A law passed in August in North Carolina has been generating controversy, but also some interesting discussion about how to incorporate uncertain predictions into policymaking.

The law, known as House Bill 819, bans the state from basing its coastal development policies on recent predictions of sea level rise. North Carolina’s Coastal Resources Commission has predicted that sea level will rise by 39 inches over the next century. Some within the state object to that number-primarily the development community, but also some homeowners who fear that their insurance rates may go up, as well as coastal property owners who have not yet built on their land and are afraid that new regulations could prohibit them from doing so. HB 819 originally dealt with development permits, but under pressure from these groups, the provision about sea-level-rise predictions was added later.

One of the law’s strongest supporters is president of a coastal development group who says he does not believe that global warming is occurring; he and other supporters say the Coastal Resources Commission’s forecast is extreme and based on uncertain science, and they want to wait until more reliable models are available before setting a policy that would limit development across about 2,000 square miles of land. On the other hand, opponents of the law cite findings from the US Geological Survey-covered here in our last issue (http://www.erosioncontrol.com/EC/Articles/Understanding_SeaLevel_Rise_18040.aspx)-that sea level rise along much of the East Coast is occurring faster than the world average. The USGS says the accelerated rate of rise is likely to continue.

North Carolina’s law has been mocked by many in the scientific community and even on Comedy Central. On the face of it, simply decreeing that a tough problem doesn’t exist seems like hiding one’s head in the (beach) sand. But as easy a target a this law might seem, it’s worth a closer look because it reflects the uncertainty inherent in almost all policymaking. Waiting until all the facts are in often isn’t an option-and even if it were, the facts can change. It may be obvious that we shouldn’t build in a floodplain, but we sometimes do it anyway; it’s clear with hindsight where the floodplain lies, but perhaps conditions have changed-the dam we thought was secure really wasn’t, or the channel that had never flooded before does now because of all that development occurred upstream. If flooding doesn’t occur, though, it’s hard to prove a negative and say whether our policies were too conservative.

Some jurisdictions have already made plans and preparations for dealing with sea level rise; for many of them, the ocean seems closer than for others, and the predictions have a greater feeling of certainty. Olympia, WA, for example-whose downtown area, built on fill material, is only a foot above the high-tide mark even now-has been working since 2010 to figure out how to protect itself. The city council directed engineers to come up with strategies for coping with 50 inches of rise, and according to some predictions, the increase over the next century could be even greater. The article on page 42 of this issue covers Olympia’s situation in detail.

North Carolina’s governor, who allowed HB 819 to pass, has now urged the state to take another look at the situation and “develop an approach that gives state agencies the flexibility to take appropriate action in response to sea level rise,” according to a statement issued shortly after the bill became law.

Is your region dealing with similar policy questions? Tell us your experiences at http://www.erosioncontrol.com.