In the spirit of Donald Rumsfeld we might distinguish between natural inevitabilities and unnatural inevitabilities. Someday, for example, the precarious flank of the massive Cumbre Vieja volcano on La Palma in the Canary Islands will collapse and send a mega-tsunami across the Atlantic. The damage from Boston to New York City will dwarf last year’s disaster in Japan. It’s inevitable, but volcanologists don’t know whether the destabilising eruption will occur tomorrow or in five thousand years. So for now, it’s merely a titillating topic for NOVA or the National Geographic Channel. Another, much more frequent example of natural inevitability is the pre-global-warming hurricane cycle. Two or three times each century a perfect storm has crashed into the US Atlantic seaboard and wreaked havoc as far as the Great Lakes. But a $20 billion disaster every few decades is why we have an insurance industry. And even the loss, now and then, of an entire city to nature (San Francisco in 1906 or New Orleans in 2005) is an affordable tragedy. But the construction since 1960 of several trillion dollars' worth of prime real estate on barrier islands, bay fill, recycled swamps and coastal lowlands has radically transformed the calculus of loss. Subtract every carbon dioxide molecule added to the atmosphere in the last thirty years and ‘ordinary’ storms would still collect ever larger tolls from certifiably insane coastal overdevelopment.