Very well put.
I've yet to read how we cope with the tides, caused by the gravitational pull of the moon. There are mucho feet between high and low tide on a daily basis and we more than manage.
In fact, it may be that the sea level at a location varies more on a daily basis than it does between ice ages. Am I missing something?
Out of curiosity, how much of the change in "sea level" is attributable to variation in distance between the ocean's surface and the center of the earth, and how much is attributable to variation in distance between land masses and the center of the earth?