From the CO2Science Archive: Ford and Kench (2015) begin their analysis by noting that “sea level rise is commonly expected to destabilize island shorelines and lead to widespread loss of land as a result of erosion.” And they further note in this regard that “accounts and projections of islands being ‘washed away’ are a mainstay of political discussions and popular media reports of climate change impacts on atolls.” But is there any good evidence for this conclusion?
Paper reviewed: Ford, M.R. and Kench, P.S. 2015. Multi-decadal shoreline changes in response to sea level rise in the Marshall Islands. Anthropocene 11: 14-24.
In addressing this important question, the two New Zealand researchers say “there has been a paucity of evidence presented to underpin such assertions.” And, hence, they proceeded to see what they could learn about the subject themselves, “using historic aerial photographs and recent high-resolution satellite imagery,” which allowed them to determine “shoreline changes on six atolls and two mid-ocean reef islands in the Republic of the Marshall Islands.”
This work revealed, as they report, that “since the middle of the 20th century more shoreline has accreted than eroded, with 17.23% showing erosion, compared to 39.74% accretion and 43.03% showing no change.” Consequently, they were able to determine that “the net result of these changes was the growth of the islands examined from 9.09 km2 to 9.46 km2 between World War Two (WWII) and 2010.” And they add that “analyses of shoreline changes since the 1970s show that shorelines are accreting, albeit at a slower rate, with rates of change between the 1970s and 2010 of 0.29 m/dec (meters per decade) compared with 0.77 m/dec between WWII and the 1970s.”
In light of these several findings, Ford and Kench thus rightly conclude that “governments of small island nations need to acknowledge that island shorelines are highly dynamic and islands have persisted and in many cases grown in tandem with sea level rise.”