[Little Bill]

Asteriod(sp) 4000 years into the Holocene, fits all of the facts.

[blam]

"Asteriod(sp) 4000 years into the Holocene, fits all of the facts."

The worldwide 'long ring' tree ring data indicate a catastropic (worldwide) event at 3195. Could this be your asteroid? Now, where did it hit? (Atlantis?)

[DonQ]

No, not an asteroid. It appears that the general climate of the planet goes in cycles of approximately 500 years. Right now we are approaching the warmest peak of a cycle and that's why the earth is warming (more than modern pollution by itself). Back around 1 AD, another warm trend, Rome was able to march all the way to Germany. 500 AD a cold trend snows in a lot of European contact, the Roman Empire weakens, and the Dark Ages set in. 1000 AD it's warm again and now the Vikings are no longer iced into Scandanavia but are able to sail out and pillage. 1500 "the wee ice age" is at its coldest point. Etc.