Medieval warming WAS global – new science contradicts IPCC

[FarCenter]

15. This is about temperature, not carbon dioxide

The IPCC basically tried to minimize the Medieval Warm Period, at least in its earlier reports, as being a local European phenomena, and then not very warm at all.

This study shows that the Medieval Warm Period of relatively elevated temperatures extended to Antarctica.

So the problem for global climate modelers is to be able to run climate simulations that reproduce a global MWP, rather than a local minor one.

http://www.sciencedirect.com/science/article/pii/S0012821X12000659

Calcium carbonate can crystallize in a hydrated form as ikaite at low temperatures. The hydration water in ikaite grown in laboratory experiments records the ?18O of ambient water, a feature potentially useful for reconstructing ?18O of local seawater. We report the first downcore ?18O 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 ?18O of ikaite crystals and hydration waters, we are able to infer local changes in fjord ?18O 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.

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Scientists use rare mineral to correlate past climate events in Europe, Antarctica

http://www.syr.edu/news/articles/2012/ikaite-03-12.html

To understand the present, scientists look for ways to unlock information about past climate hidden in the fossil record. A team of scientists led by Syracuse University geochemist Zunli Lu has found a new key in the form of ikaite, a rare mineral that forms in cold waters. Composed of calcium carbonate and water, ikaite crystals can be found off the coasts of Antarctica and Greenland.

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Ikaite crystals incorporate ocean bottom water into their structure as they form. During cooling periods, when ice sheets are expanding, ocean bottom water accumulates heavy oxygen isotopes (oxygen 18). When glaciers melt, fresh water, enriched in light oxygen isotopes (oxygen 16), mixes with the bottom water. The scientists analyzed the ratio of the oxygen isotopes in the hydration water and in the calcium carbonate. They compared the results with climate conditions established in Northern Europe across a 2,000-year time frame. They found a direct correlation between the rise and fall of oxygen 18 in the crystals and the documented warming and cooling periods.



“We showed that the Northern European climate events influenced climate conditions in Antarctica,” Lu says. “More importantly, we are extremely happy to figure out how to get a climate signal out of this peculiar mineral. A new proxy is always welcome when studying past climate changes.”