Wednesday, September 3, 2008

Sea level planning: Where's Hawai'i?

Sea levels are rising, and there are signs the water is coming up faster and farther than previously estimated.

The rising isn't calculated from arcane computer models or theory. It's pure gauge-reading. It's come up more than half a foot in the last century, and appears to be rising faster now than at the beginning of the last half-century.

New evidence—which does involve some modeling based on conditions observed in the field—suggests that already scary predictions may be understating how much more we can expect in the next half century.

Which raises the question: Are we in Hawai'i taking this seriously? What planning is underway for armoring crucial coastal roads or moving sewer lines inland? What serious thought is being given to Waikiki as Venice, its streets underwater? On an international airport awash at high tide?

Elsewhere in the world people are doing the planning. The Dutch, of course, are in the lead. They don't have much choice, since they're already below water level, and they lose a quarter of their country if the dikes fail.

They're not into theories. They are the best in the world at coastal management, and they take their sea level planning deadly seriously, Here's what their best estimates of sea level change suggest.

They're planning for four feet of rise in this century, and six to 12 more feet in the next. They're estimating it will cost them nearly $3 billion to deal with that. The nation organized a commission to plan for it—the Delta Commission—and has received the commission's first major report. Why?

"Our children will inherit this country, just as we did from our parents and we feel that responsibility," said Prime Minister Jan Peter Balkenende, quoted in a Reuters report.

One could reasonably ask where Hawai'i's commission is. What's Hawai'i's policy in rising water? Armor the shore? Retreat? Are we willing to build levees around our low-lying communities? Should we? Virtually every beach park disappears under these scenarios. Is anyone looking for opportunities for the coastal recreation of the next century, as the leaders of the last century did?

Recent research is providing suggestions that sea level rise could come faster than has been anticipated. Certainly, of the work is based on estimates and calculations that could be flawed. There is little consensus, for instance, on how much impact Greenland's melting glaciers will have on sea levels—only that if they melt significantly, the impact will far exceed most current estimates of rise.

But increasingly, coastal areas are paying attention to their vulnerability.

The threats to New Orleans have been adequately discussed recently.

In Vancouver, there's concern about risks to the lower areas, including the airport:

Where's Hawai'i?
© 2008 Jan TenBruggencate

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