A recent paper reanalyzing some old core samples suggested that the last time Greenland was ice free, atmospheric CO2 was lower than it was today, meaning that the complete collapse of the ice sheet is more a matter of when than if. Once it does go, sea levels will rise around 7 meters. Here's what New York city is projected to look like with 5 meters of sea level rise:

Show

Times Square is a bit to the north of the top of this photo but it looks like the Times has a plan to get some beachfront real estate.