I am not sure things are quite that linear. Sure, few US cities are on the coasts, but the ones that are happen to be some of the most important pieces of the

I am not sure things are quite that linear. Sure, few US cities are on the coasts, but the ones that are happen to be some of the most important pieces of the freight distribution network and economy of North America. If the frequency of catastrophic storms increases by a relatively small amount, we will cross an inflection point and there will be a rapid cascading failure across the entire continent.