I keep in touch with some of my old workmates in the Planning Office, so I'm familiar with these issues. The local authorities are well aware of them too, and are scrambling to come up with a response--without much success.

It appears the major problem initially will be salt water intrusion into the aquifer. Right now, the fresh water pressure from the 'glades is dropping fast due to over-development, not to mention a long drought. Too much of the recharge area is paved over, too many wells are being drilled, there is too much pumping and the flood control system drains rain through canals out to the ocean. What replenishment we do get is quickly discharged right out to sea. The whole area is low and flat (I live 8 miles W of the Atlantic and I'm less than 2 meters above the high water mark.) But long before we're flooded by rising seas, the canals will be under water at the highest tides and the water control gates on the coast will have to be shut, allowing rain water to flood the developed areas. We are no longer high enough for excess rain water to flow out, the ocean flows in at high water. There are already commercial areas on the barrier islands of Miami Beach, Ft Lauderdale, and Hollywood where the streets flood when offshore winds coincide with spring tides--even in dry weather. Everybody is dreading the worst case scenario, storm surge from a hurricane, a foot of rainfall, and an extreme tide. Unfortunately, most of our natural protection against wave action, vegetated sand dunes and mangrove forests, have been bulldozed, filled in, and paved over.

Of course, we've had floods before, so it will be dismissed as typical Florida weather, but its going to be happening more and more often, and it will only get worse and worse. The 100 year event will start hitting us every 20 years, then every ten... It will be a gradual process, and folks won't want to believe its happening. There will be no "consensus". By the time it gets to be undeniable, they'll be able to blame us for it, but we'll all be safely dead. Well, I will.

They're expecting about a meter of global warming ocean level rise by the end of the century, which is just about the mean high water tide. So if it happened all at once, tomorrow, we probably wouldn't even notice it, until the tide came in. And even then, it would be just a nuisance, for a few hours.

"We live in a swamp, and we're running out of water."

https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcSmSkNHMRPAa9nstmwN9ZldzukBrFlKJL3vmeyddiqLH3OJl6r9