Climatic significance of Holocene beachrock sites along shorelines of the Red Sea: Discussion

摘要

The geologic record of climate change is currently a very active area of research.The results of such studies have the potential to greatly improve our understanding of the different factors that influence climate and,consequently,may help to guide policy initiatives regarding global warming.Given the importance of such studies,it is imperative that they be scientifically rigorous and thorough.Friedman (2005) falls short on both counts.In this article,Friedman attempted to use the oxygen isotopic composition of a series of ~(14)C-dated beachrock samples to infer past changes in temperature.On the basis of increasing delta~(18)O values for beach-rock with decreasing age,he concluded that global temperature has decreased dramatically during much of the Holocene.The conclusions of the study regarding changing temperature are not supported by the data presented.Alternative hypotheses,not considered in the study,are far more likely explanations for the observed isotopic trend than decreasing temperature.