Moving back from the coastline

[Stacey King]

THE BOSTON CHRONICLE
By H.D.S. Greenway
January 27, 2009

EVER SINCE Captain Cook, mutiny on the Bounty, and Paul Gauguin, the South Pacific has held a special place in the Western imagination. The islands and atolls, swaying palms, and care-free people seemed to symbolize the great escape, a place where cares might be left behind, the closest thing this mortal world had to paradise. "Bali Ha'i your special island, come to me, come to me," as the Oscar Hammerstein lyrics go.

Future generations may never know those special islands, and today, as sea levels rise with global warming, the population of many a Bali Ha'i is preparing to come to us.

Last fall Anote Tong, the president of the Republic of Kiribati, stopped by Harvard University to give a lecture. Kiribati used to be the Gilbert Islands, formerly British, then Japanese, which the Americans took at great cost in World War II. Kiribati has 33 islands strung out over the Pacific where the International Date Line meets the equator. Its principal island is Tarawa. But the most important statistic is that it lies less than 6 feet above sea level. "Something is happening that didn't happen in the last century," Tong said.

It's too late to reverse this, he said. There is already enough greenhouse gases to ensure the continuing rise of the oceans. Kiribati is trying to adapt, he said. But unlike other lands there is only so far you can move back from the coast before "we are in danger of falling off the other side."

Kiribati's answer: train its people in skills that are needed in other lands and start emigrating. There is a shortage of nurses in Australia, so the women of Kirbati are training to be nurses. New Zealand is willing to take in islanders, and it assigns the numbers by rotation. There is no money for elaborate sea walls, and there is no country willing to give the 100,000 Micronesians of Kiribati a new homeland.

It is ironic, said President Tong, that the people with the smallest carbon foot print should be taking the brunt of global warming's damage.

In the Indian Ocean, the Maldives, with three times Kiribati's population and a great deal more money from tourism, is starting a fund to buy a new homeland. At about 9 feet above sea level, with the sea expected to rise about 3 feet this century, the nation of 1,200 islands has a bit more time than Kiribati.

With this in mind, I visited the Woods Hole Oceanographic Institution, where Bob Evans is a resident expert on rising oceans. I learned that oceans don't rise slowly and steadily like water in a bath tub. You have to imagine an energetic 5-year-old splashing as much water as possible to understand how it works. It's the storm surges that do the damage, reaching far above the mean high water mark. If the sea rise is slow, nature can adapt. But if it's too fast, nature hasn't time. And none of the present sea-level projections take into account the melting Greenland ice cap, which, if it disappears in future centuries, would cause the sea to rise 20 feet.

Sand dunes don't just sit there and drown, Evans said, they pick up and move back on shore, invading coastal marshes and eventually burying houses and roads inland. You can see that happening now. He and his colleagues wrote a paper that said there was a lack of will among policy makers to address these problems.

This is changing. Holland, with two thirds of its country below sea level, is making plans to extend its coastline. Concrete dikes have been found less effective than creating dunes and earthworks more reminiscent of the 17th century.

Massachusetts has just started a pilot program to protect 78 coastal towns against rising sea levels and accompanying storm surges. The theory is that it's better to adapt now than to wait decades until rising sea levels start to cause major damage.

It is estimated that by the end of the century, parts of Boston and Cambridge could be flooded during storms. It's unfair, but you can bet that flooding Harvard would focus attention even more than losing Bali Ha'i.

H.D.S. Greenway's column appears regularly in the Globe.