The IPCC report says sea level may rise 30-90 cm in the next 100 years because of AGW.
Al Gore says in may rise 6-7 meters, but he is cautious enough not to name a date.
The sea has risen considerably in the past.
In the first century BCE, Herod the Great built the city of Caesarea, with a magnificent harbor.
Today the Herodian breakwaters are submerged 5m below the water surface.
(Same is true of the ancient harbor of Alexandria, Egypt).
Was it sea level rise proper, or was it a sinking of earth crust (acompanied by rising elsewhere) ? I don't know, I don't think anybody knows.
One thing is certain: it wasn't AGW, it wasn't CO2.