82 feet (25 metres)

“The last time the world was three degrees warmer than today – which is what we expect later this century – sea levels were 25m higher. So that is what we can look forward to if we don’t act soon. None of the current climate and ice models predict this. But I prefer the evidence from the Earth’s history and my own eyes. I think sea-level rise is going to be the big issue soon, more even than warming itself.”
Jim Hansen, “Climate change: On the edge” The Independent, 17th February, 2006