To my Miami brethren: the higher elevation points are well taken, but what about the long-term idea of the entire housing market just crashing if/when the realization sets in the Miami is going to be underwater? That's my real fear. Granted, my preoccupation with that scenario may be less logical than worrying about a more short-term calamity.
I don't think this would happen, because you are assuming a short-term calamity on the order of total destruction from a long-term event. What is more likely to happen will be shocks, but nothing that is unmanageable, at least with the predicted level of sea rise this century. These shocks will be costly, and will drive a natural slow-scale migration from the city at some point which may depress housing markets but will not cause a collapse (unless your home in inhabitable). The examples of cities adapting to shocks are too numerous to list, but here's a partial one:
1) Miami, destroyed by two of the most destructive hurricanes of the twentieth century, is now one of the trendiest places to live.
2) New Orleans mostly sits below sea level, which was clearly evident post-Katrina. People have moved back and the Corps of Engineers continues to improve the defenses. (Granted, I'm sure property values dropped in the aftermath (especially in the flooded areas), but they seem to have bounced back.)
3) The whole country of the Netherlands, rather than fighting sea level rise, decided to push the sea out. So far it has worked out for them.
4) How many desert southwest cities have adapted to population surges and droughts that attack water supplies from both directions?
Bottom line, if you feel it is a big enough issue, go ahead and leave Miami. If you'd prefer to stay for intrinsic reasons (understandably), don't worry too much about it, as at that point it will be out of your circle of influence.
