Considering that the oceans are rising (and that humans don't seem too keen on doing anything about it) and that population is growing exponentially, is it plausible to imagine that in a not too distant future, cities will expand underwater?

• If yes, how soon and at what rate? This question is not meant to entail the design aspects of such city unless it's relevant for the timeline (for technological development for example).

• If no, why not? What are the more plausible alternatives for the growing population on a shrinking land?