Rising sea levels are an interesting question for barrier islands like Miami Beach and Florida as a whole.
Though its important to also understand some of these articles unfairly paint sea level rise and climate change as responsible for a new phenomenon, the truth is Miami Beach has always flooded (during full moons water can rise right up through the ground). Not to mention Hurricanes, but truthfully Miami Beach has been sparred for the most part considering all the potential direct hits over the years and the fact that Andrew was a relatively dry hurricane. Al things considered, the engineering has always been impressive and continues to improve, just look at pre/post Hurricane Andrew codes.
Does the Miami Beach flood, sure, but no more than say Charleston, South Carolina. Or have you ever drove on a road that wasn't cracked in NOLA because the salt, (its actually below sea level), Miami Beach doesn't have that issue.
I will say this about the article, it doesn't even bother pretending or discussing how Miami Beach/Miami/Florida might position itself to take a leadership position issues of climate change and sea level rise. Moreover, there is almost an acknowledgement and reading between the lines of the money going into development as a scam on foreign investors...personally, I think that is pretty far off, but I can't help but admit such a fraud would be so Miami that it would be poetic.