This is my last foray into the SCM document on ‘climate change’ that I have investigated twice before, here and here. But before I get into it, readers in New South Wales will have noticed that the Government of their State has issued drafts of a new approach to how local government councils should determine building regulations for coastal communities. The new approach simply ignores the IPCC’s predictions of rapidly rising sea levels. The Minister’s press release says: Since the original Coastal Protection Act was enacted in 1979 our understanding of coastal processes has improved dramatically. We know our coastline is not a fixed object, but a dynamic, ever-changing environment with a range of natural processes.

The new approach has a three-month consultation period, and my guess is that the Greens and others who believe in the orthodoxy will run a campaign against the draft. I hope the Minister is confident and determined. He would gain some  support from a droll speech intended to be given by our PM at the Paris meeting, and written by Geoff Derrick, a sceptical geologist. You can get it from him at Derrick includes a graph displaying the trend in sea-levels in Sydney Harbour over the period 1886 to 2010.


As you can see there are highs and lows, but the outcome is a tiny increase over a century and a quarter. The Sydney region is geologically pretty stable, and there’s not much sign of anything dramatic there.

OK, on to the SCM paper, or, for newcomers, a paper by the Société de Calcul Mathématique SA in France entitled ‘The battle against global warming: an absurd, costly and pointless crusade’. What interests me about the long paper is that it is mostly directed at problems of measurement, and it assembles those problems in a succinct and accessible fashion. The paper points out, once again, that we don’t have a lot of accurate data that extend over time. If one wanted to make a case that the oceans were raising at a faster rate (than when?) one would need a good deal of data over time. We just don’t have it.

What we do have are tide gauges and satellite estimates. The gauges don’t go back past about 1800, and the satellite measurements start in 1992. It is estimated that the end of the last ice age, say 20,000 years ago, was followed by an irregular melting of ice, which increased the height of the oceans by about 120 metres. That’s an average of about 6.6 mm a year. That process stopped several thousand years ago, and since then there has been a much slower increase. Tide gauges put it at about 1 mm a year, the satellites at about 3 mm a year. Given that tidal changes can run at metres a day, that a warming sea will increase in volume and thus rise, and that the Antarctic and Greenland ice melts vary in output over time, to be able to say with hand on heart that sea-level rises of a millimetre or two are worrying is an extraordinary claim, one which needs extraordinary evidence. Alas, it just isn’t there.

The CSM paper goes on to pile even more possibilities on top of those already mentioned. Our planet is changing its shape as time goes on;  an undersea mountain will have a higher sea level above it; the earth is rebounding following the loss of kilometres of ice above it; variations occur in the internal temperature of the planet; our rivers abrade the land, dumping earth onto the seabed and thereby raising it; el Ninos have a powerful effect on sea levels; and so on.

Why are we so exercised about sea levels, given the problems of measuring them accurately?  Millions of human beings live on or close to the sea, and are naturally interested in what is happening there. Australia is an excellent example, with all our major cities save Canberra on the coastline. So it is easy to run a scary story about the possible flooding of coastal suburbs, the loss of great sections of Bangladesh, the submerging of Kiribati and Tuvalu, and other awful possibilities.

And, of course, so much these days comes from ‘what the models say’. About the use of models the SCM paper is politely scathing: Conclusions based on any kind of model should be disregarded. As the SCM specializes in building mathematical models, we should also be recognized as competent to criticize them. Models are useful when attempting to review our knowledge, but they should not be used as an aid to decision-making until they have been validated. Now, validating a climate model requires thousands of years.

I return to a question I have asked myself many time before. How did we get into this? How did our measuring instruments become subverted to assist in something else altogether? As Geoff Derrick shows, in the piece I mentioned at the beginning, William Dawes, who came with the First Fleet, established an observatory on what is now know as Dawes Point and, among other things, kept accurate temperature measurements for the new colony. They seem remarkably similar in their trend to the average for the last 150 years, but that’s not really the point. Dawes was a scientist and a competent astronomer. He was laying the foundations of knowledge regarding aspects of weather.

Early settlers inland did much the same. They measured river heights, took temperature measurements, and collected rainfall data. Why? They just didn’t know anything about this new land, or area. They needed to know when the rain came, how high the rivers went in flood, when was the right time to plough, how reliable was the water supply, and how cold it might get in winter. Their purpose was straightforward: we are new here and we need to know a lot.

Of course, some of their measuring instruments weren’t all that good, and they were not meticulous with when they took the measurements. Some of their data has been lost. There are great gaps. But slowly, over time, our society got better at it. Australia was one of the early investors in good data of all kinds, censuses, temperature, tide gauges and the like.

To take this great body of data of varying quality and quantity, and ‘homogenise’ it so that its truth, spotty though it is, is pushed aside, but the message of ‘climate change’ is somehow revealed, is to prostitute science — and to dismiss the work of numerous people who maintained the data in the past.

Those who do this do not seem to realise that they are thereby reducing the status that science and scientists have had in the past — to the cost of all of us.

Join the discussion 33 Comments

  • Doug Hurst says:

    Thanks Don – very informative. To I would add that a recent NASA study shows that Antarctica is gaining more ice than it is losing – a finding contrary to the IPPC and strongly suggesting we have nothing to worry about wrt rising sea levels while this continues as most of the Earth’s fresh water is locked up in Antarctic ice.

  • Alan Gould says:

    Thanks Don, another lucid and helpful post. Of course we noted how the ABC perverted the news item about the NSW Gov’t freeing their coastal shires from IPCC predictions by turning it into a story about residents in Bateman’s Bay worried about waterfront land values. One can put down the prevailing orthodoxy in a public agency as intellectual torpor, but to see it being actively evangelised by distorting an original story to an evidently fervent agenda is wickedness, sowing the same distrust for this vital broadcaster as you show is gathering towrd our scientists and science on this matter. Dismal!!

    • JMO says:

      The deliberate corruption of climate science has turned it into a new religion. And new religions attract the Casandras, ideologues and zealots.

  • aert driessen says:

    Another great post Don. You have such a gentle yet assuring way of putting your case. We have sound evidence up to our proverbial eye balls that what is happening to climate, sea level, ‘extreme’ weather, etc is nothing more than ‘business as usual’ for the planet and that all the variations in these systems, about which we know so little, all lie well within the bounds of natural variability, at lest over the last 10,000 years since the end of the last Ice Age. And what a blast from the past. I knew Geoff Derrick from BMR (Bureau of Mineral Resources) days in the late 1970s. Geoff is a very astute geologist who did excellent work in the Mount Isa region. Geoff, if you’re reading this, BMR ain’t what it used to be. Notwithstanding that it still has good scientists doing good work, it has succumbed, at least in part, to the climate orthodoxy — scientists succumbing to the lure of computer modelling rather than the examination of evidence. Keep up the good work my friend.

  • Don Amoore says:

    Hi Don, your “You can get it from him at” does not seem to work for me. Any suggestions on how I can find this speech?

  • dlb says:

    Turnbull listening to a sceptical geologist? Things are looking up.

  • David says:

    If William Dawes, “kept accurate temperature measurements for the new colony” why do you ignore them when discussing long term temperature change?

    • Don Aitkin says:

      He was there for three years, wanted to stay, but wanted a real job. He quarrelled with Phillip, who sent him back. Pity.

      Your question is a bit like whether or not I have stopped beating my wife. When have I ignored Dawes and his measurements? As I said in the essay, his measurements look very similar to the long run average for Sydney.

      • David says:

        Well, for the last two years. Then out of the blue you announce that you have found a very accurate set of temperatures for Sydney that date back to the colonization.

        Great! Do you have a link? Lets see if the do in fact “look very similar tot he long run average for Sydney” Would you mind sharing a some means with the results from a t-test or two so we can evaluate that statement?

  • Dasher says:

    It doesn’t seem to matter what observed information is presented the position of governments and too much of the media plow on with all the passion of a southern Baptist minister locked into their orthodoxy unable to respond to reality..nuts. This effort by the NSW Government is a breath of fresh air. I notice some (all?) the councils removed the measuring devices which were were going to prove to a unformed public that the seas were really rising dangerously, except that they were not. Remember that guy with the sandwich board that proclaimed the world would end on 5 June and once the day passed univentfully changed it to 10 September…not a word of explanation..sound familiar? I don’t pretend to know the answer but at least I have an open mind and unless (for example) David can show that you are wrong he won’t get my attention. Mind you, I thought the statement of the week was Prince Charles blaming terrorism on climate change.

    • JMO says:

      I clearly remember Tim Flannery saying on ABC television in September 2006 sea levels may raise up to 4 metres within 10 to 15 years, Another climate Cassandra doomsday prophesy down the drain. s fir Prince Charles I would not walk to the end of my driveway to see him.

    • Bryan Roberts says:

      I recently heard an interview with the noted ‘climate scientist’ and adventurer, Tim Jarvis, on Radio National, in which he claimed that equatorial glaciers had been melting for more than a hundred years. Despite this, he claimed global warming was an existential threat, that had to be addressed. He is climbing all the equatorial mountains to address climate change, and will, of course, be in Paris, to recount his exploits on behalf of the planet.

  • bobo says:

    “To take this great body of data of varying quality and quantity, and ‘homogenise’ it so that its truth, spotty though it is, is pushed aside, but the message of ‘climate change’ is somehow revealed, is to prostitute science — and to dismiss the work of numerous people who maintained the data in the past.”

    The problem with a criticism like this is that it is entirely superficial and avoids stating why the homogenisation referred to is unsound. If datasets are collected using different methods then in order to merge the various datasets into a single new data set some data normalisation is required. But you need to get into the nitty gritty of the methods used in order to be able to make a substantial criticism.

    Sea level rise is occurring fastest in equatorial regions; generalising the result from Sydney Harbour to low-lying Pacific Islands or Bangladesh isn’t correct. Currently sea level rise is roughly linear, with about 1.5mm per year of global average sea level rise due to thermal expansion and 1.5 mm/year due to added mass from melting ice. One of the great unknowns in climate science is a precise understanding of how icecaps in Antarctica and Greenland will react to warming, and this introduces a great deal of uncertainty to sea level projections with time.

    • Don Aitkin says:

      My criticism is based on a lot of work, in this country by Jennifer Marohasy and her colleagues, in the USA by Anthony Watt and his large team of volunteers, and in Europe by a few who report through Pierre Gosselin. My point is straightforward: these data were not collected for the purposes of detecting man-made climate change, and there is no other ‘need’ to process them in the way that has been used. There are abundant examples of ‘adjustments’ that have converted a cooling or static trend to a warming one. I am reminded of the old criticism of factor analysis, where the analyst grabs the data by the throats and screams ‘Speak to me!’

      • bobo says:

        OK, but what you need to do is state how homogenisation has been applied to the old Sydney Harbour data, why this homogenisation was applied – i.e. what differences there are between the oldest data sets and the subsequent data sets, and why the particular homogenisation procedure used is wrong.

        Referring to ethereal work done by someone else doesn’t cut it unless you can provide a concrete link or a concrete set of reasons.
        I’m curious to know if these vaunted criticisms from the likes of Marohasy and Watts stand up to scientific scrutiny.

        • Bryan Roberts says:

          Interesting how these arguments play out. Somebody makes a remark, and is immediately faced with demands for ‘statistical validation’, ‘peer review’ and so forth. It happens in every forum i’ve watched, to an extraordinary extent in places like The Conversation, where it’s used to stifle dissenters.

          • bobo says:

            Bryan, science is extremely detailed. Don is making claims that suggest that a scientific procedure – in this case data homogenisation applied to Sydney Harbour sea level data – is unsound.

            In order for Don’s assertion to have any legs he needs to provide detailed supporting evidence, for example by providing a specific link to such analysis done elsewhere.

            It’s easy for someone to just say anything they want, but to actually show that your claim is scientifically sound you need to work a lot harder, you need to give specific and detailed reasoning – or provide a relevant reference – that stands up to scientific scrutiny.

          • Bryan Roberts says:

            The arguments are quite futile. You claim Don cannot substantiate his argument, but neither can you prove yours.

          • bobo says:

            What argument of mine are you referring to? Don is making a scientific claim. Don needs to justify it. Do we all just assume Don is correct because he says so?

            If Don says that some data homogenisation is unsound, he needs to give a sound reason for it, otherwise his claim is worthless.

            Baseless opinions don’t fly in science which is why, when the dissenters you mention make definitive, but baseless statements regarding science, they get shredded in forums frequented by scientists. A dissenter who doesn’t understand the process of science can come away thinking that science is cruel or even unfair after such an experience. Plenty of sceptics think it unfair that science doesn’t “listen” to their side of the story, but what they don’t realise is that their claims have already been assessed as being unsound, and more often than not they are repeating something that is known to be wrong or not compelling.

          • Bryan Roberts says:

            You are making a claim that your version of the facts is the ‘truth’. Do we all just assume you are correct because you say so? You claim the data homogenisation is sound; if you have the science, then back up your claims. It’s easy to rely on orthodoxy, it’s a little more difficult to justify it.

          • bobo says:

            I am making no claim to “truth”.

            I have never said the particular data homogenisation of Sydney sea levels is sound, what I have said is that the burden of proof lies with Don who claims that the data homogenisation is not sound.

            He makes a claim, he needs to provide the reasoning supporting his claim.

          • Bryan Roberts says:

            …and you disagree, so the burden of proof is yours.

            You can’t win, you know. lol

          • bobo says:

            What I have asked for is a claim to be substantiated. I have not disagreed with the claim. How can I? I can’t even evaluate the claim because I don’t even know what specific homogenisation Don is referring to.

            If I said there are fairies at the bottom of the garden and Don wanted my claim to be substantiated, don’t you think it would be odd if you suggested that the burden of proof lies with Don to show that there are no fairies just because he “disagrees”?

          • Don Aitkin says:

            I think that, perhaps it’s my fault, Bobo has jumped from my concluding remarks, which start with ‘I return to a question’, and are about temperatures (hence Marohasy and Watts), to the supposition that I think there have been attempts at homogenisation with respect to tide gauges. I did not think so, and made no such claim.

          • bobo says:

            Fair enough, I’ve obviously misunderstood what you were saying.

          • Bryan Roberts says:

            Actually, no. I would want you to produce a fairy. Strangely enough, that is science.

          • David says:

            In the past Prof Muller argued that
            homogenized data distorted AGW. To prove his point he conducted an analysis
            that utilized some 14 million data points of un-adjusted temperatures going back
            some 300 years. The analysis still confirmed
            AGW. Muller now accepts the AGW hypothesis. And you should too.

  • […] Are the seas rising? Yes, they are. They have been doing so for several hundred years. Sea levels may have been rather higher in the human past. There are two connected methodological debates about sea levels. The first is whether one should use satellite data or tide-gauge data to measure whatever rise is occurring. The second is whether global sea-levels have any meaning, given that each point on a coastline is affected by different conditions. Land can sink, land can rise, and in each case apparent sea levels will be different. There are many variables involved in measurement, and you can read about them here. […]

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