Steven McIntyre vs. the Spawn of Yamal – Grow with that?

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enchanted larch of yamal site:climateaudit.org

And here is the current Twitter thread.

Originally tweeted by Stephen McIntyre (@ClimateAudit) above August 30, 2022.

Last week, a new article https://nature.com/articles/s41467-022-32629-x… on the Yamal tree belts, co-authored by Osborn and Melvin in East Anglia, claims “recent warming in Siberia unprecedented in the last 7 millennia”. @climateofgavin giggled at the same result as the previous UEA.

Schmidt illustrated his sniper with Hantemirov’s seemingly impressive hockey stick (Nature 2022). Neither Schmidt nor Nature show a more remarkable figure from Hantemirov’s thesis showing a significant southward movement of the Yamal to Holocene bamboo line, with a very small recent HS.

the strong southward movement of the Yamal treeline during the Holocene (as observed by Hantemirov) is consistent with the long-term decrease in Greenland d18O values ​​(Vinther 2009).

Hantermirov (or Schmidt) also does not reconcile the basic findings of Esper et al (Nature 2012). https://www.blogs.uni-mainz.de/fb09climatology/files/2012/03/Esper_2012_NatureCC6.pdf shows a lack of response of tree ring chronology to large changes in JJA isolation at high latitudes for the Holocene (up to 48 wm-2 vs 1.5 wm-2 CO2)

despite claims in the journal Nature about data availability, Hantemirov (2022) does NOT store baseline measurement data. About 600 of the ~1600 cores were previously used in Briffa et al (2002,2009, 2013) and grudgingly provided.

there’s some interesting and new information in Hantemirov (2022) – long-sought data on long periods of samples – see the Templates tab on the spreadsheet at

https://zenodo.org/record/6477133#.Yw4fOXbMKUk

Hantemirov has illustrated the location of their samples in the figure below (showing locations on the Tanlova, Khadyta, Yada and Portsa rivers). The swatch does not show any bias patterns.

Here’s my plot of similar location data, colored over time – oldest puppy in blue, modern red (lived 1980-2020). One point is clear: the modern samples are far to the south, the oldest samples to the north. Note a very ancient specimen of the Yuribey River to the north, not shown in Nature

another representation of the same location data, showing latitude relative to the (start) year. The modern line lies far south of the Holocene line, and modern (living) samples were taken south of the majority of the mid-Holocene samples. Early report on Holocene early 70N

Schmidt and other publishers show a highly smoothed version of the Yamal data. The toothless version is (unsurprisingly) significantly less dramatic.

I was able to reproduce their smooth Lowess100 (of the KMean_Reconstruction series) in the Kmean tab of a hosted spreadsheet on the first try (Wordle eagle so to speak) using lowess span f = 100/ 7368. Allow me to fairly accurately comment on the smoothness of the similar spline they show.

KMean_Reconstruction is linear (100% correlation) with the underlying CRN shown below. The smooth blade starts at ~1750 and on its face simply represents a trend that has continued in recent decades starting ~1750.

In detail, the most recent ‘chronological’ values ​​(from the southern part of Yamal) are slightly higher than the previous values ​​on the 20th and late 19th, but no specific HS.

and, needless to say, Hantemirov and his co-author East Anglia do NOT attempt to distinguish any additional growth in Yamal that is directly attributable to the CO2 “greening” of the late 20th century, despite the fact that Such greening is shown in Yamal along with most other locations

https://www.science.org/doi/10.1126/sciadv.aax1396

Originally tweeted by Stephen McIntyre (@ClimateAudit) above August 30, 2022.