Understanding Climate Change in Terms of Natural Variability

Chapter 3 in Climate Change: The Facts is Nicola Scafetta on climate change and a number of natural cycles. This chapter is probably even more fun for nerds than the one about the gymnastic molecules of greenhouse gasses. I suppose you have to expect this kind of thing from Professor Scafetta because we are advised that he developed Diffusion Entropy Analysis, a method of statistical analysis to tell the difference between Levy Walk noises and Fractional (Fractal) Brownian Movement in complex systems. Obviously he could have been a rocket scientist too. You wont be tested on this but I put the links in so you don’t think that I made it up.

The point is that these techniques can detect cycles of different frequencies in a system and the cycles of temperature that Dr Scafetta is talking about are oscillations of 9.1, 10.5, 20, 60 115, 900-1000 and 2100-2500 years. These are cycles in solar activity, tidal effects of the Sun and Moon and I expected the various Milankovitch cycles. Actually he did not introduce Milankovitch cycles but there are many others involving the Sun, Moon and various planets.

There is a section on numerous studies that suggest low values for the forcing effect of CO2 and he opts for a number in the order of half those favoured by the IPPC. Other authors in the book opt for a tenth and some people of course insist that there is no forcing effect at all. Then he explains how the IPCC models have failed dismally in reconstructing the relationship between CO2 and the temperature in many of the cycles through the Holocene. There is a table demonstrating that with the record of the Greenland Ice Sheet over a period of 5-6000 years.

There is an important subsection on the hockey stick effect that brought Michael fifteen minutes of fame and excited the IPPC in 2001 (it later disappeared from the IPCC literature). Dr Scafetta explains that the first energy balance models and later the “sophisticated” CMIP5 models reconstruct the hockey stick pattern for the simple reason that they use the wrong number for CO2 forcing. There are still people holding out for the hockey stick effect because the models generate it but of course competent statistical analysis of the data led by Steve McIntyre and Ross McKitrick shows that it does not exist in the real world.

The Olympic level of mental gymnastics gets under way in the section on the decadal and multidecadal natural climate oscillations based on his spectral analysis of the global surface temperature. He finds that the spectral peaks are the same in the northern and southern hemispheres that suggests that they are coupled and have an astronomical origin. Effects due to the more immediate influence of the sun tend to be reversed in the two hemispheres due to the tilting of the Earth’s axis.

He reports a 60 year oscillation in several phenomena ranging from the Atlantic Multidecadal Oscillation (AMO) series to Indian monsoon records. An eleven year cycle of sunspot activity can be decomposed into three oscillations thus “a quasi-eleven-year main cycle modulated and bounded between the 9.93 year Jupiter-Saturn spring tidal-oscillation and the 11.86 year Jupiter orbital tidal-cycle, giving origin to two main modes at the ten to eleven-year and the eleven to twelve-year time scales.”

The bottom line is that he claims his analysis of cycles gives a very good match with the temperature record since 1860, very much better than the IPPC figures, and a projection through the 21st century that is less than 2C. Time will tell!

PS A reminder about the excellent book The Climate Caper by Garth Paltridge, very good on the historical background to the scare from “inside the whale” (the CSIRO) and a very clear account to the pitfalls of models, especially the one used by Garnaut to shape Australia’s climate policy. In case you are too busy to read it or too mean to buy it you can find an extended summary here.

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9 Responses to Understanding Climate Change in Terms of Natural Variability

  1. RobK

    All too often we are kept busy trying to make sense from non-sense.

  2. Entropy

    The bottom line is that he claims his analysis of cycles gives a very good match with the temperature record since 1860, very much better than the IPPC figures, and a projection through the 21st century

    certainly works for rainfall.
    Check this poster out, including the underlying IPO

  3. Iampeter

    “Olympic level of mental gymnastics”
    Should just be the name of the book.

    Seems to be one big exercise to avoid pointing out the fact that there’s no issue to write a book about.

  4. Nato

    Links to source documents instead of Wikipedia! No one has actually sat down and explained to you how the internet works, have they? This is very good.

  5. Rafe Champion

    Iampeter I don’t think there is a warming problem or a need to reduce CO2 emissions and so a lot of these things are of academic interest, meaning that they don’t have immediate practical importance apart from the things that people are doing out of fear of warming and CO2. But there is a lot of good science being done (academic research) and a deal of that is reported in this book as I hope you will appreciate when you read it.

    If you are not interested like Davidson then just read comics or the football news and don’t disturb the class.

  6. max

    Planet Earth is a complex, dynamic system, being “dynamic” means continuously changing.

    In a complex, dynamic system there are usually far too many components which may interact with each other, and long-term behavior can not be predicted with any accuracy.

    this is interesting from Richard Feynman:

    We turn now to what are called earth sciences, or geology. First, meteorology and the weather. Of course the instruments of meteorology are physical instruments, and the development of experimental physics made these instruments possible, as was explained before. However, the theory of meteorology has never been satisfactorily worked out by the physicist. “Well,” you say, “there is nothing but air, and we know the equations of the motions of air.” Yes we do. “So if we know the condition of air today, why can’t we figure out the condition of the air tomorrow?” First, we do not really know what the condition is today, because the air is swirling and twisting everywhere. It turns out to be very sensitive, and even unstable. If you have ever seen water run smoothly over a dam, and then turn into a large number of blobs and drops as it falls, you will understand what I mean by unstable. You know the condition of the water before it goes over the spillway; it is perfectly smooth; but the moment it begins to fall, where do the drops begin? What determines how big the lumps are going to be and where they will be? That is not known, because the water is unstable. Even a smooth moving mass of air, in going over a mountain turns into complex whirlpools and eddies. In many fields we find this situation of turbulent flow that we cannot analyze today. Quickly we leave the subject of weather, and discuss geology!
    The question basic to geology is, what makes the earth the way it is? The most obvious processes are in front of your very eyes, the erosion processes of the rivers, the winds, etc. It is easy enough to understand these, but for every bit of erosion there is an equal amount of something else going on. Mountains are no lower today, on the average, than they were in the past. There must be mountain-forming processes. You will find, if you study geology, that there are mountain-forming processes and volcanism, which nobody understands but which is half of geology. The phenomenon of volcanoes is really not understood. What makes an earthquake is, ultimately, not understood. It is understood that if something is pushing something else, it snaps and will slide—that is all right. But what pushes, and why? The theory is that there are currents inside the earth—circulating currents, due to the difference in temperature inside and outside—which, in their motion, push the surface slightly. Thus if there are two opposite circulations next to each other, the matter will collect in the region where they meet and make belts of mountains which are in unhappy stressed conditions, and so produce volcanoes and earthquakes.
    What about the inside of the earth? A great deal is known about the speed of earthquake waves through the earth and the density of distribution of the earth. However, physicists have been unable to get a good theory as to how dense a substance should be at the pressures that would be expected at the center of the earth. In other words, we cannot figure out the properties of matter very well in these circumstances. We do much less well with the earth than we do with the conditions of matter in the stars. The mathematics involved seems a little too difficult, so far, but perhaps it will not be too long before someone realizes that it is an important problem, and really works it out. The other aspect, of course, is that even if we did know the density, we cannot figure out the circulating currents. Nor can we really work out the properties of rocks at high pressure. We cannot tell how fast the rocks should “give”; that must all be worked out by experiment.


  7. Rafe

    Thanks Max he is always good value. That is the problem of clouds as described by Popper and also Paltridge who used the example of a rising column of smoke. The moment it breaks up everything changes.

  8. Iampeter

    Rafe with respect, I’d argue that I am the one who is genuinely interested. That’s why I bothered to learn at least the basics of the topic.
    I doubt very much people who talk in terms of “greenhouse gasses” are engaging in “good science”.
    Whatever your personal position is, this “academic” discussion is simply advancing the cause of climate alarmists by spreading their bad ideas.

    It would be better if the “skeptics” would go back to reading comic books and sports columns, then writing this stuff and helping to destroy our civilization.

    Anyway do what you want, this is just my two cents. I won’t troll your posts.

  9. .

    You are learning pedantry and ignoring actual facts because you do not like the somewhat flawed nomenclature.

    Warming is happening and it is a good thing. Human survival rates increase during warm periods. Check the historical and anthropological record.

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