Atoll islands such as Tuvalu are proving remarkably good at keeping their heads above water.
In 2002, Outside magazine published a story about the imminent drowning of the South Pacific island nation of Tuvalu. The story’s headline, “Tuvalu Toodle-oo,” drew on the expectation that Tuvalu would soon sink beneath the rising seas of global warming. “And guess what?” the story’s introduction informed its readers. “It’s your fault.”
Dozens, if not hundreds, of similar stories, broadcasts, films and books have appeared since then, almost all with doom-laden titles and headlines. They contemplate with grim fascination the disappearance of low-lying atoll archipelagos like Tuvalu, while blaming the high-carbon lifestyles of the West for, as Outside put it, “the obliteration of an ancient, peaceful civilisation halfway around the world.”
Well, guess what again? According to a report published in February 2018 in the scientific journal Nature Communications by three researchers in the University of Auckland’s School of Environment, Tuvalu isn’t sinking, or even shrinking—it’s expanding.
Tuvalu is the fourth smallest country in the world. It has a land area of just 26 kilometres squared (about a tenth the size of Wellington) spread across nine atolls that occupy a swathe of ocean five times the size of New Zealand.
Over the past four decades, sea level in Tuvalu’s part of the Pacific has been rising at a rate of 3.90±0.4 mm per year, roughly twice the global average. Despite a cumulative sea-level rise of 15 centimetres since 1971, an analysis of all 101 islands in Tuvalu’s atoll chain by coastal geomorphologist Paul Kench and colleagues Murray Ford and Susan Owen has found that Tuvalu’s land area has actually increased by 2.9% (74 hectares).
The researchers used data from aerial photographs and satellite imaging gathered over the same 40-year time period, and measured shoreline change across 19,403 transects of Tuvalu’s reef islands. All the islands showed physical change. Three-quarters of them were found to have expanded, with one more than doubling in size. The rest decreased in size.
Expansion was most pronounced in medium-sized and large islands on the exposed windward side of atolls. Such islands are built from coarse sediments that are typically deposited on reef platforms by storm-driven waves. Shrinkage was greatest in small sand islands on the leeward side of atolls. Only one of the 101 islands disappeared.
The study’s results challenge the widely accepted belief that low-lying islands will be submerged as sea level rises. That view, say the authors, has “normalised island loss and undermined robust and sustainable adaptive planning in small island nations.”
Not only that, it has focused adaptation efforts on ramping up island defences such as reclamations and seawalls. These responses are costly and often maladaptive. They divert scarce resources from other social needs while attempting to provide coastal protection in areas where it is unlikely to provide long-term benefit.
Perhaps the most damaging effect of the drowning-islands rhetoric is that it has conditioned atoll islanders to think of themselves as climate victims doomed to lose their islands to rising seas, and, in the worst-case scenario, to become stateless refugees. Recognition that their land will not disappear gives island dwellers hope and incentive to draw on their traditional traits of resilience, adaptability and skill in continuing to inhabit the islands they call home. It should also motivate governments and aid agencies to focus less on engineering interventions and more on a strategic approach to multi-atoll development.
“We don’t say this will be easy,” Kench told me from his current research location on the Maldives. “There are big hurdles to overcome in terms of land tenure and other social factors. Also, aid agencies love doing engineering projects. But we think the future lies in shifting infrastructure to one or more decentralised sites, rather than trying to defend the line on a single island.”
To be sure, the future habitability of atoll islands is more than a matter of land to build on. There will be other stresses to face, such as increasing soil salinity, salt-water intrusion into aquifers and damaging weather events such as droughts and cyclones.
But on the evidence from Tuvalu, this is no time to be saying “toodle-oo”.