Not particularly. Our largest cities, those best equipped to handle the growing population, mostly lay on coastal areas. These are also the centers of international trade, policy, and cultural exchange.

That sea levels will rise is almost certain, and it's a damn shame.

The only possible benefit I can see is that the loss of those cities might prompt some global powers to start construction of cities built on modern scientific principles, much as Europe was forced to after the end of the Second World War.