At the time scales we are talking about, our cities can ooze away from the sea slowly just by abandoning property that is currently flooding. The sea is rising

At the time scales we are talking about, our cities can ooze away from the sea slowly just by abandoning property that is currently flooding. The sea is rising at around 3mm / year, which is about a foot a century. Even if we multiplied this ten-fold, that's still only about an inch and a quarter a year we'd have to cope with. We'd have to raise some levies, abandon some property, and maybe update some other infrastructure. Not great, but not the end of the world.