I gather from Solomon and from reading Zbig’s articles [http://www.21stcenturysciencetech.com/Articles%202007/20_1-2_CO2_Scandal.pdf] that Friedli et al 1986 and Neftel et al 1985 made an ad hoc assumption that the average air trapped in the ice cores must be exactly 83 years younger than the ice in which it was trapped. On the face of it, even to a layman, this seems dubious.
I couldn’t find free access to the articles. Anyone already a subscriber to Nature? The article cites are:
Friedli, H., Lotscher, H., Oeschger, H., Siegenthaler, U. and Stauffer, B., 1986. “Ice core record of the 13C/12C ratio of atmospheric CO2 in the past two centuries.” Nature, Vol. 324, pp. 237-238.
Neftel, A., Moor, E., Oeschger, H. and Stauffer, B., 1985. “Evidence from polar ice cores for the increase in atmospheric CO2 in the past two centuries.” Nature, Vol. 315, pp. 45-47.
Zbig doesn’t use the F word to describe what these authors did. He uses words like “ad hoc”, “arbitrary”, and “data manipulation.” Solomon reports that in 1993 researcher attempted to prove empirically the authors’ age assumption but they failed to do so. No references cited in the book about the 1993 article.
Regardless of how one characterizes what Friedli, Neftel, et al did, Zbig’s allegations are incendiary. However, I can find no rebuttals of his allegations. It would be good to read the articles. Maybe interlibrary loan. Wait! My daughter is a liberian. Maybe she can help.