What to do with Coastal Real Estate?

David Holmgren exploring future scenarios: http://youtu.be/PQyw-2V37uw?t=58m

There's more on this topic in the latest John Michael Greer blogpost, Dark Age America: The Rising Ocean, wherein he discusses marine transgression:

'So far, at least, the vast East Antarctic ice sheet has shown only very modest changes, and most current estimates suggest that it would take something far more drastic than the carbon output of our remaining economically accessible fossil fuel reserves to tip it over into instability; this is a good thing, as East Antarctica’s ice fields contain enough water to drive sea level up 250 feet or so.  Thus a reasonable estimate for sea level change over the next five hundred years involves the collapse of the Greenland and West Antarctic sheets and some modest melting on the edges of the East Antarctic sheet, raising sea level by something over 50 feet, delivered in a series of unpredictable bursts divided by long periods of relative stability or slow change.

The result will be what paleogeographers call “marine transgression”—the invasion of dry land and fresh water by the sea. Fifty feet of sea level change adds up to quite a bit of marine transgression in some areas, much less in others, depending always on local topography. Where the ground is low and flat, the rising seas can penetrate a very long way...'