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How climate skeptics mislead

Posted on 13 June 2010 by John Cook

In science, the only thing better than measurements made in the real world are multiple sets of measurements – all pointing to the same answer. That’s what we find with climate change. The case for human caused global warming is based on many independent lines of evidence. Our understanding of climate comes from considering all this evidence. In contrast, global warming skepticism focuses on narrow pieces of the puzzle while neglecting the full picture.

What is the full picture? Humans are emitting around 30 billion tonnes of carbon dioxide into the air every year. This is leaving a distinct human fingerprint:

Signs of warming are found all over the globe (here are just a few):

On the question of human caused global warming, there’s not just a consensus of scientists – there’s a consensus of evidence. In the face of an overwhelming body of evidence, the most common approach of climate skepticism is to focus on narrow pieces of data while neglecting the full picture.

Let's look at an example. One popular skeptic argument has been to cast doubt on the surface temperature record. Skeptics claim thermometers are unreliable because surroundings can influence the reading. They reinforce this by showing photo after photo of weather stations positioned near warming influences like air conditioners, barbeques and carparks. The Skeptics Handbook goes so far as to say "the main 'cause' of global warming is air conditioners".

This myopic approach fails to recognise that air conditioners aren't melting the ice sheets. Carparks aren't causing the sea levels to rise and glaciers to retreat. The thousands of biological changes being observed all over the world aren't happening because someone placed a weather station near an air conditioner. When you step back and survey the full array of evidence, you see inescapable evidence of warming happening throughout our planet.

Our understanding of climate doesn't come from a single line of evidence. We use multiple sets of measurements, using independent methods, to further our understanding. Satellites find similar temperature trends to thermometer measurements. This is despite the fact that no carpark or barbeque has ever been found in space. Prominent skeptic Roy Spencer (head of the team that collects the satellite data) concluded about the HadCRUT surface record:

“Frankly our data set agrees with his, so unless we are all making the same mistake we’re not likely to find out anything new from the data anyway"

Our climate is changing and we are a major cause through our emissions of greenhouse gases. Considering all the facts about climate change is essential for us to understand the world around us, and to make informed decisions about the future.

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Comments 201 to 229 out of 229:

  1. #183 doug_bostrom at 11:40 AM on 17 June, 2010 It seems to me that overzealous application of Kolmogorov's axiom system could lead us to effective paralysis Yes. In real life it is imperative to be able to handle obscure issues. However, the way we do it should not be confused with applications of probability theory in the strict scientific sense. This is exactly the problem with the way IPCC presents its assessment system with guidelines for quantification. It is made to look scientific while in fact it is just plain old-style guesswork. Insufficient knowledge of sample space (field of possible events) is a serious issue. There are several extremely complicated systems like commercial airplanes or nuclear power plants where failure is not tolerated easily. Guys are developing sophisticated models to assess probability of failure but the thing is, retrospective analysis of actual accidents almost always uncovers some momentum or coincidence of otherwise independent chains of events, that no one expected, therefore it was missing from any previous risk assessment scheme as well. The rule is rare events happen often. There is an enormous tail of the probability distribution spanning unexplored expanses of the sample space. In this region each individual event has a vanishingly small probability, but all taken together, some of them is to be expected to happen rather soon. There is no good scientific way to handle situations like this. You have to rely on structural safety, engineering expertise, responsibility and common sense. There is another issue. This is personal communication from a guy trading in Decision Theory. In fact it happened in a pub, drinking beer, so I don't have references. Anyway, he described an experiment where subjects were asked to play a game and they were actually payed some small money for winning. There were a dozen or so marbles, all yellow, except one, which was blue. These were put into a black velvet bag in front of the subject, so he could see and count them. Then the experimenter pulled the marbles out of the bag one by one and the subject was to bet on its color in advance. Later on the betting strategies people followed were analyzed. There is a known optimal strategy for this game and it was found their performance was seriously suboptimal. The guy (the one I was drinking beer with) wondered why was it so. Well, there was a quirk to the experiment. The black velvet bag had a small hidden pocket inside and the experimenter trained himself in advance to be able to put the blue marble into the pocket in plain view without being noticed. This way he could always invariably present it on the last turn. It made sense, because this way he had more data (as soon as the blue marble is out, there is no uncertainty left in the game whatsoever). I told him the subjects probably guessed he was cheating on them and adjusted their strategies accordingly. He thought he had taken all the necessary precautions to prevent this, each subject played the game only once, they were not allowed to communicate with each other, and he, being an amateur magician otherwise, could really perform the cheat undetected. Well, I told him people have a general knowledge of psychologists cheating in experimental situations like this, so he has to look for the specific cheating model people had in their mind making the betting strategy they have actually followed close to optimal. So did he. Not in the pub, but during the days following. Next week he came up with a probability distribution for the blue marble along consecutive turns that made the average observed strategy optimal. It was tail-heavy, that is, looked like some mixture of the correct uniform distribution and the actual one, where the blue marble was always the last one. He could not repeat the experiment without cheating, because by then it was common knowledge among the students that the last one is blue. No one knows what has actually happened. There is a small possibility of the subjects communicating their experiences to the ones still waiting. But the distribution has not looked like that. It didn't have a single spike at the last turn, but a rising slope. People may be too dumb for this game. But it is also possible the sample space they had in mind and on which they have (mostly unconsciously) computed their strategy was wider then it was supposed to be and on top of possible configurations of marbles also included guesses on ways they might be cheated on. After all it can happen anytime, not only in controlled experimental situations. There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.
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  2. Sorry Albatross I agree this conversation has taken some esoteric turns, but since the theme of this post is the "consensus of evidence", I feel that a philosophical discussion of why such a consensus has relevance is somewhat on topic. In any case I can't help myself but indulge BP in this discussion a little bit more, I apologize if I'm just running in circles here. I think it's pretty clear he disagrees with you by the way that skeptics mislead. BP feels that a focus on minute particulars is far more relevant than weighing the totality of evidence. I'll defer to John's judgement as to whether this conversation needs to end where it stands. BP, That was a very interesting post, but it only serves to weaken your own arguments. You write that often in science we start with a huge inductive leap, then work backwards deductively establishing evidence for the general principle. I'll agree this is often the case, but not with climate science. AGW fell out of an attempt to reconstruct the behavior of our climate from our low level understanding of physical processes. It is clearly a theory borne out from inductive methods. Early attempts did try to deduce our climate's behavior from broad generalizations, but these attempts were met with failure (take a look at that link, it's a good read if you haven't seen it already). Furthermore, in your own entreaties you have urged us to stop looking at the "big picture" and working backwards, rather you'd prefer we work out the individual pieces and see where it takes us. You propose a method that is clearly inductive when applied to the general theory of AGW. Why then can we not evaluate your approach as such? > We can never be sure if these signs give us truth or not. However we have no choice but consider them true until proven false (by experiment or observation). Utter nonsense BP. You are now in direct contradiction to the basic principles of scientific skepticism (and of course, all modern judicial systems). Positive claims require positive evidence before we even entertain the idea that they are true. I propose to you that there is an invisible unicorn standing behind you right now. Did you honestly have to wave your hands in the air before assuming that my claim is false? >If something is 95% true, it may take quite a lot of counterexamples to get one convinced it must be false after all. Yes. This is exactly how the scientific method is supposed to work in fields where the evidence itself is complex, and is perfectly consistent with how theories have historically been modified or replaced. In such fields, each piece of evidence standing on its own is questionable. Only when you take the evidence in summation does a case for general theory arise. If a single piece of complex evidence can unambiguously falsify a theory, then I again submit that observations of SST's falsify your claims on UHI. >we are doing science and in this fine tradition you should let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil. That communication has been a direct and clear "YES": based on the mass of all current evidence, AGW is true. It is the "skeptics" that have harped on the question of uncertainty. >In science the standard practice is to get rid of uncertainty by improvements to your measurement system, postponing your judgment until the job is done. There is no such thing as "getting rid of uncertainty" in science BP, I thought we had established that fact already. As such, the "job" is never complete and your claim implies we will never make any judgements whatsoever. If you honestly believe there is such a thing as 100% certainty (the equivalent of saying all uncertainty has been removed), then there is no point in continuing this conversation.
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  3. Berenyi Peter, you were wrong in stating that "In science the standard practice is to get rid of uncertainty by improvements to your measurement system, postponing your judgment until the job is done." At least, you were wrong if you continue to insist that scientific decisions are binary, so that "postponing judgment" means refusing to make a decision at all until, when you have removed all uncertainty from your measurements, you make your decision with 100% certainty. Science never has worked that way, and it cannot work that way. Not in any scientific field. Uncertainty of measurement never can be reduced to zero. More importantly, fit to measurements is not the only criterion by which scientific theories are evaluated, and evaluating by using that whole cluster of criteria is a complex human judgment that involves yet more uncertainty and, inescapably, more or less subjectivity. I am a trained scientist, as are many of the posters and commenters here. Your insistence that you are the only one who knows the definition of science has become annoying rather than being simply naive. You don't have to trust our assertions. Just read good science journalism, such as Science News or Scientific American. In nearly every story you will see a range of opinions from scientists who are specialists on that topic. Some even claim to be 100% certain that the theory is correct, whereas others say they are "pretty sure," some say their certainty is 50%, and often there are others who insist they are 100% certain that the theory is wrong! And every time there is a discovery or theory that "overturns" a field, that means the majority of scientists in that field previously were certain about something they now are certain is wrong! You also wrote "In real life this procedure is not always practicable, because decision is urgent and resources are lacking. In this case you have to make-do with what you have. But do not call that science please." But science is "in real life"! Science always requires decisions, even if those decisions are whether to continue to try to validate a theory or abandon it--whether to do one more experiment or analysis despite the counter-evidence or lack of evidence that has been gathered so far, whether to even spend more time thinking about it! There is a range of "urgency" and a range of "resources," so you are correct only insofar that in some cases the "decision" about a theory (or even whether to trust an observation) is an armchair kind of decision. In those cases, scientists do indeed officially reserve judgment. But in practice they actually do make decisions about whether to continue to investigate, and rarely will they refrain from passing judgment at all; instead they will state a judgment with caveats. Science is what scientists do. You should read more about philosophy and history and sociology and anthropology of science, and even more than just Popper's opinions. Scientific decision making and probability are merely subsets of the topic of judgment and decision making, about which you need to learn; try, for example, David Hardman's book. (I apologize if this comment is too long or strident. I take the coward's way out by blaming a glass of Moylan's "Kilt Lifter" Scottish style ale.)
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  4. BP >It is made to look scientific while in fact it is just plain old-style guesswork. Yes it is guesswork BP. But it is an educated guess. This is how predictive science works my friend. We can never know the future with certainty, we can only guess at it based on our uncertain knowledge.
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  5. #199 Albatross at 09:49 AM on 18 June, 2010 please, at least have the gumption to call foul when "skeptics" mislead Foul. Or do you disagree with John's (and others') assertion that "skeptics" mislead? What kind of question is that? Some obviously do. Others not. The same with non-skeptics.
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  6. BP, the lofty traits you ascribe to science apply only to formal logic and mathematics. Perhaps science is not what you thought it was? Many philosophers to this day have grappled with the problems with science you discuss. In my mind, the only reason necessary to trust in such a vague and uncertain endeavor is that it works. Planes fly, cars drive, diseases are cured, etc.
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  7. BP, "What kind of question is that? Some obviously do. Others not. The same with non-skeptics." A reasonable and relevant question. Let me put it to you this way. Do you approve of the propensity of "skeptics" to distort, misrepresent and confuse the science of climate change? Monckton being one example. So please elaborate on your stance. I would take issue with your use of the quantifier "some" when referring to skeptics misleading. Have you not been paying attention to the content posted at "skeptical" sites such as WUWT, or the distortion but certain media outlets of late? There is a definite propensity for skeptics to intentionally mislead or embark on sub-par science. In fact, there are simply too many examples to cite here. There is also a definite tendency for "skeptics" to try and distract attention from the compelling convergence of multiple lines of evidence in the post by John. That point is clearly irksome for "skeptics", so it seems their tactic is to distract or obfuscate, and I might add that has been beautifully illustrated by the wayward discussion of the UHI on this thread (that being but one example). "e" at 202, fair enough :) Are you or anyone else here familiar with the work of Giere, specifically his book "Understanding Scientific Reasoning"? BP, maybe something to you to consider reading?
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  8. #203 Tom Dayton at 11:31 AM on 18 June, 2010 At least, you were wrong if you continue to insist that scientific decisions are binary, so that "postponing judgment" means refusing to make a decision at all until, when you have removed all uncertainty from your measurements, you make your decision with 100% certainty. John, who said all uncertainty should be removed from measurements? That's not even possible. On the other hand if uncertainty of judgment is due to poor measurability, of course it is the first thing to do to improve measurement. You know perfectly well that you do not have to remove all uncertainty from measurements to be able to form true propositions. If you measure the diameter of a speck and find it to be 1 cm, measurement error is 10%, you can be certain the speck is smaller than 1 km, can't you? On the other hand if you measure 973 m, you have to have a closer look and refrain from judgment until it's done. It is perfectly legitimate to say I-do-not-know. And yes, a scientist do not have to make public decisions. It is not his job. Otherwise of course he makes decisions all the time as anyone else. But there is nothing particularly scientific in them, not even in the case he makes a decision on performing a specific experiment.
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  9. Berényi - you continue to confuse probability theory (known universe of results, absolute identification of each case, and the likelyhood of one result from that limited known universe) with the first definition of probable, supported by evidence strong enough to establish presumption but not proof (a probable hypothesis). You have also not, as far as I can tell, read either e's or my links to inductive arguments, the basis of (to list a few) climate theory, evolution, and most of our every day decisions - not to mention how we judge competing theories every time they arise in science. We can't know all possible outcomes; we have to decide based on the strongest evidence and experimentation we have. I will be the first to admit that inductive logic is a point of contention. Every philosopher of science who has written on the subject has concluded that (a) it's not absolute proof, or an absolute conclusion, as deductive logic provides, and (b) bloody hell, we need it anyway, since we cannot know all cases, and must make decisions based on whatever experimentation we have been able to conduct - without knowing the entire universe of results. Most people take an inductive theory, and apply deduction to support it - there's rarely an acknowledgement of the inductive basis of many of the premises used in the deductive arguments. Irregardless: As I stated quite some time ago, on a completely different focus, even if your objection to the GHCN data is valid, a point of some contention, that does exactly nothing to disprove the many many other independent lines of evidence that support global warming and indeed AGW. In fact, this is now a poster-child demonstration of the skeptic approach of picking one line of evidence, bringing up some objection (of varying strength), and then stating that based on that singular objection to a particular data set that an entire theory supported by many lines of evidence is now suspect - that all supporting lines of evidence/data sets (such as the several satellite sets you refer to) are therefore invalid. Just as John Cook described in this topic, at the top of the page! Issues with a single line of evidence are limited to that line of evidence, and only propagate to derived data - and the satellite data sets are very clearly not derived from the ground station data. Single data line issues don't affect a general theory unless a significant number (again, a judgement call) of the supports for that theory are invalidated, or that a better explanation (simpler? parsimonious? Fewer crystal spheres?) is found for them. Thank you for the demonstration, Berényi.
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  10. BP "In science the standard practice is to get rid of uncertainty by improvements to your measurement system, postponing your judgment until the job is done." The key question here is what exactly is the "job to be done." One level of certainty is needed to know if an increasing trend in temp exists and another to know whether the increase is quantitatively similar to a known energy imbalance. But obviously we will never know "exactly" what the change in land or sea surface temp is. Even though we believe an exact number actually exists, we can only approximate it. Should we then say we know nothing? The closest thing in the natural (as opposed to mathematical) sciences to the deduction that BP craves is what Platt called strong inference. It involves developing a suite of alternative hypotheses that at least try to address a phenomenon from all sides and then constructing (and conducting) focused experiments to determine which among them hypothesis describes the phenomenon of interest. It's the closest to what BP would recognize as deduction - defining a range of possibilities that encompasses all possible outcomes and evaluating which provides the more probable fit to the data. In some ways we have a perfect set up for strong inference in the case of AGW. AGW provides a coherent explanation for changing climate patterns over the last 50 years that is based largely (although not exclusively) on CO2. The models developed seem consistent with climate changes in the deep past and interaction between atmospheric composition and climate on other planets. Thus we have a body of theory about drivers of climate and a prediction (actually many if you consider the various models) for the future. There are also competing explanations (it's the sun, its PDO or El Nino, its UHI effect) that tend to make somewhat different sets of predictions by emphasizing specific aspects of the energy/climate system. It would be immensely interesting to run an experiment to determine which is the winner here. Of course the problem is that we can't actually control what happens next, we don't have replication, and we don't have a control. What's more we don't actually want to do the experiment if it turns out a certain way, as we are part of the experiment. So the question is, which treatment should we do given that we have one replicate, and we're living on it. We really have no choice but to place odds on which hypothesis is likely to make the best prediction so that we can avoid, or plan for, the possible consequences. That means assessing the relative merits of the different hypotheses up until now. As a scientist I appreciate BPs insistence on precision and his skepticism, extreme as it is. However, if I'm laying a bet that I don't want to lose, I will use all the information available to me to make the best decision. Because AGW provides a very complete explanation of changes to a wide range of variables, it seems a good bet to me compared to the others, most of which were discarded long before they were raised from the dead again...and again. I have to go on a research cruise for a month so I'll be signing off for a while. It has been a pleasure to read all these cogent and mostly civil discussions. Don't have too much fun while I'm away!
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  11. 209 KR at 12:46 PM on 18 June, 2010 picking one line of evidence, bringing up some objection (of varying strength), and then stating that based on that singular objection to a particular data set that an entire theory supported by many lines of evidence is now suspect - that all supporting lines of evidence/data sets (such as the several satellite sets you refer to) are therefore invalid I have not talked much about other lines of evidence, much less the entire theory in this thread. It were you guys, who did it. I've just mentioned if UHI is proven to have a significant effect on past land surface temperatures, something has to be done to restore consistency. And this conditional statement is simply true, don't even try to argue with it. You have managed to force me into some guesswork on conceivable sources of error in satellite lower troposphere data (it was the atmospheric model used to convert brightness temperatures to air temperatures which is not independent of other datasets), but I would not stick to that on all cost, since I didn't have a sufficiently thorough look at the satellite issue (yet). At the same time I do maintain my stance on UHI adjustments of past surface temperatures as they're done in mainstream climate science being fundamentally flawed. I have shown you in detail why I think it is so and why proper adjustments should be almost an order of magnitude higher. The whole thing is pretty simple and easy to understand. If you really think there must be an error in it somewhere, because multiple independent lines of evidence contradict it, that's fine. It's like an existential proof in math. You can convince anyone who firmly believes in the external evidence you cite. However, a constructive proof is always stronger and if available, is preferred to existential ones. To see its validity, much less is to be assumed. Therefore as soon as you find the actual error and show it, even people not impressed by other lines of evidence would be either forced to get convinced or demonstrate for everyone to see they would never listen to reason. You all have chosen not to follow this constructive path, either because it was impassable or you are actually not interested in convincing anyone by reason who is not convinced already, but hope to succeed by other devices like appeal to authority, emotional extortion, referring to irreducible complexity or any number of such techniques. Unfortunately it is not an exceptional attitude, but an everyday experience of outsiders dropping into the midst of the AGW crowd. It does demonstrate something, I'm just not sure what. But it gives that sinking feeling of sorrow. Thank you for the demonstration, Berényi. You are welcome.
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  12. BP, >I have not talked much about other lines of evidence, much less the entire theory in this thread. Then why bring the issue up in a post about the "big picture" of the theory AGW? Surely you see there are some implications made in doing so? You're beginning to sound disingenuous. I take no issues with you trying to find evidence for this singular hypothesis, I take issue with its implied relevance to AGW theory as it stands today - not some hypothetical future where your claim has been "proven". As it stands now, the only evidence of this hypothesis is the contents of a blog post by Roy Spencer. Even he admits it's extremely preliminary. There is no way that our discussion here is going to change that, only peer-reviewed research can be the foundation for solid evidence of this claim. It is from this current state that I claim the hypothesis is implausible. Does that really seem so outrageous? Furthermore, KR makes the point that even in this hypothetical future where such evidence exists, your evidence would still need to be weighed against all other evidence if we are to make any conclusions about broad theory. This is exactly the point made by this post to begin with. >However, a constructive proof is always stronger and if available, is preferred to existential ones. I don't think this point is sinking in for you BP: such a proof will never be available, it cannot exist when empirical science seeks to make predictions. The proof you speak of - whether constructive or existential - is the sole domain of mathematics and formal logic. You can never "prove" that the UHI effect exists as you say it does, you can only show evidence that it exists. Even if you were able to produce some peer-reviewed evidence on the subject, that evidence itself would still be subject to uncertainty. You cannot assume your own evidence is gospel truth while other evidence is "shaky" or uncertain. If you were able to show some hard evidence for this particular UHI effect, we would be left with at least two contradictory theories that are both plausible: a) the earth is not warming to the degree scientists believe, and SST's and satellite measurements are in error (not to mention all the other evidence of a warming earth) b) the earth is warming, and your evidence for UHI is in error or some other error exists in the land surface measurements that imposes a cooling bias. Again, both of these theories would plausible with the given evidence. You cannot simply declare with certainty that one is true and another is false. If we want to come to any conclusion whatsoever, we are forced decide whether one theory is "better" or more likely than the other. This is not an arbitrary scenario, this situation (multiple mutually exclusive plausible hypotheses) is the case in any field of empirical science of non-trivial complexity. You can never truly eliminate the possibility that an alternative hypothesis - either known or unknown - is true. This is the core problem with induction that has been debated by philosphers for centuries. It's a philosophically interesting problem, but in the end, if you seek to remove the tools that allow us to compare and rate plausible hypotheses relative to one another, then you are seeking the elimination of nearly all scientific knowledge. I think we're starting to run in circles here. We keep explaining to you that there is no such thing as certainty in science (whether we are talking about conclusions or evidence for those conclusions). You seem to agree, but then go off on tangents talking about how we must keep going until we have "proven" your hypothesis or "completed the job" of removing uncertainty from our measurements. I'm starting to wonder whether you are arguing for the sake of argument.
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  13. #212 e at 05:02 AM on 19 June, 2010 As it stands now, the only evidence of this hypothesis is the contents of a blog post by Roy Spencer Puh-leeze. Not that Spencer mantra again. Go back and read, would you? Spencer was the first to notice logarithmic dependence of UHI on population density extends well below rural levels, but. As I have already told you several times it can be demonstrated in a much simpler way. And lo and behold I have given here, in this fine blog all the details you may need to understand it. such a proof will never be available, it cannot exist when empirical science seeks to make predictions Listen. I know my English is substandard, but how can you read "predictions" where I ask for "you find the actual error and show it"? I do not want you to make any prediction just some debugging job. If an instance of something (i.e. error) is actually shown, it is called a constructive proof as opposed to an existence proof, where only the existence of such-and-such an entity is proven without giving a clue how to find it. Just in case you have not studied math. how we must keep going until we have "proven" your hypothesis No, I do not want you to prove it. Where did you see that? Disprove, that's what you need to do. Really, is your tendency to attack straw men intentional?
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  14. BP, again you're ignoring my point that this post is about the big picture of AGW, a theory that is inherently predictive. Anyways, in order to form a constructive proof of your claim, you would need to go back in time and place thermometers at various distances from every site measured in the temperature record. What you are actually doing is taking limited data and then extrapolating a generalization: that there is a logarithmic UHI effect relative to population. You are then retrodictively applying that generalization to the entire temperature record. Sorry, but that's induction. And yes, I have read Spencer's post and understand the principle he proposes. Where exactly does he say that his analysis is conclusive? I will wait and see if some peer-reviewed research comes out of it, until then it is an interesting question, but it provides no reason to seriously doubt AGW as it stands.
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  15. BP, No, I do not want you to prove it. Where did you see that? Disprove, that's what you need to do Sorry, you're right I mispoke. What you suggest is that we take your hypothesis as true until we can disprove it. I maintain that that is a silly approach.
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  16. This thread is very interesting. And with BP being one of the most prominent so called sceptics on this site, he's given us a lot of interesting information about his approach. The fundamental issues seem to be:
    • No understanding or acknowledgeement of the fundamental difference between scientific problems and engineering/mathematical/logical problems
    • Related: misapplication of logic, with some confusion between what is an inductive approach and a deductive approach. As well as the inappropriate of the logical inverse where convenient (e.g. #215)
    • Failure to look at the big picture, rather inappropriately insisting that a reductionist approach is the only possible way to understand the problem space. It's pretty well established that in the non experimental sciences where complexity is a significant component, that reductionism will not result in a comprehensive explanation
    • Weighting evidence based on how it is perceived to bring the evidence for AGW into doubt, rather than on its quality, or the provenance of the source
    Don't get me wrong, this is not supposed to be an ad hominem attack. This is a long and complex thread, and I thought that some kind of summary of the issues that I've observed would be useful.
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  17. #216 kdkd at 07:28 AM on 19 June, 2010 Failure to look at the big picture, rather inappropriately insisting that a reductionist approach is the only possible way to understand the problem space Let me humbly note I was not talking about understanding the problem space. Of course the "big picture" or rather whatever picture you can put together by whatever means can have a tremendous heuristic value. But mark me, science is not about pictures. It is about propositions. And what you call a reductionist approach is not for understanding the problem space, but for understanding specific propositions, for debugging if you wish. Logic, deductive reasoning and focus on details are invaluable tools in this quest. Also, perceiving (pictures) and understanding (propositions) are two very different human abilities. Critical thinking is only possible in the latter domain.
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  18. BP >Of course the "big picture" or rather whatever picture you can put together by whatever means can have a tremendous heuristic value. But mark me, science is not about pictures. I'm not sure what you mean by that second sentence. Are you saying that a broad understanding about how things work (or as you put it, understanding the problem space) isn't a part of science? That seems like an awfully provincial definition of what science does. To what domain does the "big picture" belong to then if not science?
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  19. BP, perhaps our disagreement is mostly definitional. From Merriam-Webster, defintion 3a: science is "knowledge or a system of knowledge covering general truths or the operation of general laws especially as obtained and tested through scientific method" (emphasis is mine). The "general truth" part is where the "big picture" belongs. The "obtained and tested through scientific method" part is where your descriptions belong. Both are within the domain of science. This particular blog post however is about the "big picture" part.
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  20. A friend just remarked on how prone I am to using analogies and resorting to metaphor. Indulge me please once more. The tools and techniques we have to create a "big picture" in science produce the net effect of what artists call pointillism. Tiny bits of knowledge appear on a canvas and if they are mutually consistent and compatible a picture of a large system encompassing all the colors and positions of those dots will emerge. If there are too few dots or too many appear in the incorrect position or with the incorrect color no coherent picture can be perceived. I think most of us understand our science in this manner, a way that is imperfect, even impressionistic but is still useful. Because of our personal limitation and as well as defects in our knowledge and measurement capabilities we cannot say what the exact value of a particular dot in the picture is, we cannot say that each dot is in exactly the right position, but we can nonetheless see a picture emerging from the collection of points on the canvas recording our inquiry. When I think of counter-arguments to anthropogenic climate change, my conclusion is that the picture that can emerge from the number and type of dots supplied by the very few valid research results in contradiction to the theory as well as the galaxy of frankly wrong opinions contrary to the other school is incoherent, so abstract as to convey little or no meaning. But by contrarians we are asked again and again to focus on just a single dot whether from the coherent picture on one canvas or the incoherent image on the other.
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  21. BP #217
    Also, perceiving (pictures) and understanding (propositions) are two very different human abilities. Critical thinking is only possible in the latter domain.
    This looks like a logically fallacious argument (e.g. you're indirectly claiming we are unable to critically reflect on art, which is fundamentally a perception based activity). Lots of scientific and quasi-scientific disciplines require critical reflection on perception. How on earth do you think that a problem space is defined in the first place! Anyway, the fact that you have to perform such logical contortions to defend your argument is interesting, as it gives us a way to critically reflect on the validity of your position.
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  22. This paper Bayesian approaches to detection and attribution (J.D. Annan, 2010, in press, Wiley Interdisciplinary Reviews: Climate Change) provides some useful food for thought about how we might more reliably tease out a useful message from climate research. It addresses some of BP's concerns. Abstract: We consider the Bayesian alternative to the classical frequentist approach to detection and attribution of climate change. Some of the notable advantages of the Bayesian paradigm include a more consistent approach to competing hypotheses, a coherent interpretation of all available data, and an intuitively natural interpretation of the results. Well worth reading.
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  23. Doug #222 Indeed, the Bayseian technique (and the related but simpler Akaike information criterion) is a much better way of assessing hypotheses, than the standard hypothetico-deductive model. Especially for systems which have compleity, or where proper experiments can't be performed.
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  24. Guys, there is no merit of Bayseian or whatever technique until basic concepts are set straight. I have already explained to you why logarithmic dependence of UHI extends well below "rural" population densities, based on IPCC TAR WG1 2.2.2.1 and actual local UHI studies. I have also explained why it matters. Now I have pulled US historical population data for the 48 states of the contiguous US from the U.S. Census Bureau site and USHCN v2 monthly data from CDIAC (Carbon Dioxide Information Analysis Center), a GZIP-compressed file of the average of bias-adjusted mean monthly maximum and minimum temperatures (with estimates for missing values), as it is explained in the readme file. Both datasets cover the 110 year period of 1900-2009. As the Census Bureau site's presentation of data is a bit convoluted, it took some time to collect all the annual data. I've put it here as a gift for you. Then I've computed both temperature (t) and log population density (d) trends for each state. As part of temperature trend is clearly explained by population density trend, I've looked for a value c for which the area weighted sum of (t'-cd')2 over all 48 states is minimal. It turns out the optimum value for c on this dataset is 0.238°C/doubling, which is huge. But it is not outside the range indicated by multiple UHI studies. Without UHI correction temperature trend for the lower 48 states is 0.657°C/century while the actual trend with proper UHI adjustment is only 0.139°C/century. The US Census Bureau has population data down to county level. The exact location of USHCN stations is also documented. I leave it to you as an exercise to do it in a much more detailed way and also check the IPCC claim of UHI logarithmic dependence on population density. If it is done right, it can be published in the peer reviewed literature. I have no more time to spend on this issue, it's not my job.
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  25. so, Berényi Péter did calculations on a state wide basis regardless of the actual siting of the met stations (i.e. attributing the same increase in population to all stations) and kindly leave to us to do the proper calculations. In the meanwhile he maintains his quite strong claim, waiting for us to prove it. Great.
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  26. BP, am I correct in concluding that you believe/understand AGW to be (for want of a more appropriate word) "fraud"? I really need to know exactly where you stand on AGW in order to appropriately place your posts in context. If you have stated so elsewhere, then please direct us there. Thanks. There is a fundamental flaw in your argument/s. You are clearly extremely critical of the scientific method, yet you seem to fail to recognize that some of the more credible AGW "skeptics" use the very same scientific method and scientific philosophy in their research. Intriguing then that you seem to have no issue with their science, and in fact cite their "science" to try and undermine the credibility of legitimacy of research which demonstrates that AGW is either real or a concern. Therefore, by your logic the science used by skeptics should also be dismissed. I agree, but I suspect for different reasons.
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  27. BP, #224 That's a great example of a suspect analysis combined with small picture thinking. It is also not relevant to the other matter raised in this thread, which was about philosophical issues. Your reply appears to be an attempt to mislead by misdirection.
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  28. #226 Albatross at 06:10 AM on 23 June, 2010 am I correct in concluding that you believe/understand AGW to be (for want of a more appropriate word) "fraud"? I do not know. I am trying to figure it out for myself. In one thing you can be sure. I'll never believe a word based solely on the fact it appeared in a peer reviewed paper until I understand it properly and I think you'd better do the same. I've already seen quite some phony arguments here, on both "sides". I really need to know exactly where you stand on AGW in order to appropriately place your posts in context. That one you'll never get. This game with two camps and a noble cause is a rather silly one. What about truth? Many people here upon hearing a buzzword they reckon belongs to the other side get blind and don't even try to understand what's being said. One particular problem may be the English language lacks a genuine root for the concept "understand". People tend to underestimate the importance of a concept if it is not given at an early age as a primitive. Hungarian "ért" is a single sharp, well defined concept. It can be translated as understand, see, savvy, get, dig, catch on, etc. depending on context. With derivatives it gets even more interesting. Érthető is understandable, plain, luminous, lucid, intelligible, emphatic, comprehensible, clear, broad, articulate while értelem is understanding, signification, significance, senses, sense, reason, purport, mind, meaning, intelligence, intellect, import, headpiece, effect, comprehension or apprehension. But in fact it does not mean all these things, hardly any of them. It's a single coherent act. That's what I am looking for.
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  29. > I'll never believe a word based solely on the fact it > appeared in a peer reviewed paper Wise; that's only the beginning; then look for citing papers and followup work, which always come along if the idea is interesting > until I understand it properly What if you can't? Are you as smart and well educated as _every_ publishing scientist in every field? > and I think you'd better do the same "... everybody was finally equal. They weren't only equal before God and the law. They were equal every which way. Nobody was smarter than anybody else. ...." http://www.tnellen.com/cybereng/harrison.html
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