Natural mechanism for medieval warming discovered

[Soylent Brice]

Europe basked in unusually warm weather in medieval times, 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 Trouet at the Swiss Federal Institute for Forest, Snow, and Landscape Research in Birmensdorf, the mechanism that caused the warm spell in Europe – and meant wine could be produced in England as it is now – cannot explain current warming. It means the medieval warm period was mainly a regional phenomenon caused by altered heat distribution rather than a global phenomenon.

The finding scuppers one of the favourite arguments of climate-change deniers. If Europe had temperature increases before we started emitting large amounts of greenhouse gases, their argument goes, then maybe the current global warming isn't caused by humans, either.

To work out what the global climate was doing 1000 years ago during the so-called "Medieval Warm Period", Trouet and colleagues started by looking at the annual growth rings of Moroccan Atlas cedar trees and of a stalagmite that grew in a Scottish cave beneath a peat bog. This revealed how dry or wet it has been in those regions over the last 1000 years.

more: http://www.newscientist.com/article/dn16892-natural-mechanism-for-medieval-warming-discovered.html

[Fovea]

1. Read Jean Gimpel

The medieval machine.
Before coal mining, each forge consumed 10 acres of woodland in charcoal a month.