It's very hard to predict what will happen to sea level in the next 30 years. Marine ice sheet instability is the crux of the issue.

Here's a simulation: https://www.youtube.com/watch?v=jLdaAKIkpKA

Once the melting point moves beyond a "gate" where the ground starts going downwards, then water will just go in there and the melt will accelerate tremendously. We don't know if it's a decade or a century, as it's not been witnessed in history.