I’ve had to think hard about how best to moderate the comments on this website. A number of the recent posts have had more than 100 comments, and one has passed 200. Just following them is a decent amount of work, and it gets in the way of other writing important to me. My own practice has been to respond to anyone who I think is seeking a real answer to something, or who has found a weakness in what I have written, or who seems to have misunderstood what I wrote. I learn from such encounters. If I find I have been wrong I say so.

Since the beginning of the year there has been a significant increase in the number of comments, and in particular in the number of what I see as quite unproductive comments. A disproportionately large amount of the latter has come from two commenters, ‘David’ and ‘Ross’. I put their website names in inverted commas to indicate that they may or may not in real life possess those first names. ‘David’ has been a frequent commenter for a long time, while ‘Ross’ seems to have arrived on this website in mid-March. What is an ‘unproductive comment’? Well, I am sure that it depends on your point of view.

Mine starts like this. My essays tend to be based on data of some kind, in relation to a question of some kind. This is particularly the case where the subject matter is ‘climate change’ or anthropogenic global warming (AGW). I recognise that I have a position, and I put it forward, using the best data that are available. If there were a superior position, I would recognise it because it came with even better data and argument. I am always pleased if a commenter directs me to something I haven’t seen that is relevant to the question, and usually somewhat mortified if I ought to have seen it myself. I think those are most productive comments. I have let commenters say what they like, even when the language is abusive or coarse (there have not been many of the latter). I try to be courteous and helpful, and hope that commenters take their cue from my own style and tone. That has been the rule up until now.

Unproductive comments, in my opinion, are those that sledge another commenter, that contain no useful information, that try to lead discussion down a different path altogether, or that simply comment on a comment. You can live with a handful of these, but when they become dominant they seem to me to change the character of the website and its discussion. And people complain, not just in the Comments section itself, but in emails to the website manager — me. Not only that, some other commenters cannot resist replying in kind, or going down the new, hi-jacked path. The Comments then become an unproductive mess.

What to do? I thought I should go back to the beginning of the year. ‘David’ is fond of suggesting more work for me to do for him, so I looked at each of his comments since the beginning of the year. From January 11th to the end of April there have been 31 essays and a little over 2500 comments. Just under 20 per cent of them have been provided by ‘David’ (I may have missed one or two), twice as many as my own, and I am dealing with all the subjects that have been in all the essays. ‘David’ has a real penchant for anything to do with ‘climate change’, and early in April I felt that his attitude was so aggressive and unproductive that I said I would not respond to anything he wrote for the remainder of the month. That was perhaps not an inspired reaction, for it was as though the teacher had left the classroom, with ‘David’ if anything then increasing his verbal activity, which a number of commenters found obnoxious. He must spend a significant amount of his life on this website.

His contributions over these four months can be divided into five groups:

  • Quips, irony, sarcasm, ad homs and judgments as from on high: 186
  • Comments on other people’s comments: 150
  • Hi-jacking the thread to an interest of his own: 48
  • Criticisms with some content on the actual subject under discussion: 48
  • Offering links to something else without much or any argument or evidence: 22

It will be plain that the boundaries between these categories are rubbery, and on another day I might have provided slightly different totals for the Quip and Comment groups. But it will be plain that the positive contribution that ‘David’ offers is pretty small — about 10 per cent — while the total amount people have to wade through to get there is high. From mid-March to the end of April commenter ‘Ross’ added 239 of his own comments, of which only 36 have any useful content at all (about 14 per cent), and that is being most generous about the meaning of ‘useful’. Most are cheap shots, as the Americans call them (see Merriam-Webster).

After some consultation around the Internet, I have decided to change what I do with comments. From now on all commenters will be restricted to a maximum of three comments in any one day, which is a common rule for websites like mine. The contributions of ‘David’ and ‘Ross’ will go into moderation, meaning that I have to vet them before they are published. In their case, I will want to see two contributions that contain data and argument, not just links, for every quip or comment on someone else.

If they wish to continue the new rule will mean that both will need to avoid tedious repetition and smart-arse comments about other commenters, to stay on topic, to desist from changing the subject to one of their own choosing, and generally to engage here with good argument and data, not grand assertions that lack both.

Since ‘Ross’ believes in free speech, he will doubtless feel that Big Brother is about. He could with profit go back and read the arguments he and I have had on that subject (no, ‘Ross’, do your own work). With freedom comes responsibility: to dominate discussion with egregious comments may illustrate that one has freedom, but it is a pernicious freedom. Which is why we have rules about freedom of speech — even in the USA, where the First Amendment apparently guarantees free speech.

I am sorry that I have to do this; it has not been necessary in the four years that this website has been operating. But I did not create it in order to allow someone to have a free ride at the expense of other commenters. The same rules will apply in the case of any other commenter whose contributions become numerically excessive, or who cannot follow the general civility rules that have been part of this website since it was started.

I’ve saved this cartoon for the right occasion. I think this is it.





  • David says:

    None of this post suggests any reflection on you own writings. You are not at all averse to engaging in personal attack, when the mood takes you. You are the one that chose to personally attack Professor Mann some weeks back. You are the one that chose to characterise Cook’s analysis as an absurdity. How do you think that comes across? You routinely impugn the integrity of academics who conduct research in AGW.

    You think my contributions are insignificant. However, I would have thought that I point out your submission to Garnaut Climate Commission demonstrates a deeply flawed understanding of exactly what the error term is of some interest. No wonder you see so much “uncertainty” in AGW estimates. You do not understand what the error term actually represents.

    You say you are prepared to engage in honest debate, yet you ignore all technical discussions of statistics. I have been nagging at you for years now to re-read some basic statistics. Never once have you given any indication that you have done so.

    Good opportunity to reset the tone. I will abide by the new Ross-David rules, but let the record show it was not Ross or I who dropped the F-bomb. You will not get any more sarcastic posts, or links to the SMH from me. What about you Don? How long before you, post some disparaging commentary on the proponents of AGW? I do not think you will last a month. We shall see.

    • Don Aitkin says:

      I’ll accept this post as having content. It is boring to have to respond to your remarks because there is so much repetition in them, and you never seem to get the point. Just a few here.

      Michael Mann: Yes, I described him in unflattering ways. He deserves it. There is a whole book devoted to critical remarks about his work, by climate scientists of all kinds. You haven’t read the book. You think he is a great scientist. But I’m prepared to bet a bob or two that you haven’t read any of the critiques by people like Steve McIntyre.

      Cook: Yes, the 97 per cent claim is an absurdity, and I showed why. Your defence of his work in pathetic. Again, I doubt that you read any of the critiques that I listed. I’ve read them all, and I wrote my own analysis of his paper when it came out. The work is simply dreadful. You don’t agree. But you don’t EVER seem to offer an analysis of the critiques, or balance what you think with what others think.

      I don’t, as it happens, routinely impugn the integrity of academics who conduct research into AGW. I do frequently criticise and name academics like David Karoly, Will Steffens, Lesley Hughes and others for acting as activists in what is a policy domain, in which the science does not, in my judgment, warrant the policies that they propose or endorse. I have debated two of them, and I thought they were evasive in both cases.

      Yes, you present yourself as an expert in statistics, but I don’t see much evidence of the expertise. You have a view, and you stick to it. Fine. Quite a few people with real expertise in statistics read this website, and I’ve had a suggested correction once from one of them. It wasn’t something that you pointed out.

      You have posted much the largest number of comments to this website, but because you don’t really debate with any data or argument, the value of your comments is slight.

      • David says:

        Good so from now on three posts a day and all about earnest debate. So this is what you have posted in your submission to the Garnaut Climate Change Report.

        “This question is essentially about measurement, ‘Average global temperature’ is a construct, not a real observation, and there is considerable uncertainty about the reliability and validity of the construct. In any case, the IPCC’s estimate of global warming in the 20th century is 0.60 C ± 0.20 C, which is unlikely to be greater than the error surrounding the measurements. It is not a large increase”

        I have never seen anyone compare the “error surrounding the measurements” with a 95% confidence interval the way you have suggested. It seems like you are proposing that after estimating the confidence interval for temperature increase (0.60 C ± 0.20 C) that researchers go back and then perform some ad hoc estimate of the “error in the thermometers” and compare.

        Have you ever seen anyone use this approach? Are you able to (i) cite a paper or (ii) cite a textbook to illustrate what you have in mind?

        The confidence interval does includes all random error, including the measurement error, and any other source of random error (i.e. yi – yhat).

        • Don Aitkin says:


          Because your posts are now in moderation, I have to read them and make a decision each time. And because I am involved in the Canberra International Music Festival I am not, as I usually am, at my computer all day. Hence the delay.

          Now to your question. Is the IPCC’s ‘0.60 C ± 0.20C’ a confidence interval at all? If it is, on what is it based? It can’t be based on sampling error. The IPCC doesn’t tell us, and in default one must assume that a group of chaps sat around arguing about how uncertain that 0.6C figure was and plumped collectively for 0.20C. I find it impossible to see it as a standard error with the kind of confidence interval you think it is. Of course, if you have other information by all means tell us.

          The great problem is SST. The Pacific is about a third of the whole world, and there has not been much data from it until Argo. What we had, for the best part of a century, were occasional measurements in situ as ships went about their business. They used standard sea-lanes, so we know a bit about them. We know very little about anywhere else in that enormous body of water. I was on it for eleven days last October without seeing anything but sea.

          A statistician known to me has pointed out that, given the small number of data points, you can’t estimate an overall ocean temperature without either having some dynamic model for the movement of water in the ocean, or making gross assumptions of stability (i.e.’ it’s all the same everywhere around there’). To the best of my knowledge no one has developed the former, and there is too much reliance on the latter.

          Having said all that, I think I was guilty of sloppy writing in 2008. The sentence that you object to would have been just as strong without ‘which is unlikely to be greater than the error surrounding the measurements’. My position was and still is that there is so much error in all these measurements that being told that, for example, last year was the hottest year on record is simply fatuous. We don’t know, and will never know. But I am more or less happy to accept that the earth warmed by around a degree C, in fits and starts over the last century and a half. Yes, there will be error in that, too, but the sentence is imprecise enough for that not to matter too much. When the IPCC says 0.6 ± 0.2 my hackles rise, because this is too precise, and is unlikely to be accurate.

          Now how about you do some real work, and deal with the objections to Cook’s 2013 paper, which you think is so fine. It will be a lot of work, but I am sure you could do it if you set your mind to it.

          • Bryan Roberts says:

            Don, may I suggest that you can’t cure idiocy by saying ‘don’t do it quite so often’.

          • David says:

            Don in a perfect world it would be nice to meet you and chat about this over a beer (wine). I am sorry the conversation became over heated.

            I can agree with what your statistician friend has said. But this is an argument about bias. What they are suggesting, is that the mean temperature obtained from the small number of data points are not an accurate reflection of the “true” mean. They would need to convince me that thermometer performance has systematically changed over time. But at least I can understand where their reasoning is coming from. It makes sense to me.

            These sorts of bias arguments do exist. One nice example was when the altitude of the satellites that collect temperature data were found to have slowly and inadvertently dropped over time. Once identified it can be corrected for. However, unidentified and uncorrected bias is the bane of any statistician’s professional life.


        • JimboR says:

          “‘0.60 C ± 0.20C’ …. one must assume that a group of chaps sat around arguing about how uncertain that 0.6C figure was and plumped collectively for 0.20C. ”

          Don, I am gobsmacked that you think that’s how science works.

          ” When the IPCC says 0.6 ± 0.2 my hackles rise, because this is too precise…”

          What you see as precise, I see as very imprecise. Imagine the outrage if your electricity company had a “± 33%” next to your latest meter reading. That broad error range is spat out by their calculation and is a reflection on the variance of all the datapoints that went into their calculation and on how many datapoints they had. The reason it is so imprecise is no doubt related to all your concerns about measurement issues. Your concerns are already addressed, right there in that ± 33%.

          I refer you back to a simple spreasheet experiment I did back in this thread: http://donaitkin.com/the-first-for-2016/
          I took a virtual thermometer and broke it so that it could only read to the nearest 5C. By any measure, a thermometer that only displays: 15C, 20C, 25C, 30C is a fairly blunt instrument. I then exposed that thermometer to a linear temperature ramp of 0.7C per minute and got readings that looked like:
          25C, 25C, 25C, 25C, 25C, 25C, 25C, 30C, 30C,….. ,
          If at any instant during the experiment you’d asked me what the temperature was, I would have to reply: I’m not really sure, but somewhere around 25C (or whatever the broken thermometer was reading at the time).

          But if at the end of the experiment you asked me the rate of change of temperature during the experiment, I could reply 0.6957C ± 0.0211C with 95% confidence. In other words, I’d be prepared to bet with 95% odds that the slope is in the range 0.6746C and 0.7168C. All I had to go on was a wristwatch and a bunch of 25C, 30C, 35C… temp readings and yet I got remarkably close to the actual slope of 0.7C.

          “I think I was guilty of sloppy writing in 2008”

          Perhaps, but you repeated the claim again much more recently than that:

          “It passes belief, at least to an agnostic like me, that indicated changes of tenths of a degree C are meaningful when the measurement errors must be greater than this.”

          • Don Aitkin says:

            Sorry you are gobsmacked, Jimbo. How then do you think the IPCC arrived at its ± 0.2 estimate of error? Was it just one person?

            And I’m happy to repeat my view that indicated changes of tenths of a degree in average global temperature, or global temperature anomaly, are not meaningful. There’s too much error in the original measurements, errors of all kinds. And there’s no reason to assume that they all cancel out to zero, either.

          • JimboR says:

            ” How then do you think the IPCC arrived at its ± 0.2 estimate of error? Was it just one person?”

            See my earlier reply: ” That broad error range is spat out by their calculation and is a reflection on the variance of all the datapoints that went into their calculation and on how many datapoints they had.” I think it was spat out by the same algorithm that spat out the 0.6 number, and I suspect they used similar techniques to what I used to spit out my “± 0.0211C”.

            So just to clarify your position…. do you accept my “± 0.0211C” error estimate for my simplistic textbook example, and then going on to claim that doesn’t apply to something as complex as global temperatures? Or do you believe me quoting a slope estimate of 0.6957C ± 0.0211C when I only had a thermometer that could read to the nearest 5C is also bogus?

          • Don Aitkin says:


            Your textbook example is fine as a classroom exercise. Now apply it to one third of the earth’s surface, for most of which there are no measuring points at all for most of the past century. Those that we have do have were derived in different ways using different methods. We know nothing, or next to nothing, about how they relate to one another. People have had a go at relating them, but agree that there is a great deal of error involved, and they don’t know much about it either. They put error estimates around their data. but it is, I think, a guess.

            Why do we do this at all? Because of the almost insane desire to be able to talk confidently about an average global temperature…

          • JimboR says:

            I think the insane desire is more to be able to talk confidently about average global temperature change (and rate of change) rather than average global temperature, e.g. how does the temperature today compare with the temperature x years ago. The point of the classroom exercise is to show you can often do much better at the former than the latter.

            With my nearest-5C thermometer I could quote it to ± 3%, while the IPCC quote under discussion here (0.6C ± 0.2) is only as good as ± 33%. Their error range is a whole order of magnitude worse than my nearest-5C thermometer. I just don’t see the precision in that estimate that you see. To me their estimate screams out that they really are stuck with crap data and they’re declaring that right there in the ± 33%.

          • David says:

            Here is a simple numerical example to illustrate what JimboR and I are driving at.

            The first column of numbers is of 100 random numbers between 0 and 1 generated by excel. The numbers are reported to six decimal places. Think of these as the temperature readings from a perfectly accurate thermometer. The second are those same 6 decimal point numbers rounded to whole integers, either a 0 or 1. These are the temperature estimates from a very “inaccurate” thermometer.

            So the question is how can estimates derived from the “inaccurate” thermometers be meaningful?

            The mean of the first 10 readings from the “accurate” thermometer is 0.427575. And the mean of the first 10 reading from the inaccurate thermometer is 0.3. So we can say the inaccurate thermometer is out by 12.75%. Now look what happens when we increase the sample size to 100. The mean from the “accurate” thermometer is 0.512209 and the “inaccurate” is now 0.505051.So now the “inaccurate” thermometer is ONLY out by 0.72%.

            You will get a different response each time you select a new set of random numbers. But the point is that that even using a thermometer that reported temperature as whole degrees, it is still possible to get meaningful results reported to two decimal points as the sample size increases.

            0.490931857 0
            0.559979101 1
            0.499933143 0
            0.684712303 1
            0.209834676 0
            0.683650011 1
            0.189342969 0
            0.124260391 0
            0.375459774 0
            0.457648812 0
            0.823864333 1
            0.293765539 0
            0.461041505 0
            0.718557172 1
            0.971864133 1
            0.91599928 1
            0.818684125 1
            0.884246128 1
            0.825924082 1
            0.533149436 1
            0.278733355 0
            0.11135827 0
            0.965907942 1
            0.633028211 1
            0.947026855 1
            0.929823438 1
            0.144846999 0
            0.403954063 0
            0.121158913 0
            0.78195679 1
            0.532014499 1
            0.371880735 0
            0.216990854 0
            0.970859668 1
            0.848438939 1
            0.768614416 1
            0.567682783 1
            0.653940619 1
            0.59102558 1
            0.160053541 0
            0.478573885 0
            0.798249971 1
            0.343823689 0
            0.118317507 0
            0.764390487 1
            0.951495309 1
            0.314609368 0
            0.049875279 0
            0.129200423 0
            0.221501174 0
            0.665276702 1
            0.54154436 1
            0.413836994 0
            0.145050516 0
            0.150362881 0
            0.885705036 1
            0.530470045 1
            0.414136505 0
            0.393376941 0
            0.92766708 1
            0.392178699 0
            0.069336378 0
            0.801017865 1
            0.067420119 0
            0.447772077 0
            0.819825529 1
            0.235475562 0
            0.572287155 1
            0.661677633 1
            0.529604586 1
            0.842217724 1
            0.857691671 1
            0.682523449 1
            0.99144799 1
            0.718447579 1
            0.217997762 0
            0.722684894 1
            0.585376536 1
            0.732614162 1
            0.574970591 1
            0.384687682 0
            0.176631287 0
            0.405003502 0
            0.469682461 0
            0.485571745 0
            0.103759796 0
            0.246951879 0
            0.883939502 1
            0.055662668 0
            0.300574321 0
            0.341651736 0
            0.236799894 0
            0.225035117 0
            0.609602497 1
            0.625162177 1
            0.237372969 0
            0.570095962 1
            0.904130562 1
            0.164172318 0

          • Don Aitkin says:

            Jimbo, my three dots at the end implied what you supplied. Perhaps I should have written it all out. Yes, there can’t be climate change unless we have estimates for the globe (given that the models can’t do small parts of the globe well), so we have to have data for places where there aren’t any. So we have to estimate. I think the estimates have a large amount of error built into, so large, that I find it hard to accept ‘statistics’ about them. We’ve been through all this before. I’ll accept that it’s quite likely that the earth has warmed up by about a degree in the last two centuries, but won’t accept that statements about annual changes expressed to three decimal points mean anything at all. You disagree. So be it.

            David, thanks for yet another demonstration of your knowledge. You are invited to join Bimbo in applying all this to SST in the Pacific Ocean 1901 to 2000.

          • JimboR says:

            “I think the estimates have a large amount of error built into, so large, that I find it hard to accept ‘statistics’ about them. ”

            So Don, without even considering AGW for a moment, at what error level do you think statistical analysis should be abandoned? Can you demonstrate with a simple classroom example of your own why statistical analysis breaks down at that level?

          • Don Aitkin says:

            Dunno. Doesn’t seem really relevant to what I am writing about. Let’s suppose you had three measurements for the 18th century, separate in time and space and three for the 19th, likewise. One could average them and find a century-on-century trend. I would think that pretty silly, and imagine that you would, too. Somewhere past that would come a time where I would take such averages more seriously, but I would need really representative data points for the whole planet before I started inspecting the differences between averages with real interest.

            As so often, I feel that you are not really contributing to the discussion, but trying to lead me astray! Your comment isn’t really a response to what I wrote (the bit that you quoted). Why doesn’t it pass belief for you?

          • JimboR says:

            David, one reason the oversampling worked so well in your example is because your input was so dynamic, jumping around the full range from 0 to 1. Imagine if you were trying to measure a very steady value and there was very little noise in the system. Your left column would be just a long string of 0.490931857s and your right column would be a long string of 0s. At first blush you might think you’ve got no way of teasing out all those digits with just a long string of 0s to work with. The clever boys in Sig Proc came to the rescue with dithering, whereby you add white noise to the signal you’re measuring to shake it up a bit. You need to be somewhat careful in your choice of noise amplitude: too much and you’ll end up with a noisy result, too little and you’ll still be stuck with too many 0s. And your noise must be truly white and balanced around zero so as not to introduce a DC offset to the result.

            If you read the BOM’s publication entitled:

            Techniques involved in developing the Australian
            Climate Observations Reference Network – Surface Air
            Temperature (ACORN-SAT) dataset
            CAWCR Technical Report No. 049

            you’ll see they do something similar. Early AWSs apparently only reported temperature to the nearest degree. They state that this “will have no systematic effect on mean temperatures”; a concept that the show-us-your-error-bars botherers continue to struggle with. But they go on to point out it does add a bias to statistics like “number of days below 15C”. They fixed that by adding white noise to the measurements.

            Don: “trying to lead me astray! ”

            Au contraire Don. I’m trying to get you focussed….. on the maths! If I were trying to convince Garnaut that the “0.6 ± 0.2” result is bogus I’d seek out the dataset and algorithms that produced the results. I’d study them and the science behind them until I understood them as well as the authors. Assuming their mistake wasn’t a trivial one, I’d then probably have to learn their craft even better than the authors so as to spot the flaw they missed. Then I’d present all that to Garnaut with an accompanying note along the lines of “the error is on line 242, I’ve highlighted it in red”.

            Clearly Garnaut wasn’t persuaded by your vague hand-waving about error measurements being larger than the slope of the trend line. I dare say that like me, he probably knows from his own field that is often the case. He may well even have demonstrated it to his undergraduate students with an example similar to my classroom example above.

      • BB says:

        I think David’s comment is a rationalisation which would not have been forthcoming unless if you had not taken the action you did. He is either a Green party member or Green in thought. One of my brothers is a member of the Green party and when presented with the deep ecology manifesto couldn’t see that much wrong with it. The only sticking point for him was how to remove some billions of people to put civilisation back into the 1800s. I absolutely despise him for it and much of his argument is the same as David’s. David revealed something in his comments about Mann and Cook. Both of these people presented something of great import one claimed that temperature was climbing dramatically and the other that 97% of climate scientists agree with this. But they are the same in one crucial aspect neither thought it was important to reveal their data or their method. They position themselves as authority David and my brother do not have to have a reason to believe it. They believe without question and for them the worst sin is to doubt and question it. This is the essence of what you and many on this blog are not. We do not accept anything as a faith and that’s what is being written about. I brother and I suspect David are incredibly ignorant about the whole subject, they pursue it as a faith. For example brother has no idea of the role of water vapour as a greenhouse gas.

        • David says:

          BB your brother sounds nice.

        • JMO says:

          And I bet your brother has no knowledge on CO2’s IR absorption lines and how they relate to Earth’s IR radiation into space.
          It is just the mantra – CO2 is a greenhouse gas and is causing climate change. All so simple, no thought, analysis or critical thinking allowed or required here.

          The Green’s belief is CO2 is a toxic polluting greenhouse gas, it is bad for the environment and must be stopped. No further discussion, end of story.

          It reminds of George Orwell’s Animal Farm mantra – 4 legs good- 2 legs bad; until Napoleon (the head pig and leader of the farm) walkedon2 legs! Then the mantra changed to 4 legs good, 2 legs better.

    • Rusty of the West says:

      David, I’m new to this site and you lost me at the point where you started defending Mann, that was the end of your credibility.
      Good idea and strategy Don, too many of this type of site get hijacked by the likes of David who work hard to try to keep the masses misinformed.

  • BB says:

    Thanks Don I have no problem with what you want to do. They were taking over and do not have any regrets you were pushed to do something or lose the blog. I have no problem with your rules and I have no problem with a contribution from David or Ross which follows your rules. I too have been following the percentages not as far back as you did but of late what was happening with just over the odds. I don’t know what it is that there are some blogs Joe Nova I think which has a thumbs up and thumbs down thing it might be a better alternative for your but I don’t know.

  • Highly appropriate cartoon, Don!

  • Peter Kemmis says:

    Parodying Johnson about patriotism, one might say “in argument, ad hominem is the last refuge of the empty”. To quite an extent, the frequent failure by warmists to counter the data and argument provided by “AGW sceptics”, convinces me further of the soundness of the sceptics’ position. A retreat into the appeal to authority, or worse into ad hominem, assures me that the warmist cupboard is very bare.

    I’m happy to live with your ruling, Don. Hopefully, there will still be challenge raised against the sceptic side of the debate.

  • Alan Gould says:

    Yes, you give a fair anatomy of the infection that your website seems to have attracted, and your measure to deal with it is moderate and also fair-minded. One recalls Freud’s image for the suppressed item in the Unconscious Mind – a seminar where someone is shouting everyone down, so he is removed, the trouble with this being that he continues his rumpus on the outside of the lecture hall, only now everyone can hear the rumpus, but cannot decipher what is actually being said.

  • Neville says:

    This is okay for me Don and I think we’ll all have to lift our game. But it doesn’t surprise me that the true CAGW believers cannot provide any real evidence to counter our arguments and PR studies.

  • Bryan Roberts says:

    Since I was the source of the intemperate language, I note it is generally agreed that Ross and David are unapologetic pests, and I do not resile from my suggestion. David, in particular appears to be completely disconnected from reality, if you consider his absurd conceit that ‘Professor’ Cook “is one of the most influential academics analyzing climate change at the prestigious Global Change Institute at the University of Queensland”. Cook has a total of 15 publications, of which several are comments, two are blog posts, and none of which have been cited in any journal publishing serious climate science.
    I think you could have achieved the same result, with a lot less effort, by simply banning both of them.
    My apologies go to gnome, whose chiding was pointed and deserved: “Only a drivelling idiot has ever called Cook a professor”.

  • whyisitso says:

    Yes the deterioration of the comments section recently does diminish the value of your site to some degree. But I enjoy reading your posts. They make a lot of sense and are certainly based on real knowledge, unlike a lot of ‘issue-based’ blogs.

    It’s difficult to engage in permanent moderation of comments. Even Andrew Bolt has a comments section that is very poorly moderated, sometimes leaving over half a day before comments are continued. And he has the resources of News Corp at hand (although I do think his days at News is coming to an end. He certainly lacks true support from that organisation).

  • dasher says:

    Don…an elegant compromise. I can be accused of the odd ad hominem against the dreary duo, but I concede that the blog would be better without it. Cheer up mate its a good read and well worth your efforts…easy to snipe, hard to put forward well considered opinion that stimulates discussion.

  • Lenny says:

    Don, I read your site alot, post infrequently. I think your rules make alot of sense.

  • Neville says:

    This is slightly O/T. UAH temp update for April is Globe 0.02 C lower than March. NH is 0.09 C lower, SH is 0.06 C higher and Tropics are 0.05 C lower.

    http://www.drroyspencer.com/2016/05/uah-v6-global-temperature-update-f or-april-2016-0-71-deg-c/#comments

  • Geoff says:

    Thanks for your thoughtful and well argued pieces, Don. Endorse your action re the comments. Had virtually ceased reading after their hijacking by the serial pest “David”.

  • PeterS says:

    Well done Don. I am an avid reader of your blog and frequently refer your articles to others in my circle.

    I don’t comment often as I don’t have much to offer to improve what you have written. Being rational, and a critic of the climate change religion, much of which is based on pseudo-science, you were bound to attract one or more of the “trolls” who belong to the religion.

    Prof Judith Curry, the former chair of Earth and Atmospheric Sciences at the Georgia Institute of Technology:

    “It is inappropriate to dismiss the arguments of the so-called contrarians, since their disagreement with the consensus reflects conflicts of values and a preference for the empirical (i.e. what has been observed) versus the hypothetical (i.e. what is projected from climate models). These disagreements are at the heart of the public debate on climate change, and these issues should be debated, not dismissed.”

    As a scientist who has crossed swords with these trolls on “The Conversation”,I couldn’t have articulated a summation of my own position so succinctly.

    I appreciate your professionalism and the reasoned arguments you advance. Keep up the good work.


    Don, I was an avid reader of your site, but the climate change subject was become a drawn out series of “touche” movements.

    Perhaps the Climate Change subject be left out as it is a topic that has been thrashed to death.

    I feel there are regional issues, far more pressing than Climate Change, that can be be discussed.

    See you in a couple of months.

    • Don Aitkin says:


      I too would like to write about other things than climate change, which is why I am doing this long summary of my position. It will be done soon, so when you come back in a couple of months you will (hopefully) see a difference!

      • dasher says:

        Fair enough Don, but it would be a pity if your vacated the field of battle on this subject….as someone who listens to the ABC and reads Fairfax (as well as the Oz) I am astounded by the one sided presentation of climate change. Indeed I ruffled the feathers of an old (very smart) friend who was parroting ABC/Fairfax group think on climate change and suggested that he should read more widely as he appeared trapped by an inflexibility and lack of curiosity on the subject. I hit the target because I could see the penny drop…his arguments were not destroyed by mine but he had clearly not even considered that sensible people could no believe the orthodoxy. I referred him to your, and Judith Curry’s blog as sensible alternative views that will challenge his views. Keep up the good work mate.


        Don, perhaps leaving a topic open for (say) 4 weeks, and then closing it. I know this sound arbitrary, and it would prevent genuinely interested people arriving as “latecomers” months later. It may stop the matter becoming a touche orgy.

        And of course, you would need to generate a new topic every 4 weeks. But hey, you need a break too !

  • Neville says:

    Labor’s ETS scheme will just introduce more fraud and corruption into the already fraudulent CAGW mitigation mess. And of course zero change to the climate after wasting endless billions of our borrowed dollars for decades to come. Worthless scraps of paper costing billions that have no basis in fact, just ask Dr Hansen and Interpol.
    Yet we have fools that are happy to vote for the corrupt Green and Labor parties. Unbelievable.

    http://blogs.news.com.au/heraldsun/andrewbolt/index.php/heraldsun/comm ents/labor_is_signing_up_for_an_international_rort_in_carbon_offsets/# commentsmore

  • David says:

    Jimbo R
    “David, one reason the oversampling worked so well in your example is because your input was so dynamic, jumping around the full range from 0 to 1….”

    Yes agree. Statisticians take the law of large numbers for granted, but there are still doubters. Its history is interesting.

    “The Italian mathematician Gerolamo Cardano (1501–1576) stated without proof that the accuracies of empirical statistics tend to improve with the number of trials.[1] This was then formalized as a law of large numbers. A special form of the LLN (for a binary random variable) was first proved by Jacob Bernoulli.[2] It took him over 20 years to develop a sufficiently rigorous mathematical proof which was published in his Ars Conjectandi (The Art of Conjecturing) in 1713. He named this his “Golden Theorem” but it became generally known as “Bernoulli’s Theorem”. This should not be confused with the principle in physics with the same name, named after Jacob Bernoulli’s nephew Daniel Bernoulli. In 1837, S.D. Poisson further described it under the name “la loi des grands nombres” (“The law of large numbers”).[3][4] Thereafter, it was known under both names, but the “Law of large numbers” is most frequently used.”


    I will have a look at the BoM publication.

  • margaret says:

    Not to hijack the content but more to put this link in a more prominent place than where I put it yesterday so that ppl can read the contrasting styles of Canada and Australia.

    Contrasting styles of Westminster system.

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