New Scientist: Europe basked in unusually warm weather in medieval times âEUR” so much so that wine was produced in England âEUR” but why has been open to debate. Now the natural climate mechanism that caused the mild spell seems to have been pinpointed. The finding is significant today because, according to Valerie Trouetat the Swiss Federal Institute for Forest, Snow, and Landscape Research in Birmensdorf, the mechanism is not now of sufficient strength to explain current warming. The …