The Response of Reef Islands to Warming-Induced Sea-Level Rise
Webb, A.P. and Kench, P.S. 2010. The dynamic response of reef islands to sea-level rise: Evidence from multi-decadal analysis of island change in the Central Pacific. Global and Planetary Change 72: 234-246.
In a study designed to explore the seriousness of this situation, Webb and Kench examined the morphological changes of 27 atoll islands located in the central Pacific in four atolls that span 15 degrees of latitude from Mokil atoll in the north (6°41.01'N) to Funafuti in the South (8°30.59'S). This they did using historical aerial photography and satellite images over periods ranging from 19 to 61 years, during which time interval they say that instrumental records indicated a rate of sea-level rise of 2.0 mm per year in the central Pacific.
Based on their analysis, the two researchers -- one from Fiji and one from New Zealand -- say "there is no evidence of large-scale reduction in island area despite the upward trend in sea level," and that the islands "have predominantly been persistent or expanded in area on atoll rims for the past 20 to 60 years." More specifically, they say that 43% of the islands "increased in area by more than 3% with the largest increases of 30% on Betio (Tarawa atoll) and 28.3% on Funamanu (Funafuti atoll)." Given these findings, the results of this study "contradict widespread perceptions that all reef islands are eroding in response to recent sea level rise." Quite to the contrary, the authors note that "reef islands are geomorphically resilient landforms that thus far have predominantly remained stable or grown in area over the last 20-60 years," and they say that "given this positive trend, reef islands may not disappear from atoll rims and other coral reefs in the near-future as speculated."