The Pacific island nation of Tuvalu has long been considered at great risk of sinking beneath rising sea levels due to climate change. However, scientists at the University of Auckland have learned that it is actually increasing in size, with the island’s total land area having grown 2.9 percent between 1971 and 2014. “We tend to think of Pacific atolls as static landforms that will simply be inundated as sea levels rise, but there is growing evidence these islands are geologically dynamic and are constantly changing,” study co-author Paul Kench told Phys.org. “The study findings may seem counter-intuitive, given that (the) sea level has been rising in the region over the past half century, but the dominant mode of change over that time on Tuvalu has been expansion, not erosion.”
Researchers used aerial photography and satellite imagery to study the geographical changes on Tuvalu’s nine atolls and 101 reef islands. They found that eight atolls and nearly three-fourths of the reef islands grew during the period studied, all while sea level at Tuvalu rose twice as quickly as the global average. Wave patterns and sediment deposits brought by storm activity seemed to have counteracted any “sinking” effects due to sea level rise.
While climate change remains an existential threat to island nations like Tuvalu, this study could prompt a rethinking of how sea level rise will actually manifest in light of compounding factors that resulted in Tuvalu’s growth. “On the basis of this research we project a markedly different trajectory for Tuvalu’s islands over the next century than is commonly envisaged,” said Kench. “While we recognize that habitability rests on a number of factors, loss of land is unlikely to be a factor in forcing depopulation of Tuvalu.” The study authors recognize the need to make drastic changes while acknowledging that there is still time to adapt. “Embracing such new adaptation pathways will present considerable national scale challenges to planning, development goals and land tenure systems,” the authors said. “However, as the data on island change shows there is time (decades) to confront these challenges.”