Nineteen tropical storms have struck or brushed by coastal North Carolina since 2009. Rising seas make the impact of these storms incrementally greater. The barrier islands no longer have enough time or sand to rebuild themselves naturally through dune formation and other processes.

The combination of accelerating sea level rise and increasing storm impacts has pushed the island past a threshold. It has become more dynamic than stable. The sand moves easily and frequently. The changes in the future will be rapid and dramatic.

The East and Gulf Coasts have hundreds of miles of barrier island shoreline. The vast majority are developed, from Wells Beach, Maine, to Padre Island, Texas. As sea level rise continues, these islands are facing the same dual threats as the Cape Lookout barriers. In the 19th and early 20th centuries, communities often responded to this exposure by moving inland, just as the citizens of Portsmouth Village, the small community on Cape Lookout, moved across to the mainland. They did so for very practical reasons. The federal government did not rush in to make vulnerable communities whole after coastal storms.

In a recent article in the journal Science, A.R. Siders of the University of Delaware’s Disaster Research Center, Miyuki Hino of Stanford and Katharine Mach of the University of Miami make a convincing case. They argue that managed retreat from flood-exposed areas is not only sensible and economically manageable — but also inevitable. In fact, buyouts of flood-prone properties have become an important way to mitigate damage across the country. There is a crucial exception. We are still not retreating from even the most hazardous locations on our barrier islands.