the Air Vent

Because the world needs another opinion

Mike Hulme – Consensus Science

Posted by Jeff Id on February 25, 2010

This is a paper written apparently by Mike Hulme, UEA climatologist on the consensus arguments of the IPCC.  I’ve copied it here in its entirety and have several things I’d like to say but no time right now.

H/t Reader RB – Keep it civil please.

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The IPCC, Consensus and Science

In all of the claims and counterclaims made in recent weeks about climate change, climate scientists and the IPCC, one aspect of the debate which rarely gets examined in any detail is what is meant by the idea of ‘consensus’ in science. Advocates say that there is a strong scientific consensus about the reality of anthropogenic global warming. Detractors will say that scientific knowledge is not produced by consensus. Mike Hulme examines the different meanings that people attach to the idea of consensus in science, and how it is used by the IPCC.

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One of the more frequent criticisms made of the IPCC is that it works to create a scientific consensus about climate change. Critics claim that science doesn’t work by consensus, but rather by testing and refuting hypothesis on the basis of evidence. Just because 95 per cent of scientists agree about something doesn’t make it true.
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On the other hand there are those who point to the IPCC consensus about climate change as being its central characteristic which gives validity and relevance to its conclusions. ‘The consensus of the world’s leading scientists is that it is very likely that most of the recent warming is due to greenhouse gas emissions’. This is just the sort of clear and considered judgement that politicians like to hear – and it was they after all who set up the IPCC in 1988 to deliver just this form of knowledge.

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It seems that not only do we disagree about climate change, but we disagree about whether or not we should even be reaching a consensus about it.
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The term consensus typically refers to a commonly agreed position, conclusion, or set of values. It is most commonly used with reference either to group dynamics or to broad agreement in public opinion. For example, over 20 years ago Denmark introduced the idea of Consensus Conferences into the national politics in that country as a way to strengthen democracy. But why should a process for reaching a common position in politics be adopted as a way of generating scientific knowledge? After all, politics is about opinions or beliefs; science surely is about facts and evidence.
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The problem is that in areas of science which are seeking to understand the behaviour of large complex systems which can’t be replicated in the lab, it is very hard if not impossible to apply the scientific litmus test of falsification through experimentation. And climate change is one such area of science. We have scientific theory, we have empirical observations. What we haven’t got are lots of different Earths that can be experimented on in controlled conditions. Virtual climates created inside computer models are the best we’ve got.

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All of this means that climate scientists frequently have to reach their conclusions on the basis of the partial, and sometimes poorly tested, evidence and models available to them. And when their paymasters – elected (or non-elected) politicians – ask them for advice, as in the case of the IPCC, opinion and belief become essential for interpreting facts and evidence. Or rather, incomplete evidence and models have to be worked on using opinions and beliefs to reach considered judgements about what may be true. This approach is a well recognised for evaluating some forms of scientific evidence, and quite sophisticated procedures have been established to make it work. Bayesian statistics and expert elicitation are two such methods, and they both lend themselves to consensus-making.
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But these ‘consensus methods’ don’t suit everyone. For some scientists, statements that commence with ‘We believe …’ sound much too close to religious creeds or political manifestos to be accredited as reflecting scientific knowledge. I have heard scientists of many stripes – both those accepting the scientific orthodoxy about climate change and those disputing it – say “it’s not about belief, it’s about evidence”.
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Reaching consensus about climate change, recognising that these statements emerge from processes of deliberation and discussion rather than from pure observation, experimentation and falsification, can therefore be an uncomfortable thing for scientists and public alike. Scientists need to be prepared to argue about their ‘considered opinions’, to embrace consensus but without closing down argument or suggesting that matters are settled. And the public need to recognise that sometimes consensus is the best that science has to offer about a topic, especially when decisions need to be made by politicians – even if the decision is to do nothing.
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Yet there are two final observations to make about how the IPCC does consensus. First, consensus-making in science can be done to reveal the extent of expert disagreement rather than to erase it. For example, expert elicitations – which the IPCC have not used – would reveal where the ‘centre of opinion’ lay in expert beliefs, whilst also showing explicitly how wide the spread of opinion was. After all, consensus processes only make sense – whether in politics or in science – if there is disagreement. If all scientists agreed about every aspect of climate change there would be no need for a consensus process.
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The second thing is to note that the rules of IPCC procedure do not demand that a consensus be reached about all aspects of their assessments. If consensus is judged not possible in any area of the reporting process, then ‘differing views shall be explained, and upon request, recorded’. This provision applies as much for the final Summary for Policymakers – where this option has never in fact been enacted – as it is for the detailed technical chapters, where differences in the assessed literature have more frequently been retained.
Understanding the nature of consensus-making in science, the circumstances when it is appropriate to embark on and that it is process that is never closed, would improve the quality of the conversation about climate change between scientists, politicians and public.
Mike


63 Responses to “Mike Hulme – Consensus Science”

  1. timetochooseagain said

    “First, consensus-making in science can be done to reveal the extent of expert disagreement rather than to erase it.”

    Can, yes, but it isn’t. It is used solely in this case to erase disagreement.

  2. RB said

    From his post on Revkin’s Dot Earth blog ..

  3. JAE said

    The big problem, especially in the case of climate science, is conflict of interest (as usual, one needs only to follow the money). If you have a few thousand scientists and environmentalists, whose very financial support depends upon public moneys and the possibility of some type of “horrible problem,” then you can bet your ass that a “consensus” will be quickly formed that the problem exists and is indeed horrible. Research results that indicate there is not a problem have to be suppressed, or all the funding dries up and all the “experts” have to find a new issue or go on welfare. What to do??

  4. Dr. Robert said

    The only consensus about climate science is that we don’t know what the hell is going on. We don’t know how unique our warming is, we don’t know if we’re really any warmer than earlier this century, and we don’t know if human produced greenhouse gases are contributing to it.

    To put forth the idea of a scientific consensus is an outright lie. It’s a misrepresentation of the facts and all you are trying to do is make it seem that the dissenters are flat-earthers/morons/etc.

    ClimateGate revealed this. Briffa doesn’t agree that the our current temperatures are warmer than the MWP. Apparently neither does Phil Jones. Gavin Schmidt would mumble something about decadal variability or whatever he would make up for the day to cover his ass.

    We’ve seen facts that the IPCC report “consensus” was no more than 70 people. 70! We saw that the bulk of the comments by reviewers did not support the chapter. And yet it’s the consensus?

    What on earth?

  5. Phillip Bratby said

    If you stuff the IPCC with alarmists, you are bound to get the consensus the politicians want.

  6. leftymartin said

    Hulme states “in areas of science which are seeking to understand the behaviour of large complex systems which can’t be replicated in the lab, it is very hard if not impossible to apply the scientific litmus test of falsification through experimentation. And climate change is one such area of science. We have scientific theory, we have empirical observations. What we haven’t got are lots of different Earths that can be experimented on in controlled conditions. Virtual climates created inside computer models are the best we’ve got”.

    Hulme thus appears to be suggesting that climate change science should get a “free pass” from the principles of falsification, and thus we should not be so hard on the GCM jockeys (or, as I prefer to call them, climate astrologers).

    Codswallop, Dr. Hulme.

    Let’s quickly run through a list of just what has been falsified thus far:

    1. Hansen’s 1988 GCM predictions (a 20 year test of these has been kindly provided by Mother Nature) – falsified.
    2. CO2 as a primary lever of climate change – nope, we have millions of years of records, and most notably ice core data, showing that CO2 lags temperature and is at best a feedback mechanism that has spectacularly failed to produce runaway warming – thus, falsified.
    3. High climate sensitivity to increasing CO2 – given that all models have overpredicted temperature, high climate sensitivity is falsified – it is not yet even clear that feedback is net positive for cryin’ out loud.
    4. Late 20th century temperatures unpredented in a millenia or so – falsified (sorry warmists, the hockey stick is dead, dead, dead and ain’t comin’ back to life)
    5. Rate of temperature rise in late 20th century as an indicator of dominant anthropogenic influence – falsified, just look for example at CET records

    And on it goes.

  7. Bruce said

    The first thing that stands out is the fact that a consensus is necessary because the system is so large and complex that the behavior “can’t be replicated in the lab, it is very hard if not impossible to apply the scientific litmus test of falsification through experimentation.” Yet based on the weakness of scientific evidence, ‘The consensus of the world’s leading scientists is that it is very likely that most of the recent warming is due to greenhouse gas emissions’. I believe that the term used “very likely” is either 90% or 95% probability. I really have a problem with the high confidence level based on consensus, not science.

    THe second thing important in his essay is another admission that the science is not settled. That’s the third time in the last couple of weeks; first Phil Jones, then Judith Curry, now Mike Hulme.

    The third thing is the mention a couple times the importance of other scientists being able to apply the tests of replication or falsification. Since he is from CRU, I wonder how he feels about them not releasing the methods that they use to select the temperature stations and the code that they use to adjust the temperatures.

  8. “Detractors will say that scientific knowledge is not produced by consensus.” Probably true. But that’s not the point.
    As some scientists rush about crying “The sky is falling, the sky is falling” ordinary voters and taxpayers wonder if it’s really true. Are they hearing a few crackpots or is there something really in it? So they ask how many scientist belong the the sky is falling viewpoint and how many do not. In short, when layman ask for a consensus view, they are trying to sort out the crackpots from serious scientists. Layman are not producing scientific knowledge, they are trying to evaluate the truth of a scientific theory. A theory supported by all scientists is more likely to be true than one which is in dispute.

  9. In other words, climate science is hugely dependent on “belief and opinion,” but claims scientific “certainty” to the point of labelling those who have different beliefs and opinions “deniers” (really, heretics). In short, we’re dealing with religion here, not science. And we’re supposed to take alarmist climate scientists seriously.

  10. Dr. Robert said

    When we discuss pseudo-science, it’s fun to look at pseud-medicine, such as homeopathy or chiropractics. Consider you are at a meeting full of chiropractics. The consensus for sure will be that this is an efficacious form of medicine. But there is no data to support that.

    We find ourselves in the same situation with climate science. You have a bunch of believers supporting pseudo-science all saying it’s true. But the data doesn’t support it!

  11. PeterB in Indianapolis said

    I can form a scientific consensus very easily.

    I am a UN organization that believes that the moon is made of green cheese. The fact that the moon is made of green cheese is exceptionally dangerous, because giant space-rats may well consume the moon in its entirety, and this would cause massive tidal disruptions on earth, which could well submerge all of the earth’s coastal cities under giant tsunami.

    My UN organization has proposed the following terms for researching this horrible and imminent problem:

    1: Scientists are encouraged to submit grant proposals for the study of the potential short and long-term impacts of the significant loss of moon-matter (green cheese) on the coastal cities of earth.

    2: Only studies accepting the facts that (A) the moon is indeed made of green cheese, (B) giant space-rats might eat the moon in its entirety and may well be beginning or even well-advanced in this process currently, and (C) this will have a profound effect on the coastal cities of earth, will be funded.

    3: All other study proposals that do not meet the criteria laid out in #2 will have their grant proposals summarily rejected.

    Voila! Scientific consensus!

  12. Sean Peake said

    Sorry Dr. but I don’t buy the argument. Besides, consensus it not the issue. Never has been. Not being able to replicate the claims is the issue. Deliberate manipulation of data is the issue. Falsification and misrepresentation by the IPCC is the issue. And stifling verification and contrary views is the issue. On these points there is consensus and it is growing every day.

  13. Mike Riordan said

    Mike Hulme says “The problem is that in areas of science which are seeking to understand the behaviour of large complex systems which can’t be replicated in the lab, it is very hard if not impossible to apply the scientific litmus test of falsification through experimentation. And climate change is one such area of science. We have scientific theory, we have empirical observations. What we haven’t got are lots of different Earths that can be experimented on in controlled conditions.”

    This is the problem isn’t it? There is no way round the falsification requirement for any field of study that purports to be scientific. If a theory cannot be falsified, then it isn’t a scientific theory in the first place. Unfalsifiable theories are little more than gossip. They may be interesting or even useful – but cannot be true – or false for that matter. The only way round the problem is to make a series of adequately accurate predictions over a climatically significant period of time, something current climatology hasn’t done and probably can’t do. The fact that climatology is technically very difficult doesn’t give some kind of exemption from the absolute requirement that scientific theories must be falsifiable. It just means that climatology is work in progress.

  14. i don’t see anything specifically wrong about the IPCC having a mandate to report on the consensus views on the science. Where the process seems to have gone awry is where the IPCC becomes the authority which becomes quoted (e.g. by wikipedia) and is regarded as more significant than the primary evidence.
    Something has also gone wrong when some points which are presented as showing a consensus agreement are strongly contested by experts in the field (e.g. Pielke jr ‘we assumed he changed his mind’).
    In the past, the IPCC has been held up as a gold standard in analyzing and distilling a wide range of evidence. Does this show how easily people are drawn to a false consensus if it is offered, or how easy it is to manipulate the outcome of this sort of analysis?

  15. Jerzy Hart said

    “All of this means that climate scientists frequently have to reach their conclusions on the basis of the partial, and sometimes poorly tested, evidence and models available to them.”

    Is Hulme just not familiar with the scientific literature? In fact, the GCMs that the IPCC extolls do make predictions that can be and have been used to test (to validate or invalidate) the models. E.g.:

    Koutsoyiannis, D. et al. On the credibility of climate predictions. Hydrological Sciences Journal, 53(4) August 2008:

    “Abstract Geographically distributed predictions of future climate, obtained through climate models, are widely used in hydrology and many other disciplines, typically without assessing their reliability. Here we compare the output of various models to temperature and precipitation observations from eight stations with long (over 100 years) records from around the globe. The results show that models perform poorly, even at a climatic (30-year) scale. Thus local model projections cannot be credible, whereas a common argument that models can perform better at larger spatial scales is unsupported.”
    (http://www.itia.ntua.gr/getfile/864/1/documents/2008HSJClimPredictions.pdf)

    In their follow-up study of additional stations, the authors conclude:

    “The performance of the models at local scale at 55 stations worldwide (in addition to the 8 stations used in Koutsoyiannis et al., 2008) is poor regarding all statistical indicators at the seasonal, annual and climatic time scales. In most cases the observed variability metrics (standard deviation and Hurst coefficient) are underestimated.

    The performance of the models (both the TAR and AR4 ones) at a large spatial scale, i.e. the contiguous USA, is even worse.

    None of the examined models reproduces the over-year fluctuations of the areal temperature of USA (gradual increase before 1940, falling trend until the early 1970’s, slight upward trend thereafter); most overestimate the annual mean (by up to 4°C) and predict a rise more intense than reality during the later 20th century.

    On the climatic scale, the model whose results for temperature are closest to reality (PCM-20C3M) has an efficiency of 0.05, virtually equivalent to an elementary prediction based on the historical mean; its predictive capacity against other indicators (e.g. maximum and minimum monthly temperature) is worse.

    The predictive capacity of GCMs against the areal precipitation is even poorer (overestimation by about 100 to 300 mm). All efficiency values at all time scales are strongly negative, while correlations vary from negative to slightly positive.

    Contrary to the common practice of climate modellers and IPCC, here comparisons are made in terms of actual values and not departures from means (“anomalies”). The enormous differences from reality (up to 6°C in minimum temperature and 300 mm in annual precipitation) would have been concealed if departures from mean had been taken.”
    (http://www.itia.ntua.gr/getfile/900/2/documents/2009EGU_ClimatePr.pdf)

    There is no reason for Hulme to engage in the deception that we are hopelessly relegated to groping in the dark about the validity of the models. The models–at least a fair representation of them–have been tested, and they fail.

  16. JAE said

    LOL. Whatever is said about consensus, it sure can change quickly. Only 3-4 months ago IPCC was the last word for much of the world. Now the consensus is that it is an utter joke.

  17. Tim said

    Science by consensus is a very dangerous thing if it is used as an excuse to suppress dissenting views.

    That is what has been happening in climate science which renders all of Mike Hume’s point moot.

  18. Sonicfrog said

    Just because 95 per cent of scientists agree about something doesn’t make it true.

    Why does this remind me of a bad toothpaste commercial from the 70’s “4 out of 5 dentists agree…”.

    With ridiculous broad statements like these, how can anyone take this seriously.

  19. TerryS said

    1. Climate has changed over the industrial period
    2. The amount of CO2 in the atmosphere is increasing
    3. Everything being equal, increasing CO2 in the atmosphere will lead to higher temperatures
    4. In general glaciers have retreated over the past 3 to 4 decades.
    5. Satellite measurements show a decreasing trend in arctic ice extent
    6. Increasing temperatures will result in increased hardship for some people in some parts of the world
    7. Increasing temperature results in a positive feedback, due to water vapour, that greatly amplifies the temperature increase.

    I agree with 6 out of 7 of the above statements even though the statements aren’t complete. For example, item one should also say that climate changed over the pre-industrial era. Since I agree with six of them does this make me part of the consensus?

  20. Jeff this is from feb 7 have you seen this?
    http://www.jgc.org/blog/2010/02/something-odd-in-crutem3-station-errors.html

  21. In my early twenties I spent a few years associating with a handful of peace movement and women’s groups. It became obvious to me then that the idea of consensus was merely a tool the bullies used to shut down other people’s views. “You don’t want to block consensus, do you?” you’d be asked during a discussion in which you might be the only dissenting voice. If your spine was wobbly you’d abandon your objections, the discussion would be over, and the bully’s point-of-view would prevail.

    When I first began researching the climate change debate I found it shocking that the mass media kept insisting there was a “scientific consensus” even though there’s a very long list of highly-qualified scientists who disagree with many aspects of this so-called consensus.

    That willingness – on the part of both the scientific community and the media – to pretend that such scientists didn’t even exist was a huge red flag.

    If your evidence is solid there’s no need to “disappear” certain scientific perspectives, thereby misinforming the public in the process.

    At first I thought it was rude and disrespectful. Now I consider it insidious and dangerous.

  22. harry said

    The main problem is that the ICPP consensus is based upon a minor line in the report. Crucial to all ICPP predictions, forecasts, is the fact upon which all ICPP drama is founded: CO2 alone is reponsible for the current (or last 20 years) (or the last 50 years) (or the last 100 years) (or whatever period) of global warming. Digging through AR4, nothing can be found which relates CO2 to longtime GHG effects: it is assumed to be longlasting (Ch 2, 4, 8 and 10). Only in Chapter 10 we get a glimpse of how this is based on calculations. In Table 2.14, note a, it is revealed.
    The decay of a pulse of CO2 with time t is given by
    a0+sigma(i=1to i=3)ai*exp(-t/taui)
    Parameters are given:a0=0.217, a1=.259, a2=.338, a3= .186, tau1=172.9 years, tau2=18.51 years, tau3= 1.186 years.
    Reference is given to chapter 10 of this report (Bern 2.5CC; Joos et al 2001) using a background concentration of 378 ppm. The most striking thing of this formula is the fact that it has a constant of .217 of any given addition of CO2 to the atmosphere which will remain there forever: 21.7% of the initial carbondioxide released will last forever in the atmosphere.

    In Joos 2001, however, this formula cannot be retrieved. Something similar is there: Joos et al 2001, Glob Biochem. Cyc. 15:891-907.

  23. RB said

    Harry: 20% of emitted CO2 indeed remains inthe atmosphere for many millennia – see AR4 FAQ answer to Question 10.3

    Donna: you are making a similar appeal to authority. You have no idea how many of those scientists are making well-founded objections. I’m familiar with at least one scientist on the List of 700 with a formidable prior record who was not aware of existing literature that answered some of his objections.

  24. RB, I’m not saying those other scientists are correct. All I’m saying is that their existence should not be denied. Nor should the public be prevented from hearing their point-of-view.

  25. JAE said

    “I’m familiar with at least one scientist on the List of 700 with a formidable prior record who was not aware of existing literature that answered some of his objections.”

    ??? That would be 0.014 % of the 700. What are you trying to say? It seems to me that Donna’s point is “consensus” doesn’t necessarily mean a damn thing and you should not automatically accept it.

  26. harry said

    @RB

    This nonsense, it would require the existence of a completely new and isolated atmospheric compartment. Your reply is B*S*.

  27. harry said

    @RB:

    All FAQ are based on the formula in table 2.14. No wonder they match with the answers. Start thinking. Who do you think you are fooling?

  28. RB said

    Harry,
    Please take your objections to the legitimate scientists:
    http://geosci.uchicago.edu/~archer/reprints/archer.2005.fate_co2.pdf

  29. harry said

    @RB,

    The entire ICPP report uses this formula, as can be seen from the graphs in chapter 10. The entire report is B*S*. The reported CO2 halflife times do not fit with the observerved halflife times of atomic bomb 14C values. You cannot imagine anything more accurate and sensitive than the measurement of radioactive nuclides.

  30. RB said

    Harry,
    It’s IPCC. And if you want to close your ears and say that you don’t want to hear what current literature has to say about it, suit yourself. I’ve given you a reference, you can look up David Archer and let him know how wrong he is.

  31. harry said

    @RB
    This paper is only a representation of a model.

    I can make any model, resulting in any outcome, whatsoever. My personal evaluation of model studies is that they are not worth the paper they are printed on. And yes, I am profesionally involved in model evaluation. I have sofar not been able to find a model without flaws. I categorically reject model studies when real field data are available. And in this case they are. Model flawed.
    Next try.

  32. Jeff Id said

    #23, I still don’t have time but that paper you reference is bogus. We know less about the geological re absorption of CO2 than we do about moisture feedback. It’s like a pile of simple assumptions taking the bulk of the earth into account with a conclusion that doesn’t fit the data. I’ll look for the recent article on absorption rate which even in the short term isn’t explained by the paper you showed. To think that we could project it for millennia (as the paper does) is not even close to reasonable.

    Even the first biodome experiment failed when they found the concrete absorbed all their CO2, eventually starving them of oxygen.

    What would you say to my half baked theory that rainwater carries CO2 through porous rock where it’s sequestered through chemical reactions. The rate of rainfall in the area where it happens doesn’t change but the absorption rate is proportional to the concentration, but less than the current output. CO2 would build and when we stop using it, it would fall quickly.

  33. RB said

    Harry,
    If you wrote up your objections in a technically sound way and published it, you could prove the scientist(s) wrong and establish yourself. I too will be willing to read what you have to say then. Even a blog post that is read by people with relevant competencies to evaluate (not me) the claims will do for starters.

  34. Dizzy Ringo said

    Anyway, wasn’t consensus the word used when the inquisition “talked” to Galileo?

  35. harry said

    Modelling is nice and tempting in retrospect. It is ugly and burdensome in predicting the future. There is not one model which performes beyond statistically significant borders. If so, name it. I am waiting for your replies.

  36. harry said

    @RB

    Do you have a suggestion for a journal in which I could publish my reservations? Peer reviewed? (I am a publishing scientist, so I now about the hassles with peer review)

  37. CuriousScott said

    So called “consensus” is also about sharing blame. Having signed up to the consensus view, either through action or passive silence, it makes it hard for one to later declare a dissenting opinion or acknowledge mistakes. In the corporate world it’s called “buy in”. The process helps to entrench those who would later question the establishment.

    No one likes to be portrayed as a lemming which is what they would be for supporting previous arguments without evidence. At worst, who would want to be later immortalised as one of the zealous fools as Galileo’s inquisitors were in Art.

    At the extreme, one is shamed into silence. Later on, after the damage, who is held to account? Surely not all of those who where directly or indirectly complicate in fraud. Surely not the innocent bystanders who were mislead, of which would be deemed naive by implication. Surely not a “scientist” who models himself as a philosopher king of old. A Lord of knowledge.

    At this point, they are the Lord of the Flies.

  38. ‘The consensus of the world’s leading scientists is that it is very likely that most of the recent warming is due to greenhouse gas emissions’. This is just the sort of clear and considered judgement that politicians like to hear – and it was they after all who set up the IPCC in 1988 to deliver just this form of knowledge.

    And that is what many scientists accepted as the statement they were being paid to deliver. Others opted to be more honest and point out that their research was being misrepresented. Some of those, and others, simply quit. They opted to choose the path of truth.

    The problem is that in areas of science which are seeking to understand the behaviour of large complex systems which can’t be replicated in the lab, it is very hard if not impossible to apply the scientific litmus test of falsification through experimentation. And climate change is one such area of science. We have scientific theory, we have empirical observations.

    The theory being applied is a very, very, small portion of a vastly complex system. Hence, further work needs to be done before any conclusion (consensus) can be established. Further; a great deal of the empirical is ignored, discounted, and hidden by those desiring to maintain the consensus. Thus the consensus presented breaks the bounds of science and is really nothing more than a political lie.

    The term “consensus” in regards to climate science is as valid as the current usage of “peer reviewed”. Both are unfortunately more indicative of distortion and corruption than ‘science’.

  39. harry said

    @All,
    This is the basic idea behind the global warming scam:
    harry said
    February 25, 2010 at 5:56 pm

    The main problem is that the ICPP consensus is based upon a minor line in the report. Crucial to all ICPP predictions, forecasts, is the fact upon which all ICPP drama is founded: CO2 alone is reponsible for the current (or last 20 years) (or the last 50 years) (or the last 100 years) (or whatever period) of global warming. Digging through AR4, nothing can be found which relates CO2 to longtime GHG effects: it is assumed to be longlasting (Ch 2, 4, 8 and 10). Only in Chapter 10 we get a glimpse of how this is based on calculations. In Table 2.14, note a, it is revealed.
    The decay of a pulse of CO2 with time t is given by
    a0+sigma(i=1to i=3)ai*exp(-t/taui)
    Parameters are given:a0=0.217, a1=.259, a2=.338, a3= .186, tau1=172.9 years, tau2=18.51 years, tau3= 1.186 years.
    Reference is given to chapter 10 of this report (Bern 2.5CC; Joos et al 2001) using a background concentration of 378 ppm. The most striking thing of this formula is the fact that it has a constant of .217 of any given addition of CO2 to the atmosphere which will remain there forever: 21.7% of the initial carbondioxide released will last forever in the atmosphere.

    In Joos 2001, however, this formula cannot be retrieved. Something similar is there: Joos et al 2001, Glob Biochem. Cyc. 15:891-907.

    Without this, no manmade warming can be made real.

  40. harry said

    Science is not by concensus. Science is by being right. By publishing in Nature, Science. I know by now that publishing is one thing, but that being right is something different. My son was diagnosed with HCC, which is impossible for his age and history of illness. His case will reach Nature, Science. But not due to the science. Only due to my personal dedication. And that is what is overlooked in all discusions-dedication. I will go far beyond people like Jones and Mann. Mann and Jones will look like infantiles once I come out with what I have done.
    Harry

  41. stan said

    I just wish that climate scientists were willing to reach a consensus about need to use the scientific method.

  42. Pat Frank said

    As regards consensus science, let me point out Dan Hughes’ post:
    NASA’s Gavin Schmidt and Penn State’s Michael Mann are Liars

    It’s an older post, but quite relevant to Mike Hulme’s recent claims about the efficacy and reliability of the IPCC’s “consensus science.” both named scientists are central to the AGW claims of the IPCC.

    Dan Hughes is in the business of verification and validation of complex numerical models. He speaks with complete understanding of the issues, and I’ve learned a lot reading his posts.

  43. Jeff Id said

    #42 Yup.

  44. JAE said

    Homework for RB: Name the ONLY “scientific report” in history that releases a “summary for policy-makers” months in advance of the supporting evidence, so as to make sure the supporting evidence matches what is said in the “summary report.”

    Hint: it was produced by the UN.

  45. anon said

    This is what’s so odd. The toughest science imaginable reaches a consensus faster than special relativity. Maybe if Einstein had said time dilation was likely to occur he would’ve saved some time.

  46. RB said

    #44, the point being?

  47. JAE said

    46: If you don’t know what the POINT is, then I question your understanding of science and the scientific method. That’s all.

  48. RB said

    #47, if you are giving me homework, I want to know why.

  49. JAE said

    RB: you are instructed to do your homework, so you can possibly follow the Boy Scout’s Pledge: To be trustworthy, loyal, helpful, friendly, courteous, kind, obedient, cheerful, thrifty, brave, clean, and reverent. So far, you appear to have some deficincies. And it appears that you also don’t understand science or even basic logic.

  50. bob said

    In the context of science consensus is not a bad thing, nor is it necessarily a good thing. Consensus is not necessary or sufficient for a scientific theory to be shown to be accurate.

    We all heard the stories of a world-wide consensus on eugenics, and the Nazi’s application of that consensus approved “science”. The global warming consensus has actively repressed the opinions of those who disagree, and that is where the global warming consensus departs from civilized behavior into a something sinister.

    With the CRU Climate Gate revelations, and all the IPCC-Gate scandals raging through the press, it is apparent that the consensus was built with bad information. Arguing that there is a consensus is not necessarily a valid argument. A consensus is just a collective set of opinions.

    Opinions change.

  51. brent said

    Climate Change 2007: The Physical Science Basis
    Summary for Policymakers
    by Vincent Gray

    “Validation”, as understood by computer engineers, involves an elaborate testing procedure on real data which goes beyond mere simulation of past datasets, but must include successful prediction of future behaviour to an acceptable level of accuracy. Without this process no computer model would ever be acceptable for future prediction. The absence of any form of validation still applies today to all computer models of the climate, and the IPCC wriggle out of it by outlawing the use of the word “prediction” from all its publications. It should be emphasised that the IPCC do not make “predictions”, but provide only “projections”. It is the politicians and the activists who convert these, wrongly, into “predictions.”, not the scientists
    An unfortunate result of this deficiency is that without a validation process there cannot be any scientific or practical measure of accuracy. There is therefore no justified claim for the reliability of any of the “projections’ They have tried to draw attention from the undoubted fact that the models have not been shown capable of making predictions by seeking the “opinion” (or “guess”) of a panel of “experts”, all of whom have a financial stake in the outcome, and apply to these guesses levels of “likelihood” which have even been given a spurious numerical value. If the experts were employees of oil or coal companies, and their opinions were undesired there would be an outcry. As the “experts” are employees or recipients of funding from governments promoting the notion of greenhouse warming, criticism is not heard.
    The 2007 Summary for Policymakers
    The current document is really a Summary BY Policymakers
    http://www.pensee-unique.fr/GrayCritique.pdf

    The 2/3 likelihood touted in the TAR and the 90% likelihood touted in the 4AR are simply as noted by Vincent Gray, spurious numerical values representing firmness of belief by “true believers”
    Should we have a contest on whether they will claim 3 or 6 (or shudder higher) sigma for their next episode, their 5AR based on their 5th set of Non-Predictions from the 5TH set of unvalidated models ?

    Posted by Scientist for truth on WUWT Ravetz thread

    I’m amazed. Looking at the ecstatic comments, I think most of you are about as happy as the Trojans who wheeled the horse, a gift from heaven they thought, within their walls and got drunk, only to find that night that their city had been infiltrated and lost after years of battle. Beware! Ravetz is a very bright guy, and very perceptive, but Ravetz and Hulme have done their utmost to dispatch ‘normal’ science. Now their ideas will destroy you. More on Ravetz and Hulme here
    Climate Change and The Death of Science
    http://buythetruth.wordpress.com/2009/10/31/climate-change-and-the-death-of-science/

    Climate consensus and the end of science
    Terence CorcoranFinancial Post
    Friday, June 16, 2006
    http://www2.canada.com/components/print.aspx?id=d35ca1eb-50b8-4546-8950-ca9ad18eb252

    Climate Consensus & The End of Science: Terence Corcoran versus Thomas Kuhn
    The piece is interesting, it does correctly emphasis the extent to which the word ‘consensus’ is repeated invoked with the word ‘science’ and ‘climate change’ to justify support for the concept of anthropogenic global warming (AGW).
    Terence Corcoran’s piece might have been improved with some reference to two well know philosophers of science, Karl Popper and Thomas Kuhn.
    Popper had no time for consensus, for him science was advanced through ‘falsification':
    http://www.jennifermarohasy.com/blog/archives/001446.html

    Lindzen (discusses Hulme’s PNS)
    http://ceiondemand.org/2009/10/26/cooler-heads-event-with-dr-richard-lindzen-on-cap-and-trade/

  52. DeWitt Payne said

    Re: harry (Feb 25 19:08),

    I think the formula can be tested by feeding it the total emissions data per year and seeing whether the atmospheric CO2 concentration predicted is anywhere close to the measured value. There’s fairly good data for emissions and very good data for concentration starting in 1959 or so. The emission data is very close to a linear ramp. If I had the math fu, I could probably write the differential equations implied by the equation and solve them for a ramp. But it should be possible to do it by brute force numerically in either R or Excel. The fossil fuel contribution to CO2 emission is fairly solid. The contribution from land use change is more questionable. Just eyeballing the equations with my minimal mathematical intuition, I don’t see a constant proportion (I forget whether it’s 40 or 60%) of new emissions disappearing each year.

    And yet again: The (short) lifetime of an individual atom of carbon in the atmosphere is not the same as the decay time of the concentration. 14C measures only the lifetime, not the decay time.

  53. brent said

    re Donna Laframboise @ 21

    Donna,

    Research “the consensus process” and Delphi technique if you haven’t already

    There’s a decent description here

    http://www.learn-usa.com/transformation_process/~consensus.htm

    This particular site is oriented to some traditional values , and you or I may differ on some of those, however look past that and focus on the description of how the “change process” works

    The process is essentially for a facilitator to bring a group to agreement with a preordained agenda.

    Bullying can be a tactic (of a trained facilitator) to center out those who may resist

    all the best
    brent

  54. ditmar said

    Ipcc Consensus science seems to me to be a similar to collective responsibility assumed by members of the uk government cabinet. Decisions are taken and may be unpopular in the room but each minister is charged with defending the position regardless of their personal views on the decision or how they voted. If a cabinet minister feels so strongly that it is a position they cannot, in all honesty, defend then resignation is their only option. This does not happen very often as it appears that ministers are reluctant to sacrifice their status and privileges that being a minister brings. Pm blair took the country into an illegal war in iraq with the “support” of the cabinet despite their doubts about its legality and,afaik, only one, claire short minister for overseas aid, resigned from the government leaving her free to criticise the decision from the back benches. There are examples of ipcc scientists resigning for various reasons including the distortion of the evidence in their field. The are more often than not labelled as loose cannons, oddballs, deniers etc just as, in truth, clair short was. I think those that adhere to scientific principles of truth, integrity etc risk their careers and reputations and should be applauded by all.

  55. bob said

    Ditmar #55: I agree, to a point. A consensus is a necessary thing when going to war, or finding a murderer guilty regardless of the strength of the evidence. Juries in the US have found people guilty of crimes who are later exonerated by new scientific evidence evaluation procedures.

    Since science depends on verifiable facts, a consensus is simply an inadequate concept in the determination of what is factual or not. It is nice to have a consensus on the evidence, but, a consensus is not a factual finding.

    Facts are nasty things, and the difference between what looks factual and what is not rests on the uncertainties in the situation. In some cases we will never know the actual mechanisms of complex systems. To replace scientific investigation with a simple vote, or consensus, is dangerous.

  56. vsaluki said

    “It seems that not only do we disagree about climate change, but we disagree about whether or not we should even be reaching a consensus about it.”

    This seems to be the most blatantly ignorant of his statements. That we should or should not be reaching a consensus shouldn’t even be a topic of discussion. Science should never be motivated by an objective of reaching a consensus – or of not reaching one. Scientists should simply worry about where the data and the theorys leads them. If consensus is a result of such investigation, fine. If it is not, equally fine. The IPCC should work in the same way. What the politicians want is irrelevant. Hulme’s consideration of their desires is exactly why climate science is in the sad and deplorable state that it is currently in. The appeal by so many climate scientists to the so called consensus is clear evidence that they have given in to the demands of the pay master.

  57. Kenneth Fritsch said

    Come on girls and guys this whole consensus debate is meaningless unless we can define exactly what it is that we have consensus on. The more general the supposed consensus the more likely a detailed definition is missing and the consensus has little or no meaning.

    The more specific one gets the more likely we will not have a good degree of certainty or a true consensus.

    I would bet a very large sum of money that the consensus we could readily demonstrate from the climate scientists who have a stated “consensus” on the AGW, its extent and consequences is that they mainly would agree that government mitigation of AGW would have little chance of having detrimental and unintended consequences. In fact, I would wager that, if asked whether more and stricter government control of emissions of GHGs is a good thing whether the case for the extent and effects of AGW is proven or not, the consensus scientists would be in consensus that it is indeed.

  58. pdcant said

    Am I the only one who read Michael Crighton’s “State of Fear”? He gave a very good example of science by concensus after the novel. Here is a biased Wiki article:

  59. [...] Mike Hulme – Consensus Science – This is a post on The Air Vent discussing consensus science and what is meant by that term. [...]

  60. RB said

    Some of the old interviews with Hulme are actually quite interesting:
    http://www.theregister.co.uk/2009/05/06/mike_hulme_interview/

  61. harry said

    I apologize for my ranting in comment number 40. Frustration. Very much OT.

    Sorry.

    But I remain true to my ideas: that the CO2 modelling of the ICPP is wrong. And I think I can give a clue: they have overlooked burning of waste and wood(biomass), and the massive decompensation going on in the biosphere, releasing back the 14C that was captured 40 to 50 years ago. This enriches the 14C free carbon from fossile sources, and can contribute as much as 50% of the active CO2 in the atmosphere above mega cities like Mexico city. Ref: Atmos Chem Phys 9, 4973-4985, 2009. No magic compartment, just release of biomass sequestered carbon with an isotopic fingerprint identical to the atmospheric carbon composition. The constant can be eliminated from the ICPP formula, replaced by biomass burning with a similar half life as the other carbon: less than 15 years. Stop the scare, models are ALL wrong.

  62. brent said

    #57 re:Kenneth Fritsch

    Ken,

    In Swindle Lindzen said;

    “People want to convince other people, that if no scientist disagrees, you shouldn’t disagree either. But whenever you hear that in science it’s pure propaganda”

    I’ve paraphrased the above from memory, but think I’ve got it real close, probably exact. Anyone feel free to check.

    The IPCC is explicitly a political organization, not a scientific one. I think that’s the most difficult thing for people to realise. The scientists real role is as a “new priesthood” to give blessing to the preconceived political agenda.

    Despite some of Hulme’s waffle, the notion that there is no consensus (For AGW alarm) would not even be considered for a summary for policymakers.

    They’ve ramped up the propaganda with every “assessment”

    The IPCC needs a summary which they can term a “consensus”, so they can then use an appeal to authority to “consensus of the new priesthood” to bless the preordained political outcome of implementing carbon pricing.

    When one realises that the whole scheme was politically driven from the start, it becomes clear why all the shenanigans to fit the “supposed science” to justify the political agenda

    I don’t know how he is perceived elsewhere, but in Canadian terms David Suzuki is THE ICON of the environmental movement. Think of say Hansen, plus Schneider plus the next couple high profilers in the US… All rolled into one. That’s what David Suzuki is in Canadian Terms.

    Originally a geneticist, he’s long been a journalist and pop science/enviro popularizer.

    Pay careful attention to the process Suzuki describes in the following short clip, because he discloses exactly what the process has been!!!

    Although he portrays himself to the sheeple as a voice of science, remarkably he does say in the clip that that he’s a journalist.

    However in effect, Suzuki’s scientific “Mentor” is none other than Al Gore.

    Forecast Earth In Depth: David Suzuki, Part 2

    Suzuki says as a journalist how can he help his scientific mentor Al Gore. Gore tells him to go out and proselytize the gospel until the sheeple demand action from the politicians.

    Note that the agenda was politically set right back in 1988 when the big publicity drive was launched on public by Gore, Thatcher, etc

    At links below Suzuki, discloses another of his scientific mentors, Lucien Bouchard (old law school buddy of Brian Malarkey)

    Note that the “supposed scientist” Suzuki,explicitly lets Bouchard, the politician/lawyer define the answer to a supposedly scientific question for him.
    How the hell would Bouchard know??

    The fix was in from the start.

    The Big Lie works. It’s worked before, and with the passing of time a new generation thinks they’d never get fooled like their forefathers . And so they can be.

    cheers
    brent

    “I interviewed Lucien Bouchard two months after he was appointed, and I said, Mr. Minister, what is the most important issue we face? Right away, he said global warming. In 1988! I said, how serious is it? And he said it threatens the survival of our species.”
    http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20070422/green_qp_070422/20070422?hub=TopStories

    Environment hurt by Quebec separatism: Suzuki
    http://www.cbc.ca/canada/montreal/story/2007/02/08/qc-suzuki20070208.html

  63. [...] to Jeff at the Air Vent, whose post yesterday sparked this [...]

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