Pacific islands growing, not sinking

Islands in Tuvalu, Kiribati and the Federated States of Micronesia are among those which have grown, largely due to coral debris, land reclamation and sediment.

The findings, published in the journal Global and Planetary Change, were gathered by comparing changes to 27 Pacific islands over the last 20 to 60 years using historical aerial photos and satellite images.

Auckland University's Associate Professor Paul Kench, a member of the team of scientists, says the results challenge the view that Pacific islands are sinking due to rising sea levels associated with climate change.

"Eighty per cent of the islands we've looked at have either remained about the same or, in fact, gotten larger," he says.

"Some of those islands have gotten dramatically larger, by 20% or 30%.

"We've now got evidence the physical foundations of these islands will still be there in 100 years."

Kench says the growth of the islands can keep pace with rising sea levels.

"The reason for this is these islands are so low lying that in extreme events waves crash straight over the top of them," he says.

"In doing that they transport sediment from the beach or adjacent reef platform and they throw it onto the top of the island."

But Kench says this does not mean climate change does not pose dangers.

"The land may still be there but will they still be able to support human habitation?" he saks.

Surprise finding

Adelaide University climate scientist Professor Barry Brook says he is surprised by the findings.

"Sea levels are obviously rising - I think in the short term [the study] suggests that there's maybe more time to do something about the problem than we'd first anticipated," he says.

"But the key problem is that sea level rise is likely to accelerate much beyond what we've seen in the 20th century."

Naomi Thirobaux, from Kiribati, has studied the shape of Pacific islands for her PhD and says no-one should be lulled into thinking erosion and inundation is not taking its toll and displacing people from their land.

"In a populated area what would happen was that if it's eroding, a few metres would actually displace people," she says.

"In a populated place people can't move back or inland because there's hardly any place to move into, so that's quite dramatic."

Both Kench and Brook and scientists agree further rises in sea levels pose a significant danger to the livelihoods of people living in Tuvalu, Kirabati and the Federated States of Micronesia.