But the water held as ice on land can't reach the sea until the temperature at the edge of the landmass rises above 0 deg C, which it obviously won't do until the ice sheet has melted.
I'm still intrigued by the recent finding of dormant bromeliads under a retreating glacier, indicating that the surface temperature was a lot higher (at least in Canada) 500 years ago. What was the sea level then?
And going back to Marchesa's last post, can anyone tell me how they measured the global mean surface temperature in 1880? Nobody had been to the north pole, or even begun to explore the Antarctic land mass, at that time, and the number of survey ships in the South Pacific was no more than two. An awful lot of "historic data" is frankly unjustified guesswork.