COASTAL SYSTEM RESPONSE AND HUMAN ADAPTATION TO COLLAPSE OF THE CRYOSPHERE: A NORTH CAROLINA CASE STUDY

The consequence of a crisis in the Earth’s cryosphere looms heavy upon the world’s coastal systems and its populations. As the climate warms and cryosphere collapses, sea level will rise and the world’s coastal systems will migrate and change character in response; there will always be coastal zones, but not as they are today. The response of coastal systems to fluctuations in sea level vary depending upon the geographic location, underlying geologic framework, geomorphology of the flooding surface, available sediment supply, and the character and pattern of storms. The origin and evolutionary development of the North Carolina coastal system are well understood and represent an important case study with implications for similar coastal plain settings.

The mid-Atlantic region is dominated by three general types of coastal shorelines (headland strandplains, complex-, and simple-barrier islands) and three types of estuaries (drowned-river, open-embayed, and collapsing strip estuaries). Each system is characterized by its own set of variables and processes that dictate the evolutionary succession and must be understood and incorporated into adaptation strategies in response to rising sea level. During the last glacial episode (~25,000 to18,000 years ago) the NC ocean shoreline was ~125 meters below current MSL and ~25 to ~110 km off the present coast. Coastal zone migration, driven by storms, has been upward and landward since the last glacial maximum, and will continue as long as the climate warms and cryosphere melts.

But today the migration is severely jeopardized by human development with ever increasing catastrophic conflicts. The critical issue is how we will respond to the imminent changes brought on by the collapsing cryosphere. Dependence on engineering strategies to maintain status quo policies of unlimited growth and development on mobile coastal systems will kill the goose that laid the golden egg of a dynamic and healthy coastal resource! Therefore, it is essential to develop coastal policies that facilitate future adaptations to ongoing changes within the coastal system, maintain a viable-coastal economy, and preserve the natural resources upon which that economy is based.