Vulnerability of the U.S. to Future Sea Level Rise

The differential vulnerability of the conterminous United States to future sea level rise from greenhouse climate warming is assessed, using a coastal hazards data base. This data base contains information on seven variables relating to inundation and erosion risks. High risk shorelines are characterized by low relief, erodible substrate, subsidence, shoreline retreat, and high wave/tide energies. Very high risk shorelines on the Atlantic Coast (Coastal Vulnerability Index ≥ 33.0) include the outer coast of the Delmarva Peninsula, northern Cape Hatteras, and segments of New Jersey, Georgia and South Carolina. Louisiana and sections of Texas are potentially the most vulnerable, due to anomalously high relative sea level rise and erosion, coupled with low elevation and mobile sediments. Although the Pacific Coast is generally the least vulnerable, because of its rugged relief and erosion-resistant substrate, the high geographic variability leads to several exceptions, such as the San Joaquin-Sacramento Delta area, the barrier beaches of Oregon and Washington, and parts of the Puget Sound Lowlands.