<i>It's not difficult to walk away from an ocean? Please explain New Orleans.</i>

Are you under the impression that climate change rise in ocean level will look like a dike breaking? All references to sea levels rising are reported at less than 1 cm a year, but lets say that rises 100 fold to 1 m/yr. New Orleans flooded a few meters in at most a few days, about 1 m/day.

A factor of 365 in rate could well be the subtle difference between finding yourself on the roof of a house and finding yourself living in a house a few miles inland.