[RightWhale]

As late as 1890 scientists doubted that meteorites came from the sky. Since then there have been few major impacts. Maybe the last big one was the Barringer Crater 50,000 years ago. So, on the basis of that short time of fairly good observation, major meteor impacts are rare. They have happened, there is no question, and they can be very disruptive, but meteor impacts aren't necessary to account for climate changes since the Ice Age. Volcanos do a fine job messing up things, and solar activity changes would be devastating, too. A period of increased major impacts is speculative, and such a period is a possibility, it just isn't necessary to account for Carolina Bays or the wipe-out of Egyptian civilization. My money is on solar activity, insolation variations.

[blam]

"My money is on solar activity, insolation variations."

I will consider all possibilities. We probably had some of all.