From an interview with National Center for Atmospheric Research in Coloradoâ€™s Gerald Meehl discussing an NCAR paper in Science:
Experts say sea levels have risen 4 inches already over the past century and could rise between 4 and 40 inches more in the next century.
If completely melted, the Greenland ice sheet would add 25 feet to overall sea level and the West Antarctic Ice Sheet would raise it by 16 feet â€” enough to swamp most of Florida, Bangladesh and New York Cityâ€™s Manhattan island.
So thatâ€™s the upper limit on sea level rise. And while the modelers predict a mm/year rate, ice sheets melt catastrophically and weâ€™re getting into the range of losing some of them, so Iâ€™ll make a wild-ass guess that weâ€™ll see a bad decade with a foot or so sea level rise this century.
(To digress, this reminds me of how bad the premise of Waterworld is. You know a movieâ€™s science is bad when it makes you look fondly on the scientific plausibility of Planet of the Apes. Waterworld is a full point higher on the Scientfic Implausibility Richter scale.)
From the abstract of the paper, â€œThe Climate Change Commitmentâ€. Wigley, TML. (2005) Science 307:1766-9:
These constant-composition (CC) commitments and their uncertainties are quantified. Constant-emissions (CE) commitments are also considered. The CC warming commitment could exceed 1Â°C. The CE warming commitment is 2Â° to 6Â°C by the year 2400. For sea level rise, the CC commitment is 10 centimeters per century (extreme range approximately 1 to 30 centimeters per century) and the CE commitment is 25 centimeters per century (7 to 50 centimeters per century).
The CE senario predicts 2.5 mm/year rise, but emissions are rising so this is definitely an underestimate.