Abrupt Climate Changes

This article was about the opposite situation of the current problem of global warming. The possible relevance is that it shows that the current assumption that climate changes are gradual is wrong. For all we know, we could be on the verge of a tipping point already.

http://www.sciencedaily.com/releases/2008/08/080801152137.htm

ScienceDaily (Aug. 4, 2008) — Researchers in Germany, Switzerland, and the United States have shown, for the first time, that an extremely fast climate change occurred in Western Europe. This took place long before human-made changes in the atmosphere, and is causatively associated with a sudden change in the wind systems.
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The proof of an extreme cooling within a short number of years 12,700 years ago was attained in sediments of the volcanic lake Meerfelder Maar in the Eifel region of Germany. The seasonally layered deposits allow to precisely determine the rate of climate change. With a novel combination of microscopic research studies and modern geochemical scanner procedures, the scientists were able to successfully reconstruct the climatic conditions even for individual seasons. In particular, the changes in the wind force and direction during the winter half-year caused the climate to topple over into a completely different mode within one year after a short instable phase of a few decades.