Sea-level rise is upon us, and in the near future we will be forced to retreat from the shoreline. Two new peer-reviewed studies have suggested that a 3.5-to-6-foot sea-level rise by 2100 is a real possibility because of the increasing instability of the ice sheets in Greenland and West Antarctica.
Already in North Carolina, widespread killing of trees in the lowermost coastal plain is evidence of sea-level rise. The trees die when intruding salt water pushes up the lighter freshwater and drowns the roots.
Globally, coastal dwellers are beginning to pull back from low-elevation lands and eroding shorelines. For instance, coastal inhabitants of the Alaskan and Canadian Arctic shorelines are actively contemplating relocation. Thousands of Pacific islanders from coral atoll islands have already moved to safer high ground, many of them choosing to relocate to other countries since there is little high ground on atolls.
Retreat from river deltas, where hundreds of millions live, is just beginning. Isle de Jean Charles, Louisiana, on the Mississippi Delta will have the distinction of being the first U.S. community to be relocated with federal funds because of sea-level rise. The cost of relocating America’s first climate change refugees, who number just 60 residents, is $48 million.
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Next on the firing line are the barrier islands that are made up of easily eroded, unconsolidated sand at low elevations. The U.S. has more barrier islands than any other country, extending 3,000 miles from the south shore of Long Island to the Mexican border. Barrier islands front almost the entire coast of North Carolina, but despite this vulnerability, North Carolina stands at the bottom of the list of barrier-island states in terms of planning and preparation for the sea-level rise.
The N.C. Coastal Resources Commission forced its science panel to come up with sea-level rise projections extending only 30 years into the future. Frank Gorham, CRC chairman, incorrectly wrote that the science panel and not the CRC decided on the 30-year prediction. Limiting the prediction to 30 years was a political decision to avoid a frightening (and realistic) 100-year projection such as that used by the U.N. Intergovernmental Panel on Climate Change.
The CRC’s science panel initially prepared a report predicting sea-level rise for the year 2100 – a 15-inch rise for certain, a 39-inch rise likely and a 55-inch rise possible – but after a political firestorm, the final report used the less alarming 30-year prediction. The short-term prediction was likely chosen because the rate of sea-level rise is expected to increase relatively slowly for the next 30 years and then accelerate rapidly, driven by melting ice.
North Carolina’s 30-year rule is simply a means to put off preparations for sea-level rise and continue with unhindered money-making activities at the beach for several decades. Some steps toward retreat from the coast have already been taken in other states, such as the buy-out approach on Staten Island, New York, and Galveston Island, Texas. Instead of preparing for sea-level rise, North Carolina has chosen the impossible path of holding the shoreline in place.
We now understand that hard structures like seawalls, groins or even sandbags hold the shoreline still for a while but ultimately destroy the beach. We also know that beach replenishment is costly and only temporary. According to the Program for the Study of Developed Shorelines, Carolina Beach has been replenished 31 times and Wrightsville Beach 25 times. Replenishment will become increasingly less feasible as the lifespan of beaches grows shorter, apace with sea-level rise.
To start preparing for sea-level rise, the state should make sure that building density does not increase on our barrier islands. Buildings destroyed in future storms should not be rebuilt. Construction of high-rises must be altogether prohibited. New roads and bridges and other infrastructure that tend to increase density of development should be avoided. North Carolina fails on all these fronts.
The relatively slow pace of sea-level rise over the next decade or two gives us a chance to plan. Taking action now to curb further coastal construction in areas that will increasingly be subjected to storm surges and ultimately flooded will save money. However, by choosing to ignore climate change and sea-level rise and continue business as usual, North Carolina’s state government is locking the next generation into a future filled with catastrophic loss of property and human lives.
Orrin Pilkey is a James B. Duke Professor Emeritus in the Nicholas School of the Environment at Duke University. Keith Pilkey is an administrative law judge with the Social Security Administration