And what is a thousand-mile-wide storm pushing eleven feet of water toward our country’s biggest population center saying just days before the election? It is this: we are all from New Orleans now. Climate change—through the measurable rise of sea levels and a documented increase in the intensity of Atlantic storms—has made 100 million Americans virtually as vulnerable to catastrophe as the victims of Hurricane Katrina were seven years ago.

Arriving atop fantastically warm water and aided by a full foot of sea-level rise during the last century, Hurricane Sandy is just the latest example of climate change’s impact on human society.