They're going to increase anyway, there is never a point in history where the sea was not raising sans the ice age. Antarctica and Greenland combined have enough ice melt to bring us 65 meters more water level, lol. Of course, that assumes a 100% melt-off (probably not likely). If you think that's bad, well it's rose about 30m since the last ice age, if I recall.
So we are talking flooding in say extremely long time frames, but we'll all be dead and hopefully our future progeny have the sense to build on higher ground.
Anyway, I think we should control these things as pollutants. Unfortunately for most of the people here this is one of my nerd subjects, and I assure you about 90% of the global warming / climate change data is cooked. I don't take that tack lightly, in fact I find it frustrating.
Modern climate scientists are lying to keep their jobs and funding, and the proof is in things they do -- under-reporting glacial ice gains and movements, measuring temp changes that are inside their margins of error, and setting the goal-posts to pander to their biases. Even the most capable of scientists are able to do poor science, if no one challenges their assertions.
To go further would just be diverting from the OP - it's probably another thread, so that's where I'll leave this.