Citizens Of Kiribati Seek To Purchase Land Elsewhere - Islands' Sea Level Rising 5.1mm/Yr Since '91

[hatrack]

Feb. 9 (Bloomberg) -- Kiribati, a Pacific island-nation in danger of being submerged because of global warming, may purchase land elsewhere to relocate its people, President Anote Tong said. “We would consider buying land,” Tong said in an interview in New Delhi. “The alternative is that we die, we go extinct.” Kiribati, between Hawaii and Australia, is the second island-nation after the Maldives that’s floated the idea of buying land should their islands be swamped by rising seas and more powerful storms.

Warmer temperatures are melting icecaps, expanding the volume of oceans and causing more intense storm systems. Higher tides in Kiribati’s 33-island archipelago are making potable water for its 100,000 residents too salty to drink. Tong appealed Feb. 5 to leaders who will meet in Copenhagen in December to turn their attention to islanders hurt by global warming.

“I can fully understand why responsible leaders of countries like Kiribati and the Maldives want to take action now and I think we’ll see more of this,” said Kim Carstensen, climate-change program director for the environmental group WWF International.

EDIT

The sea level around Kiribati, the former Gilbert Islands, has been rising 5.1 millimeters a year since 1991, Australia’s National Tidal Centre reported. People have been steadily moving their homes back from the shoreline as the sea level rises, said Tong, in India for a conference on sustainable development that ended Feb. 7. “There is inundation of our shoreline,” Tong said. “The high tide with moderately strong winds has resulted in sea water coming into the soft water. It has affected food crops.”

EDIT

http://www.bloomberg.com/apps/news?pid=20601081&sid=a0kuXMsICBhg&refer=australia

[Xithras]

1. I'm not a GW denier, but GW isn't what's destroying Kiribati

Normal life cycle of an atoll: 1) Volcanic island develops. 2) Volcanic activity ends, and island begins subsidence. 3) Erosion wears away most of island, leaving large flat areas for coral development. 4) Subsidence continues to lower island and fringing reef, but coral grows upward and eventually encircles the shrinking central island. 5) Island eventually erodes and subsides beneath the sea, leaving only the fringing reef around a lagoon. 6) Susidence exceeds coral growth rates, and the atoll plunges beneath the sea to become a seamount.

The IPCC puts the current rate of sea level rise at about 1.5mm per year, and not the 5.1mm per year that the Kiribati government is claiming. While GW certianly isn't helping the situation, and may be making it about 20% worse, the reality is that Kiribati's problems result from sinking islands, and not rising seas.

Either way, the islands are doomed...for people anyway. Island-less atolls are havens for sea life.

[hatrack]

2. Yes, but what's the rate of atoll subsidence?

I suspect it's somewhat less than 5.1 mm/yr - or 1.5 mm, for that matter. However, I don't know that for a fact.

Are there data on natural rates of subsidence?

One of many specifics on which I'm oceanographically clueless . . . .

:hi:

[Xithras]

3. They vary, but for comparison...

The Hawaiian island of Lanai is subsiding naturally at a rate of about 2.4mm/yr, and it's much younger than Kiribati...subsidence accelerates as volcanic activity beneath the island wanes. This doesn't bode well for locations like Hilo Hawaii, which is already subsiding at 4.8mm/yr. There is no question that Kiribati is subsiding (all non-volcanically active Pacific islands are), and a subsidence rate of 4.3mm/year is entirely possible. When combined with human-induced subsidence caused by groundwater over-extraction (a known problem on most South Pacific islands following the post-WW2 introduction of powered wells), it becomes a fairly safe bet to claim that global warming is just one component to Kiribati's problems.

[happyslug]

4. The Gilbert Islands are CORAL based islands NOT Volcanic

http://en.wikipedia.org/wiki/Gilbert_Islands

As a Coral Base island, i.e. built on the exposed part of a Coral reef, These are rarely that much above sea level. Coral Island are believed to have been Coral Reefs during the last time ocean levels went up (About 120,000 years ago) and have been exposed to erosion ever since (And more so during the Ice Age, for more of the reef was exposed).

The "Madhouse Century" of about 120,000 years ago:
http://www.imaja.com/as/environment/can/journal/madhousecentury.html