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North Carolina's Friendly Mountain Breezes, Sandy Beaches and Sea-Level Rise

By: Dr. Ricky Rood, 5:08 AM GMT on June 30, 2014

North Carolina's Friendly Mountain Breezes, Sandy Beaches and Sea-Level Rise

In the last entry, I promised to write more about sea-level rise on the East Coast of the U.S. My motivation is, partially, the North Carolina General Assembly putting a moratorium on rules, plans and policies that were based on the projections of greater sea-level rise. The NC Coastal Resources Commission was directed to provide a sea-level projection to be used by planners. Time marches forward and that commission needs to make a report in 2016.

Another motivation for wanting to revisit North Carolina’s position on sea-level rise is a recent article in the Washington Post on Norfolk, Virginia. Norfolk is just north of the North Carolina border. Norfolk is the home of the Naval Shipyard. The Navy has long recognized the vulnerability of their facility to rising sea levels, and this concern reaches throughout the community and the region. (Also NPR story on Norfolk)

Let’s start with North Carolina. There are a growing number of news stories about the state’s approach to sea-level rise. At this point, many of the stories are about whom to place on the NC Coastal Resources Commission. Frank Gorman III has been appointed chairman of the commission. Gorman has so far been credited with bringing order to chaos. He works in the fossil fuel industry, lives on the coast and is widely viewed as taking knowledge-based positions. Of note, he has focused the mission of the commission on the next 30 years. With a focus on 30 years, he removes the arguments about the rate of climate change because it takes 30 years or more for the different projections to diverge. (2014 update of the North Carolina story)

Much of the controversy in North Carolina started when it defined a planning number of 39 inches (1 meter). Such a high number is in the middle of the range of projections in reports such as the technical report on sea-level rise for the National Climate Assessment, yet few if any other states had chosen such a high figure for planning. By limiting the time span for consideration to the next 30 years, the 8-inch projections fall into a credible range. At 30 years, current knowledge suggests that sea-level rise will be accelerating. Thirty years is a short planning horizon for towns and counties and states. Is it responsible or legal to put blinders on our knowledge? What about the precedent of legislatively prescribing that which is outside of the control of legislation? Thirty years is politically expedient, and perhaps the limited guideline allows discussion that is otherwise not possible, but if planning follows it limits strictly, decisions will be made in denial of likely reality.

Turning to Norfolk. In late 2012, a team led by Adam Parris published a report Global Sea Level Rise Scenarios or the United State National Climate Assessment. Citing the Parris et al. report as the most appropriate for planning, the Virginia Institute for Marine Sciences submitted the Recurrent Flooding Study for Tidewater Virginia to the Virginia General Assembly in January 2013. This report is full of maps investigating the impact of sea-level rise on communities on the Virginia coasts. The report concludes “Recurrent flooding is a significant issue in Virginia coastal localities and one that is predicted to become worse over reasonable planning horizons (20-50 years).” Further, “Review of global flood and sea level rise management strategies suggests that it is possible for Virginia to have an effective response to increasing flood issues BUT it takes time (20-30 years) to effectively plan and implement many of the adaptation strategies.”

Here is a figure from the report, which shows the increase in the number of hours per year that there is flooding at The Hague, a neighborhood on an inlet off of the Elizabeth River in Norfolk. There has been a steady increase since about 1980. Examination of the details of flooding reveals that there are factors other than sea-level rise at play, notably there is also some sinking of the land (subsidence). However, when the budget of all the factors that play into the level of water at the coastline are taken into account, there is little doubt that the rising sea is at the core of the changes. (Link to Sea Level Rise and Flooding Risk in Virginia, Sea Grant Law and Policy Journal, 2013)





Figure 1: Hours per year of flooding in Norfolk’s Hague neighborhood. From Recurrent Flooding Study for Tidewater Virginia

Returning to the article in the Washington Post on Norfolk, Virginia and sea-level rise, there are a number of adaptation decisions that have been made. Currently, as houses are being rebuilt after storms the foundations are being raised. The city requires foundations on new construction to be 3 feet above flood level (a number implicitly the 1 meter of the original North Carolina plan). There is increasing discussion of buying people out and moving roads. There are plans for floodgates to protect The Hague neighborhood. A plan from a Dutch consulting firm suggests a cost of one billion dollars to provide protection from a foot of sea-level rise. And, for this to be effective, there needs to be planning along the whole coast. Otherwise, the patchwork of planned and unplanned, protected and unprotected, places along the coast will make a policy and management nightmare.

The areas I have talked about here, the North Carolina and Virginia coasts, are areas where I have spent time. Much of my childhood was building and rebuilding home-contrived ways to protect our cabin on the Neuse River in North Carolina. One lesson you learn in this little world is that if you don’t have a plan up and down the shore, what you do is vulnerable to what your neighbors don’t do. They are vulnerable to what you do. One can’t adapt alone to 39 inches of sea-level rise. The scope of planning required, neighbors, cities, counties and states is daunting. Decisions will not be uniform. And to add to the challenge, if we plan for 30, 50 or 100 years, all of those plans have to anticipate that sea level will still be rising. Thinking of that meter of salty water in places I have lived and worked makes it crystal clear that we need to work for the best future rather than preservation of the past.

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Presentation on Planning in Virginia Thanks to bappit.

Land Subsidence and Relative Sea-Level Rise in the Southern Chesapeake Bay Region Thanks to nymore

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The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.