The Register 
March 25, 2012
More peer-reviewed science contradicting the warming-alarmist “scientific consensus” was announced yesterday, as a new study shows that the well-documented warm period which took place in medieval times was not limited to Europe, or the northern hemisphere: it reached all the way to Antarctica.
The research involved the development of a new means of assessing past temperatures, to add to existing methods such as tree ring analysis and ice cores. In this study, scientists analysed samples of a crystal called ikaite, which forms in cold waters.
“Ikaite is an icy version of limestone,” explains earth-sciences prof Zunli Lu. “The crystals are only stable under cold conditions and actually melt at room temperature.”
Down in the Antarctic peninsula that isn’t a problem, and Lu and his colleagues were able to take samples which had been present for hundreds of years and date their formation. The structure of Ikaite, it turns out, varies measurably depending on the temperature when it forms, allowing boffins to construct an accurate past temperature record.
A proper temperature record for Antarctica is particularly interesting, as it illuminates one of the main debates in global-warming/climate-change: namely, were the so-called Medieval Warm Period and Little Ice Age merely regional, or were they global events? The medieval warmup experienced by northern Europeans from say 900AD to 1250AD seems to have been at least as hot as anything seen in the industrial era.