A recent study by A.R. Agatova et al investigated glacier dynamic and climatic variations in the southeastern part of the Russian Altai during the last 7000 years and show distinct natural climatic changes had occurred.
Not surprisingly, these changes coincide with changes occurring at other parts of the globe, and so add to the massive weight of evidence refuting the claim that climate fluctuations on centurial in millennial scales are regional phenomena and occur over a small temperature range.
The scientists exhumed organic material and carried out radiocarbon dating on wood remains from buried dead trees at the upper tree limit, and from rock glaciers on trough slopes from six glacial valleys in the North Chuya Range, SE Altai. They compiled an extensive dataset, which form the basis for understanding the relative magnitudes and timing of the most important glacial and climatic events of SE Altai.
New data refute the traditional concept of the Russian Altai Holocene glaciations as a consecutive retreat of the late Würm glaciers and argue their complete degradation at the head of trough valleys at least 7000 cal. years BP.”
Moreover, they identified three periods of glacial advances: from 4900 to 4200 cal. years BP (Akkem stage), from 2300 to 1700 cal. years BP (Historical stage) and in the 13th–19th centuries (Little Ice Age (LIA) or Aktru stage). The coincident extremes of lowering temperature and increasing precipitation during the Akkem stage led to abrupt glacier advances and forming of the most remote moraine complexes downstream in the valleys.
The authors also write that in addition to the radiocarbon data, the time limits of the Historical stage were defined more precisely using dendrochronological and archaeological data from Scythian burials of Pazyryk culture in SE Altai.
Repeated forest regrowth in the presently glaciatiated area indicates significant retreat or even complete glacier degradation during interstage warming. The decreases of glacier length in the following stages argues for intensification of aridity in the SE Altai during the second half of the Holocene. The thermal minimum in the middle of 19th century, the greatest in the last millennium, did not positively influence the mass balance of glaciers, which also supports this conclusion.”
So much for bogus claim that climate was more or less stable before man populated and developed.
Also strong glacial variations in the Alps as well
Interestingly, Prof. em. Dr. Gernot Patzelt, University of Innsbruck, made a presentation at the International Climate and Energy Conference in Munich late last year, which the European Institute for Climate and Energy has just released.
In his presentation, Dr. Patzelt also reveals glacier advances and retreats in the Alps throughout the Holocene, thousands of kilometers away from the Russian Altai. Forests existed at elevations that were higher than today – in areas that are presently covered by glaciers.
At the 12:22 mark, Patzelt summarizes the data of the three glaciers examined in the Alps and presents a temperature reconstruction. His conclusion at the 13:42:
Over the last 10,000 years it has been warmer than today 65% of the time. Our current climate does not in any way show an anomaly in temperature development. That’s an important result.”
Top curve shows the reconstructed temperature of the Alps over the Holocene. Dark-shaded areas show warm periods. (Snipped from Patzelt’s presentation at the 13:30 mark).
Clearly from his chart one sees the millennial cycles that coincide with documented solar activity. And as Dr. Sebastian Lüning showed yesterday in Chicago, we are not talking about fluctuations of a couple of tenths of a degree, but of fluctuations over 1, 2 or even 3°C.
At 14:50 Patzelt shows the Greenland ice core reconstruction for comparison.
Clearly there are natural forces at work. Claims that natural factors retired 100 years ago are simply absurd.