Solar science Heartland style

[I wrote this some time back, but got distracted by Lord Monckton’s inability to use a scroll bar, and then lost momentum. Given Willie Soon’s return to media attention, I thought I should give his presentation a little loving, but for starters, here is an account of Sebastian Lüning’s presentation]

No fake climate skeptic conference would be complete without a session on the sun and the Heartland’s recent jolly did not disappoint, at least in this regard, holding a session on  Solar Science and Climate (video) with Dr. Sebastian Lüning, Dr. Habibullo Abdussamatov, and Dr. Willie Soon discussing the latest and best evidence. The session was a bit of a mix, the speakers got some thing right – for example the title of this post – some things wrong, and some things weird.

Lüning thought it necessary to remind the audience that 99.98% of the energy in the climate system comes from the sun, and then goes through the list of periodicities present in solar activity, suggesting that changing the solar energy “slightly” will have “an effect” on the climate system. He then moves to Soon’s recent paper which identifies “fundamental solar modes at 2300-yr (Hallstattzeit), 1000-yr (Eddy), and 500-yr (unnamed) periodicities” in palaeoclimate proxy data. Unfortunately it appears that Soon et al got some of their proxies upside-down so their claim that the reconstructions are in phase is dubious. I wrote to Soon to inform him of this problem months ago but have not received a response.

Moving swiftly on, Lüning compares the IPCC figures on radiative forcing from greenhouse gases and solar variability and argues that because he wrote a book with “sixty pages of references” collating lots of dubious examples of sun-climate interactions (it even cites the absurd di Rita 2013), the IPCC numbers should be doubted. That’s not exactly how he phrased it.

He claims that search “solar forcing” gets 22683 hits on science direct (the most recent of these is “Phenolic profiles in leaves of chicory cultivars (Cichorium intybus L.) as influenced by organic and mineral fertilizers” – perhaps not so relevant – only 1717 include the string “solar forcing”) and complains that these papers are not covered by the mainstream media – “the scientist, they write they papers but they don’t go public because then they fear their funding will be cut” (6:58). This is unevidenced conspiracy-theory feeding nonsense.

Enough with the quantity of evidence, what about the quality. Lüning cites four papers as evidence of the importance of solar forcing.

  • Steinhilber et al (2012) combine records of the cosmogenic isotopes 14C and 10Be to make a Holocene length reconstruction of solar activity and correlate this with the oxygen isotope record from Dongge cave, China. The correlation is remarkably good for a solar-palaeoclimate correlation (r=0.3), but this record is not chosen by accident, it was selected because it was known to have a good correlation with 14C. Does anyone see any potential problems with that? Haam and Huybers (2010) show that the correlation between the Dongge cave records and 14C record is not significant. The significance levels of the spectral analyses in Steinhilber et al seem to be against a white noise null hypothesis. Given that the spectra look red, this is going to give a huge risk of type 1 errors.  Contrary to what Lüning claims (8:05), the solar-palaeoclimate correlation is announced in the abstract of this paper.

    (A) solar activity (blue) and δ18O from Dongge cave, China (green). Both records have been detrended. (B) Wavelet of solar activity (TSI). (C) Wavelet coherence of solar activity (TSI) and δ18O. De Vries cycle at approximately 210 y and Eddy cycle at approximately 1,000 y are marked with horizontal, grey dashed lines. Arrows pointing to the right indicate that the records are in phase. Black boundaries mark the 95% significance level.

  • Junginger et al (2014) includes excellent and innovative work reconstructing the lake level of palaeo-lake Suguta in the Kenyan rift valley, but then has a severe attach of weasels, correlating the lake level curve with the solar activity record from Solanki et al. (2004). The correlation is not particularly persuasive, especially when the chronological uncertainty is considered. The 14C dates are mostly on mollusc shells and need to be corrected for an old carbon effect estimate from the offset between 14C dates on contemporaneous charcoal and shells. The offset varies between 1700 and 2200 years in the four samples where it was estimated. The mean offset is used, with no allowance for uncertainty. I would argue, therefore, that the uncertainty on their dates has been underestimated by about 200 years, which is, coincidentally, about the length of the wiggles they were trying to correlate. Not impressed.Lake level and solar activity.  Junginger et al (2014)
  • Moffa-Sanchez et al (2014) link salinity changes in the Atlantic  over the last thousand years with solar variability. I find their attribution of the variability to solar rather than volcanic forcing less than convincing, but otherwise it is a good paper . There remains however, the problem of publication bias.
  • Ogurtsov and Oinonen (2014) report that “Greenland and Antarctic nitrate correlate at least fairly significantly with the Gleissberg cycle”. The authors argue that cosmic radiation produces nitrate in the atmosphere – no climate link – so this paper is perhaps not the most convincing evidence of a solar-climate link.

Of Lüning’s list of selected papers, only one is good evidence for a solar-climate link. Is this the best he could do?

Lüning tries to argue that current climate change is all part of a cycle and that the sun is now in an active phase so must be responsible. Of course the Medieval Climate Anomaly is discussed, showing figure 5.7 from the IPCC AR5 and arguing that models cannot reproduce the MCA. If only he had read as far as figure 5.8.

Somehow Lüning manages to avoid the details of how small changes in solar activity can be responsible for large changes in climate, but that radiative forcing from CO2 is almost irrelevant. Perhaps the next speakers will grasp the nettle.

Abdussamatov‘s talk is awful. Watch it if you don’t believe me (it is stuffed full of irrelevant and long-refuted fake climate sceptic talking points). I’m going to skip over it and go directly to Willie Soon’s talk in the next post.



About richard telford

Ecologist with interests in quantitative methods and palaeoenvironments
This entry was posted in climate, Fake climate sceptics, Peer reviewed literature, solar variability and tagged , . Bookmark the permalink.

One Response to Solar science Heartland style

  1. Pingback: Willie Soon at Heartland: “The sun is big” | Musings on Quantitative Palaeoecology

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