[fencepost]

Nobody knows what the fuck is going to happen to Miami in 50 years including the author

True enough if you want detailed predictions, but the generalizations that are pretty much assured are bad enough. Will there be 3 feet of rise in that time? Unlikely. 1? Maybe, maybe not. How much rise does there actually need to be for raw sewage in the streets to be an issue any time there's a heavy rain?

The other thing is storm surge in hurricanes. Nobody can tell you now exactly how high future storm surges will be, but a foot of rise still means that the same amount of storm surge will be a foot higher than in the past - 2 feet higher than a century ago. With increasing storm intensity due to higher energy levels those surges and rainfall totals are only going to get higher.