Despite a rapidly rising sea level, the island nation of Tuvalu has actually increased in area. This might sound paradoxical, but it hints at an under-appreciated dynamism of reef islands that – for now at least – is stopping them from sinking beneath the waves.
On the surface, this might seem like a climate change deniers’ wet dream, but let’s not get ahead of ourselves here. While it is true that the island nation did indeed grow in size over the last few decades, the country also experienced a sea level rise twice that of the global average. The waters are still rising, it just so happens that the movement of sediment around these atolls is a lot more dynamic than previously understood.
“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,” says Paul Kench, co-author of the study published in Nature Communications, in a statement.
“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.”
The researchers from the University of Auckland used satellite images to keep note of Tuvalu’s nine atolls and 101 reef islands from between 1971 and 2014.
Between this period, they noted that despite the sea level rising at a rate of around 4 millimeters a year, eight of the nine atolls and close to three-quarters of all the islands actually increased in size, while the remaining quarter decreased. Overall, they found that the total area of Tuvalu has grown by 2.9 percent over the last four decades.
Don’t be lured in by the idea that this means that climate change is not happening or that these islands are safe. The authors still stress that climate change “remains one of the major threats” to these countries.
For example, there's been a lot of discussion about the inhabitants of low-lying Pacific nations being left stateless and what will happen to these eventual climate refugees. It now seems that there might be a lot more resilience in some islands than others, and perhaps the best course of action would be to identify which ones these are and figure out a way for migrants to move there.
While this latest research may mean there is a respite for some tropical island nations, it does little for many coastal towns and cities in other parts of the world that are threatened with encroaching waves. Shifting sediments are not going to negate the impact of rising waters in Miami, or prevent communities in Bangladesh from drowning.