There are two debates about ‘climate change’

A little while ago I came across a remark by Stephen Mosher, whom I’ve mentioned before, to the effect that unless the sceptical minority came up with their own theory about how and why climate changes they would never be taken seriously. I didn’t think he was right, because one doesn’t need one’s own theory in order to see weaknesses in another. If they are there, you can point out weaknesses in any theory — you don’t have to argue from the  position of a rival theory. Or, perhaps, a sceptic can start from the position of the null hypothesis: there is nothing to explain. The sceptic suggests to the believer that he set out what he think has to be explained, and then offers a critique of that theory.

Then I came across the same point again, this time on a website that is new for me, that of the Fabius Maximus Website, which seems to me a real find. The Editor of the site, in reviewing new survey findings about the supposed ‘consensus’ of climate scientists, said that there were two debates, one about science the other about policy, which were often conflated, but that until sceptics developed their own theory they would always be in a minority. This time I got out my pen, so to speak, and wrote as follows:

You may be right in saying that unless skeptics can put together a theory they will remain minor players in the science debate about climate. But I don’t think that is the case with respect to the policy debate. There the issues are, at least in principle, much clearer. The MAGICC calculator shows that no matter how much we reduce greenhouse gas emissions, global temperature will stay largely unaffected. Why therefore are we doing this? The policy outcomes involve costs and benefits, and are easier to argue on the part of those who don’t come from the lab bench.
Otherwise, I agree with your post and its conclusions.

To my surprise the Editor accepted my argument, and changed his text to incorporate it. That is the first time such a thing has happened to a comment of mine, so it was a cause for celebration. Then I thought I ought to enlarge the point, and set out what the two debates are, here.

The science debate

I have set this out several times, most recently here. The orthodox position is that adding carbon dioxide to the atmosphere must led to warming, the warming will lead to more warming, the rising of sea-levels, droughts, floods and extreme weather events; the end is dire. Therefore we must quickly reduce greenhouse gas emissions, by ending our reliance on fossil fuels.

The sceptical counter to this is that carbon dioxide is not the only influence on climate, that warming does not necessarily lead to more warming (if it did we wouldn’t be here), that the dire forecasts are based on assumptions and modelling that have not shown themselves to be reliable. Ipso facto, there is no need to demonise fossil fuels. Not only that, the real evidence so far is that more carbon dioxide is good for the ecosystem. Inside all that is the null hypothesis: what is there actually to explain?

The policy debate

As I have said on a number of occasions before, I don’t think that the ‘science’ of climate, as embodied in the orthodox position above, is so complex and laboratory-based that only a real scientist can understand it. But the policy debate is even easier to comprehend, and it may not actually be helpful to be a scientist in coming to terms with it.

The policy debate starts with the assumption that there really is a problem, and we have to deal with it now. That is the basis of the Garnaut Report, and the frequent statements, most recently by Mr Shorten, and before him Mr Rudd, that humanity faces a crisis, and that only deniers refuse to take it seriously.

Then the sceptic asks what it is that is proposed to deal with this problem. If the answer is a carbon tax or an ETS, you ask what its central purpose is, and whether or not the benefits outweigh the costs (answer: the benefits are non-existent). If you are told that the aim is to keep temperature below the magic 2 degrees C increase, you ask on what basis that figure has been produced (the answer: it was a political compromise). If someone tells you that aim is to reduce global temperatures, you show them the MAGICC calculator, that suggests there would be no decrease that was discernible, even by 2050.

And you keep asking why are we doing this? Mind you, the sceptic will need to know a good deal of the literature, but not at a highly scientific level. The real problem in all of this is that, as I said in a recent essay, once you have decided to accept a job, like Ross Garnaut, or you are a senior public servant told that the Government’s position is that ‘climate change’ is real and dangerous, you have no alternative other than to take it seriously.

That leads to a second mind adjustment. Once you have done this for a little while, you find yourself committed to it for all sorts of reasons. The reasons may have only been a shrug at the beginning, but once you have put some time, energy and work into the question of how to deal with ‘climate change’, you become committed to it emotionally too. That means that you will be unable to deal with serious objections to the policy.

It is that awkward position, I think, that causes such people to yell at you that ‘the science is settled’, or that ‘the time for talk has passed’, or refuse to debate the issue publicly, or put your objection on their website into moderation, from which it never returns. The policy debate drives the science.

I haven’t thought about the issue from quite that perspective before, but I think it is at least one of the reasons that ‘climate change’ is so difficult. There may not be all that many believers in high places, but they are stuck with it. And they will remain stuck with it until we move into a long cooling period, or someone, somewhere, points out that the Emperor has fewer clothes than was at first thought.

Join the discussion 88 Comments

  • stevenmosher says:

    Don you miss the point.

    Let me state my argument simply.

    I give you a choice between two alternatives:
    A) be a skeptic who can only point out problems
    B) be a skeptic with an alternative theory that explains climate better.

    Which do you choose? Which is better? which will give you more influence,
    more standing. Have a look at all the names you know in science. Newton..
    Einstein, principles were not named after them because they only did critiques.
    They built new understandings. They did the whole job not half of it.

    Without an alternative theory you will quite simply have less power and you will be marginalized.Without an alternative theory, you are nothing.

    Your argument was that you didnt NEED an alternative theory to point out problems. That’s true, and doesnt come close to addressing my argument.
    Every theory has holes. Every theory has flaws. Pointing them out is step 1.
    Fixing them is step 2. you dont need an alternative theory, but if you dont have one, then you will be marginalized. If you have one, you’ll be better off.
    That is not a hard point to grasp

    If you want to be taken seriously you need to both. Sure, you can just do 1.
    but if that’s all you do, you will be marginalized and not taken seriously

    Here is how you can refute me.

    Find a collection of scientists who ONLY did step one. ones who only criticized
    and demonstrate how they were not marginalized or forgotten when the alternative theory came along.

    • David says:

      Well argued!

    • aert driessen says:

      Let me say it again. There is no single theory to explain climate change. Climate changes as the net result of multiple influences. Here are a few: Milankovitch cycles, solar cycles, solar wind fluxes affecting intensities of incoming cosmic radiation, shifting continents changing ocean currents, albedo effects of snow/ice cover, CO2 solubility, and more. Greenhouse gases very likely do affect temperature/climate to some3 extent but don’t forget that water vapour is by far the most potent and abundant (95%?) greenhouse gas. For goodness sake, CO2 comprises only 400 ppm (0.04%) of atmosphere!

      • stevenmosher says:

        There is a single theory. It consists of all the things that you mentioned. A side note you got the percentage of co2 wrong. The important percent is the percentage of opaque molecules. Transparent gases have no effect on radiation. Furthermore a tiny amount of co2 is enough to cause the growth of plants across the whole planet. How could such a tiny amount have a big effect? See how silly that tiny percentage argument is.

    • Don Aitkin says:


      Let me first agree with you that many of the objections put forward here do not constitute a theory. And you are right in saying that the CO2+ theory is the dominant one at the moment.

      But now let me defend the link between the two debates. If I can point out a series of objections to the AGW theory, dominant though it is (and I agree with John McLean that there is no single sceptical point of view), then it becomes harder (for me, at least) to accept that we MUST do THESE things NOW. It is only in the last few years that the orthodox have shifted the time of crisis from NOW to 2050 plus. Why have they done so? On the face of it, because there has been no warming of any significance for much more than a decade.

      Why should we restrict coastal development in areas where the sea-level rise over the past century was of the order of 9 cm? Why should we move expensively into subsidised alternative energy for which there is minimal storage capacity and know-how, when CO2 has been rising but temperatures relatively static?

      Yes, CO2 + is the dominant paradigm, but it is pretty weak, and does not justify large-scale economic and social change. I don’t have to have a rival theory to enter the policy debate with those objections.

      The difficulty is as I said in the essay, that very many in high places, both in science and government, have become committed to CO2 +. I think some of them would love for it to go quietly away, but while the passionate keep on telling us about how important Paris is going to be, they can’t help defending it.

      • David says:

        “I don’t have to have a rival theory to enter the policy debate with those objections.”

        So can you see why the ABC wont invite you on ?

      • Don Aitkin says:

        Sorry, should not mis-spell your first name, Steven. My apologies.

      • stevenmosher says:

        Let me first agree with you that many of the objections put forward here do not constitute a theory. And you are right in saying that the CO2+ theory is the dominant one at the moment.

        A) My argument which has gone unrefuted is more than that.
        B) My argument is that you wont be taken seriously unless and until you have a alternative theory.
        But now let me defend the link between the two debates. If I can point out a series of objections to the AGW theory, dominant though it is (and I agree with John McLean that there is no single sceptical point of view), then it becomes harder (for me, at least) to accept that we MUST do THESE things NOW.
        A) your acceptance of policy is not relevant
        B) policy makers will decide based on what they judge
        to be the best available evidence.
        C) if you object to the policy the best course of action is
        to come up with a better explanation.
        D) the fact that there isnt one sceptical viewpoint, is either
        wrong or trivially true. Wrong in that their viewpoint amounts to a collective no, and trivially true in that anyone
        can fiind minor differences between any two skeptics.


        It is only in the last few years that the orthodox have shifted the time of crisis from NOW to 2050 plus. Why have they done so?
        On the face of it, because there has been no warming of any significance for much more than a decade.
        A) There really isnt any orthodoxy in the science about
        the time of crisis. As with skeptics you can find
        a variety of opinion which shifts over time.
        B) Trying to hunt for motives ( why people say or think things)
        is both a logical fallacy ( the genetic fallacy) and
        a more uncertain endeavor than the very science we
        are talking about
        Why should we restrict coastal development in areas where the sea-level rise over the past century was of the order of 9 cm?
        A) Because the best science we have suggests that the future
        rise will be greater than the past rise. Skeptics
        have refused to construct a better science. So its
        rational to make your decision based on the best
        available evidence
        B) Your alternative theory here is that you can merely extrapolate the past to predict the future.
        C) Even under your alternative theory a policy maker can rationally conclude that more saftey margin is required.
        For example– google japanese mayor tsunami sea wall.
        D) Not all solutions require the restriction of coastal development. In the US for example we subsize rich liberals
        to build mansions on the beach. The point could also be
        addressed by insurance.
        Why should we move expensively into subsidised alternative energy for which there is minimal storage capacity and know-how, when CO2 has been rising but temperatures relatively static?
        A) because the best science says that the rise in temperature is the result of MANY forcings and C02 is just
        B) because the best science says that we can expect
        periods of no rise and should not be surprised when we
        see them.
        C) because “the temperature” you refer to is less important
        than OHC which is headed upwards.
        Yes, CO2 + is the dominant paradigm, but it is pretty weak, and does not justify large-scale economic and social change. I don’t have to have a rival theory to enter the policy debate with those objections.
        A) as I showed above you do in fact need a rival theory
        to do a better job of objecting
        B) you do infact need to understand the standard theory better because your positions are based on straw men.
        C) there is no evidence that there will be large scale economic and social change. The cost of mitigation is a paltry
        fraction of GDP.


        The difficulty is as I said in the essay, that very many in high places, both in science and government, have become committed to CO2 +.

        A) yes, skeptics thought that criticism was enough and they were wrong.
        b) in the vacuum, of course politicians will act rationally
        and choose the best science has to say no matter how weak.
        C) if the science was as weak as you say an alternative theory
        should have been a weekends work.
        D) The fact that skeptics refused to do this work, indicates that they may not fear the solution ( renewables) as much as they pretend to. After all if the economy and society is at stake you’d
        think that skeptics would call an all hands on deck to come up with a better theory than this weak one that has ruled for decades–

        • Don Aitkin says:


          This has been a long response to me, and unfortunately I am in Central Australia about to disappear into the desert (so to speak) for a few days.

          In brief, I accept that I will not be taken seriously by those who support the dominant paradigm.They have the power, don’t debate (you are a rare exception), and keep on saying the same things, whatever has happened.

          As it happens, I have been a policymaker, of a sort, and know well how policy occurs and is used by governments, in my own country and others. My experience is that people always overstate the originality and the power of their proposal, whatever it is. My experience and skill lie, in part in making sense of what is proposed, and providing those in power with what I think is an accurate account of what is proposed. My summary of what has been the dominant paradigm in climate science for twenty years is that it is scientifically weak and not good enough to justify the ‘remedies’ proposed for it. I may of course be wrong, but I have been studying this issue now for nearly ten years, and it seems to me that the science is more equivocal now than it was in 2004/5. The ‘certainty’ and vociferousness of those who promote the orthodox view, however, is if anything greater.

          I do not think that in my country, or yours, or in Europe, it is actually the case that ‘in the vacuum, of course politicians will act rationallyand choose the best science has to say no matter how weak’. Rather, politicians are governed in large part by what they have said in the past. Governments never admit error. What happens is that they are replaced (in democracies), and the new one is not necessary committed to the positions of the last one.

          I remain of the view that I can make a contribution — not a decisive one — by pointing out error, learning more as I go, and encouraging discussion.

          And I do not think it is ‘a weekend’s work’ to develop a new theory. After all, the dominant paradigm has not dealt with the role of clouds, cannot talk definitively about climate sensitivity, cannot explain why warming and cooling periods in the past have been linked to carbon dioxide emissions, and cannot explain the lack of significant warming in the last two decades. The fact that we go on debating all this is a pointer to the lack of clarity in the whole issue. If it really were all cut and dried, this website would not exist, and you would not have written your excellent book.

  • david purcell says:

    Reply to stevenmosher

    You want another theory? OK.
    Over the billions of years the climate has changed thousands of times, some significantly some minor like the present. For all these changes nature has been responsible. Look at all the variations since we came out of the last ice age and before fossil fuels were used.

    You have no way, therefore, to assume the burning of fossil fuels is the predominant cause of the relatively minor warming from about 1980 to perhaps the late 1990’s. Were we responsible for perhaps 0.3 deg of the 1 deg and nature the rest? And thats assuming we have been able to accurately obtain a worldwide average, which I doubt. Margins of error can be greater than the calculated increases.

    So my theory is that nature will always trump our outputs of CO2.

    • stevenmosher says:

      That is not a theory. A theory must explain the past and predict the future. Standard theory does that however imperfectly. To be taken seriously you need a quantifiable alternative that improves on the standard theory weak as it may be. When Dalton proposed the first theory of the atom it was crude. No scientist thought that merely criticizing it was sufficient. Criticism is necessary but you cannot stop there. My point remains. Until you beat the standard theory you will be marginalized.
      In short your replacement theory has no numbers.
      Words are not enough

      • dlb says:

        Do those who have the computers which run the GCMs allow researchers to run models that challenge the standard theory?

        • stevenmosher says:

          That is a good question and one of the problems that I see with how research is structured. That said Hans von storch once offered a room of skeptics free time on his cluster to test their ideas. The room was silent.

          • aert driessen says:

            Real scientists don.t use computers to project quadratic functions. They study evidence which means they focus on the past, well, at least for climate and other natural phenomena that can’t be replicated in a lab.

  • John McLean says:

    No, no, no. The expectation is that the sceptics will present a SINGLE counter-argument. That would be both unscientific and foolish. Multiple alternative explanations exist, my own included. Just check the more than 50 suggested reasons for the absence of warming over the last 17 years and you’ll find several that in essence say “Temperatures haven’t risen with increased CO2 because CO2 has negligible impact on temperature and the more like driver is .., (whatever)”.

    • stevenmosher says:

      Focusing on the pause does not constitute an alternative theory of the climate.

      • aert driessen says:

        Precisely, but if you can’t explain the pause, you can’t explain the cause. For me that rules out CO2 as a sole cause.

        • David says:


          True, CO2 is not the sole cause of temperature variation. But it is the cause of AGW.

          • aert driessen says:

            David, a molecule of CO2 is a molecule of CO2 regardless where it comes from. There is no distinction between ‘AGW’ molecules and any other molecules of CO2. The concentration of CO2 in the atmosphere goes up a bit and down a bit as a function of ocean temperature and additions from natural sources like volcanoes. So I don’t know what you mean by “AGW’ CO2.

          • David says:

            Have another read of what I wrote.

          • aert driessen says:

            David, you’re right. In the light of your original comment my reference to CO2 molecules is hardly relevant. But what I read now is that you think that anybody who wants to challenge the orthodox hypothesis must have their own theory to put up a a counter to the orthodox hypothesis (AGW has not made it to a theory for me — remains a hypothesis and a failing one at that). I see my first duty as exposing where the orthodox hypothesis does not conform to the evidence. I can point to lots of such evidence but I’ll start with 2.
            1. Ice core data show conclusively that temperature changes (for whatever reason) before CO2 responds, not the other way around. The lag is around 1000 years. This fits hand in glove with the chemistry of CO2 which shows that CO2 is more soluble in cold water than warm water or (less soluble in warm water) so that when oceans warm for whatever reason they release CO2 to atmosphere. And these releases can dwarf any other sources because oceans contain some 70 times more CO2 in solution than what the atmosphere holds.
            In the light of this, my point 2 is hardly relevant but the correlation between rising temp and rising CO2 is poor. The two trends diverge from the late 1940s to the mid 60s and there has been no correlation since 1998; no warming for 18 years despite ever-rising CO2. And so I say that CO2 does not drive climate change but could be a very minor contributor because of its ‘greenhouse’ property.. So we look for other evidence and the strongest correlations of data are atmospheric warming/cooling and solar cycles, but that’s another discussion. The study of those data are much more likely to lead to a theory than the study of warming/cooling and atmospheric CO2 concentration data sets.

        • stevenmosher says:

          Co2 is not the sole cause. See the forcing inputs for the cmip5 simulations..
          Solar ,so2, methane black carbon land use aerosols.. It’s a long list.

  • Keith Bates says:

    There are two big issues in the science part of the debate that actually make the sceptical position on climate change impossible to prosecute:

    1. The confirmation bias inherent in the system. The science, such as it is, has been so corrupted by the trillions of dollars stumped up by Governments to find human-induced climate change that it is in the researchers’ self-interest to find it, no matter how tenuous. Also those in the club viciously turn on the heretics and seek to exclude them from the insiders circle when they express a dissenting opinion.

    2. The second part is the propaganda war. People who only get their information from sources such as Fairfax, the ABC and similar once-authoritative media, will not know about dissenters (or “deniers”), or about the 18 year pause, or about other explanations for the warming of the late 20th Century. The role of propaganda is not to shape public opinion but to so control the information flow that any comment that differs from the received truth jars the consciousness and is immediately dismissed.

    I am heartened by the fact that despite over 20 years now of the alarmism and the failed prophecies of doom, “climate change” is rated as the least important problem facing the nation in most polls around the world.

    I am also heartened by real scientists such as Judith Curry, Joanne Nova, David Evans, Anthony Watts et al who keep looking at the facts, not the models and who are looking for explanations of what is happening.

    • David says:

      Keith your argument is not convincing. Any Climate Scientist who could “disprove” AGW would win a Noble prize. There is plenty of incentive and rewards for anyone who is able to do this.

      FYI, Judith Curry uses climate models.

  • dlb says:

    Your mind adjustment also belongs within the scientific debate. I shall just change a few words.

    “The reasons may have only been a shrug at the beginning, but once you have put some time, energy and work into your theory, you become committed to it emotionally too. That means that you will be unable to deal with serious objections to the theory.”

    • Don Aitkin says:

      Good scientists, indeed good researchers anywhere, take good objections seriously. If one’s work then requires a modification of some kind, you say so.

  • David says:

    What you have consistently failed to understand is that “cherry picking” is implicitly proposing a “theory” of AGW, but without the supporting scientific evidence. For this reason it is considered to be a weak argument. Skeptics argue that since 1998 the rate of warming has slowed. Orthodoxy will ask what is so important about the year 1998?

    For skeptics to be taken seriously, in the AGW debate, they need to begin their argument with some theoretical reason explaining why 1998 is special. Otherwise the argument will be dismissed as cherry picking.

    Even Judith Curry, in her submission to the US senate, evoked “possible unknown unknowns” to support her argument. This type of argument has a use by date, after which skeptics will be asked to propose a better model.

    • dlb says:

      What is important about 1998.
      What is important about July 16th 1945.
      What is important about July 20th 1969.
      What is important about December 23rd.
      What is important about January the 2nd.

      Nothing according to David, they are all cherry picked dates.

    • Geoff Brown says:

      What is important about 1998? CRU’s Phil Jones thinks it is significant.

      Dr. Phil Jones – CRU emails – 5th July, 2005
      “The scientific community would come down on me in no uncertain terms if I said the world had cooled from 1998. OK it has but it is only 7 years of data and it isn’t statistically significant….”

      Dr. Phil Jones – CRU emails – 7th May, 2009
      ‘Bottom line: the ‘no upward trend’ has to continue for a total of 15 years before we get worried.’

      1998+15=2013. It is now 2015

  • Doug Hurst says:

    Stevenmosher – David Purcell gives you the ‘alternative theory’ you seek, only it’s not a theory, it’s a simple and correct statement that the climate has always changed, often by much more than the recent very small changes of less than 1.0C in 130 years. Ice ages have come and gone in recent times, but for 80% of Earth’s history there were no ice caps. The proof of natural change is everywhere in the geological record.

    It is up to the alarmists to prove that something unprecedented and dangerous is happening to the climate (in the real world, not in computer models) given the above facts. They must then, as Don says, prove that curbing CO2 would help if we did have a problem. To provide such proof ‘climate sensitivity’ was developed, predicated on the belief that CO2 acts like the Earth’s thermostat. It was always challenged by some atmospheric scientists and, after no significant change in satellite readings for 25 years (according to Prof John Christy who runs the Alabama Climate Centre) is now largely discredited.

    In summary, a look at history tells us we don’t have a problem and if we did what we are doing wouldn’t solve it. As the old cliche says; ‘All we can do is hold up the mirror of truth, it’s not our fault if those reflected in it look foolish.’ What more do you want from us?

    • stevenmosher says:

      The climate has always changed is not an alternative theory. It is part of standard theory. An alternative theory must be able to explain the climate better than the standard theory

      • aert driessen says:

        Stevenmosher – the fact that climate has always changed may not be a theory, but it is evidence that, compared to how climate has varied naturally over the last 10,000 years (the Holocene, and indeed over the 4.6 billion-year history of the planet), the less than 1C degree rise in the last 130 years lies well within the limits of natural variability and therfore we have nothing to worry about at the moment. There are several theories, each one contributing to natural warming and/or cooling, of which solar cycles are probably the most important, but I don’t think that this is the place and time to discuss them, but I can if you press me.

  • Fabius Maximus (Ed.) says:

    This is a helpful discussion of this important subject. I’ve added a note about it and link to my post. (Side note: I would appreciate a link to my article for those readers interested in seeing it).

    Is there an alternative climate paradigm yet?

    Several climate scientists responded to my post, saying that there an emerging alternative paradigm. It is somewhat like the Gaia hypothesis first described by chemist James Lovelock. That is, it places greater emphasis than today’s models about feedback mechanisms that maintain Earth’s climate in an equilibrium state. For example, warming produces clouds which block sunlight (increase Earth’s albedo) and cool it.

    Perhaps the clearest statement to date is this review article in the March 2015 issue of the AGU’s Reviews of Physics: “The albedo of Earth” by Graeme L. Stephen et al (ungated version here).

  • aert driessen says:

    An excellent piece Don. I hope that it is read far and wide.

  • PeterE says:

    Warmists say that the climate is changing alarmingly. Why? Their theory is that the cause is the small amount of carbon dioxide that humans add to the total in the atmosphere. But hang on a minute. There is only a barely perceptible change in the climate, nothing out of the ordinary record over billions of years. So an alarm has been conjured out of nothing. There is no need for any theory. The supposed theory is just a flight of fancy, a scientific pipe-dream. But the warmists are alarmed; they need a policy. They don’t know how to formulate a policy, so they turn to the economists. The economists go to their bag of tricks. ‘Easy,’ they say, ‘put a price on it.’ The policy-maker knows that experts should be on tap, not on top. He figures that the debate has been going for a generation without perceptible harm. He formulates a policy: do nothing, keep an eye in it. If the scientists can justify their theory in due course, that will be the time to act. Meantime, lock the funds away from the economists. Also, do a cost-benefit analysis on what the scientists are producing. Maybe we can tighten the belt a bit there, since nothing unusual is happening. One thing is certain: there is absolutely no need whatever for an alternative theory.

  • Geir Aaslid says:

    Well written.
    The null hypothesis demands that the orthodox side must point out the observations proving how humans have caused significant climate change. In the absence of observations all significant change change is natural.

    However, in the second (political) debate, facts do not matter, observations do not matter, our starving plants are ignored. There is insufficient scientific understanding among our politicians. It’s all group think, faith or something else.

    The Emperor has no clothes. This is indeed the end of the Age of Reason.

  • Ross Handsaker says:

    “What is there actually to explain”. This seems a good question.
    We were concerned in the 1970’s about global cooling because temperatures had fallen since the mid 1940’s. Yet during this period carbon dioxide levels had been rising. Again, since the turn of the current century, the rise in carbon dioxide levels has continued but the trend in global temperatures is almost flat. From ice cores we know that changes in temperatures precede changes in levels of carbon dioxide. Temperatures plumetted at the end of the Eemian inter-glacial when carbon dioxide levels were at their peak for that period.
    Most of the absorption of outward long-wave radiation by carbon dioxide occurs in the first 100ppm (now 400ppm) and the effect of adding more to the atmosphere is logarithmic. Laboratory tests suggest a doubling of carbon dioxide would increase troposphere temperatures by around 1degC. According to enhanced “greenhouse effect” theory the upper troposphere should warm more than the lower troposphere which in turn should warm more than the surface. Data from weather balloons and satellites indicate this has not occurred.
    In any event why are we concerned about a warmer climate; historically, humans struggled during the cooler Little Ice Age when population in Europe fell by 30%.

    • There is actually a three sided FAKE debate between the elitist directed BIG Warmists, the controlled opposition Luke LITTLE Warmists and the informed, independent NO Warmists. > Climate Change & Thermodynamics

      two hour interview, heard on 615 radio stations by +2 million….

      “Greenhouse Gas Ptolemaic Model” at FauxScienceSlayer site for more…..

      • Don Aitkin says:

        On the evidence before me, I accept that CO2 accumulations do warm the earth, and that makes me a lukewarmer, as I have argued in a recent essay

        • “Four Known Scientific Ways Carbon Dioxide Cools Earth’s Climate” by Dr Pierre Latour, PhD Chemical Engineering posted at Principia Scientific International website.

          The “Greenhouse Ptolemaic” article has five known ways that water vapor, the ‘other’ warming gas COOLS the planet.

  • Don Amoore says:

    The expertise level here is daunting but if I may add something you all probably know already, I read in Jonova that her husband is very busy.

    om her blog—– ” To venture a guess I would say that among skeptics the dominant hypothesis is that some factor to do with the Sun is far more important than man-made CO2. To the end that skeptics need an alternate hypothesis, I agree, and there are many working on just that. Dr David Evans (my other half) is still hammering through climate model architecture, assumptions, and solar datasets. Readers may be impatient waiting for an update; I can only say that sometimes the art of real research and discovery is better done in silence and without the pointless “bloodsport” of blog publication, but we are thinking “August” or “September”, and there are many posts in draft. David prefers to keep a lower profile while researching, but he is working full time, and will be suggesting a paradigm shift in model design which looks like it will resolve a great many of the current model failures. The shift is only a small change in architecture, while keeping most core assumptions of IPCC models, yet it makes a profound change to the output. He has gone right back through the central assumptions of calculating climate sensitivity and the leading papers of the last fifteen years. As far as we know, he is the only skeptical scientist who comes from a professional background in model development combined with major league maths.’

    Also from an article I found in WUWT I read this refutation of the CO2 assumptions, especially the Al Gore stuff up. It is here

    The Maths of CO2

    There are more deniers in the orthodoxy!

  • Peter Kemmis says:

    A few years ago Walter Mitty and I were working on a murder case with another detective. To protect his identity, I’ll just call him Steven M. As we gathered evidence, our suspicions turned heavily to a suspect that Steven had initially fingered. Alas, one day Walter and I discovered that a key piece of circumstantial evidence on which the case would stand or fall, was wrong, incontrovertibly. We broke the news to the invincible Steven.
    For a moment, he was crestfallen. Only for a moment. Turning to us with that gleam in his eye that we knew so well, he cried “So who did it, then?” I looked at Walter. “We don’t know” was all he could reply. “Aha!” challenged Steven. “So you have no alternate theory?” We shook our collective head. “Well, until you do, my theory must be right!”
    Walter and I left Steven tapping away on his computer, stringing more of his ephemeral chains of evidence, like loose strands of DNA stretching into space. “Must be something in that bottled water he drinks all the time. Do have any other ideas?” “No”, replied Walter.
    Walter and I never developed another theory, but we certainly avoided drinking any of that brand of bottled water.

    • dlb says:

      Well Peter half the townsfolk are baying for Steven’s suspect, what’s the Guv mint to do? Most of the scholars agree with Steven and say he’s only going to strike more often.

      Unfortunately this suspect is considered guilty till proven innocent, unless you can mount a valid case. He may be a good gardener and make the plants grow but unfortunately he has now got an ill deserved reputation.

  • JimboR says:

    Don you continue to compare today’s temperature with 2050’s temperature under various “let’s turn everything off” scenarios and conclude they’ll be roughly the same so there’s no point turning everything off. Most warmists would consider it a major victory if 2050 turns out to be about the same temperature as 2014… mission accomplished.

    Why not compare today’s temperature with 2050’s temperature if we continue to increase our CO2 emissions by 3% each year? That’s the “do nothing” option you seem to be proposing.

    • Don Aitkin says:

      Jimbo, about a third of al the human-produced carbon dioxide emissions have occurred since 1998, but without any significant increase in temperature. So the effect doesn’t seem to be decisive, or, if you like, there are other factors at work that can enhance or minimise the CO2 effect.

      Will that do?

      • JimboR says:

        I’d still be curious to know what your MAGICC calculator comes up with for a “business as usual” ever increasing CO2 emission trajectory.

        • Don Aitkin says:

          Go to the link in the essay above, and see what you can find.

          • JimboR says:

            You repeatedly cite the calculator as evidence that there’s no point reducing emissions from our current trajectory because it will make no difference to the temperature in 2050, but it seems you’ve never used the calculator to test that hypothesis.

            I’m surprised someone with your CV would make such a basic modelling mistake.

          • Don Aitkin says:

            Why is it a mistake? Other people have used it, and set out their calculations. That’s in the link. If you see something wrong with them, perhaps you could let me know where the errors lie.

  • JonL says:

    The only debate seems to be in this (and presumably similar) echo chamber (s). Meanwhile, elsewhere on the web you’ll find this from ex-coal executive:

    • Don Aitkin says:

      The article you cite is simply a set of assertions, like this one: ‘We are experiencing substantial economic and social damage at the 1degC warming which has already occurred relative to pre-industrial levels, let alone the additional 1degC to which we are probably committed by virtue of historic emissions.’ I know of no evidence at all that would support the first assertion, while the second is based on assumptions form modelling.

      Perhaps you might ask yourself why you agree with the article. It seems implausible to me, given the evidence.

      • David says:


        Of course the second assertion (i.e., .let alone the additional 1 deg C to which we are probably committed by virtue of historic emissions) “is based on assumption from modelling”. Its a prediction!

        No one is in possession of facts about the future.

        Perhaps you might like to ask yourself why your argument reflects such an unsophisticated understanding of the relationship between “facts” and “models”,

        • Don Aitkin says:

          If there is no evidence of the substantial social and economic damage we are said to have experienced, why should we take note of the prediction of future damage that we are probably committed to?

          If there were obvious damage from warming already I might take the second statement more seriously. In fact, the evidence of greater food production, greater greening and better life for more people suggests that IF the warming has been caused by CO2,THEN it is a good thing.

          • David says:


            To wait until there was “evidence of the substantial social and economic damage” before we implemented policy change would be very foolish!

            The WHOLE point of prediction is to avoid these potential problems in the first place.

          • Don Aitkin says:


            The damage is supposed to have occurred already. What is it?

          • David says:

            Nice try Don. 🙂

            Changes in climate have occurred, but the “substantial social and economic damage” is a prediction that policymakers are intent on avoiding.

          • Don Aitkin says:

            Sorry – that’s not what he said. He said ‘we are experiencing’, but didn’t say what it was that we are experiencing. I know of nothing that is adverse, but a lot that is positive.

      • JonL says:

        And maybe you might ask yourself why you disagree with this:

        and, just for good measure, this:

        But, clearly, this only serves to illustrate there is no common ground for a ‘debate’. Still, I appreciated your ‘photo bombing’ of John Menadue’s site, which led me to your one. That’s all.

        • Don Aitkin says:

          The first one is by Michael Mann, who is a poor scientist at best. The second is a scare piece. I don’t have the time to go through either in detail, but if you don’t know about the 97 per cent furphy you could look it up. The Rolling Stone story is full of ‘reality’ but not full of data. I’m not a reader of stories like these, much more into the science and what we learn each week from new papers.

    • Don Amoore says:

      I am shocked!! I worked with Ian Dunlop while in Shell both in Australia and Britain. What has happened to his brain!!!

    • dlb says:

      I would hardly call this an echo chamber with the number of discordant views expressed. The site you link to is nothing but an advocacy site, no debate there.

  • Bryan Roberts says:

    My experience has been that the advocates of AGW are so blindly committed that they are completely incapable of considering any other viewpoint.
    Dr Ducan Steel, a highly respected astrophysicist, has postulated that orbital precession has not been adequately considered in climate models (, and may contribute, at least in part, to present conditions.
    I put this viewpoint to both ‘The Conversation’ and to ‘skepticalscience’. On both, I was subjected to the most astonishing torrent of abuse, as ‘an ignorant denier’. Neither could show any flaw in his calculations, but both rejected them outright.
    Ironically, Steel states in his discussion that he is not denying AGW, but is pointing to a possible flaw in the assumptions.

    • Don Amoore says:

      Commiserations, I know how you feel.

    • David says:


      1. Are you able to provide a link to your comment?

      2. There are ample data available on the earth’s orbit. Dr Steel should analyse the data and publish his results.

      • Bryan Roberts says:

        Steel’s ‘Changing Spring Insolation’ hypothesis ca be found here:

        • David says:

          Thanks Bryan.

          But I am curious to understand what you wrote and why you were abused on these other web sites. So do you have links to your comments on The Conversation and Skeptical Science

          • Bryan Roberts says:

            Hi David,

            I cannot remember what I wrote, but it was not dissimilar to the paragraph above.
            As I argued about the ‘kill the messenger’ attitude, I was subsequently barred from both sites, and I cannot find any of the posts, which presumably have been deleted.

          • David says:

            I find it hard to believe that you would be banned from “The Conversation” for those benign comments. ??

          • Bryan Roberts says:

            As I said above, TC has a philosophy whose adherents do not tolerate dissent.

          • Don Aitkin says:

            My experience was not that I was banned, but that my comments were removed by the moderator. Too much of that, and you stop wanting to take part, in a discussion, because it has ceased to be a discussion. Eventually, I simply ceased to subscribe, and life has continued, nonetheless.

          • Bryan Roberts says:

            My experience, not so much that, as the ‘in’ group got away with a lot more sly and overt abuse than the ‘out’ group. Moderation was quite selective. Not to mention names, but there were regular posters whose diatribes would have never been tolerated had they come from me, and been directed against different groups.

          • Boyfromtottenham says:

            Hi Don and readers,

            If “The Conversation” is not actually what its title suggests (i.e. a ‘conversation’) because in practice it stifles, ridicules and smears those with opposing views, then pray what is it – simply a propaganda outlet? And if so, for the benefit of what group?

          • Don Aitkin says:

            Perhaps you might red my earlier essay on TC, at


            I think it has simply been captured, ideologically speaking.

  • Peter Kemmis says:

    In reviewing all these comments as well as Don’s initial post, it strikes me that here in this claim that Steven Mosher is prosecuting, we see the AGW proponents once again mounting yet another and different defence.

    My recollection of the different kinds of defence is patchy, and others may happily correct me. But first we were being given the dire warnings of what was going to happen: the skies would dry up as would the dams; drought and starvation would follow; the poles and glaciers would melt, the oceans rise by metre upon metre, and we’d see 50 million climate refugees by 2010, was it?

    But that pesky and inconvenient pause in temperature rises set in, and finally had to be acknowledged. At least that was pretty well hushed up – the admission by the UK Met Office came out on Xmas Eve (was that 2012?), and at least the ABC in Australia knew how to keep quiet about it. After all, who wants to know on Christmas Day, spoiling our complacent barbecues in the lovely sunshine?

    Ah, but the missing heat has gone into the deep oceans! Never mind how it got there, never mind the ARGO floats and what their careful observations tell us, it has to be there, because it had to go somewhere. And as you all know, the Kracken will wake!

    Wait on – those oceans will acidify! The shellfish will die, the food chain fail, and all we’ll have left to eat in Australia will be rabbits and kangaroos. But they’ll be raw, I suppose, because there’ll be precious little vegetation remaining in this drought-stricken land. Never mind the experiment that shows improved shellfish growth when the air contains not a mere 400 ppm of carbon dioxide, but 600 ppm .

    One by one, the defence has valiantly fallen back to the next position.
    So Steven, bless his heart, is busy proclaiming that the sceptics must mount an alternate and credible theory. And when this position crumbles, what will be the next line of defence?

  • […] wrote about the tension between policy and politics in a recent essay, and Behm offers a good example. Having worked on an issue that was divisive, he unavoidably chose […]

  • […] There are two debates about ‘climate change’ […]

  • […] For more about the two debates see this by political scientist Don Atkin: “There are two debates about climate change“. […]

  • […] way of setting things out. I think it is where I am, and where I have been, too. It helps me with the argument with Stephen Mosher that was the subject of a recent essay. I entered this debating arena ten or more years ago by […]

  • Margaret says:

    I was browsing for a term I had used in a post – I couldn’t find it but came across this.
    Three years ago in response to Two Cheers for Peer Review, Christine wrote:

    “It is interesting to note that some of the scientists with an interest in climate science through their work in allied disciplines have a view of climate change which is not about whether or not in their opinion anthropogenic global warming will cause catastrophic climate change if it is not addressed by public policy.
    Rather they have a view on the public policy position, for example the economic costs and benefits of action or where the social costs of action are most likely to be borne.These are, however, second order issues.”

Leave a Reply