. . . a pesky little thing called science.
Quoted below is the abstract of a science article titled “An ikaite record of late Holocene climate at the Antarctic Peninsula”, published by Earth and Planetary Science Letters (Volumes 325–326, 1 April 2012, Pages 108–115).
Calcium carbonate can crystallize in a hydrated form as ikaite at low temperatures. The hydration water in ikaite grown in laboratory experiments records the δ18O of ambient water, a feature potentially useful for reconstructing δ18O of local seawater. We report the first downcore δ18O record of natural ikaite hydration waters and crystals collected from the Antarctic Peninsula (AP), a region sensitive to climate fluctuations. We are able to establish the zone of ikaite formation within shallow sediments, based on porewater chemical and isotopic data. Having constrained the depth of ikaite formation and δ18O of ikaite crystals and hydration waters, we are able to infer local changes in fjord δ18O versus time during the late Holocene. This ikaite record qualitatively supports that both the Medieval Warm Period and Little Ice Age extended to the Antarctic Peninsula.
Proponents of AGW keep claiming that science is on their side. Well, science keeps telling us that the Medieval Warm Period was a global phenomenon. So, if the recent global warming trend was caused by human activity, then what caused the global Medieval Warm Period?