2 degrees warming = 70 ft sea level rise?

A recent study of past climates suggests that, even if we limit the total global warming to 2 degrees Celsius (a very challenging task that we are not working very hard on today), the ultimate sea level rise will be 40 to 70 feet higher than present.  That would mean goodbye to Pacific Beach, many island cultures, and most of Florida!  Hello, Waterworld?  As we saw in class, a global rise of 2 degrees results in stronger warming at the poles, and major predicted losses of ice on Greenland and Antarctica.  But only 2 to 3 feet of this sea level rise will occur by 2100.