The Image above shows a map of Florida after a 20 meter rise in sea level. More than half of Florida would be be under the sea, along with the Bahamas.
An article by Chris Mooney | Thu Jan. 31, 2013 3:02 AM PST | was published in Mother Jones 6 days ago and is being widely republished. You can read this article, titled
Humans Have Already Set in Motion 69 Feet of Sea Level Rise
at this link.
I located a resource for viewing a number of areas of the world that will be starkly effected by this developing situation, and it is at the next link.
At this link, viewers can see the effect of different sea level increases at the highly populated places listed at the top of the image above, where you can see that I chose Florida and 20 meters of sea level increase to create the image.
20 meters is approximately 65 feet