Term (also medieval climate optimum or medieval climate anomaly) for a long period from about 900 to 1350 AD with warm climate, The climate phenomenon was weighted differently in terms of region and time. Because in other parts of the world it was much colder than today, for example in the tropical Pacific. The temperatures in the areas affected by the warming were around 1 to 2 degrees higher than during the subsequent cold period, the Little ice age, In the northern Atlantic, the pack ice retreated north, and the land glaciers partially disappeared. This warming allowed the Vikings to colonize the island of Greenland (since 986) because the Arctic Ocean was ice-free in both directions and therefore navigable. The myth of a green, fertile Greenland that is particularly widespread by climate change deniers viniculture but is only a fairy tale This rumor comes from the time when the navigator and explorer Erik the Red (950-1003) was exiled to Greenland towards the end of the first millennium. It was bitterly cold there and life difficult and Erik invented this lie to lure compatriots from Iceland to Greenland.
The cultivation limits in the German low mountain ranges were about 200 m higher than today, so that agriculture in the high Middle Ages (1050-1250) experienced a large expansion. The winegrowing limit was then on the southern Baltic coast. Viticulture was thereby in East Prussia, Pomerania and southern Scotland, as well as grain growing in Norway even possible up to the Arctic Circle (66 ° north latitude). Until the beginning of the 14th century, especially in Germany and France the vineyards extended to steeper slopes. The medieval warm period was less pronounced in other parts of the world. In some regions, the temperatures were even somewhat lower and in others there was no significant change. The causes are believed to be significantly increased solar activity and unusually low volcanic activity worldwide (volcanic activity darkens and sulphates the atmosphere and causes a colder climate). These phenomena are related to a feared today climate Change quite similar. Nevertheless, you cannot compare this, because the reasons for the warm period are not exactly known.