Yet another study illustrates that the Medieval Warming Period was not regional, but global

Yet another study illustrates that the Medieval Warming Period was not regional, but global

Michael Mann and his team of data manglers like-minded scientists like to tell us the Medieval Warming Period was just a “regional” event rather than global, because if it was global, that destroys their narrative. This new study shows it also occurred in South America, and adds to the growing body of southern hemisphere locations. as we can see in this map below, note the red markers where it was warmer than normal. Sure seems global to me.

Climate reconstructions of the ‘Medieval Warm Period’ 1000-1200 AD. Legend: MWP was warm (red), cold (blue), dry (yellow), wet

Interactive map source:

Preindustrial climate change in South America: the Middle Age was warm, glaciers shrank

By Dr. Sebastian Lüning and Prof. Fritz Vahrenholt
(German text translated/edited by P Gosselin)

The climate of the Middle Ages is still a mystery. In many parts of the world a warming period occurred, which can still not be satisfactorily simulated by the current climate models.

The problem: natural climate factors play almost no role in the models.

It is therefore all the more important to first carry out a proper mapping of the climate for this important period. A research group led by Sebastian Lüning has presented an overview of the medieval climate in South America and now appears in the journal Quaternary International.

Here the scientists summarized a large number of case studies of the entire continent. The climate archives included pollen surveys in lake sediments of the Andes, which documented the rise and drop of the tree line.

Other studies reconstructed the oscillating shrinking and growth of Andean glaciers or dealt with tree rings. As a result, Lüning and his team found that the vast majority of the 76 individual studies indicate warming during the early 2nd millennium. The Medieval Warm Period was also strongly represented in South America. Exceptions were some coastal waters, where increased buoyancy of cold water led to a cooling.

Full story here

Here is the paper:

The Medieval Climate Anomaly in South America

SebastianLüning. Mariusz Gałka, Florencia Paul, Bamontec Felipe, GarcíaRodríguezd, FritzVahrenholte

The Medieval Climate Anomaly (MCA) is a climatic perturbation with a core period of 1000-1200 AD that is well-recognized in the Northern Hemisphere (NH). Its existence in the Southern Hemisphere (SH) and the level of synchronicity with the NH is still a matter of debate. Here we present a palaeotemperature synthesis for South America encompassing the past 1500 years based on multiproxy data from 76 published land and marine sites. The data sets have been thoroughly graphically correlated and the MCA trends palaeoclimatologically mapped. The vast majority of all South American land sites suggest a warm MCA. Andean vegetation zones moved upslope, glaciers retreated, biological productivity in high altitude lakes increased, the duration of cold season ice cover on Andean lakes shortened, and trees produced thicker annual rings. Similar MCA warming occurred in coastal seas, except in the year-round upwelling zones of Peru, northern Chile and Cabo Frio (Brazil) where upwelling processes intensified during the MCA due to changes in winds and ocean currents. MCA warming in South America and the NH appears to have occurred largely synchronous, probably reaching comparable intensities. Future studies will have to address major MCA data gaps that still exist outside the Andes in the central and eastern parts of the continent. The most likely key drivers for the medieval climate change are multi-centennial Pacific and Atlantic ocean cycles, probably linked to solar forcing.”


Superforest,Climate Change

via Watts Up With That?

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