[Reverend Bob]

OK. I've done it -- and learned little in the process. Lots of hyperbole, too few facts.

A few factoids though to amaze the global warming hysteriacs:

1. The average mean temperature in Montana during the Eocene was 27 degrees warmer than now. Oh, and life thrived! The cooler Oligocene age that followed (still much warmer than now) was less diverse than either of the warmer epochs that bracketed it.

2. The Arctic ice cap is a relatively recent development. It did not exist until the mid-Pliocene (about 1.5 MYA).

3. Pleistocene climate cycles, no matter how they're tracked, match most closely to the Croll-Milankovitch cycles (the eccentricity of the earth's orbit, the tilt of it's axis, and the wobble, or "precession", of that axis).

4. Even living in an interglacial as we are, our era, geologically speaking, is far colder than virtually anything that has come before.

And, finally: 5. Warmer temperatures support biotic diversity. Colder temperatures inhibit biotic diversity. Ergo: Global warming is good for diversity. :-)

[cogitator]

Even living in an interglacial as we are, our era, geologically speaking, is far colder than virtually anything that has come before.

Rev Bob: one of the main concerns is a rapid pace of warming such that ecosystems will be unable to adapt to the change. When rate-of-change is the concern, the actual temperature compared to any other time is not as important. Extinction rates go way, way up whenever climate change is rapid. (And there are sound reasons for that.)