A committee of coastal scientists was convened to discuss the potential impacts of future sea-level rise in the mid-Atlantic region of the U.S. Atlantic coast. The committee discussed and deliberated on the nature of a regional assessment of sea-level rise impacts that could occur over the next century. The group agreed that a high degree of uncertainty exists in predicting long-term shoreline changes because of the variety of factors involved and the complexity of their interaction. Principal unknowns identified by the committee include regional sediment budgets and anthropogenic influences (e.g., erosion mitigation efforts such as beach nourishment).

The committee conducted a qualitative review of potential shoreline changes that could be expected over the next century under different sea-level rise scenarios. Using a combination of criteria defined by Fisher (1982) and Hayes (1979), the shore of the mid-Atlantic study area was divided into four geomorphic compartments: spits, headlands, wave-dominated barriers, and mixed-energy barriers. A range of potential coastal responses was identified for each compartment based on four sea-level rise scenarios. The sea-level rise responses included an increased likelihood for erosion and shoreline retreat for all geomorphic compartments, increased likelihood for erosion, overwash and inlet breaching for barrier islands, as well as the possibility of a threshold state (e.g., segmentation or disintegration) for some barrier island systems.