On Wednesday night, New York University’s Institute for Public Knowledge sponsored a public forum on the recent superstorm‘s implications for New York City, where many low-lying areas face a long and painful recovery — if full recovery is indeed the goal. Moderated by Chelsea Clinton, now a special correspondent for NBC News, the forum included four panelists from the fields of earth science, climate science, philosophy and sociology who reflected on how the likelihood of more frequent storm surges might be woven into the city’s urban planning.  “Climate change means more surprises, and more simultaneous surprises,” warned Heidi Cullen, the chief climatologist for the nonprofit science journalism organization Climate Central.  Klaus Jacob, a special research scientist at Columbia University’s Lamont-Doherty Earth Observatory, said the city had three basic options for responding to the recent devastation and loss of life. The first is to bolster flood protection remotely with structures like sea gates or barriers so that neighborhoods can continue to exist as they have for decades. Another way to pursue that goal is to tinker with protections in the low-lying areas themselves, rebuilding houses by adding stilts, for example.  “The last is managed retreat,” Dr. Jacob said. And he made clear that this would be his choice. “Hard” engineering like concrete barriers and levees has long been the bulwark of flood management in other places, but such technology has a finite existence and cannot always weather a storm, he noted. Increasingly, people are turning to “softer” measures like rebuilding oyster beds, cultivating reedy buffers along a city’s coastal edges, building natural earth systems like dunes and using zoning to restrict development on shorelines.  All the same, retreat is in order, he said. “We need to think of a transformative approach.”  Offering another perspective, Dale Jamieson, a philosophy professor at N.Y.U. who directs the university’s environmental studies program, presented a visualization of the ancient natural systems that used to carpet the city’s watery edges, buffering the ocean’s rush and flow. Next, he showed a map of the areas that were worst affected by Hurricane Sandy. The map of the long-gone edge ecosystems matched up almost perfectly with the flooded evacuation zones.  But like Dr. Jacob, Dr. Jamieson advocates a purposeful retreat from the rivers and the sea rather than choosing to rebuild to restore the status quo. As my colleague Rachel Nuwer noted here this week, natural buffers cannot necessarily do the job on their own.  Dr. Jacob pointed to a paradox. While New Yorkers crowd the city’s waterfronts, he said, “we have cemeteries in the highest places in Brooklyn and Queens.” He implied that this was the wrong way around, prompting the audience to chuckle. “You laugh, but I am deadly serious,” Dr. Jacob said. “We should switch the living and the dead.”  Dr. Jamieson acknowledged that coastal land is now so valuable that persuading people to move inland is quite difficult. “The land we happen to need to retreat from costs billions of dollars,” he said.  “Now,” Dr. Jacob interjected dryly.  Perhaps Hurricane Sandy will reshape not only the city’s waterfront but its perceived value as real estate. In the meantime, Wednesday night’s panel discussion suggested, urban planning will not only become a central issue but could well be completely rethought.
Should the city retreat from low-lying shorelines, or seek to restore ruined neighborhoods? Four experts weighed in at a New York University forum.