BEST changes so much, for example.
      Say what? Do you have a link to any raw data that BEST uses which isn’t processed from an already produced ‘global’ dataset?

      Nice attempt at deflection, though!

      Look at how BEST changes so much, for example

    • Bart R,
      Please ignore the final line of my last post – typo.

    • people involved are creating ”uncertainness” there are so many factors known; no need for uncertainties. Honest / real Science is; elimination off the irrelevant, not exploiting the irrelevant, to con the ignorant. All the uncertainness are created for confusion, Reason $$$$$. Most of the people have fallen in their rap. Ignorance is not a crime, but exploiting the ignorant…. used to be illegal, before the Kyoto conference… Should be made illegal again, retrospective! Crime shouldn’t pay!!! All the taxpayer’s money squandered to prevent the phony GLOBAL warming, should be returned back to the Urban Sheep.

  3. Amazon rainforest can be lost for few different reasons, but extra CO2 in the air can only make healthier rainforest. Les H2O in the atmosphere makes rainforest vulnerable; but CO2 improves condensation = improves rainfall. Warmist are not just wrong, but back to front on everything, also.

    • The Amazon rainforest has suffered two exceptionally severe droughts in the last five years.

    • Amazon will suffer much more droughts, but most definitely not because of extra CO2. If you are genuinely concerned, I have all the proofs on my website and in my book. If not, just to give you a small example regarding decrease in rainfall there: More and more ice around Antarctic is demolished by ice crusher ships – ruff water brakes much more. Currents that bring warm-water from Indian / Pacific – that water is less shielded by the ice as best insulator – that water absorbs EXTRA COLDNESS and is taking it north into Atlantic. Because at different temperature (is deep down), it doesn’t show directly on the surface temperature – but the presence of extra coldness = less evaporation = less rain… There are few more factors that decrease the ice around Antarctic; you will find them here: http://globalwarmingdenier.wordpress.com People have being blinded by the CO2 hysteria – lost capacity to see the real problems; many of those problems can be eliminated, or minimised. Therefore, continuing to blame CO2, is a double crime!!!

    • stefanthedenier,

      The notion that climate can be affected by changes in ocean circulation due to loss of sea ice is, AIUI, a reasonable one, although when it is suggested that the loss of arctic sea ice could have such an effect we are accused of undue alarmism. In fact arctic sea ice is expected to retreat much more quickly that antarctic sea ice (IIRC some research actually shows an expected increase in the latter) so maybe those of us living in the NH should indeed be worried. I have to say I find your claim that ice crusher ships could be having a significant effect to be unconvincing. Can you point to any actual research which backs this up?

    • Andrew, Russian nuclear ice crusher ship takes spectators to the north poll every two weeks, was on TV. 2]Because ice there moves slowly clockwise; they cannot use same corridor twice. 3]Slices as from a cake are floating south and melt in warmer waters. 4] Ice is as brittle as glass. Imagine the glass on your window is attached on 3 sides of the frame – not easy to push it out with your finger. b] make few more cuts in the glass…

      What I am trying to say: lots of corridors are made around Antarctic, to get to land. Ruff water brakes the ice 100 times easier, when is corridors. Andrew, as being from the N/H, you can help me to get the message there, that: .less ice on Arctic’s waters = more snow / blizzards in Europe / USA. The common believes they have is not just wrong, but back to front – can be avoided / minimized catastrophes. It’s in details explained in my book, lots on my website. Please, is too much to explain here, it’s urgent / important – the proofs are all there – as long as you don’t skip sentences.. thank you

    • The Amazon is an area that would fill much of the United States.
      Droughts have happened there since there was an Amazon.
      Once again the alarmist community confuses weather with climate.

    • hunter,

      Of course droughts will always occur, that’s a complete non-sequitur. But t0 get two such severe droughts within such a short space of time is certainly unusual, and both were worse than any recorded in the last 100 years. That doesn’t neccessarily mean that they were caused by AGW, it could just be a statistical blip, but it’s a cause for concern.

    • Andrew, for everything that happens, there is a legitimate reason. Tragically, because people are obsessed with the essential CO2, the real problems are overlooked. Let me point to you the offender: two droughts in Amazon, in a short space of time… Do you remember: 5-6 weeks after the Copenhagen flop; ice sheet attached to Antarctic – larger than Texas has bracken off… White ice is full of air = perfect insulator… minus that ice – warm-water that was coming from the north by the currents – was insulated by that ice from the unlimited coldness…

      Minus ice large as Texas, water was exposed… that water doesn’t come to there and stay – but goes back north into Atlantic, colder water = less evaporation = ?! Please go to my website, stop being Warmist. I am not articulate in English, you convey the truth to the Urban Sheep in the N/H, why they had 3 Januaries of extreme cold – will be more, if my truth / proofs are silenced

    • “The Amazon rainforest has suffered two exceptionally severe droughts in the last five years.”

      Wouldn’t one drought for 5 years be more significant?

  4. Well, there’s certainly a lot of uncertainty about, all of a sudden.

  5. Dr. Curry,
    As mentioned before, because we do not have a correct and acceptable climate science, public vote is presently the authority of the climate science. By engaging the public, there will be more uncertainties down the road. Not because the science itself is probabilistic in nature, but because the main-stream climate science followed a wrong and unscientific procedure and failed miserably. You should not assume that probabilistic approach to climate science will be any better than the main-stream science.

    • Dear Wagathon,
      I will have to agree with you regarding misuse and abuse of the science and funding, but there is no scientific proof that the Sun was the cause of past climate change or the Sun is the cause of the present warming trend. Let us say that for now we do not know the cause of global warming and let the public vote be the climate science authority for the time being.

    • How much proof do we need that it is gravity that causes the apple to fall to Earth?

    • Wagathon,

      Your posts are usually rather good. However, climate science has no physical hypotheses that go beyond Arrhenius’ work and that can be rigorously formulated and used to predict climate phenomena. We have to wait for empirical research to create reasonably well confirmed physical hypotheses that explain the so-called “forcings” and “feedbacks.” Svensmark and Kirkby will tell you that empirical research is required. At this time, there is no physical science to prove.

    • Even so the apple still will continue to fall to Earth irrespective of the language and abstract constructs we choose to use to denote our common understanding of the phenomenon we both observe. As with global warming: nomininally, it’s the sun, stupid; and, all of the fears and superstitions of Western civilization will not change that.

    • Wagathon, if it was only up to gravity, the apple would have fallen when was still a flower only. Disregarding multiple influences is self-destructive.

  6. Worryingly for the IPCC’s “consensus,” there is a counterparadigm, relating to the serious uncertainties of water vapor and clouds, now waiting in the wings. In the words of Dr. Henrik Svensmark, director of the Center for Sun-Climate Research at the Danish National Space Center: “The greenhouse effect must play some role. But those who are absolutely certain that the rise in temperatures is due solely to carbon dioxide have no scientific justification. It’s pure guesswork.” A key piece of research in this emerging new paradigm was published in the Proceedings of the Royal Society A (October 2006): “Do electrons help to make the clouds?”

    ~Philip Stott, Political Science, February 3, 2007; Page A11 WSJ

    • Is it ok to simply state we don’t yet understand?

      Have you seen a single paper that you believe credibly demonstrated why a warmer world will be worse for humanity overall over the long term? If you have I’d like to read it.

    • Rob,

      Our planet was not developed for humans sake.
      It evolved and in doing so, man popped up.
      Our planet has no care or worries on our safety or changes.
      It is just evolving to the changes it is experiencing.

  7. More on uncertainty

    “For the skeptic, however, the problem remains, as ever, water vapor and clouds. Enormous uncertainties persist with respect to the role of clouds in climate change. Moreover, models that strive to incorporate everything, from aerosols to vegetation and volcanoes to ocean currents, may look convincing, but the error range associated with each additional factor results in near-total uncertainty. Yet, there is a greater concern. Throughout the history of science, monocausal explanations that overemphasize the dominance of one factor in immensely complex processes (in this case, the human-induced emissions of greenhouse gases) have been inevitably replaced by more powerful theories.” (Ibid.)

    • What are the degrees of freedom so that we can determine the statistical significance of a model that that is constructed in that manner? Surely, the statistical significance can never be asserted because the degrees of freedom can never be known.

    • Yes, H2O, clouds control the climate, more clouds = better climate. If one doesn’t know what is a good climate – ask the trees. Ask them the second question: is it extra CO2 better or not.

      By the way, H2O / CO2 are ”shade-cloth affect gases” not greenhouse affect. They decrease day them, increase night temperature. What’s wrong with that?

    • Waghaton, before the misleading started, everybody was aware of the water / clouds affect. CO2 / H2O are ”shade-cloth affect gases” not greenhouse affect. That’s where the confusion is. Brazil and Sahara are on similar latitude / distance from the equator / from the pols.

      Sahara has HOTTER days / COLDER nights – Brazil has COOLER days / WARMER nights = overall same temperature. Collecting the temperature only from the hottest minute of the day as evidence is exclusively for brainwashing. Above Brazil, the upper atmosphere is warmer than above Sahara. I.e. when proportion in difference between upper atmosphere and the ground is greater = faster cooling = colder nights. If upper atmosphere gets warmer, because of extra CO2 + H2O – on the ground cooler… that is not GLOBAL warming or cooling… same warmth units! Upper atmosphere belongs to the same globe.Therefore, all is known, people that don’t have stomach for the truth, are avoiding my website… Laws of physics control cooling / warming, not CO2 or the climatologist. everything is known: http://globalwarmingdenier.wordpress.com TAKE THE CHALLENGE, OR JOIN ME, IN BRINGING THE TRUTH / PROOFS TO THE WORLD, please.

  8. Norm Kalmanovitch

    The practice of science is essentially the practice of removing uncertainty by starting out with facts developing a hypothesis about an uncertainty and testing this hypothesis through observation and experimentation.
    Correlation is not causation so the uncertainty in the climate change issue is whether or not there is an causal relationship to the stated correlation of CO2 emissions with rising global temperatures.
    Before causation can be determined it is first necessary to determine if there is a valid correlation between global temperature and increased CO2 emissions from fossil fuels.
    This is a rather simple task since there is relatively accurate CO2 emissions data and global temperature data dating back to 1880 when CO2 emissions first started increasing from industrialization.
    The HadCRUT3 dataset presented in the IPCC 2001 TAR (sometime after this the HadCRUT3 data was altered to remove the cooling that took place from 1942 to 1975) shows a slight cooling trend of about 0.05°C from 1880 to 1910 as global CO2 emissions increased from 0.5gt/year in 1980 to 3.5gt/year in 1910 indicating no correlation between CO2 emissions and increasing global temperatures. The HadCRUT3 data shows rapid warming of approximately 0.45°C from 1910 to 1942 but during this 32 year period CO2 emissions only increased by 0.5gt/year to 4.0gt/year by 1942 demonstrating very rapid warming with a very small increase in CO2 emissions.
    The HadCRUT3 data and the MBH99 temperature proxy shown in the same figure in the IPCC 2001 TAR both show approximately 0.15°C of cooling from 1942 to 1975 but during these 33 years of cooling CO2 emissions increased from 4gt/year in 1942 to 20gt/year in 1975 demonstrating no possible correlation between CO2 emissions and increasing global temperatures.
    In the 95 years from 1880 to 1975 there were 30 years of slight cooling with a 0.5gt/y to 3.5gt/y increase in CO2 emissions 33years of further cooling with a 4.0gt/y to 20.0gt/yincrease in CO2 emissions and 32 years of rapid warming with only a slight increase in CO2 emissions of 0.5gt/y from 3.5gt/y to 40.gt/y.
    The critical uncertainty therefore in the climate change issue is the uncertainty of whether increased CO2 emissions have a direct causal relationship with increased global temperature.
    We have 0.05°C of cooling associated with a 3.0gt/y increase in CO2 emissions which gives a rate of 0.0125°C of cooling per gt/y of emissions increase, 0.45°C of warming associated with 0.5gt/y increase in CO2 emissions which gives a rate of 0.9°C of warming per gt/y, and 0.15°C of cooling associated with 16.0gt/year increase in CO2 emissions which gives a rate of 0.009°C per gt/y.
    Three different rates and both positive and negative relationships provide a very high degree of certainty that there is no causal relationship between CO2 emissions from fossil fuels and global warming.
    My only concern is the relationship between CO2 emissons and global warming because it is this relationship that forms the basis fro the Kyoto Accord which demands a reduction in CO2 emissions to stop global warming.
    Since there is such a high degree of certainty that there is no causal relationship between CO2 emissions the question that the IPCC must face is why they claimed in the IPCC 2007 4AR that there was a 90% certainty that this causal relationship existed!

    • Guillermo Gefaell

      Your mentioned examples of CO2 – temp relationship disagreement may be explained by natural multidecadal temperature oscillations (+/- 60 years) over a general warming multicenturial trend (+/- 1750—> present) allegedly due to increasing CO2 concentrations.

      The real problem, in my opinion, is to know if in fact anthropogenic CO2 is the main reason for such subjacent multicenturial trend or then it is also natural variability.

      Prof. Boris Komitov (http://www.astro.bas.bg/~komitov/) supports this last possibility. See his papers on “Sun-Climate relationship”.

    • Norm Kalmanovitch

      When the oil price skyrocketed in 1979 oil consumption was reduced to such an extent that there was a year to year decrease in CO2 emissions for three consecutive years.
      The CO2 record from Mauna Loa Observatory shows no detectable change resulting from this three year to year decrease.
      http://www.esrl.noaa.gov/gmd/ccgg/trends/
      This and several other lines of investigation demonstrate that while CO2 emissions from fossil fuels contribute to the atmospheric CO2 concentration; this contribution is less (and likely far less) than 5% of the total contribution and therefore natural contribution is greater than 95% answering the question of anthropogenic source

    • Kalmanovich, other sciences are for removing the uncertainties; climatology is for creating uncertainties. There is enough known about climate / warming, no need for guessing; but the truth is boring…there is much more spoils in panicking the people. When the whole truth is known; they have to readjust the laws… I hope they will make those laws retrospective, for people avoiding my proofs!

  9. Re: Some gems from Palmer and Hardaker’s Introduction.

    Why is there no discussion about the economic and loss of life consequences of tectonic activity? How much damage is known to have happened, how many lives lost, due to earthquakes compared to how much damage and loss of life from AGW events? It’s a no brainer. There is not one conclusive loss of life due to the effects of weather intensity caused by our CO2 emissions. What about the future? Same. We can be pretty certain as to the loss of life in Los Angeles due to the next “big one”. We know it’s going to happen, just not the when. Yet with climate related events because of our CO2 emissions we don’t even know if the if will even happen.

    And it looks like the IPCC may pour cold water on the whole thing anyway.

    • These are good questions. An old classic that sheds (some, not total!) light on you questions is:

      Slovic, Paul, Baruch Fischhoff and Sarah Lichtenstein, 1982, Facts versus fears: Understanding perceived risk, in: D. Kahneman, P. Slovic and A. Tversky, eds., Judgment under uncertainty: Heuristics and biases. Cambridge University Press, Cambridge.

      Slovic also edited a more recent volume on risk perception:

      Slovic, Paul. 2000. The perception of risk. Risk, society, and policy series.
      London, England: Earthscan Publications. 2000.

      Slovic’s a bit too much of left-winger for my taste, but you can read around that and get a lot of interesting insights from him.

      The short story is that a good bit of what people fear, risk-wise, seems to be governed by aspects of the alternatives that don’t have a whole lot to do with any prescriptive model of decision under uncertainty. For instance, perceptions of personal control (real or imagined) have a big impact on the degree to which people fear risks.

      I suspect that the “personal control” aspect has a lot to do with fears related to climate change. Almost no one fears traffic accidents but they’re a helluva lot more likely to be affected by those than climate change. The difference is people are behind the wheel in cars. They are not behind the climate wheel.

    • Richard, also, I think some of this is related to the “naturalistic fallacy” or, more specifically, the “appeal to nature.” Earthquakes are natural; AGW by definition is not (at least given a conception of ‘nature’ that places man outside of it, which is dubious of course). See here:

      http://en.wikipedia.org/wiki/Appeal_to_nature

    • NW, Appeal to God? The Bible tells us that He uses earthquakes as a warning of coming judgement. Plot this:

      http://earthquake.usgs.gov/earthquakes/world/historical.php

      Maybe it is ‘natural’, you be the judge.

    • Richard, there is no money, funds / grants in tectonic activity; unless you can pin those activity on CO2…? Then they will all follow you. I can see that tectonic activities increased for the last few years – any correlation with increase in CO2? Most probably is because of increase in the number of climatologist.

  10. The article is a crock of malarkey.

    The essential conclusion is that “people should believe our conclusions because we have models that really make good predictions–trust us“

    How about we not believe the output of any models for implementing major governmental policies until the model has been demonstrated to accurately predict the future condition that are germane to the policies being considered. In the case of AGW, those who fear additional CO2 claim that some areas of the planet will be harmed because it will get wetter, or dryer, or hotter, etc. These claims are based on the output of models that have not ever been demonstrated to be able to make accurate predictions within the margin of error necessary for any analysis of the models predictions to be relevant at all.

    How about “climate scientists” stop being untruthful about the capabilities of their models.

    BTW- the article is also dead wrong when it stated–“However, the resolution of climate models, still typically 100 km or more, has been constrained fundamentally by a lack of computing resources”

    Imo the models have been constrained because they require tons of computing power to run, and after you run them you get unreliable results- especially for policy major decisions.

    • Chris Essex claims that for climate models to have any closeness to reality they would need to run longer than several trillion ages of the universe.

    • Richard

      The truth is I don’t really care how they develop their model, or how much computing power it takes to run the model. I only care that the model accurately predicts future conditions.

      My above statement is only partially true.

      I also care that MANY who fear AGW have taken the outputs of current models that can’t accurately predict squat about changes in specific areas, and written articles (that get peer reviewed and accepted) that claim that people in this area of the planet will suffer great harm because they will get less rain, or their crops won’t grow.

    • This is a clash of deterministic versus stochastic approaches. The scientists who apply stochastic methods firmly believe (and I agree with them) that the only way to make any kind of predictions is to essentially give up on deterministic approaches unless they focus on mean values. And even this requires stochastic considerations since the mean or expected value is defined via probability distributions. A prime example of this is in the distinction of the rate equation and the master equation. These often have a similar formulation, yet the former involves expected values, while the latter uses probability density functions.

      So basically we need to use dynamical systems as a guide and not rely completely on them for projections.

      Great paper by Bricmont called “Science of Chaos, or Chaos in Science”:

      Chaotic dynamical systems are of course unpredictable in practice, at least for long enough times, since there will always be some error in our measurement of the initial conditions.

      http://arxiv.org/abs/chao-dyn/9603009

    • Web

      The fact that you agree with an approach that accepts the conclusions of models demonstrated to be inaccurate is indicative of your perception of the issue and a personality flaw on your part (Imo).

      This has nothing to do with errors in the measurement of initial conditions,

      This has nothing to do with the use stochastic approaches for a scientific study. and it certainly has nothing to do with “peak oil”

      It involves the use of models proven to be inaccurate for determining the net impacts on humanity of warmer world.

      Looked at another way-If you had a model (or multiple models for different regions) that could accurately predict future rainfall and temperature as a function of CO2, and if these models could show that humanity would really be harmed as a result of the planet being warmer, I would support a change in our policies on CO2 emissions. Unfortunately, there are no such models, only people like yourself writing bologna about why people should accept the output of models that can’t predict anything relevant to government policy.

    • They need to predict catastrophes – to get more cash / power. Predicting everything good ahead = no cash… they are not that stupid. From thousands of them, not one predicted that: Sahara will get more rain, now is a bit extra CO2 – lots of trees will start growing there. Sahara can absorb + in more lakes – enough water for sea-level to go down by an inch. Maybe one of them did predict… what was his name?…..?!

  11. Speaking of uncertainty, it seems professor Muller stuck to his guns during the congressional hearing re the “Anthro” in AGW….

    DIdn’t catch the webcast, but this comment on WUWT sounds pretty clear:

    “Muller said pretty categorically that their studies prove the world was warming but repeatedly stated that the amount of this due to humans is subject to much debate. The guy on the right, however, was a rabid alarmist from the get go.

    Muller also mentioned that whatever we decide to do as policy is mitigated by what India and China won’t do which brought the political response that if the US leads in green technologies we can provide this (at a profit?) to the 3rd world.

    Also, the congressman tried to bash down other types of causes like cosmic rays for climate change and quoted his selected studies to show that it all has to be human caused, but he did not get the full agreement with those seated except the guy on the right.

    Given the choice of the 3 scientists did not agree with each other and only the most rabid of these 3 agreed with our representatives, I’m not sure they got what they were expecting from this panel.”

  12. Resolving uncertainties of future climate are predicated upon believing that understanding the past climate somehow provides insight into future climate.
    Likewise, using complex equations provides little meaning if the context of their use is misapplied. Slingo & Palmer identify the precise issue with models: “We may believe, for example, that the motion of the unsaturated portion of the atmosphere is governed by the Navier–Stokes equations, but to use these equations properly we should have to describe each turbulent eddy—a task far beyond the capacity of the largest computer. We must therefore express the pertinent statistical properties of turbulent eddies as functions of the larger-scale motions. We do not yet know how to do this, nor have we proven that the desired functions exist.” The uncertainty in describing turbulence, whether air, water, magma flow moving tectonic plates should give us pause in confidence to predict any future climate. If our climate really is a system not in equilibrium, nor linear, yet oscillations that converge to change states makes the calculation of uncertainty, unlikely.

  13. It is not just uncertainty, and it is not just climate science. It is incompetence, and across the physical sciences, due to the willful, biased establishment of a false paradigm (undirected, uniformitarian evolution, of everything in the material universe, due only to randomly acting physical processes) that is still being emotionally (!) defended as sacrosanct. That paradigm is failing; consensus scientists are denying reality. In climate science, while the consensus (and most of the skeptical community as well) believes in the possibility, and even inevitability, of a “runaway climate”, in a “chaotic system”, I have shown the atmosphere is not a chaotic system, nor prone to “run away”, simply by pointing to the long-known existence of the Standard Atmosphere, and its confirmation (along with definitive disproof of the greenhouse effect) in a simple comparison of its tropospheric temperatures with those measured in the atmosphere of Venus. The Standard Atmosphere is THE equilibrium state of Earth’s atmosphere, and all the weather and/or climate change is just a tempest in a teapot compared to that fundamental and well-regulated reality. The “uncertainty” you fear is just the projection of something even scarier on the horizon of science, something you are bringing upon yourselves.

  14. I particularly like the Slingo and Palmer excerpts because they confirm what I have known was the case regarding models just based on the fundamental math and numerics. What is troubling is that Team members have a great deal of difficulty admitting these things and instead resort to obfuscation and changing the subject. Then they say that the models aren’t really used as the basis for sensitivity anyway, as if the IPCC didn’t base their forecasts on the models. It’s just unethical how these things are used without explicit acknowledgment of their limitations. The impression is left that these models are as reliable as models of orbital mechanics where accurate forecasts are possible for millenia.

    There is some hope though given by some recent theory for the Navier-Stokes equations bounding the dimension of the attractors. These bounds are large but may be very conservative for any real system. Anyway, one might hope to do some kind of a decomposition of the attractor into component time varying modes that would offer new insight. It’s a challenge but perhaps we should devote the resources currently used to run climate models to attempt some computational work on this. Oh and by the way, I am still shocked that there haven’t been some careful studies on numerical and subgrid model errors in the GCM’s.

    Held’s work on smaller scale simulations of convection is perhaps a beginning toward developing subgrid models that are more rigorously justified.

    • David – You make good points, with which I largely agree. For perspective, though, it’s worth quoting from Slingo and Palmer (with my bolding):

      “So how much will uncertainties in climate-change predictions of the large-scale reduce if models are run at 20, 2 or even 0.2 km resolution rather than say 100 km resolution? Equally, we may ask whether there is a certain resolution (e.g. 20 km), where it might be feasible to represent small-scale motions using stochastic equations, rather than trying to resolve them? These questions urgently need answering as the pressures grow on the climate science community to estimate, and if possible reduce uncertainties, and provide more reliable and confident predictions of regional climate change, hazardous weather and extremes

      As their article indicates, much GCM uncertainty relates to advective processes and is less relevant (although not entirely irrelevant) to global temperature change, particularly over intervals exceeding a decade, as opposed to regional change. This uncertainty is important, because societies and governments want to know what will happen where they live rather than in some global “everywhere”. At the same time, global changes are likely to show up regionally given enough time and can’t be neglected.

      You mention that the “Team” says the models (GCMs) aren’t used as the basis for sensitivity anyway. If so, that is probably an overstated version of a statement that is mostly correct – we probably don’t need GCM simulations to arrive at fairly well constrained ranges for climate sensitivity not much broader than the ranges often cited by the literature – e.g., between about 2 and 4.5 C per CO2 doubling. A similar range can be derived by extrapolating from transient climate sensitivity estimates derived from simple energy balance models utilizing observed climate data. That range is still broad, but not too broad to preclude some estimate of future global temperature trends for given CO2 scenarios. (Note though that these estimates are probably inapplicable to short term fluctuations due to ENSO phenomena, which have been the subject of recent studies by Lindzen/Choi, Spencer/Braswell, and Dessler. Climate sensitivity to these phenomena will inevitably differ, perhaps radically, from sensitivity to persistent forcings from greenhouse gases, solar changes, or other long term global perturbations).

      Finally, as Slingo and Palmer, you, and others will argue, there is an irreducible uncertainty that GCMs will never overcome. They imply that we haven’t reduced current uncertainties to that level yet, and so there is still room for improvement. That seems to me to have been one reason for their article.

    • Fred, I just reviewed yesterday a guest post here by Nic Lewis on the Gregory and Foster 2006 empirical estimate of climate sensitivity. He notes that this is the only estimate that does not use model simulations. He further notes that the IPCC wrongly converted their data to sensitivity. When properly done the most likely sensitivity turns out to be 2.3K and rules out sensitivities higher than 4K. Just another example of the IPCC finding the answer they wanted to find. 2.3 has a lot different implications than 4K. I also note that the low tail of their distribution gives significant probability to sensitivities between 1K and 2K. I keep finding things like this that tell me that the literature is questionable. How does Forster and Gregory fit into your quoted ranges for sensitivity?

    • David – I believe that in the same thread, a number of us, including Piers Forster, pointed out that their later data showed a higher climate sensitivity, very similar to findings by others. Forster and others also rebutted other aspects of Nic’s analysis. There have been a number of transient climate sensitivity estimates since 2008 that are most consistent with the standard 2 to 4.5 C range when the transient responses have been extrapolated to equilibrium responses – this is also consistent for example with IPCC estimates of transient responses, so there is no contradiction. If there are other TCR estimates that imply a significantly lower value, I haven’t seen them.

      (When you said above that the “IPCC wrongly converted their data to sensitivity”, I don’t know what you’re referring to. As I recall, the disagreement was about the shape of the priors used for the estimate and not a “conversion to sensitivity”. The choice of priors was a matter of judgment, and Forster stated that he didn’t object to the IPCC choice.

      We have now seen many efforts to constraint climate sensitivity estimates, and while they haven’t narrowed the range much, they haven’t changed the median values either. There is, to be sure, much less credence given to very high “fat tail” estimates (much greater than 4.5 C), but the possibility of a true value much below 2 C is also becoming diminishingly small. (But note again that we’re talking about CO2 forcing and not short term responses to ENSO, which involve very different climate dynamics).

    • Fred,
      The better explanation is that GIGO is ruling the convergence.

    • I’m having trouble finding Forster’s comments on that thread.

    • Having reviewed the Lewis threads in more detail, I see no posting by Forster but a post by Lewis reporting what he was told by the IPCC lead author about Forster’s opinion. In any case, Fred, what I see is a disagreement between you and Lewis about the relative reliability of the 08 vs. 06 papers. You seem to feel that the 06 paper was an outlier. Lewis disagrees and cites data on ocean heat uptake etc.

    • David – Here is a link to one of Forster’s Comments.

      It is not merely I but Forster himself in the thread, as well as a number of papers from 2008 onward that support Forster’s conclusion for a climate sensitivity whose median value is close to that of reported in the literature and by the IPCC in 2007.

    • Fred, I went back and read Forster’s post. He starts off saying that the analysis on the thread (Lewis’ analysis) was correct, but he disagrees with the interpretation!!! OK, the only thing that leaves me with is that its a careful attempt to not offend people, especially the IPCC. But, he cites some other papers including his 08 paper. But his last paragraphs are strange saying in effect, they didn’t convert to climate sensitivity because the data is not good enough to justify it!! With all due respect, it looks like to me like non-GCM methods to estimate sensitivity are vastly better than GCM based methods (an obvious conclusion to me) and there is great uncertainty in the data. So, Fred, this makes your great confidence in the “concensus” range very difficult to explain given its reliance on GCM’s and your professed acknowledgement of my primary contribution to this blog, viz., that GCM’s may be little better than very expensive ouijy boards. As is usual, we see that different valid methods yield widely different results. Fred, I find this hilarous and it just reinforces my view that climate science is “a small primitive field beset by immense uncertainty.” So lets fire the Hansens and Trenberths and start a real effort by real scientists to reduce uncertainty. But, Fred, the first step of any recovery program is to admit the enormity of the problem. Are you there yet?

    • Forster pointed out that several recent papers based on transient sensitivity estimates rather than GCMs yield climate sensitivity values that are very similar to the earlier IPCC values. This would appear to add confidence to the earlier estimates rather than detract from it. The range is still broad, but the 2 to 4.5 C boundaries appear to be increasingly secure. The “consensus” is based on both the GCM estimates and the transient sensitivity estimates rather than relying on either one alone, but it’s reassuring that they don’t contradict each other.,

      The virtues and deficiencies of GCMs is a different topic, and I don’t want to confuse this discussion by going in that direction. However, your criticism of GCMs strikes me as biased and based on inadequate information about their performance on specific tasks – information not easily gleaned from Internet chatter. That’s not to say there are no problems, but rather that you may not be approaching the issue with sufficient objectivity. I’m not a modeler and have no investment in believing one thing or another about these models, except that the main conclusions about anthropogenic climate change are less dependent on them than you appear to believe. I still think you can make useful contributions to the modeling efforts by offering your input, but that has to be constructive.

    • Fred, We seem to be at the point we have been at before. As I have said many times, the first step in recovery is to admit that there is a problem. Constructive criticism is ignored until that step is taken. I resent your characterization that I might be basing an opinion on internet “chatter.” You are perhaps the most prolific source of this chatter. I am interested in the standard and well known consistency and error checks that have become standard in other areas of computational physics where people’s lives are at stake. If you really want to comment usefully on this issue, I suggest you start with Richtmyer and Morton’s book on numerical methods. Its old, but is an example of the theory that climate model methods are based on — the best methodology of the 1960′s. A more modern treatment is Strang and Fix’s book on the finite element method. Then you can look at Babuska’s paper on solution adaptivity. That will take you up to 1980. Then get back to me for further assignments. You are probably about 5 years of rigorous graduate training away from understanding the issues. Anyway, the problem here is that rigor is needed to analyze these things. Rigor is something that is as rare as an honest politician in climate science. I only hope to contribute to this coming “overflowing of liberty” to paraphrase Jefferson as the truth become more obvious. You would be well advised to learn a little about it yourself since the models seem to be the basis of so much in this primitive field.

    • Sorry about the “Internet chatter” comment – that was probably unfair. I still see you as trying to prove something that is almost certainly not true, which is that we don’t understand climate change well enough to predict that continued rises in CO2 will significantly warm the Earth, very likely within the boundaries of the generally cited sensitivity values of 2 to 4.5 C per CO2 doubling. As to your other points, I would very much like to know more about the numerical methods and error checking you mention. I merely wanted to point out that it is wrong to conclude that because the GCMs need improvement, we really don’t know what is going on. We know many things well, and others less well. The long term CO2 effects are among those we know well. Outside of temperature change and its consequences, we also have good information about the ocean acidification potential of increased CO2, which is another phenomenon deserving attention.

    • Fred, I’m not trying to prove anything. I just want to avoid another vertabraeplasty fiasco. You have never responded to any citations of other prominant failures of mainstream science in fields where rigor is rare, especially in medicine which is apparently your area of expertise, not climate science. Ocean acidification?? Come on Fred, next you will be warning me that hurricanes are increasing in the US. Most ocean species evolved when CO2 levels were much higher. This whole myth of corals dying is just nonsense and the typical cherry picking. Ecosystems were much more productive when our coal reserves were laid down and that was due in no small part to higher CO2.

      I keep seeing evidence of great uncertainty in climate science and you never really address it except to say that there is “growing confidence in estimates of climate sensitivity.” Fred, do you know what mathematical rigor is? In some fields, we actually prove things.

    • It’s hard to respond to you when you say things like “This whole myth of corals dying is just nonsense”. If it isn’t Internet chatter, then there must be some other source of your misinformation about a subject you seem to know hardly at all. I truly wish you would stick to fluid dynamics and methods for addressing differential equations. You have something to teach in those areas. As soon as you venture outside of them, though, you start to forfeit the credibility you’ve earned from your areas of expertise.

    • Fred, You seem to have a lot of spare time this evening. Do you actually have a reference for coral dieback? I’ve seen some data on it and just like the tornado and hurricane stuff, it has not basis in the actual primary data. Didn’t you offer the same tired defense of the severe events increasing literature some time ago? You are forfeiting whatever credibility you have with me. You show no critical faculties, but are surely an encyclopedia of the literature, no matter how flawed. Fred, have you ever read Russell’s History of Western Philosophy of Kaufman’s Critique of Religion and Philosophy? But I perhaps pose a question to which the answer is obvious. You know Will Rogers’ comment about Congressmen don’t you? “Today I met a Congressman and after a long conversation I discovered he was a venal liar. But I repeat myself.”

    • David – It has been falsely attributed to Will Rogers, but it was actually Josh Billings who said something along these lines: “The problem ain’t what we don’t know, but what we know that ain’t so.”

      To answer your question, I can come up with some ocean acidification references tomorrow or within a day or two, including some you haven’t seen. Wouldn’t it have been more useful to visit those references first rather than declare dying corals a myth first and then ask if there’s any information on the topic?

      Just sayin’.

    • David –

      You show no critical faculties,…

      This is the problem for me with some “skeptics.” Some of them write about technical subjects in ways that appear to me, as someone without the requisite background to make an independent assessment, to be logical and credible and plausible.

      But then they go and make ridiculous statements that are obviously false.

      It’s unfortunate, because it makes it very difficult to evaluate their perspective overall.

      If they are perfectly willing to draw obviously flawed conclusions in one area, who’s to say that they aren’t willing to do the same in other areas as well?

    • Fred, I am calling it an evening. Just opened a bottle of Baer Ursa 2008, the 6th best wine in the world for 2011 according to Wine Spectator. And the best part is that I have 80 bottles in my cellar. If you are ever in Seattle, I will share a bottle with you. Cheers!!

    • Joshua, I might even invite you, if you mind your p’s and q’s.

    • David -

      I have to wonder if your taste in wine is influenced by confirmation bias. Statistics would suggest that it is:

      http://scienceblogs.com/cortex/2007/11/the_subjectivity_of_wine.php

      That said, if I manage to mind my p’s and q’s, the next time I’m in Seattle I’ll see if you want to have an opportunity to prove that your conclusions with wine are more carefully considered than your conclusions about Fred’s reasoning.

    • I know its subjective, but Wine Spectator in my experience is trustworthy, more trustworthy than the climate science literature. Fred might not fare too well though because I would also invite my physicists friends who are more knowledgiable about physics but who realize that science advances through skepticism. Good night

    • “I am still shocked that there haven’t been some careful studies on numerical and subgrid model errors in the GCM’s.”

      Is this really true? I guess it is pretty shocking if true. But maybe not unexpected… Is this something that can be done analytically, or do you essentially have to do it by running the programs over and over again with slightly different tolerance parameters? If the latter–and if computational time is such a big burden here–maybe no one can stand the thought of devoting substantial computational resources to this, rather than running another ensemble. I am thinking of numerical issues here of course.

    • NW – David and Gavin Schmidt have argued about this on RC. I remain a bystander, but although David makes a convincing case for the need to address these inaccuracies, he hasn’t convinced me that they are being ignored by the modelling community.

    • Fred, I’m sure they are worried. But I maintain that there is no evidence that there is much awareness of how bad things can be. I have seen no references in the literature addressing these issues. It’s kind of like the statistical methods used by Schmidt, Mann, et al that were critiqued by McShane and Wyner. With all due respect, Schmidt showed no evidence whatsoever that he understood the issues. He seemed to even be unaware of the errors inherent in Reynolds’ averaging, something that is really well known in fluid dynamics. It seems strange since the models are reliant on turbulence models that seem to never be mentioned in the literature. Certainly Schmidt didn’t volunteer any information, indicating to me that they are just “consumers” of the methods. Always a dangerous position to be in. A smarter version of Hansen would hire a turbulence modeling expert to straighten things out. Just as he would hire a statistician. But interdisciplinary scrutiny is anathema to climate science, or at least it seems so.

    • The percentage of people involved into climate since the 70-80′s has sky-rocketed by 1000%. Increasing numbers is good for creating confusion. Unfortunately, more of them = much more expenses. The only way to part the Urban Sheep from their money is: create uncertainty / panic = cash. If that one person in the 80′s didn’t figured out that: to get themselves out of the Nuclear Winter lies – go 180 degrees in the opposite direction… now most of those people would have being in productive / honest professions. What will happen, when people find out that many of those ”professionals” have being avoiding or silencing my proofs…?

    • Maybe shocked is too strong a term. In any other field relevant to policy people would demand more rigorous analysis and control of these errors. One would do grid convergence studies, sensitivity studies, etc.

      The analysis can be done analytically, but with complex models like these computational experiments are probably essential. The real problem is that the rigorous modern methods needed would probably require rewriting the model software with different numerical algorithms. One tool is adjoint solvers which can be very difficult to graft onto old finite difference methods. I suspect that in climate science there is no incentive to do this. According to Lacis, the pressure is always to do more running of existing models with different variations on forcings, etc.

    • Certainly I know from experience that algorithms can matter a lot. People who don’t use computational algorithms themselves do not appreciate this. I remember refereeing a paper that used Nelder-Mead to find some optima. I happened to have the data set, and tried a quasi-Newton algorithm instead. The results were totally different and completely overturned the author’s results. I don’t think it was intentional. People just trust that the optimization package they are using has reasonable defaults. Sometimes I wonder how many conclusions in scientific papers are wholly artefacts of seemingly irrelevant algorithmic choices. Not every referee will happen to have the same data set and the curiosity to check the results under different algorithmic choices.

    • Right on the money. Models not specified by theories are tinker toys. The research money has to go into theories, sets of physical hypotheses, and not models. A model on its lonesome can do no more than hindcast. It has no predictive ability whatsoever. Our existing models cannot even hindcast with some reasonable degree of accuracy.

  15. Economics has a popular reputation for being spectacularly useless.

    To my mind, that onerous spike beckons promisingly to look and search further. The reductionist analysis and viewpoint is appropriate.

    The end target is dumb. The ‘uncertainty’ end targets of this thread seem similarly dumb flat and featureless … screen doors on submarines …

    Shouldn’t stop looking at the edge of uncertainty. Never can know those unappreciated possibilities residing in the space beyond without having a go-see.

  16. To sum up:

    “Climate is just too difficult for us to be anywhere near certain and it looks like we’ll never have the computing ability anyway so how about we all get together, change the goalposts and define a new level of uncertainty we’ll call certainty.”

    Does that about sum it up? Latimer? your help is needed in refining the above “quote”.

    • In other words…
      Start from the beginning and follow strictly facts.
      There are enough of them.
      Many areas are “interesting” but still being ignored as they are insignificant to temperature data.

  17. Judith,

    HANDLING UNCERTAINTY IN SCIENCE

    Ignore it and hope it goes away!

  18. Dr. Curry,
    Thank you for the honesty with which you share this. I always learn from reading your blog posts/comments. Your willingness to stand up for the truth of uncertainty has given Climate Science some much needed gravitas.
    Cheers,
    Big Dave

  19. Uncertainty is as unwelcome in postmodern science as
    Flaws in new cars and appliances, and
    Flatulence in closed elevators.

    I know one of the participants, Dr. Philip Campbell (Editor of Nature) and requested his resignation from that position last year for:

    a.) Failing to follow Nature’s own Mission Statement of 1869, and

    b.) Promoting misinformation about the formation of the Solar System, the Sun’s origin, chemical composition, source of energy, and influence on changes in Earth’s climate.

    He did not resign, continued to censor my comments, but I was not solicited to renew my subscription when the old one recently expired.

    The last part of this quote from the abstract of Dr. Campbell’s paper illustrates why many scientists and ordinary citizens feel betrayed by leaders of the scientific community:

    “Their approach to communicating uncertainty should depend on the context but,

    except in some extreme emergencies, transparency is generally a virtue.”

    Apparently AGW was considered an “extreme emergency.”

    With kind regards,
    Oliver K. Manuel
    Former NASA Principal
    Investigator for Apollo

  20. I think it is possible to state with certainty that something bad will happen. Somewhere, sometime, somehow. Do they think that by enumerating potential tragedies they can frighten us into action? Unexpected tragedies? How many other kinds are there? Bangladesh immersed – oh, no! The rainforest depleted – oh, no! Floods, droughts, plagues, more snow, less snow, more rain, less rain. To quote Bill Murray in Ghostbusters, “dogs and cats living together – mass hysteria!” There is some probability of any calamity you care to name. I guess they think that maybe if they just throw enough mud against the wall some will stick. I’ve heard so much at this point that I do not believe any of it, any time, from anyone. And that is the real problem for the ‘if only we communicated better’ crowd – the public has had it with their manipulative pleadings.

  21. “By ‘unquestionably dangerous’, we could mean the complete loss of the Amazonian rainforest owing to shifting rain patterns, or of large parts of Bangladesh becoming uninhabitable owing to persistently intense monsoons, storm surges and substantial sea-level rise, or of permanent Sahelian drought of the type seen in the 1980s? How probable before taking mitigating action can be justified: 50, 10, 1 or 0.1 per cent?”

    Is the best they can come up with?
    The Amazonian rainforest is not threaten by drought, if threaten at all it’s threatened by logging. And such issues are the responsibility of the governments in involved.

    “or of large parts of Bangladesh becoming uninhabitable owing to persistently intense monsoons, storm surges and substantial sea-level rise”

    Has been a problem long before any measurable affect of human activity on global temperatures.

    And Sahelian droughts have been long term problem.
    It should be obvious, assuming the citizens involved desire it, to build a dam. A few dams and some irrigation could be good idea to mitigate drought problems.

    • Amusingly, Banaladesh is increasing in surface area. Monsoons and floods are the stuff and staff of life there; they bring soil and fish and prosperity, such as it is.

      The whole d*** country is a river delta, folks.

    • Interesting when they threaten with less rain in Amazon, sinking Bangladesh BOO! But not one say: climate change will increase the rainfall in Sahara…? Fear warmongering has always being big currency, but never as big as since the Kyoto conference. Floods and droughts BOO!!! But nobody mentions of building few new dams… why? Because dams are built by honest people.

  22. In respect of the Slingo & Palmer

    “We must therefore express the pertinent statistical properties of turbulent eddies as functions of the larger-scale motions. We do not yet know how to do this, nor have we proven that the desired functions exist’. Thirty years later, this problem remains unsolved, and may possibly be unsolvable.”

    The following link is a good read of how the problem of handling eddies in non-linear dynamical systems could be addressed:

    http://arxiv.org/ftp/physics/papers/0503/0503028.pdf (pp1/2)

    Tomas Milanovic is one of the few denizens who might more fully appreciate this paper. I merely point out that as climate is both non-linear and non-ergodic in nature, it seems that we need to be looking further afield for solutions than classical science.

  23. The skeptical drivel in the comments today is particularly bad.

    Uncertainty is composed of ignorance and noise. Here is a blog post that concentrates on the noise aspects, and is a good antidote to the Ludecke papers:
    http://theoilconundrum.blogspot.com/2011/11/multiscale-variance-analysis-and.html

    • Climate science comprises large areas of unacknowledged uncertainty (“ignorance and noise”). The best way to handle it is to shut down the purveyors of both.

    • Brian H said:

      Climate science comprises large areas of unacknowledged uncertainty (“ignorance and noise”). The best way to handle it is to shut down the purveyors of both.

      I am really trying to advance the yardstick via analysis, and this kind of comment confuses the issue. Yes, ignorance and noise are both technical terms relating to uncertainty. Ignorance is uncertainty in our understanding and knowledge of the system under study, while noise is a technical term describing other factors that obscure the real signals that we are interested in. Noise can also be either aleatory (part of the system under study) or epistemic (a side effect of our imperfect measurements).

      If aleatory, the noise may be just as important as this can tell us the distinction between natural variability versus forced variability, as, for example, caused by anthropogenic factors. That’s what I am trying to convey by bringing up the distinction, and also what Ludecke was trying to accomplish.

      You basically conflated the discussion with the uncertainty of people that shouldn’t be involved in the discussion. So I assume that you will wildly applaud what I am trying to do?

    • I’m deleting a bunch of comments that are just way off topic. will add a moderation note to the main post

    • Web,
      I would suggest that the drivel is from those who thin that in the face of massive uncertainty they know the way things work: The AGW community offers plenty of noise and drivel on any topic. The community seems to get up in arms anytime in particular the obvious lack of fact and knowledge behind the AGW tents are pointed out.

    • If in fact, the climate is “hypersensitive” as claimed in the referenced post, we are in big trouble and had better concentrate on adaptation. Mitigation is not going to work. It seems to me that all this assumes that mankind will not be able to eventually geoengineer the planet to keep disasters from happening. That seems rather likely to me. The problem of coarse will be who controls this and how is the desired end state defined.

  24. IPCC AR5 – Draft

    And for the future, the draft gives even less succour to those seeking here a new mandate for urgent action on greenhouse gas emissions, declaring: “Uncertainty in the sign of projected changes in climate extremes over the coming two to three decades is relatively large because climate change signals are expected to be relatively small compared to natural climate variability”.

    http://bbc.in/sZeltq

    The PAUSE continues: http://bit.ly/cO94in

  25. Judith,

    I used to believe our scientists 100% that they were accurately feeding me good knowledge.
    Through my own researching that figure is only at 1%. Possibly 2% on a generous day. :-)

  26. “Thirty years later, this problem remains unsolved, and may possibly be unsolvable.”

    Indefensible defeatism.

    “The richness of the El Nino behaviour, decade by decade and century by century, testifies to the fundamentally chaotic nature of the system that we are attempting to predict. [...] a classic demonstration of the need for ensemble prediction systems on all time scales in order to sample the range of possible outcomes that even the real world could produce.”

    EOP (Earth Orientation Parameters) indicate with absolute clarity that there are simple constraints on the variability. More care is needed from climate science data explorers to patiently get a handle on the asymmetries in the geometry. It’s patently NOT all-scale chaos; we can conclude this with certainty from EOP. Climate scientists need to communicate more with EOP experts and abandon catastrophically derailing statistical inference paradigms that demand patently untenable assumptions.

  27. This thread has gotten off to a noisier than usual start, I’ve deleted a number of posts that are way off topic, and have added a moderation note to the main post.

  28. We all seek certainty
    But there’s none.
    Except the certainty
    That things must change.
    We collect antiques,
    Shore up the family home,
    But dynasties fall,
    Plans soon come undone.

    • Beth,

      The problem is scientists are looking at temperatures as the main driver for the whole planet. Trying to make prediction on something they really are too lazy to study as they found temperature data for an extremely short period of time to suffice.
      Now the uncertainty is a crutch to what they do not know or want to know.
      The funding is still flowing.

  29. Thanks for posting this Judith. Some really interesting work here.

  30. Earth a jewel in the eye of God
    Moment to moment, age to age
    Catch the bus at last; no fees
    Translated out of time in joy

  31. I would like to comment in some depth on the Slingo and Palmer paper.

    The fundamental flaw of this paper is that the authors start with the Lorenz system (e.g temporal chaos) and then they attempt far reaching extrapolations to weather/climate (e.g spatio-temporal chaos).
    As I have explained here several times these 2 dynamical systems have very little in common so that (almost) no result obtained in the temporal chaos , let alone in the particular case of Lorenz equations can be ported to spatio-temporal chaos.

    For example while it is true that : “Lorenz’s theory of the atmosphere (and ocean) as a chaotic, nonlinear system pervades all of weather and climate prediction .” , it is not true that “while some weather patterns
    or regimes may be highly unpredictable, others may contain substantial
    predictability; in other words, the predictability is itself both variable and
    predictable (figure 1). This property has fundamental implications for weather and climate prediction as it allows an assessment of the reliability and hence confidence in the probability distribution of the forecasts.

    Indeed what the figure 1 shows is the dispersion in the phase space on the Lorenz attractor. This particular case has 2 specific properties :
    1) It is finite dimensional (3)
    2) It is ergodic (e.g there exists an invariant PDF of the state distributions)
    Both properties allow to formulate some statistical predictions of the future evolutions but only for this Lorenz case. Of course this special kind of statistical predictability says nothing about the flow itself (infinite dimensional phase space and generally no ergodicity) and its predictability.
    I find here the much too frequent “overhyping” of the Lorenz’ system which people with insufficient non linear dynamics experience consider consciously or inconsciously as a proxy for ALL chaotic systems.
    And this is clearly wrong as the true discoverer of chaos, not Lorenz but Poincarré, knew already 100 years ago.

    I can also answer the wondering of the authors This lack of spread suggested that the perturbations to the initial conditions were sub-optimal and did not necessarily capture the most rapidly growing modes [4]. Considerable research into identifying those modes using singular vector
    techniques was undertaken [5], and significant progress achieved in increasing the spread of the ensemble. Nevertheless, the ensemble remained under-dispersive so something else must be missing.

    In this case the phase space is the infinite dimensional Hilbert space of functions f(x,y,z,t). The dynamics of the system are represented by a vector in the phase space.
    Now what does it mean to generate “ensembles” by random perturbations?
    Well it clearly means that the phase space is supposed isotropic and that the attractor (a Hilbert sub space) is isotropic too – e.g any random perturbation will do.
    However this is apparently wrong – any attractor if it exists has privileged directions what means that the Hilbert vector in some initial position, will have some privileged directions too. The evolution/perturbation that will happen will not be random – some will have a very high probability while some other will have a probability 0.
    If the region of the attractor is very “rugged”, the dispersion may be very high what a smooth isotropic probability distribution could never simulate.
    Actually my conclusion from the authors’ comment is that the models are obviously unable to correctly reproduce the anisotropy of the attractor.

    A word about the figure 3 in the paper which nicely illustrates the above comment.
    Top left we have the initial spatio-temporal pressure field with a quite dramatic depression.
    Below we have 50 computer runs obtained with random
    (isotropic) “perturbations” giving the result a few days later.
    18 of them show also a dramatic depression on different places. 32 show that it dissipates.
    A naive approach would be to predict a hurricane with a 36% (18/50) probability.
    Of course this prediction would base on totally unjustifiable assumptions that :
    a) 50 runs are enough
    b) the probability of the result of every run is iid, e.g 2 % (1/50)
    c) the distribution of the 50 runs is independent of the arbitrary choice of “perturbations” which generate them.

    In reality the highly energetical initial state in which the system is, is likely also highly anisotropic.
    For instance that could mean that the direction in the phase space to the final state shown in run 13 has a probability of 0 while the direction to the final state shown in run 11 has a probability of 80%. The distribution of these probabilities could be of course dependent on the initial state (e.g the system is not ergodic) and the attractor highly anisotropic.
    Consequence is that the probability of a hurricane would be no more 36% but near 80%.
    This short example shows that this kind of hypothesis doesn’t play at “margins” – it may change the order of magnitude of the result!

    I also add a technical comment related to figure 4 – the only correct metric for a Hilbert space is the Hilbert scalar product. That’s why all dispersions must be expressed with this metrics and the notion of “ensemble average” is irrelevant.
    Therefore it appears paramount that before one rushes in some (often stupid) climatic computer runs and averagings over too long time scales, it is necessary to clear the very fundamental theoretical basis – what is the attractor? How anisotropic is it? Is there any hope for strong ergodicity? Or any weaker kind? What about pseudo periodical spatial structures at all time scales?

    For the conclusion I would join Theo Goodwin who said it in a much shorter and relevant way :
    Models not specified by theories are tinker toys. The research money has to go into theories, sets of physical hypotheses, and not models.

    • Tomas, your comments are appreciated, even if my lack of background in dynamical systems has left me unclear as to the basis of some of your conclusions.

      My intuition tells me that the study of chaotic systems should be based on the application of more generalised laws of physics applying equivalently to smaller scale sub-atomic particles and macro-scale weather/climate systems.

      I agree, that a great need exists for more resources be allocated to the development of theories and hypotheses in climate science and feel further that climate science itself is in need of strengthening.

    • Researchers from almost all disciplines apply the i.i.d. assumption FAR too casually, which suggests a deep (& patently false) belief that it’s logically inconsequential.

      Necessity’s the mother of invention. The need for mathematical tractability drives wishful assumptions. Everyone with lucid awareness is an “innocent” bystander while the false assumption crime rate accelerates unchecked.

      Tomas draws our attention to the fundamental differences between temporal chaos & spatiotemporal chaos. There also exist fundamental differences between temporal data exploration and spatiotemporally-aware data exploration. Many simple paradoxes FUNDAMENTALLY bias naive interpretation, for example the modifiable areal unit problem.

      With a handle on key features of the spatial geometry, it’s possible to do spatiotemporally-aware temporal data exploration – for example: http://wattsupwiththat.files.wordpress.com/2011/10/vaughn2.png .

      Before we can have meaningful theories & inference, explorers will have to listen FAR more carefully to the data.

      Any climate model that can’t reproduce EOP (Earth Orientation Parameters) isn’t worthy of consideration.

  32. “irrespective of the climate-change scenario chosen, the availability of fresh water in the latter half of the twenty-first century seems to be dominated by population increases that far outweigh climate-change effects. Paradoxically, fresh water availability may become more critical if there is no climate change”

    This is the kind of statement that pretends to be accurate, but isn’t. It is the kind of statement that is never properly examined on this site. It is uninformed, not only in relation to the science, but in relation to a broad range of social issues.

    An increase in global precipitation does not mean an increase in potable water; an increase in water temp does not mean less water degradation/water-borne disease; warming oceans do not equal less salinity; and rising sea level does not mean a decrease in the salinity of the water available to coastal communities.

    On the contrary, increased temperature means an increase in the intensification of water cycles resulting in e.g. more flooding, which equals more water contamination and soil erosion/less agricultural viability. More heat means more evaporation of water on the near- surface of soil which equals less replenishing of groundwater sources. Melting glacial ice means less – not more – sustainable water supplies in South America and Asia. Etc.

    Then there are the development issues. Obviously, freshwater resources on the planet are not divided equally, and climate change does not mean that it will suddenly become more equally divided: poverty and equity issues that either support or deny adequate management of available resources are central ideas in any comprehensive understanding of climate change and water issues.

    Besides an uninformed stance on the broad science of water, Webster demonstrates a very limited understanding of shared social issues relating to water scarcity. No one working in the field of water issues can take such a statement seriously.

    One more thing: I question whether the other author’s understanding is accurately represented in this paper and I object to the exploitation of current or former graduate students by professors, to promote their own goals.e more thing: I doubt the then-student’s views are actually accurately represented in this paper and I object to the exploitation of students by professors, to promote their own status.

    • Martha,
      How does your misanthropic instiinct permit you to waste so much time misinterpreting something so straight forward?

    • Martha

      When you claim:
      “increased temperature means an increase in the intensification of water cycles resulting in e.g. more flooding, which equals more water contamination and soil erosion/less agricultural viability. More heat means more evaporation of water on the near- surface of soil which equals less replenishing of groundwater sources. Melting glacial ice means less – not more – sustainable water supplies in South America and Asia. Etc.”

      Aren’t you offering nothing more than your unsupportable opinions?

    • Rob,
      For the dedicated true beleiver like Martha, not only does hot, cold wet or dry prove AGW, but more water is less.
      Her insight on salinity raises yet another opportunity for believers to obsess on yet another non-event regarding the oceans that AGW promoters can seize on to get more grant money: the risks from CO2 of salinity changes in the oceans. So fear mongers can claim the oceans are turning to acid and getting more salty.
      The miasma of the hardcore true believer is endlessly entertaining until they start playing with guns or laws.

    • Martha,

      As I read the elliptical language of the last paragraph of your above comment, you appear to know of some sort of inaccuracies in Webster’s paper and improprieties in his treatment of students. May I ask that you be more specific? I’m genuinely interested in the detail of your concerns.

    • I agree with mike, Martha sees victims under every rock. It’s her thing. She is just honing her skills at finding victims. If done properly, it can be constructive. Here she doesn’t appear to current on how little glaciers actually contribute to water supplies, but still, those issues should be discussed.

    • “she doesn’t appear to current on how little glaciers actually contribute to water supplies”

      Please correct your ignorance of geography and water. Consider using google to inform yourself of where vanishing glaciers will affect water supply, and why.

      Or are you just concerned about yourself and since you’re water is fine, everything’s fine?

      Unbelievable.

    • ” inaccuracies in Webster’s paper and improprieties in his treatment of students”

      Hi, Mike.

      My comment was on the specific statement I quoted in context.

      Everyone knows (or should know) that we have already arrived at a situation that can be described a water scarcity, apart from the worsening effects of climate change. His statement ignores the inter-relationship between issues, as I explained above.

      Regarding proper practice, I am referring to the academic practice of co-authorship for student, or doctoral or post-doctoral researcher. This can be an important opportunity for a new graduate; on the other hand, as a person of merit, a student or newly graduated associate researcher should not have to accept all the statements of a major professor in a co-authored paper. That is what I am saying.

      In the case of Webster and Curry, they have a small private commercial venture associated with the resources and pool of students at their academic institute, and this may or may not be problematic in individual cases – including this one. I have no knowledge of the details, and my comments are in relation to general issues in the practice of academic communities, authorship, and c0-authorship in the advancement of both faculty and students. It’s always helpful to know who has rights of authorship, and what specific contribution a c0-author has made to both main and other claims in any paper. cheers

    • Martha,
      Now you are back peddling and ar waving. You have nothing on the water, AGW making it worse or on Webster.
      We are not now at a water shortage by any rational definition of the term.
      And as for your slander against Webster, you were just pullilng that out of some yet darker part of your mind.

    • Besides the technical papers in IPCC AR4 summarizing the (then) current science on climate change and water, I read a lot of current domestic climate science and agricultural from dozens of countries, along with comprehensive analysis in development, food and water issues. I base my opinion on this.

      You?

      Regarding your other comment, apparently, you are unfamiliar with the university as a community of practice and the diversity of issues and viewpoints on the role of research trainees, and have no idea what I am talking about. Fortunately, what experience you do or do not have with this doesn’t matter. The point was that the criticism is for Webster, not the co-author. Why? Because I think Webster, not the co-author, is saying it. If in fact the co-author would agree with what I quoted from their paper, as presented by Webster, then the points of criticism are addressed to both of them because the statement is not supported in the paper, the science or comprehensive analysis of the issue.

      If you are still not understanding, let’s leave it.

      take care

    • Hey Martha, try reading the paper.

    • Hey Judith, I did. I understand that Peter hopes that probabilistic forecasts will alleviate poverty (by reducing loss of property, displacement, etc). That’s good, as far as it goes; but it is a naïve and limited view of the intersection between climate change and poverty, around the world. His broad statement of conclusion, which I quoted, is not supported in the science, or by analysis of the global poverty and equity issues. If the context is only the region of China previously the subject of their analysis, then that’s fine; however, this is not reflected in the sweeping developoment conclusion (never mind the title) of this paper. Maybe you could try reading and understanding comments.

    • Would the climate stopped changing, if it wasn’t any industrial revolution? Overpopulation will destroy everything green in nature, not CO2. Before 1850′s CO2 in the air was to criticality low level, for healthy vegetation. Vegetation is made of CO2; the more of it – the better and more prosperous trees / crops. It’s too obvious than, all of the carbon molesters are avoiding the real problems of overpopulation, why?

      Without fossil fuel, earth can sustain 1,5 billion people – have they decided what to do with the other 5 billion?

    • “Without fossil fuel, earth can sustain 1,5 billion people – have they decided what to do with the other 5 billion?”

      I wonder if that is correct. I wonder what max pop the world could have
      without fossil fuels.
      I would say right off that there is enormous amount waste in government.
      To get rid of fossil fuel could get rid of a lot government- the government workforce simply could not be afforded.
      Though it’s possible that would a bigger military force.
      But such military could be composed of mostly or partially with private militant groups. You could what is known loosely as a police state.
      Or different way to say this is the government role could be limited to security concerns.
      One might look at modern countries which have low GDP.
      Half the world is poor today. And unlike poor in poor US, the world’s poor can’t afford fossil fuels.
      “Almost half the world — over three billion people — live on less than $2.50 a day.”
      So mostly these 3 billion people aren’t currently using much fossil fuels,
      though doubt they maybe assisted in various ways which involve fossil fuel use.
      But as saying above, it’s unlikely these 3 billion are doing much to support a government.
      I think it might possible to have much higher populations without fossil fuel. But most people would farmers and labors and life would shorter and a lot less comfortable.

    • Martha, what the heck are you talking about?

      “One more thing: I question whether the other author’s understanding is accurately represented in this paper and I object to the exploitation of current or former graduate students by professors, to promote their own goals.e more thing: I doubt the then-student’s views are actually accurately represented in this paper and I object to the exploitation of students by professors, to promote their own status.”

      Jun Jian is a former student of Webster’s, he currently holds a faculty position at a university in China. Where is the exploitation, and how does including Jian as a coauthor promote Webster’s status? This is the wackiest comment I have seen from you yet. Not content with smearing me, you start working on Webster?

    • I agree. In the absence of evidence for “exploitation” or other improprieties (and I saw no evidence that can be inferred based simply on the existence of co-authorship), I can’t find a justification for this type of innuendo.

    • See my comment to hunter, above.

      I must say, your experience of being ‘smeared’, every time someone raises points of objective criticism or questioning, is melodramatic.

      By the way, Jian is apparently now at Dalian Maritime University, in China.

      If you do not understand why I questioned who authored that particular (false and unsupportable) statement I quoted from their paper, then you do not understand much about accountability, co-authorship, and integrity.

      It is perhaps small wonder that any time anyone wonders aloud about graduate students and research trainees who you also employ in your commercial venture (whether or not Jian was one) you don’t get that, either. To be clear, that would not be permitted in some other academic communities. Yes, I am aware it is permitted in yours; but that does not mean it is not problematic beyond the usual role relations between major professors and those who are secondary authors and/or research interns.

      Do you understand the term ‘problematic’? It refers to an asymmetry in power relations.

      Anyway, until Webster and Jian can support the cited statement with science and analysis, it stands as a very weak point in their synthesis/concluding comments. Too bad, because it is otherwise a good and in many ways important paper. I was surprised to see such a careless conclusion drawn, essentially without being supported by the substance of the paper.

      That is what is bizarre, if you have any interest in science, climate change and water issues. That is obviously my main point, so please don’t continue to pretend I am more interested in your commercial ventures and relationships with graduates, than I am. If you have an explanation on Webster and Jian’s behalf, for such an ininformed statement in their joint paper, feel free to provide it — since you cite it as a main influence on your thinking. Thanks.

    • Martha, the statements in the paper are supportable by the evidence in the paper. The reviewers and editors at Proc Roy Soc seem to have thought so also.

      With regards to our commercial venture, CFAN. for the past 3 years, CFAN has been subsidizing (out of overhead, which is basically out of mine and Webster’s pockets) continued operational flood forecasts in Bangladesh (after the technology transfer occurred and the Bangladeshis could not sustain making the forecasts themselves). For more information on this, see Webster’s earlier paper
      http://webster.eas.gatech.edu/Papers/BAMS_Webster_etal_2010.pdf

      WIth regards to an asymmetry in power relations: the few Georgia Tech employees that are involved in CFAN have a committee of people assigned by the administration that oversee any potential conflict of interest issues related particularly to students.

      So, tell me how many lives and $$ have you saved lately in vulnerable third world countries? If you have saved more than Webster, then lets talk.

    • You frame your activity as exceptional charity work, rather than the assistance that anyone provides within their abilities and professional knowledge. Why?

      Operational flood forecasts and saving lives with probabilistic forecasting does not address the main point I was making regarding the broader poverty, equity and water and food resource issues.

      As I said, everyone knows (or should know) that we have already arrived at a situation that can be described a water scarcity, apart from the worsening effects of climate change. The statement I have been discussing from that paper ignores the inter-relationship between issues, and if you don’t want to understand this, then that’s fine.

      The minor question I raised re. co-authorships is not answered by you or what policies Georgia Tech does or does not have in place for students, interns or for any employees of your company who are students. If you don’t understand that, either, that is fine.

      The point is one of being responsible for that completely uninformed statement – whether or not other statements are well supported.

      It defies comprehensive analyses of these inter-related issues. Where, exactly, is Webster’s evidence that population trumps effects of climate change? It is one of several signficant impacts on water issues. Where, exactly, does Webster get his evidence for such a signficant claim for developing countries? It has implications for policy.

    • martha, do the math. if population is doubling, and water resources are expected to change by at most 20% (one way or the other), then population increase trumps changes in water resources. The conclusion was made for the river basins in Asia that were analyzed

      Re the bangladesh forecasts, there is substantial costs associated with making them. We have to pay peoples salaries who are working on the project.

    • I shouldn’t bother, Judith. She is beyond reason and redemption but curiously attractive nonetheless.

  33. Judith Curry

    You have given some comments on a few of the RS papers.

    Here is my quickie review of the papers.

    1. Palmer and Hardaker
    Cites Feynman: Uncertainty is inherent in chaotic systems and handling it ”is an inherent part of the scientific method”
    How handled? How communicated?
    Decisions must be made based on uncertain scientific input.
    What to do?
    Reduce uncertainty, improve computers, better communication, share experience. ”Develop methodologies to handle uncertainty”

    [Feynman is cited, but what I miss is the insistence on empirical data to validate new hypotheses and the need for repeated attempts to invalidate them, before they can be considered corroborated and also before they can be presented to those making policy decisions based on them.]

    2. May (article is behind a paywall)
    From abstract:

    the truth is to be found not by appeal to authority but by experimental tests and evidence.

    Skeptical questioning and insistence on empirical evidence is a key part of scientific method.

    [Makes sense, but cannot read whole article since it is behind paywall.]

    3. Brown (article is behind paywall)

    [Seems to be limited to philosophy and quantum mechanics.]

    4. Stewart (article is behind paywall)
    Stewart is a mathematician. In the abstract he starts off with:

    The discovery of chaotic dynamics implies that deterministic systems may not be predictable in any meaningful sense

    The article provides an “informal overview of sources of uncertainty in nonlinear dynamics”

    We briefly discuss possible ways to detect, exploit or mitigate these effects.

    [Sounds interesting, but without the full paper it is hard to tell.]

    5. Spiegelhalter and Riesch (article is behind paywall)

    Authors appear to be statisticians. From abstract:

    Numerous types of uncertainty arise when using formal models in the analysis of risks. Uncertainty is best seen as a relation, allowing a clear separation of the object, source and ‘owner’ of the uncertainty, and we argue that all expressions of uncertainty are constructed from judgements based on possibly inadequate assumptions, and are therefore contingent.

    We conclude that the contingent nature of risk-modelling needs to be explicitly acknowledged in advice given to policy-makers, and that unconditional expressions of uncertainty remain an aspiration.

    [Amen!]

    6. Slingo and Palmer

    it can also be shown that the number and spatial patterns of regimes remain the same, but their frequency of occurrence is changed…On the other hand, it is possible that for larger forcings, the number and pattern of regimes can change. An important question is whether anthropogenic climate change due to increasing greenhouse gases constitutes a strong enough forcing to lead to a population of new regimes.

    The authors state that all forecasts are probabilistic by definition, that very small differences in initial conditions can result in dramatically different solutions and that near-term predictions have a higher level of probability than longer-term ones.

    Uncertainty in climate-change projections presents some different challenges from uncertainty in weather forecasting or seasonal prediction. The influence of the ocean initial conditions is small beyond a decade or so, and ignoring the uncertainties in the emission scenarios, the major source of uncertainty then comes from the formulation of the models, related particularly to the sensitivity of the climate system to greenhouse gas forcing.

    The authors point out the limitations of computer model projections and conclude that many of these problems may turn out ”to be unsolvable”.

    Nevertheless, however much models improve, there will always be an irreducible level of uncertainty—‘flap of the seagull’s wings’—because of the chaotic nature of the system. Even the climate we have observed over the past century or so is only one realization of what the real system might produce.

    Using a simulated data series on 2000 years of El Niño behavior, the authors show ”the fundamentally chaotic nature of the system that we are attempting to predict”.

    The authors’ last three words are:

    Nothing is certain.

    [This is a very interesting paper, that gets to the heart of the discussion of uncertainty in model-based climate predictions.]

    7. Webster and Jiam

    The authors discuss severe weather events and adaptation strategies for the developing world.

    Better short-term forecasting of floods is cited as one solution, which can help despite the ”uncertainty associated with predicting extreme weather events”

    The authors cite one example where ”anticipation of extreme events through probabilistic weather and climate forecasts could enable a user group to minimize their adverse impacts.”

    Availability of clean drinking water for a growing population is seen as a most important problem:

    However, irrespective of the climate-change scenario chosen, the availability of fresh water in the latter half of the twenty-first century seems to be dominated by population increases that far outweigh climate-change effects. Paradoxically, fresh water availability may become more critical if there is no climate change.

    The authors discuss ”model error” and “uncertainty in initial conditions” as key problems today with short-term forecasting of extreme weather events.

    They do not comment on the validity of IPCC estimates based on expert judgment that some extreme weather events will increase with human-induced greenhouse warming.

    ”Risk” is defined as the ”probability of an event” multiplied by its “cost”

    Several example are given to show that preemptive adaptation, i.e. ”minimizing the cost” of an event is more effective than attempted mitigation, i.e. ”altering the probability” of the event.

    The paper goes into great detail on the use of models in flood prediction and control and concludes:

    The incorporation of quantitative risk assessment into the daily lives of diverse user groups can have the effect of minimizing property and income loss. It also provides a good adaptation strategy for future challenges associated with climate change and increasing population.

    [This paper gives a very interesting summary on risk management with regard to local and regional weather events, but does not have much to say about longer-term climate forecasts (or Trenberth’s suggested “null hypothesis” on how extreme weather is directly tied to human-induced greenhouse warming).]

    8. Aikman et al. (article is behind paywall)

    Authors appear to be bankers. From abstract:

    The paper has to do with uncertainty in economic policies as related to the recent bank crisis. The authors call for a “financial system that is resilient in the face of the unpredictable and extreme”.

    The authors ”show how the Bank of England tries to deal with some of these challenges in its communications about monetary policy”.

    [Interesting, but off-topic here.]

    9. Smith and Stern (article is behind paywall)

    The paper is on ”Uncertainty in science and its role in climate policy”. Authors appear to be economic advisors. From abstract:

    Risk assessment requires grappling with probability and ambiguity (uncertainty in the Knightian sense) and assessing the ethical, logical, philosophical and economic underpinnings of whether a target of ‘50 per cent chance of remaining under +2°C’ is either ‘right’ or ‘safe’. How do we better stimulate advances in the difficult analytical and philosophical questions while maintaining foundational scientific work advancing our understanding of the phenomena? And provide immediate help with decisions that must be made now?

    [Good questions. Too bad the article is behind a paywall.]

    10. Krebs (article is behind paywall)

    Paper discusses ”risk, uncertainty and regulation”

    Scientific evidence may be ambiguous. Scientific experts are called upon to assess risks, but there is often uncertainty in their assessment, or disagreement about the magnitude of the risk. The translation of risk assessments into policy is a political judgement that includes consideration of the acceptability of the risk and the costs and benefits of legislation to reduce the risk. These general points are illustrated with reference to three examples: regulation of risk from pesticides, control of bovine tuberculosis and pricing of alcohol as a means to discourage excessive drinking.

    [Very interesting, but the article is behind paywall and the examples used are not directly related to our topic.]

    11. Wells et al. Department of Health perspective on handling uncertainties in health sciences (article is behind paywall)
    The authors discuss the “use of science to reduce unknowns and to support decision-making”.

    [Not much in the abstract alone, but sounds interesting.]

    12. Penrose Uncertainty in quantum mechanics: faith or fantasy? (article is behind paywall)

    The theory itself appears to be questioned here:

    There are, indeed, seeming internal contradictions in the theory that lead us to infer that a total faith in it at all levels of scale leads us to almost fantastical implications.

    [Too bad the article itself is inaccessible – sounds like it could be very interesting, although not related to our topic.]

    13. Campbell Understanding the receivers and the reception of science’s uncertain messages. (article is behind paywall)

    This article, by an editor of Nature is more about how to communicate a message based on uncertain science to make sure your audience understands it. Climate science is one of the three examples cited.

    The most important conclusions are that scientists communicating with the public need to develop their methods deliberatively, involving their target audiences; and that they need to avoid undue dependence on traditional media and public authorities for such communication, and to develop multiple channels to those audiences, including Internet-based and more traditional social networks. Their approach to communicating uncertainty should depend on the context but, except in some extreme emergencies, transparency is generally a virtue. Above all, they need to persist in such public engagements even when the going is rough and extends over long periods. They need support in doing so.

    [It’s all about communications and the approach sounds very good: less emphasis on traditional media and public authorities, more on Internet, increased transparency, get involved with public. Too bad the paper is behind a paywall.]

    14. Peters

    The author is a mathematician involved with climate science. The subject involves the Saint Petersburg paradox, a statistical problem involving a theoretical “heads or tails” lottery game.

    [The article gets pretty hairy, except for someone heavily involved with statistics, but does not have a direct bearing on our topic here.]

    What I find to be missing in all of these papers is a clear sentence – particularly to climate scientists today:

    Until it is supported by empirical scientific data from physical observations or reproducible experimentation, with a clear understanding of any uncertainties that may still exist, it is not a real risk requiring any policy decisions.

    This statement definitely flies in the face of “post-normal” science, which I was happy to see was not mentioned in the papers (unless I missed it).

    Max

    • Hopefully some of these papers will emerge from behind paywall, will revisit in a few months to see if any become available. Based upon the talks, i am most interested in Spiegelhalter (I have a copy of this paper), Stewart, Smith and Stern

    • The Smith & Stern paper is available here.

      Until it is supported by empirical scientific data from physical observations or reproducible experimentation, with a clear understanding of any uncertainties that may still exist, it is not a real risk requiring any policy decisions.

      Ignoring for a moment that such evidence does exist, let’s explore this with a hypothetical situation:

      Say you work in the executive branch of government and you receive a tip-off that there are several bombs planted on different, unspecified planes around the country, which are set to go off at some time over the next week. Would you consider this a real risk requiring a decision?

      Now let’s say you make an initial decision to use the little time available to investigate the probability that it is a real threat. Expressed as a percentage, how much ‘certainty’ would you require to decide that some action needs to be taken?

      Going further (this part isn’t relevant to what you said, but may have some importance for wider issues), let’s say certainty is near 100% but it’s worked out that the short-term overall economic costs of taking action will outweigh the costs of allowing things to run their course to the worst possible outcome. What’s the decision?

    • Thanks for spotting this.

  34. My I ask why the proposed resources spent of stopping the increase in atmospheric CO2 are not spent on protecting us from Extinction Level Events?
    We know that the cause of episodic mass extinctions and more local extinction events is due to meteorite impacts.
    Asteroids with a 1 km diameter strike the Earth every 500,000 years and larger 5 km objects happen once every ten million years.
    Why are we not spending trillions in setting up an early detection system and manufacturing space craft to intercept these objects before they make Earthfall?
    Seriously, why is it better to spend capital on halting CO2 emissions and not on a defensive space program?

    • Asteroid Protection

      Near Earth Asteroids

      Capital is being spent. Whether it’s enough depends on how much additional protection could be bought for additional expenditures. If it’s a great deal, I would support additional expenditures. However, probabilistic calculations have led NASA and other agencies to the conclusion that the combination or risk probability and impact magnitude is greater for anthropogenic climate change than for an asteroid collision, and so spending more on the latter shouldn’t be undertaken by sacrificing the former as opposed to finding additional resources to do both..

    • Its a ‘fat tail’ Fred, there is a big difference between changing the environment for a small fraction of humanity, making marginal land more marginal in some places and making marginal land less marginal in other places, and killing all species larger than a mouse.

  35. Judith

    Agree that Stewart, Spiegelhalter, Smith/Stern would be most interesting, based on the abstracts. Hope you can get links.

    Max

  36. “I shouldn’t bother, Judith”

    You know the answer then, RobB?

    What is Webster’s strong evidence to support the claim that population-driven water scarcity (which I do hope no one is denying, since it’s real and it’s here) will trump effects of climate change in relation to water scarcity in the latter part of this century, according to the most current climate modeling, analyses of observed/projected changes in climate as this relates to water, and (for consistency with claims on this website) non-mitigation scenarios?

    According to PNAS and the IPCC, among other sources of the most current science analysis, the effects of climate change on water scarcity are set to be significant, especially under non-mitigation scenarios. How significant? Hard to say. When combined with population issues in e.g. South Asia, and the poverty and equity issues in most parts of the developing world, as well as the consumption and efficiency issues in America and Europe and other areas, the analysis offered by science, and fields like development and health and agriculture, are evolving and complex. You can see why it is a bit of a myster, and naturally, I can’t wait to be directed by you to various sources of analysis supporting Webster’s claim that it is population increase that will trump climate change, poverty and equity issues, in relation to water scarcity in the latter part of this century.

  37. Norm Kalmanovitch

    Proc. Roy. Soc. Special Issue on ‘Handling Uncertainty in Science’
    One way to handle uncertainty in science is to change what scientists write in reports to state what those who promote AGW wanted them to say, replacing a statement of uncretainty with one that makes the opposite case in more certain terms:

    The Intergovernmental Panel on Climate Change (IPCC)
    Second Assessment Report, Working Group I, Chapter Eight

    NOTE: The original Working Group I report was approved by the IPCC in December, 1995. Subsequent to that approval, IPCC has apparently allowed additional edits to the document. Some changes are editorial, serving to add clarification or to correct sentence structure. However, other changes appear to go beyond that and have the effect of changing the substance and tone of this chapter.

    Section 8.4.2.1

    deleted: “None of the studies cited above has shown clear evidence that we can attribute the observed changes to the specific cause of increases in greenhouse gases.”

    new: “Implicit in these global mean results is a weak attribution statement–if the observed global mean changes over the last 20 to 50 years cannot be fully explained by natural climate variability, some (unknown) fraction of the changes must be due to human influences”.

    We are now certain that humans cause global warming because we are uncertain that anything else does!

  38. martha, do the math. if population is doubling, and water resources are expected to change by at most 20% (one way or the other), then population increase trumps changes in water resources. The conclusion was made for the river basins in Asia that were analyzed JC

    You are misusing statistical analysis, again; and not understanding why poverty, equity, urbanization and consumption/efficiency issues, when combined with climate change, is probably at least as significant an impact as population — even in the best climate scenario and even in that specific region.

    I find it impossible to speak with you, Judith — as do many other people. The only people you seem able to relate to, are your denizens. Perhaps that is a red flag, but understandable in terms of the intensity and constancy of your time on your blog.

    take care

    • Ciao, Martha.

    • Martha

      You are funny in that you logic is only reasonable in your own universe.

    • Martha, you just helped make Webster’s case. Human factors like poverty, urbanization, consumption issues (along with population) will swamp any impact on water resources associated with climate change.

    • I can see why you might say that. To be clear, Webster cited population — not these other factors. Regardless, I am not arguing that human factors will ‘swamp any impact on water resources associated with climate change’.

      I said: ‘understanding why poverty, equity, urbanization and consumption/efficiency issues, when combined with climate change…
      I am talking about multi-dimensional effects of climate change when I speak of such factors COMBINED with climate change.

      The arguments are not the same, even if they sounds alike to you.

      I am saying that the multi-dimensional, and indirect, effects of climate change make the claim about population increase trumping effects of climate change tenuous. For example, floodwater effects of climate change will create much more water-borne illness; and other effects of climate change will reduce the overal quality of water and food, resulting in death, disability and suffering (especially in relation to maternal and infant death).

      These and other climate-related health and food security problems are a serious barrier to adaptation, with or without flood warnings – as helpful as those may be.

      Many people could not (and did not) move and then return to their small farms, following the flooding. Re-settlement is much more complicated, and dangerous, when you’re poor and do not have the health and food resources to cope with personal crisis. (While I deeply appreciate that you and Peter advocate for funding for adaptation and that you put money on the table for forecasting assistance, many people do what they can to help others, including financially.)

      It makes no sense to me, and to many other people, to view multidimensional effects of climate change (i.e., climate-related exacerbations of poverty and coping issues) as secondary to population or other existing human factors, in relation to impacts on water resources.

      Maybe it’s easier to understand, now, what I wanted to discuss, and why.

      These are two fundamentaly different arguments or approaches to understanding effects, and they have different policy implications, Judith.

    • Martha, for Pete’s sake, just write your own paper.

    • byee….
      :-)

  39. I know this is O/T (and definitely not technical), but it is related from a layperson’s perspective. Two years ago (when I took my first tentative steps into the climate war-zone), there were a lot of concepts – and organizations – I’d never heard of (not the least of which was the IPCC … I was such a novice, I don’t think I’d even heard of the hockey-stick!).

    Uncertainty?! My impression – at that time – was that this particular concept was somewhat akin to one of those words which is never, ever mentioned in polite society!

    I haven’t conducted any survey (scientific or otherwise), but it seems to me that even a year ago, “uncertainty” was – at best – a very distant blip on the climate conversation radar, obscured by the latest press release on the latest scary story (and/or inevitably pushed aside by the C02->(C)AGW imperatives).

    And I could be mistaken (or even perhaps overly optimistic!), but it seems to me that the (gestation and) birth of Judith’s “Uncertainty Monster” (with perhaps a little help from the IAC) has broken through a number of “flood-gates” – and uncertainty is bustin’ out all over!

    It’s popping up with increasing frequency in some (you should pardon the expression!) very unlikely places! Not the least of which (assuming it survives until the puff of green smoke on Friday) is the “leaked” draft of the SPM of the IPCC’s Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation [SREX].

    And this – as the real Martha would say – is a good thing! At least, that’s the view from here ;-)

    • hro001

      I like your account of the birth of the ubiquitous “U-word”.

      The sequel is the use of the word in the sense of “it could be even worse than we thought” – i.e. we need to ACT with even greater sense of urgency (the second “U-word”) in view of the many uncertainties

      Trouble is, that one appears to be having a harder time getting off the ground.

      The transition (fairy-tale style)

      1. “Help! There’s a wolf out there!”
      morphed to:
      2. “Help! I’m not sure, but there may be a wolf out there!”
      escalated to:
      3. “Help! I’m not sure, but there may be two wolves out there!”

      Max

  40. Judith

    This Martha finds it impossible to talk with you, yet pollutes even technical threads with rants which relate to the issues only tenuously if at all.
    Look just at the last third of this thread – it became all about whether Webster is an exploiting monster or whether there will be more poverty here and less there. Then it swamps everything and the thread peters out what is a pity especially for this thread which I found rather interesting … in the first 2/3.

    Couldn’t you create a special thread “Talk with Martha” and put all her rants in it?
    So people who would be interested to participate with her in similar mud fights could go there and enjoy it.
    Anyway sofar I could judge from the few posts I had the patience to read, her discourse always only rotates in sterile circles, repeats the same axioms and generally contributes nothing cogent to the threads.
    Personnally I would find it a very significant improvement for the more technical threads.

    • Judith – this is a great idea – give Martha her own thread! I’m sure WordPress will enable you to automatically move her posts to it. and leave a placer on the thread she posted it to, so she can’t whinge about being censored, and so we know where to go if we get really, really sick of dealing with grownups, and fancy ducking out for a few minutes of light relief. In the unlikely event that she drops the petulant teenager act, she can always be invited back into the salon.

  41. Aw, c’mon, folks – we’d all miss out on a lot of fun if M. were ostracized.
    As long as she minds her manners (like everyone else) she should be able to join the lively discussion IMO.

    Her participation just confirms that there are all kinds of widely divergent views in this scientific and political debate (and that the “science” is definitely NOT “settled”).

    Max

  42. I think that the papers are too abstract. What would be more informative would be a detailed and referenced list of the limitations, inaccuracies, and other cavities in current climate science that make it difficult to predict what exactly a doubling of CO2 will cause.

    Will it cause increased or decreased cloudiness on average? That is not known.

    Why exactly do the GCMs produce different predictions? That is known only vaguely.

    How inaccurate have the GSMs been to date?

    How will increased CO2 affect the hydrolic cycle?

    How is it known that climate sensitivity is constant? It isn’t known.

    How accurate (or inaccurate, it’s the same thing) are the equilbrium approximations to a system that is never in equilibrium?

    etc.

    The claim that the weather system is chaotic is not important: just because it is chaotic does not imply that statistical aggregates can not be predicted; what implies that statistical aggregates can not be predicted is the lack of a history of consistent predictions.

  43. Apparently the full text has been posted as of December 8, 2011. I was able to download full text (PDFs) for each of the 14 articles listed. However, it took chasing about 3 links to reach “full-text” PDFs for each paper.
    Cheers!

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