The effect on sea levels of a given temperature rise (or, conversely, the temperature increase needed to produce a given rise in sea levels) has a large element of guesswork about it, mainly because we aren't entirely sure what's going to happen to the Antarctic ice. It may slowly melt, or big chunks of it calve off, or huge glaciers detach from the rock and slide downhill into the sea. What is certain is that by the time we do know, it will be a bit late to do anything about it.

And not wishing to seem unconcerned, but at least I won't be around to see.