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First the link to this week's complete list as HTML and as PDF.
I’m really and truly not competent to assess Durvasula & Sankararaman and Roger et al., but do their results as shown really uphold their detailed and far reaching claims?
Tylén et al. is a convincing study and I agree with their conclusion. That said there is one serious blunder. When they say
“On average, earlier stimulus engravings were identified in 2.27 s, intermediate stimuli in 2.03 s, and late ones in 1.82 s.” they mean no such thing. These are not three independently determined averages but three points on a single straight regression line from all the data. As stated their claim is simply wrong.
Inferring diet and trophic level from zinc isotopes is a novel idea and Bourgon et al. do well to pursue it, even if I doubt it will ever attain meaningful predictive value. But once again, what happened to proof reading, peer review and editorial oversight? Their abstract claims
“The 66Zn/64Zn ratio (expressed as δ66Zn value) shows an enrichment of the heavy isotope in mammals along each trophic step. [...] Distinct enamel δ66Zn values of the fossil taxa (δ66Zncarnivore < δ66Znomnivore < δ66Znherbivore) according to their expected feeding habits were observed.”
Their figure 2 bears the legend “Log. Concentration (ppm)” and values go up to 8 or 9. Trace elements at 109 ppm? Really? Of course if we were to read “Log.” as the natural logarithm we'd get about 8 ‰. Is this an example of stating facts clearly and legibly or of setting up a riddle of guesswork? Will everyone quoting these results be able to that correctly? Remember iron in spinach, anyone? How can such nonsense pass even the most superficial of scrutiny? Whatever happened to sensible and legible logarithmic scales in place of confusing linear ones expressed in ambiguous logarithms?
I’ve been known to be critical of climate modelling and I'm still not prepared to treat extrapolations from fitted models as established fact and indirect projected conclusions from them even less. That said anthropogenic carbon dioxide enhancement is an irrefutable fact and the soon to be achieved doubling will be unprecedented in more than the last two million years. So far only about half or less of fossil burning emissions have ended up in the atmosphere, the rest were sucked up in sizeable negative feedbacks. If, as Rammig and Hubau & Lewis et al. convincingly project, these will soon be saturated, this is something to be taken seriously.
Zharkova et al. has been retracted and their revised republication so far not accepted anywhere. I think that's for the wrong reason. Their study divides into two quite distinct parts, a novel observational result supported by data and a theoretical explanation. All the retraction is based on, is an aside as addendum to the theory. Even if the theory were completely bonkers that would not invalidate the measurements of the first part with their two long cycles that were not, as far as I'm aware, reported before.
It is from this observed, not theorized, cyclicity that they project a coming temperature rise of 2.5 °C from purely natural causes. If that really is the case, then anything we add as humans will come on top of that. The claim may well be wrong, but it should not be ignored completely for totally irrelevant reasons.
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