The Case Against Rebuilding the Coastline After Superstorm Sandy

One year after Sandy, many of the affected communities remain vulnerable to another storm because of indecision about how best to respond. There are three basic options to mitigate risks from sea level rise and storm surge: Protect against the rising tides with engineered structures, accommodate the rising waters and make structures as resilient as possible, or retreat from risky low shorelines to higher ground. Our challenge is to tailor these options to particular locations, and to balance this with cost-effectiveness and sustainability over the long run. Retreat needs to be considered not as a defeatist last-resort, but as proactive strategy needed in some places.

Take New York City, for example, where Mayor Michael Bloomberg has proposed 257 initiatives to be pursued over the next 10 years at an estimated $20 billion. He has repeatedly emphasized that the city "will not retreat from the waterfront." But it will be hard to stand by this categorical commitment as sea levels continue to rise.