Getting weary of arguing with poster who says that 3 foot sea level rise won't matter

[FBaggins]

26. You may have noticed that Katrina overwhelmed coastal defenses.

More than one noteworthy area would have benefited from three fewer feet of water, wouldn't you say?

Since a Katrina-scale hurricane can hit any of the Gulf coast, that is what needs to be managed.

That's an odd statement. We don't currently plan to "manage" Katrina-scale disasters all along our coastline. Or did I miss the 30-ft seawall running all along the southern boarder. There is always a tradeoff between estimated risk and the cost to avoid that risk. Each additional foot of protection adds more expense than the last one.

The area flooded by the actuall 14 ft surge is not much greated than that for the predicted 12 ft surge.

Sorry... that's ridiculously misguided. All along that border are homes that missed flooding by, say, six inches... that would have been near total loses with two and a half feet of water in them.

I don't know how to state it more simply... three extra feet in any flooding disaster is almost always a big deal. And, more importantly, three feet is often the difference between defenses that hold, and those that collapse. Your misguided appeal to Katrina demonstrates this clearly. There were entire neighborhood (perhaps almost all of NOLA) that would have seen little damage with three fewer feet of storm surge.