50m, and I’d be living on a little island a couple of miles offshore at that point. Thankfully whilst the school and village hall would have already gone, one decent pub would be left as well as the rubbish one. Though I have a double sea kayak, and a very nice pub at the nearest point on the mainland. The funny thing is, it has flooded up to about half a mile away and we have been cutoff from all other dry land in one direction fairly recently.
Not sure why anybody is surprised at how much the sea would have to rise – I knew I lived at 50m ASL. More interesting is seeing the required level to separate bits of the country – 50m appears to be the crucial figure to generate the Isle of North Yorkshire.