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Don’t like sea level rise projections? Make them illegal

  • 15 Jun 2012, 13:00
  • Verity Payne and Ros Donald

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Stephen Colbert discusses North Carolina's response to sea level rise.

North Carolina has come up with an unexpected new method of dealing with climate change: legislating sea levels lower.

Fed up with scientists threatening the future of the state's property developments with tiresomely high projections of sea level rise, the state senate has just passed a bill that would forbid taking estimates of accelerating sea level rise into account when planning new coastal developments.

Sea level is a bit of a preoccupation in North Carolina because the state is low-lying, flat and has an extensive coastline. You might think this would lead local policymakers to argue for better flood protection or even efforts to address carbon emissions, but apparently not so.

The people behind the bill clearly understand the risks sea level rise poses. Senator David Rouzer explained the devastation a 39-inch (about a metre)rise predicted by a group of local scientists would cause to the local economy:

"How's that going to affect property values? And because of the effect on property values, that's going to affect tax revenues for those coastal counties. It's going to affect Insurance rates and everything else."

Bill HB 819 would require North Carolina's Coastal Resources Commission - which controls planning along the coast - to base its future predictions of sea level rise on those made by NC-20, a group representing coastal development companies, businesses and local people which predicts sea level rise of just eight inches (20 centimetres) by 2100, by basing calculations on previous linear trends and discounting the possibility that sea level rise could be accelerating.

So why are scientists so intent on ruining coastal development plans?

Gloomy scientists

The Science Panel on Coastal Hazards, appointed by the North Carolina Department of Environment and Natural Resources, concluded from a review of research that policy and development planners should prepare for a sea level rise of one metre by 2100.

This projection is based on the idea that as the planet warms global sea level rise will accelerate, as the world's ice melts faster - known as a 'semi-empirical' approach. The method is not without its critics, but projections that don't consider this accelerating relationship are thought to underestimate future sea level rise, so are assumed to provide only a lower bound on future sea level rise.

Another scientist's work appears to bear out the panel's conclusions. Professor Ben Horton, University of Pennsylvania and his team analysed sediment cores from coastal marshes in North Carolina containing layers of microfossils that contain information on past sea level change. He told us that his team's research shows:

"[A] consistent link between global sea surface temperatures and changes in sea level for the past millennia".

As sea surface temperatures have risen, he adds:

"[T]he rate of sea-level rise on the U.S. Atlantic coast is greater now than at any time in the past 2,000 years."

Horton's team also matched up the sediment core sea level record with local and global tide gauge records. They also found that their observations could be described using a model relating the rate of sea-level rise to global temperature, similar to that used by the science panel to calculate the one metre by 2100 projection. All three methods showed good agreement, as you can see in the graph below:

Sea level graph

NC-20

But local development group NC-20 decided to take a stand against these so-called projections. According to Science magazine, 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 [NC-20 chair Tom] Thompson.'"

Instead, NC-20 wants scientists to forecast sea level rise by extrapolating forward the linear increase in sea level over time from one tide gauge in North Carolina, giving a sea level rise of about 20 centimetres by 2100 - a fifth of that suggested by the science panel.

This interesting approach attracted the attention of Comedy Central's Stephen Colbert, who points out in his segment on the bill that this is like deciding that based on previous data, you won't die:

"I've been alive all my life. Therefore, I always will be."

NC-20 has written a paper setting out its opposition to the scientists' position. Most of the experts it cites are too modest to be named, but one familiar name is Nils-Axel Mörner, who has a penchant for downplaying sea level rise. Mörner's former colleagues ungallantly distanced themselves from him earlier this year when he claimed the Maldives are under no risk from flooding, based on an unusual, if rather limited evidence base, including the shape of the islands and the position of a woman's skeleton found in the area.

NC-20's stated aims include furthering development through scientific research - which seems difficult to square with a decision that runs counter to many years of scientific research which, as Horton points out, "is rigorously peer-reviewed, vetted, prior to ever being published and presented to the public".

In its response to the science panel report NC-20 also disputes the theory of global warming. We quote:        

"The bottom line here is that until we can do all of the following, that coming up with a future sea level rise prediction is nothing short of reading tea leaves:
1) scientifically prove AGW [anthropogenic global warming], and
2) scientifically prove the exact effects of each of the numerous other factors identified to influence sea-level rise, and
3) scientifically prove the additional AGW component, if any."   

It's a refreshingly old-school position that even most climate skeptics tend to shy away from these days.

The bill's broader implications

Senate Minority Leader Martin Nesbitt, one of the 11 senators who voted against the bill, says:

"This bill has made us the laughingstock of the country".

Although this may be right, it might also be short-sighted. As Horton told us, the proposed bill has implications beyond North Carolina's sea level over the coming century:

"The bill is the beginning to the end of using science in developing policy for the State of NC. The proposed bill will ultimately prevent the state from obtaining scientific facts when developing future projections of sea level and coastal vulnerability."

Professor Orrin Pilkey, Duke University, told Science magazine:

"The level of irresponsibility of NC-20 is really fantastic [...] What this legislation does is prevent the state of informing people of the hazards that they are facing."

North Carolina's not the only place that has had enough of scientists influencing people with their findings. Canada's Prime Minister, Stephen Harper, now no longer allows the media access to federal scientists without the consent of media relations officers. While it's perhaps not quite in the same league, in the UK, Natural England, the Forestry Commission and the Environment Agency are all forbidden from commenting on policy.

Professor David Vaughan, British Antarctic Survey, told us that the accelerating sea level rise might be "difficult to spot" for the residents of coastal communities:

"This is not about the sea chasing people up the beach, it's really about a progressive change in the frequency of flood events.  Even on the mid-range projections, towards the end of the century many coastal communities will see flood events every decade that they previously suffered only once a century".

Sounds expensive. Luckily, at least in North Carolina, that sort of talk could soon be against the law.

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