The IPCC often claims its climate models are infallible and all knowing when it comes to the climate - new study reveals major climate modeling failure as they are unable to accurately simulate Greenland's past climate accurately
(click image to enlarge - source here)
Read here. Greenland's current climate is heavily influenced by the Atlantic Multidecadal Oscillation (AMO), which has a lengthy periodicity. The AMO is a natural climate variability phenomenon having a strong impact on North Atlantic's regional temperatures.
Recent analysis of the Greenland ice cores, by Chylek et al., has proven that the powerful AMO variability has been part and parcel of the Greenland climate for thousands of years, pushing temperatures higher and lower depending on the cycle point.
This natural, internal variability has no connection to external factors (forcings) such as the CO2 greenhouse gas.
In addition, the scientists determined that the climate models, favored by the IPCC and other non-empirical based scientists, are unable to faithfully mimic the ancient past AMO variability due to geographic differences (location differences) - a major climate modeling failure.
"...examine evidence of the AMO that is contained in several ice core records distributed across Greenland. The researchers were looking to see whether there were changes in the character of the AMO over different climatological periods in the past, such as the Little Ice Age and the Medieval Warm Period—periods that long preceded large-scale human aerosol emissions. And indeed they found some. The AMO during the Little Ice Age was characterized by a quasi-periodicity of about 20 years, while the during the Medieval Warm Period the AMO oscillated with a period of about 45 to 65 years...The observed intermittency of these modes over the last 4000 years supports the view that these are internal ocean-atmosphere modes, with little or no external forcing...However, the geographic variability of these periodicities indicated by ice core data is not captured in model simulations." [Petr Chylek, Chris Kenneth Folland, Leela Mary Frankcombe, Henk A. Dijkstra, Glen Lesins, Manvendra K Dubey 2012: Geophysical Research Letters]