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Legislating Sea Level Rise

Linear thinker. North Carolina State Senator David Rouzer (R) backed a bill that limits consideration of accelerating rates of sea level rise.

North Carolina Senate

By a 34-to-11 vote, North Carolina's Senate today approved a controversial bill prescribing how the state can forecast future sea level rise for planning purposes. Approved by a Senate committee last Thursday, the bill has drawn ridicule from late-night comics and fierce opposition from some climate scientists.

The bill, HB 819, requires North Carolina's Coastal Resources Commission, which sets rules and policies for coastal development and grants permits, to base predictions of future sea level rise along the state's coast on a steady, linear rate of increase. Opponents say that would prevent the commission from considering events, such as melting of polar ice caps caused by increased global temperatures, which might accelerate the rate at which seas are expected to rise.

The bill's supporters, however, worry about the money it would take to plan for accelerated sea level rise, and that any predicted acceleration is based on flimsy data. They brush aside the fact that most scientists agree that rising seas will accelerate. "Science, according to [the science fiction author] Michael Crichton, is not about agreement, it's about facts," says Tom Thompson, chair of NC-20, a nonprofit advocacy group comprised of representatives from local businesses and governments as well as private citizens. "[And] there is no record of acceleration anywhere in the world that we know of."

Opponents of the bill aren't buying that argument. The legislation would force state planners to downplay the potential impacts of global climate change, says climate scientist Robert Jackson of Duke University in Durham, North Carolina. He estimates that models using linear rates of increase based on past sea level changes would forecast 0.2 meters of sea level rise along the North Carolina coast by 2100; in contrast, models that allow for accelerated rates would forecast a 1-meter rise. He was the sole climate scientist to speak in front of the Senate committee that approved the bill on 7 June.

"The level of irresponsibility of NC-20 is really fantastic," says geologist Orrin Pilkey of Duke University. "What this legislation does is prevent the state of informing people of the hazards that they are facing."

The conflict has its origins in a 2010 report prepared by the Science Panel on Coastal Hazards appointed by the planning commission. The panel was asked to recommend a planning target for sea level rise through 2100, and "we didn't think that it was prudent to plan for just the historical rate of rise," says Spencer Rogers, a member of the panel and an expert on coastal issues at the North Carolina Sea Grant program in Raleigh. Instead, the group agreed that they should use models showing that global warming could cause accelerated rates of sea level rise, and set a 1-meter rise by 2100 as a realistic planning measure.

That conclusion touched off criticism from NC-20. The group fears that planning and retrofitting buildings and roads with a 1-meter rise in mind would be a tremendous waste of money. "You can't mandate [something] for an entire region of the state based on hypothetical data," says Thompson.

In an attempt to address those concerns, a bill limiting the Coastal Resources Commission to using linear, historical data, introduced by Senator David Rouzer (R), made its way into the existing House Bill 819 earlier this year. The full Senate passed a revised version today that states:

Historic rates of sea-level rise may be extrapolated to estimate future rates of rise but shall not include scenarios of accelerated rates of sea-level rise unless such rates are from statistically significant, peer-reviewed data and are consistent with historic trends.

The language leaves the door open for the commission to consider accelerating rates of sea level rise sometime in the future, but not now.

NC-20's Thompson says his group is happy with that approach, and encouraged passage. But Duke's Jackson wanted lawmakers to vote it down. The bill "invokes the words, the language of science, but not the intent of science," he says.

Earlier this month, the bill caught the attention of star comedian Stephen Colbert, who quipped that "if your science gives you a result you don't like, pass a law saying the result is illegal. Problem solved."

The bill still needs to be approved by the North Carolina House of Representatives and signed by the governor to become law.