Walter Ovenstone, engineer: The city of Miami is not just a single conglomeration of buildings, e.g. Manhattan Island. Miami has many inlets, waterways and man-made concrete-walled canals bordered by boats accessed by stairs down from the edge of the canal where buildings are situated along the top. If one has just boarded a boat, you are just an arm’s length from the concrete wall where the water level, (i.e. sea level) can be seen close at hand. Any long-time resident who has lived there for, say 10 years or more, would be very much aware of any rapid rise of the waterline, especially if it was as significant amount or rapidly increasing as we've been led to believe. Has Sea Level Changed Before? Yes. Sea levels around the globe have fallen and risen dramatically over millions of years, driven primarily by glacial advance and retreat. Sea-level changes in the distant past were often substantial and occurred faster than our current change.