Sea level rise, 10', 20', or more?

It is hard to understand the magnitude of change predicted from the effects of global climate change.  Just take a moment and read this Washington Post Article.  Not only are there huge ice sheets on land in Antarctica and Greenland with the individual potential to raise sea levels on the scale of stories on a building as they flow into the ocean---and they have started flowing into the ocean.  The mass of ice above sea level in Antarctica is hard to visualize.  This huge volume of matter has a gravitational attraction and pulls the southern ocean upward to meet it.  As it melts, not only is it adding the water from the ice above ground, the mass is spreading out over the ocean which causes the sea levels to lower around the antarctic relative to the rest of the world.  Where does that extra water go?  It moves north and adds to the effect of sea level rise.