LONDON — We are a coast-hugging species. About 44 percent of the world's population live beside the seaside, and that number is set to rise. Why? Maritime commerce and easy access to all that lovely seafood spring to mind. But maybe there's a more fundamental reason, a human instinct touched upon by the sailor Ishmael, explaining his aquatic affection on the very first page of Moby Dick: "If they but knew it, almost all men in their degree, some time or other, cherish nearly the same feelings towards the ocean with me."
Unfortunately, the sea doesn't always return that tender affection. Like the number of coast-huggers, it too is set to rise. Between 1950 and 2009, global coastlines rose between 0.6 and 1 millimeter annually. Taken together, those two trends spell global disaster, albeit of the very, very gradual kind. So what if the sea swallows up a low-lying atoll here and there? Who cares if entire (albeit tiny) Pacific nations may be engulfed in a few decades? If it happens slowly enough for the victims to row away to safety, it surely happens too slowly for anyone else to notice. So, if you're a low-lying island nation, you probably need a clever media stunt for the world to pay any attention.
But add a noticeable rise in extreme weather to those creeping sea levels, throw in a high tide surge, and you've got Superstorm Sandy. Suddenly, New York looks eerily like it does in all those apocalyptic movies that were enjoyable because they seemed distant enough. Director Roland Emmerich's cinematic schadenfreude feels like a guilty pleasure now. It won't forever.
New York will survive, get on with business, and Sandy will recede in memory. But from now on, New Yorkers won't be able to say Mother Nature didn't give them notice. Folks in New Orleans got a similar, albeit more distressing, wake-up call in 2005 from Hurricane Katrina. In both cases, the storms are forebodings of the cities' future demise. Nothing is eternal. Like people and countries, cities too eventually kick the bucket. The likeliest scenario for New Orleans and New York is that they will die a watery death, swallowed up eventually by the otherwise life-giving sea. The waters will rise, steadily but imperceptibly, while Poseidon will occasionally reach into his war-chest for tempests to whack their defenses with — until they break.