I came across a little video in which Gavin Schmidt, the Deputy Director of NASA’s Goddard Institute for Space Science, an important temple of the AGW orthodoxy, sets out to explain how dealing with ‘climate change’ is like going to the doctor. It’s a short and straightforward little explanation. You turn up at your doctor’s surgery and he gives you a number of tests. Individually they might not seem directly related to your condition, whatever it is, but the set provides data for the doctor and when all the pieces of data are put together he is likely to see a pattern that will give him clues to the right diagnosis, and to a cure for you.

I’ve come across this little analogy many times, and every time I do it seems to me that there’s an important missing bit in the analogy. Because I (in this case, the planet)  haven’t gone off to the doctor with a condition. I’m healthy and well, so far as I can see. What happens in the ‘climate change’ domain is that the doctors are coming to me, and telling me, indeed, hectoring me, that I have a dangerous condition and that I must do something about it — now! In vain do I tell them that I’m fine, and things are going well. No, they tell me. We know better: you are in a serious situation, and things will go alarmingly wrong unless you do as we say.

The doctors have taken it upon themselves to seek out the patient, rather than the patient seeking out the doctor. Well, the orthodox doctors might reply, it’s only an analogy, because the world can’t go and seek the doctor. To which I might respond  but there’s no real evidence that the world is actually in serious trouble: food production is way up, arid areas seem to be a little greener, people are living longer and healthier lives, hurricane frequency is down, and so on. Ah, you’re living in a fools’ paradise, say the doctors, and they turn to governments and berate them for not doing anything about it, and whip up concern within the community.

It’s not a good analogy at all, because it breaks down when you look closely at it, and it leads to another problem for the orthodox. Which is that people employ the argument by analogy when it is hard for them to explain to someone why they ought to do something they don’t want to do, or can see no great good in doing. To say it once again, wearily, the science is not by any means settled.

Yes, most sceptics would agree that increasing CO2 accumulations in the atmosphere will in time increase temperature. But the increase is logarithmic, not linear, which means it happens slowly, and in any case there is climate variation caused by a range of natural factors as well, which can and do seem to buffer the effects of greenhouse gas emissions. And in any case a warmer world, at least on current indications, looks like being a better world for planets and animals.

Ah, but it could get much worse, say the climate doctors, and we are the experts, and you must listen to us — look, it’s like going to the doctor! But it isn’t.

To return to the usual practice in medicine, if I were to become increasingly worried about my losing weight and other disagreeable symptoms connected to my stomach, it is indeed highly likely that a panel of doctors would use tests and agree that I have stomach cancer of some kind. They would show me the test results, the X-rays, the specialists’ reports and so on, and I would go away, read, study and come to a view. It would likely be that of the doctors.

But in the absence of my plainly having something wrong with me, presenting at the surgery and asking for an opinion, nothing would happen. I am not yet a patient, and on the present evidence the planet is in fine shape. Humanity is conserving and caring for it as never before, in some respects overdoing it. I can’t see any clear sign that it needs a climate doctor, and even if it did I would be going to a wide range of specialists indeed.

[Update: Coincidentally, I did go off to my GP this morning, for a routine matter. I remarked that I felt extremely healthy, to which I got the following: ‘What is the definition of a healthy man? Someone who hasn’t had enough tests!’ I think that could be applied to the ‘climate change’ business, too.]

  • David


    “Yes, most sceptics would agree that increasing CO2 accumulations in the atmosphere will in time increase temperature. But the increase is logarithmic, not linear, which means it happens slowly, and in any case there is climate variation caused by a range of natural factors as well, which can and do seem to buffer the effects of greenhouse gas emissions. “

    You have an amazing amount of self-confidence. I defy anyone to look at this graph of global temperature for the past 100 years and confidently say that the functional form is log. I have posted a link to some log functions so you can compare and contrast.

    https://www.google.com.au/search?q=global+temperature+since+2000&espv= 210&es_sm=93&tbm=isch&imgil=vP4KFTB0mzEcrM%253A%253Bhttps%253A%252F%25 2Fencrypted-tbn2.gstatic.com%252Fimages%253Fq%253Dtbn%253AANd9GcQWMiMc 1VEBnn_0Y-GhWSePhs8DhHxytQEJpxy4pmcbudHBu6zr%253B2506%253B877%253B4-Dl uMFEScyP0M%253Bhttp%25253A%25252F%25252Fwww.giss.nasa.gov%25252Fresear ch%25252Fnews%25252F20120119%25252F&source=iu&usg=__Ryq43yj42mOTQ_Wkv9 OLcB5UsfE%3D&sa=X&ei=cRXwUqyzAYmriAeRgIHAAg&ved=0CEcQ9QEwBA&biw=1366&b ih=643#facrc=_&imgdii=_&imgrc=vP4KFTB0mzEcrM%253A%3B4-DluMFEScyP0M%3Bh ttp%253A%252F%252Fwww.giss.nasa.gov%252Fresearch%252Fnews%252F20120119 %252F616910main_gisstemp_2011_graph_lrg%255B1%255D.jpg%3Bhttp%253A%252 F%252Fwww.giss.nasa.gov%252Fresearch%252Fnews%252F20120119%252F%3B2506 %3B877

    Some log functions

    https://www.google.com.au/search?q=graph+of+a+log+function&espv=210&es _sm=93&tbm=isch&imgil=U5kYdBmihVLWHM%253A%253Bhttps%253A%252F%252Fencr ypted-tbn0.gstatic.com%252Fimages%253Fq%253Dtbn%253AANd9GcREbkBTnZRCmr 32VdvEadfbTqBdDNmP93iNzYqg2cWYlAYjlQoF%253B305%253B298%253B4MaY9mLKX9l EIM%253Bhttps%25253A%25252F%25252Fpeople.richland.edu%25252Fjames%2525 2Flecture%25252Fm116%25252Flogs%25252Flogs.html&source=iu&usg=__Cedli6 rLmRsSdlb2WpjN6vmUfxg%3D&sa=X&ei=Bx3wUqzYEce3iQfbs4GYAg&ved=0CDUQ9QEwA Q&biw=1366&bih=643#facrc=_&imgdii=_&imgrc=U5kYdBmihVLWHM%253A%3BZbWSCm Tdw51R_M%3Bhttp%253A%252F%252Fpeople.richland.edu%252Fjames%252Flectur e%252Fm116%252Flogs%252Flog2.gif%3Bhttp%253A%252F%252Fgetoffmyinternet s.net%252Fforums%252Fhealthy-living-bloggers%252Fundressedskeleton-now -blatantly-giving-out-ed-tips%252Fpage-125%252F%3B305%3B298

    If anything over that time period the increase in global temperature has been exponential rather than log. But the functional form is a bit of a furphy. The more important question is whether the projected increase in temperature, be it predicted with log, exponential or linear model, is going to be manageable.

    • Don Aitkin

      David, you’re missing the point. That CO2’s effect on temperature rise is logarithmic is simply part of radiative forcing. It is not a simple linear relationship. Look it up in Wikipedia (‘radiative forcing’). Your graph is not a demonstration of the relationship. I tried to put in the Modtran graph but I don’t think it worked. Anyway, you can see a version in the Wiki article.

      • David

        OK I will check it out

      • David


        If you look at the graph you have provided the rise in “Net Downwards Forcing” over the CO2 range of 400 ppm (the world’s current status) to say 800 ppm is essentially linear. So there appears to be little meaningful “slowing” of Net Downwards Forcing. Form my understanding.

        • dlb

          Yes, it is essentially linear in that range but the slope is almost negligible. From memory I think this forcing would equate to just over one degree C of warming for a doubling of CO2.

          Of course this rise is without the dubious positive feedbacks added to climate models. Like Don said above, the feedbacks could well be negative. As the earth has not turned into a frozen ball or boiled off its oceans, my money would be on the negative feedbacks predominating from any perturbation.

          • Don Aitkin

            I agree. There is an obvious slowing if you look at the horizontal axis, and recognise that it is also a measure of time. The red line represents perhaps 1780, and the green (?) say 2000. The black line represents the future moment when CO2 has doubled. The rate of increase is always slowing. The first additions of CO2 have more effect than any later addition of the same size. At the rate of increase shown by RSS for the past 17 and a half years, it will take something like a millennium to get to double the pre-industrial level of CO2.

            I don’t mean at all that such a tiny rate (almost none) is going to continue. I have no idea. But you can see the effect of a logarithmic relationship from the Modtrans graph which, to my surprise, did survive my attempt to include it!

  • BoyfromTottenham

    Good article, Don. However I would add a bit about after “Ah, but it could get much worse, say the climate doctors, and we are the experts, and you must listen to us”, that goes something like: “…because we have a magic computer model that knows everything about everyone on earth and can predict (sorry, project) whether they will get really sick in (plug in a scary number) years if they don’t take our very expensive medicine, the details of which we cannot divulge (and, sotto voce, “the results of which we take no responsibility for”)”. Sound about right?

    PS – Unfortunately I think the CAGW P&D (propaganda and disinformation) team have been flooding the media with this false ‘doctor’ analogy for so long now that it has become ‘received wisdom’, which is almost incurable.


  • PeterE

    I agree, the analogy is false. The Drs have arrived with a barrowful of guilt and offered us a solution. It used to be said of guilt purveyors: ‘don’t take the rope of rescue they offer you’ – or you’ll be dancing to their tune forever. It was a wise man who said ‘science is too important to be left to the scientists.’ The people who once called themselves Australians prided themselves on a scepticism towards authority. The question is: is the globe warming, or is the climate changing, in an unprecedented way? Taking into account what we have been able to discover from geological and other means about changes over the ages, the answer to that has to be no. There are too many cooks preparing this climate change broth. They range from the honest scientist to the manufacturer of windmills to the bureaucrats, national and international, and the media, to the would-be social engineers whose real aim is to redistribute wealth, and there are others as well. In short, ‘the jury is still out, so I would like a second opinion, Doctor. Don’t call me; I’ll call you. Thank you and goodbye.’

    • dlb

      “The people who once called themselves Australians prided themselves on a scepticism towards authority.”

      Perhaps “Whitso” is right, Australian civilization may have begun with the First Fleet. Though I could imagine the aboriginals having a good laugh at Georgian and Victorian clothing.

      Not sure what happened to this scepticism in recent years? Fortunately some of us still have critical eyes when fashionable theories like AGW emerge.

  • David

    So, Don did your “non-symptomatic”
    grandchildren get their childhood vaccinations? Are you taking a Statin or Ace-inhibitor?
    Ever had you blood pressure checked by
    your GP even though you did not complain of radiating pain down your left arm or blurred vision? Did you healthy wife attend
    ante-natal classes when she was preganant?

    • Don Aitkin

      And what is the point of these questions?

      • David

        “Because I (in this case, the planet) haven’t gone off to the doctor with a condition. I’m healthy and well, so far as I can see”

        These are all examples to varying degree of preventative medical care. Each intervention will typically be prescribed to a non-symptomatic patient or patient with early symptoms of a disease that will get worse if left untreated.

        I am not arguing if AGW is correct or incorrect per se. Nor do I accept that medical treatment should accepted without review or consent. But I think the medical analogy is a reasonable one, in many respects.
        Don I suspect that our views on science of AGW are reasonably close. Where we differ is in our emotional response to the debate. Where as you are irritated by extreme Green rhetoric I am irritated by extreme right wing rhetoric.

        • Don Aitkin

          It is a reasonable analogy, as I said, but with an important missing bit, which is what my post was about. The evidence shows that the planet’s biosphere is in good shape in many respects, and does not need the surgery that the AGW doctors are prescribing. Their diagnosis is not soundly based, and their proposed remedy both unnecessary and harmful. They may be right in the very long run, but again on the evidence we have plenty of time to find out more. My hunch is that Nature provides negative feedbacks that will prevent runaway warming that could be highly significant. We will learn more as time goes on.

          Rhetoric — I try to avoid it, wherever I find it, and go for the data and the argument.

          • David

            I probably should stop but I tend to use the word
            “rhetoric” in a non-pejorative way as the Ancient Greeks first
            intended to simply describe the art of discourse etc.

  • Julian McLaren

    If climate change was not an alarming issue, a lot of scientists would lose a lot of funding overnight, so of course they heighten the scare. Whether you agree or disagree, you still have to say that taxing CO2 in an attempt to solve the problem was stupidity at its finest. With carbon capture, bio fuels from algae, and all sorts of future energy sources that haven’t been developed yet, the future of humanity is sound. Humanity will always find solutions to seemingly intractable problems. Don, have you visited gapminder.org?

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