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Thirteen thousands years ago, Europe was much like it is today -- cool but temperate, with great forests carpeting the land. Ice sheets still nibbled at Finland and Sweden, but for much of the continent the last Ice Age was a distant memory. Suddenly, the climate went haywire. Warm Gulf Stream currents that brought heat from the equator up toward the pole began to fail. Temperatures plummeted 3 to 4 degrees Celsius, and stayed that way for a millennium.
Now scientists believe they've pinpointed the exact time the northern hemisphere was plunged back into a deep freeze. Examining sediments preserved at the bottom of a remote lake in western Germany, they found that what's known as the Younger Dryas cold period took just a year to sweep across the continent, starting in the autumn, 12,679 years ago. More >>>