Coral Islands Adapt to Rising Seas: New Study

About a decade ago, former President Mohamed Nasheed made global headlines by holding a cabinet meeting underwater. This “stunt” was supposed to raise public awareness about how the Maldives would soon disappear underwater as a result of climate change.

A year prior, Nasheed had told The Guardian that the Maldivian government was purchasing land from foreign countries to prepare for the possible future of Maldivians losing their homeland. An Australian newspaper reported that Nasheed had been planning to purchase large swathes of the Australian bush to accommodate these future climate refugees.

Many scientists believe that the Maldives would disappear into the sea within the coming century. According to conventional climate change models, the average sea level is projected to rise by 100 centimeters within this period, which would submerge the low-lying island nation.

Statements made by a country’s president regarding an imminent disaster caused many people much concern, and was a barrier to future infrastructural investment.

New research from the past decade, however, is complicating the simplistic picture of disaster depicted thus far.
A study published in Geology in 2015 showed that low-lying coral islands adapt to rising sea levels, a fact that has previously remained unaccounted for by climate change models.

The scientists studied the behavior of Funafuti Atoll, in Tuvalu, which consists of 29 coral islands in the Pacific Ocean by comparing and analyzing maps from the 19th century produced by the British Royal Society of Expedition and aerial photographs taken in 1943, 1971, and 1984 along with satellite images from 2005 and 2013.

After their analysis of a century’s worth of data, the team found that despite the 0.3 meter rise of sea-levels in the Pacific Ocean there was no evidence of much land erosion having had occurred in Funafuti Atoll.

Although some islands had lost some land-mass through erosion, the total land-mass of the atoll had increased by 7.3% over the past century. The team also found that the shapes of the individual islands had gradually changed, as well.

In 2018, the same team attempted to confirm their findings by analyzing data from Tuvalu. They found that in the past 40 years, 101 islands in Tuvalu had increased in land-mass by 2.9%, which amounted to 73.5 hectares.

In 2019, a combined effort of British, Canadian, and American researchers built a 1:50 scaled model of one island in Funafuti Atoll named Fatato at the COAST Laboratory in the University of Plymouth, UK. The COAST Laboratory is a research facility that can recreate different kinds of ocean current activity in a controlled environment.

The team found that even though the model island incurred some erosion at its coastal regions, the central areas of the island rose by 1.13 meters.
They also found that their model island “ran” across the water, demonstrating that coral islands were capable of adapting to the activity of ocean currents and the rise of sea-levels by changing its shape and essentially “moving”.

These findings do add more complexity to the already heated debates regarding climate change and climate change policy, particularly with relation to low-lying island nations such as the Maldives.

Despite the former President Nasheed’s prior enthusiasm for the environment and the projections of a Maldives disappearing underwater, neither Nasheed nor his party have given these concern much of a voice in the months since their electoral victory in 2018.