The Plasticity of Ice Core Interpretations and Correlation
It’s easy to be impressed by the sheer weight of all the ice core data interpretations and the correlations that are thrown at you when you read either the popular literature or the scientific journals. We are told that a particular interpretation of a certain part of the ice core, representing such and such epoch of time, has been corroborated by pollen counts and sea core markers in other parts of the globe. This all sounds very impressive, but a search of the scientific journals themselves reveals a slightly different story.
It seems that the various interpretations and supportive data really are not absolute or set in stone, and that any given scenario for time or weather can be changed and the markers that correlated it can be “massaged “ to fit entirely new scenarios or time frames. Tens of thousands of years can come and go and their purported weather histories with them. The pollen counts and sea cores can be “reinterpreted” to fit a different scenario with relative ease.
An example of this type of data massage can be seen in the way the Eemian interglacial period was treated in the scientific literature. In the 1993 literature we are told that after an examination by a team of Europeans, the GRIP ice core gave evidence of sudden temperature changes (evidence of runaway climate change) and that this was backed up by pollen counts and further, it was correlated with marine sediments and to add even more weight to the analysis, it was also said to be supported by isotopic records from the margin of the Greenland ice sheet (GRIP, 203-206).
However by 1997, an American team looked at the same cores and then we are told that the oxygen isotope readings of the GRIP core in the Eemian period were actually caused by ice-flow disturbances (Lehman, 117). What the Europeans had deduced as evidence of rapid climate change supported by three groups of evidences from other areas, was dismissed as an artifact (effect) of ice flow.
This then led to adjustments, “revised interpretations” of all three of the correlations that were more consistent with the new scenario (Lehman, 117). In other words, the pollen counts and marine sediments and isotopic measurements at the edge of the Greenland Ice Sheet said to support the first interpretation of the ice cores, were easily reappraised and found to fit an opposite scenario. Therefore the so called proof or evidence which looked so compelling in the European papers found in the leading scientific journals proved to be extremely plastic, and therefore really unreliable or useless as absolute or objective checks and balances on ice core “interpretations” and subsequent theories built on them.
A another example of the plasticity of data that can come into play here involves the use of the LLS method. Apparently the number of dust layers that can be visualized and counted depends on the size of laser used to do the counting. This became important when it was discovered that there was a 25,000 year discrepancy between the GRIP core and the Vostok ice core (a discrepancy between a reference point such as a volcanic spike which was believed to correlate both cores to the same date). The chief scientist went back and recounted the “visual stratigraphy” using the 8mm LLS beam that had been used to count the previous 1800 meters of the core. No additional annual layers could be discovered. However a 25,000 year gap is a huge discrepancy and could not be allowed to remain. But by switching to a 1mm LLS beam she was able to recount that section of the core and discover another 25,000 annual layers that had been “invisible” previously (Meese 26416). Now the two cores could be said to be in agreement. It must be noted however, that if the apparent discrepancy between the two cores hadn’t been noticed, the missing 25,000 years wouldn’t have been required and both cores would still have been said to be in agreement. One wonders how many more thousands of years could be found if the 1 mm LSS laser had been used on the rest of the core. This is what is known in the scientific community as “data massage” and there is little found in the ice core data, whether volcanic, pollen counts, etc, that can’t be imitated by other data or misread, as the scientist often admit in their journals, but which never makes its way into IPPC reports or the news media.
While research on arctic ice cores is very interesting, despite the fact the scientists are all burdened by a uniformitarian view of geology, we really might want to hesitate before making major world wide decisions on energy policy based on such research.
But I’m just a woodcutter. You might want to go with Chicken Little instead.
“Climate Instability during the last interglacial recorded in the GRIP ice core”,
Nature, 364, July 15, 1993, 6434 pp.203.
Lehman, Scott, “Sudden end of an Interglacial”, Nature: 390, 1997, pp 117-118