10 feet (3 meters)

Australian scientist Dr John Church is one of the world’s leading experts on sea level rise (he’s been studying it for a couple of decades) and was a co-ordinating lead author of the relevant chapter in the latest IPCC report.

“I would not dispute the idea that you could get substantially larger rises (beyond the end of this century) particularly with parts of West Antarctica being grounded below sea level and potentially unstable.

I don’t think that three metres is out of the question. Since the IPCC report, studies have shown that this process is now happening. We have triggered something that is potentially unstoppable.”
The Guardian 5 May 2015

thanks to Badgerbod