Watt about Nicola Scafetta?

Given that I claim that my goal is to address what is said on Watts Up With That (WUWT), and not to simply criticise, I thought I would briefly highlight Willis Eschenbach’s recent post Congenital Cyclomania Redux. In this post, Willis talks about the work of Nicola Scafetta who seems to think that climate change is simply some kind of natural harmonic variation.

However, as Willis points out quite well, what Nicola Scafetta does is simply a curve fitting exercise. He attempts to model the variation in surface temperatures using a set of harmonic functions with different frequencies and amplitudes. What’s more he seems to increase the number of harmonics whenever he discovers that his previous model is no longer fitting particularly well, so he now has a large number of tunable parameters. As Willis quite rightly points out, it doesn’t even matter if the frequencies he uses are associated with something real (solar oscillations, planetary orbits) you still need a physical mechanism to explain how this can influence our climate.

Anyway, there you go. Admittedly I haven’t read Willis’s post in extensive detail but it does appear to be a WUWT post that I’m finding hard to criticise. The comments, on the other hand, are a slightly different story, but I’ll leave it at that.

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This entry was posted in Anthony Watts, Climate change, Global warming, Watts Up With That, Wilis Eschenbach and tagged , , , , . Bookmark the permalink.

5 Responses to Watt about Nicola Scafetta?

  1. Lars Karlsson says:

    A really funny thing is that Scafetta also has included one term in his “model” which is the average hindcast (and forecast) modeled temperature of the CMIP5 climate models! Without that, his “model” starts deviating significantly from observations around 1980.

  2. I didn’t notice that directly, but when I looked through his paper he did seem to discuss the CMIP5 models in quite some detail, which seemed surprising if he was just using harmonic oscillations. What you’ve said presumably explains why. Amazing.

  3. Nick Palmer says:

    Before you know it, Scafetta will reinvent biorhythms and, given enough time, astrology…

  4. I also for once find myself agreeing with Willis. -plus it also deflates claims of scientific censorship here:
    http://www.glaciology.net/Home/Miscellaneous-Debris/anunconvincingcaseofcyclefitting

  5. Aslak,
    Nice post. It does amaze me that there are still people who think that simple curve fitting can tell us anything more than they’ve found a set of curves/parameters that they can tune to fit some dataset. Without some kind of physically-motivated model, it really doesn’t tell you very much at all.

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