New Orleans isn't the most unsustainable place around. The intractable swampy surroundings have prevented it from becoming as suburbanized as most American cities; if you look at it from a satellite, there is a sharp boundary between the city and the swamp. The situation is much worse in, say, Miami. Many other coastal cities will also need levees and have uglier boundaries.
>New Orleans isn't the most unsustainable place around
You can't really treat New Orleans as a single entity. The French Quarter and where the high rises are is (relatively) comfortably above sea level. The sprawl that stretches towards Lake Ponchartrain isn't. That area is well and truly screwed. They keep sinking, the sea keeps rising, and the hurricanes get stronger.
There's no real solution. You can keep building the levees higher, but that's sort of like paying off a credit card with anotehr credit card. It's a temporary solution that makes the reckoning a lot worse when the piper comes calling.
