Hi Will:

Good post.  Yep, I agree, a return to Pliocene marine highstands would (will?) change the coastlines of the world in a dramatic way.  If it happens over the course of two weeks time, that's a catastrophe for a couple billion people.  If it happens over the course of a couple millennia (my bet), Not So Much of a disaster.

Of course, some would argue now that we're *locked in* to disastrous sea level rise unless we contrive a way to suction vast amounts of CO2 out of the air.  That would mean my little coastal house would end up under ca. 30 feet of water.  But I'll let my remote heirs and assigns worry about that, just like my remote great-great grandparents had to leave to some things aside for me to worry about now.