Keith you are incorrect about the amount of sea level rise from the West Antarctic Ice Sheet. It only has the capacity to raise sea level by 6-8 m or 21-26 feet. Nor has it been predicted by any glaciologist that will happen during this or early next century. You must do a better job of getting your facts correct, or the resulting work is useless. As a glaciologist who has worked on the WAIS I would suggest that as a rough guide it is not useful to planners as it not based on appropriate sea level rise or timeline. Note the link to the IPCC report .