Mike Jonas

My paper (“the paper”) on the “100,000-year problem” has been published. Many thanks to WUWT reader Burl Henry for recommending the WJARR journal – most journals are quite simply too expensive for unfunded authors like me (eg, 9,500 Euros to be open-access in Nature).

The paper: The inter-glacial cycle is not a 100,000-year cycle, it is a shorter cycle with missing beats

The main point of the paper is that the 100,000-year and 41,000-year inter-glacial cycles that are the subject of the “100,000-year problem” never existed.

I won’t repeat the abstract here – you can access it, and the whole paper which is open-access, at the above link. I find it difficult to believe that any rational person could still believe that climate models can work, given the IPCC’s statement that “long-term prediction of future climate states is not possible“. The paper provides empirical evidence supporting that IPCC statement. Even though the paper refers only to multi-thousand-year cycles, it seems reasonable to suppose that similar non-linear chaotic features apply at both longer and shorter time-scales too. There still seem to be plenty of irrational people in climate science, though.

This supposed “100,000-year problem” has an interesting history:

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• Wikipedia states : “The 100,000-year-problem refers to the lack of an obvious explanation for the periodicity of ice ages at roughly 100,000 years for the past million years, but not before, when the dominant periodicity corresponded to 41,000 years.“.
• The “problem” has been written up in Wikipedia since at least 2007 (possibly much earlier?), when the article ended with “Alternatively, the 21,000 year Precession cycles may be responsible.“.
• Once there was an established perception that the inter-glacial cycles changed dramatically from a 41,000-year cycle to a 100,000-year cycle about a million years ago, that idea got “stuck” and couldn’t be removed. When Liesecki and Rahmo put together their temperature chart for the Quaternary ice age, for example, they “tuned” the data to make it come more into line with the 41,000-year obliquity cycle: “In our second tuning we loosen the LSR constraint in order to keep the δ18O signal approximately in phase with the obliquity component of the ice model.“.
• Back in 2006, Ralph Ellis and Michael Palmer published a paper which identified the much shorter Precession cycle as the main driver, but with missing cycles. ie, the cycle sometimes failed to start an inter-glacial period, with very low versus not-so-low concentrations of CO2 being a significant factor. The whole Ellis and Palmer paper is really worth reading!
• For a long time, the Wikipedia article on the 100,000-year problem had no indication that the Precession cycle played a role in the inter-glacial cycle, with the 2007 “Precession” statement having been removed[*] . In particular, there was no mention of Ellis and Palmer.
• It is difficult to believe that the Wikipedia authors were unaware of the Ellis and Palmer paper, because there was a “Ralph Ellis” page in Wikipedia, which explicitly referred to the Ellis and Palmer paper under the heading “Ice ages, precession and dust-albedo feedbacks“.
• Even worse than that, and looking suspiciously like an attempt to remove Ralph Ellis’s ideas completely, in 2017 the “Ralph Ellis” page was deleted from Wikipedia. See Deletionpedia.
• A recent addition[*] to the Wikipedia “100,000-year problem” page now mentions Precession again, but still with no mention of Ellis and Palmer.

[*] I say this from memory, because I cannot remember seeing in the last year or two any Wikipedia suggestion that Precession plays a significant role. I may be mistaken. The Wikipedia page has been edited 5 times in March 2022 alone, so unravelling its history would be rather time-consuming.

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The paper should be indexed in Google Scholar in due course. Journal editing placed the “Discussion” section before “Conclusion”, although I thought the other way round was more natural because “Discussion” discusses issues arising from the Conclusion.

I hope that the paper will go at least some way towards resurrecting the ideas put forward by Ralph Ellis and Michael Palmer, and that the climate modellers will start to take seriously the IPCC statement that “The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible.“.