Matthias Ruth, an economist at Northeastern University who focuses on climate impacts, says the key is to provide a financial return for planning ahead. “We know that what once was the 100-year floodplain now is the 10- or 5-year floodplain. So what we need to do is give the incentives to either fortify buildings, elevate them, flood-proof them, or have a controlled retreat.” Instead, “we pretend it’s not an issue and we put ever more infrastructure into the coasts and ever more people.”

Ruth ticks off the expected costs of climate change on the coasts—seawalls, flood insurance claims, disaster response, not to mention dislocation, stress on communities, and lost social connections. And what if, after a major storm like Sandy, there were an ice storm or maybe another hurricane the following year? “It’s these one-two punches, the cumulative effect that they have on our infrastructure, our social systems,” he says. “What we already see is worrisome, but this is going to be an order of magnitude more worrisome.”