Atolls grow (and not shrink) despite global warming

You've been led to believe that global warming leads to rising sea levels. This, in turn, would lead to the disappearance of low-lying atolls. That would certainly be a disaster for communities that are living on those islands.

But, now, against all odds, most low-lying reef islands actually appear to be growing in some parts of the world, despite rising sea levels, increasing their footprint and defying calamatous predictions.

Geomorphologist Murray Ford led a team of researchers who examined Jeh Island, one of the 56 islands that make up the Ailinglaplap Atoll in the (Republic of the) Marshall Islands in the Pacific, itself considered one of the most endangered nations on Earth.

Ford and his team pored over old aerial and new satellite imagery of the island from above and made the startling discovery that not only has Jeh increased in total land area by 13 percent since 1943, it may actually have once been four separate islands which have now morphed together due to net land-mass gains[1].

”Counter to predictions, popular media coverage and political proclamations, recent studies have shown the majority of reef islands studied have been stable or have increased in size since the mid-20th century," Ford, explains.

According to the geomorphologist and his colleagues, the more dire sea-level rise predictions were based on the assumption that islands are static and unchanging and would therefore simply drown once the tides rose enough.

The research team found that the islands grew by organic material formed by the reef and that sediment washed ashore by the tides.

"The coral reefs which surround these islands [are] the engine room of island growth, producing sediment which is washed up on the island shoreline," Ford explains. "Healthy coral reefs are essential for this process to continue into the future."

Research dating back as far as 2018 found that among 30 coral atolls, accounting for over 700 islands in total, 88.6 percent remained stable or increased in size in recent decades, while none lost land overall.

[1] Ford et al: Active Sediment Generation on Coral Reef Flats Contributes to Recent Reef Island Expansion in Geophysical Letters - 2020. See here.