North Carolina and King Canute

North Carolina’s Senate passed a bill this week limiting how far the U.S. state can project sea level rise — watered down from a much ridiculed draft that sounded like it might have been written by King Canute, his toes getting wet as he tried in vain to order back the rising tide on a beach in England in the 11th century.

Developers in the state have been worried by some scientific studies that suggest that sea level rise might accelerate to a metre (39 inches) or more by 2100 — forcing a redefinition of many coastal areas as flood zones, rather than prime sites for beachside condominiums. A group known as NC-20 — which says “coastal development is the primary economic engine” of the state’s 20 coastal counties — has been especially sceptical about sea level rise. The evidence for an acceleration is simply too vague, they say.

The Senate’s final version, passed on Thursday, says that:

“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.”

That’s a bit of a shift from an earlier head-in-the-sand draft that virtually outlawed sea level rise:

“…rates shall only be determined using historical data, and these data shall be limited to the time period following the year 1900. Rates of sea-level rise may be extrapolated linearly to estimate future rates of rise but shall not include scenarios of accelerated rates of sea-level rise.”
All of this sounds reminiscent of King Canute (above), a Viking and 11th century King of England, who in some accounts took his throne to the beach and told the tide not to rise, perhaps to show his courtiers that even kings could not rule over nature. (He has got a bad press ever since, with many commentators, perhaps wrongly, accusing him of arrogance).
A gap in the North Carolina logic is still that projections have to be “consistent with historic trends”. (While happily grazing day after day in a field, how many millions of cows raised for beef have decide, based on historic trends, that farmers have their best interests at heart?)

And the North Carolina Senate omits to notice that sea level rise has already picked up.

“There is strong evidence that global sea level gradually rose in the 20th century and is currently rising at an increased rate, after a period of little change between AD 0 and AD 1900. Sea level is projected to rise at an even greater rate in this century,” the U.N. panel of climate scientists said in a 2007 report.

 

It says sea levels rose 17 cms in the 20th century (1.7 mm a year) but picked up to about 3 mm a year since about 1993. It projects a rise of between 18 and 59 cms this century, without counting the possibility of an accelerated thaw of Greenland or Antarctica that might add, in one U.N. scenario, up to 20 cms.
And since 2007, many scientists have become more worried by the giant ice sheets and reckon that seas could rise by perhaps a metre by 2100.
Despite wide ridicule, the North Carolina debate is a great illustration of the global dilemma — how do you plan for sea level rise when societies have to pay for education, pensions, healthcare, roads, etc?
Should societies plan for the worst — and risk gigantic, unnecessary investments in coastal infrastructure? Or should they ignore it and hope for the best — and risk far more damaging losses?
Rather than talk about 2100, a sensible way to start would be to make low-cost decisions to cope with early signs of sea level rise — worse storm surges and erosion. Roads along a coast, for instance, should be sited inland with spurs down to the coast so they don’t get entirely washed away in a storm. Try to build homes that can flood without getting ruined.
Because, after all, even Kings can be wrong.
(top photo: port of Wilmington, North Carolina, taken by U.S. Dept of Transportation; Map by U.S. nationalatlas.gov)

 

 

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