28 Oct 2013

More research needed to examine how Pacific islands respond to rising sea levels

6:22 pm on 28 October 2013

A New Zealand academic says more research is needed to examine the varying impact of rising sea levels on Pacific Island shorelines.

Dr Murray Ford, from the Auckland University's School of Environment, used historic photos from World War II and satellite images to study the shoreline of the Wotje Atoll in the Marshall Islands.

He told Daniela Maoate-Cox that the atoll's shoreline has mostly increased since 1945 despite the rising sea levels.

MURRAY FORD: Primarily, I'm comparing the oldest shoreline, from 1945, with a modern shoreline just simply to measure how much change there's been in the island's size and shape.

DANIELA MAOATE-COX: So what did you find out?

MF: Wotje has generally grown between the period 1945 and 2012. It hasn't been huge changes. It's a relatively stable island compared to what's been seen elsewhere, although there's some evidence that needs to be explored in more depth to suggest that since 2004 there's possibly been a shift towards more erosion than stability.

DMC: So since 1945 the shoreline has actually been growing?

MF: Yes, on average. If you look at the islands as a collective sample, more islands have accreted than eroded, which is kind of surprising given the period coincides with rising sea level. But it's not unexpected.

DMC: How dangerous is the situation?

MF: Well, none of this research suggests in any way that future sea level rise won't be a problem. This research more or less illustrates the complexity of these islands and how little we understand about the dynamics and changes to the island shorelines. Any future sea level rise is going to have massive impacts on the islands. Some of these impacts are relatively well known. Some of these impacts we don't actually know a lot about.

DMC: There is a lot that we don't know. What do we need to do to learn more about this?

MF: I think the low-hanging fruit is systematic monitoring in a robust scientific form so we can actually assess some of these impacts to be able to make comparisons with different areas in the Pacific. There's a definite need for monitoring and just better science.

DMC: Is there enough funding for the research and resources needed to do this?

MF: The short answer is probably no. The islands are complicated and change across a range of time scales. These short-term changes are sitting on top of log-term changes in the way the island forms and how it will respond to rising sea level. We still don't have a good handle on how quickly these processes change and how the islands respond.

Murray Ford says this research is important for making decisions on future projects like schools so they can be built on more stable ground.