Will the Maldives Survive the Rising Seas?
Will the Maldives Survive the Rising Seas?
Author’s note: I had almost finished the script for this video, with the exception of the conclusion, but never felt good enough about it to move it into video production. But I did all this research and reading, so I figured I can release it as a newsletter-only exclusive.
To be honest, the other thing that I felt uncomfortable about when dealing with this topic was the climate change pushback I knew would come. A few weeks ago I released a video about the Soviets going to Venus and one of the things that most really bothered me was the sheer amount of anti-science commenters I got. So many people screaming at me that Venus did not exist and that space is not a real thing.
I know it is the internet and all, but it really shook my faith in humanity and the audience that I attract. And I lost the heart to finish this video.
I have been working on a little project recently. An audio feed for the Asianometry video channel. Don’t call it a podcast. Because it isn’t. But if you feel like you don’t need the visuals and just want to listen to me talk, then here you go
The world’s oceans are rising. Models vary on exactly how much. But it is true that they are rising, and it is unlikely that they are going to stop.
This situation will eventually affect the livelihood of everyone on this planet. But those living on the low-lying islands of the Pacific arguably face the most significant disruption.
In this video, we are looking at what the residents of the Maldives and other small island states are doing about the rising seas.
Islands and Atolls
The Maldives archipelago sits 434 miles or 700 kilometers southwest of Sri Lanka. The whole archipelago has over 1,200 islands but the population of 351,000 are spread out on about 194 of those islands. The country is one of four atoll nations on earth.
The word "atoll" comes from the Maldivian word, meaning the palm of the hand. It is an apt description as it refers to a ring shaped coral reef partially or totally surrounding a lagoon. The land is made up of loosely held together sediment from the skeletal remains of coral reefs.
These islands are some of the youngest landforms on earth. Radiometric measurements judge the Maldives' islands to be some 3,000 to 5,000 years old.
Almost all of the world's 440 atolls are located in the Pacific and Indian Oceans. In addition to the Maldives, significant amounts of the land in Kiribati, Tuvalu, and the Marshall Islands are also atolls.
The Threatened Islands
Existing models find that the oceans of 2100 will be 2 meters higher than what they were in 2000. Over 80% of the 1,190 islands making up the Maldives are just a meter above sea level.
The question that immediately comes to mind then is: Is it possible that the seawaters can get so high that the islands themselves will vanish under the waves? Then their hapless inhabitants would have to flee and find new ground elsewhere.
Such an incident would bring up questions of statelessness and national sovereignty. For instance, the loss of an island would also mean that the country loses the island's Exclusive Economic Zone. An area of 200 nautical miles beyond the shores where the country enjoys sovereign fishing and building rights.
People might have to flee the islands and find new lands to settle. In 2015, the Pacific nation of Kiribati bought 5,460 acres of land in Fiji as a possible settling ground in the future. And so on.
Will the Maldives Sink?
The notion is intuitive. One meter high islands and a two meter rise in sea level, equals sinkage. It equals disappearance. Right?
Yet such a thought is not entirely borne out by the data. As it turns out, these islands are not static and it is not inevitable that they will all drown under the rising seas. The situation is pretty nuanced.
A 2017 study compared present-day photographs of 184 islands in the Maldives with photographs taken back in 1969. What they found was that, on the whole, the islands' net land area increased by 59 hectares or 2.4%. But that aggregated number hides a lot of variation between the different islands themselves.
42% of the islands, 77 of the data set, saw shoreline contraction of over 3%. 19.5% or 36 islands grew. The rest have been stable.
But there are also 12 islands that have been affected by human-generated land reclamation projects. Take those out and you find then the remaining islands have lost 28.5 hectares or 1.5% of their total land area over the past 40 years.
The amount of lost shoreline seems to be correlated to the island's size. The larger islands grew, while the smaller islands shrank.
The Maldives is in the Indian Ocean. Out in the Pacific, the situation is more conclusive. Their islands seem to be getting larger. A 2010 study of the Marshall Islands compared aerial island photography from World War II and 2010. It found that since the 1940s, over 80% of the islands' shorelines either grew larger or saw no change.
Another 2018 study looked at the 101 islands in the nation of Tuvalu from the period of 1971 to 2014. And again, a majority of the islands grew rather than shrank. Since 1971, Tuvalu's total land area expanded by 2.9%. No large-scale land reclamation has taken place on any of the Tuvalu islands, due to their low population density.
These results have been subsequently confirmed in multiple other studies. In general, these islands are gaining mass.
There are a number of theories for why this might be happening. One theory is that higher sea levels means stronger and higher waves. These waves deposit more sand and dead coral reef sediment onto the islands' shores, growing their shorelines.
One possible concern has to do with the coral reefs around the islands. If the oceans warm up or acidify too much, then it is possible that those coral reefs can die off. This removes a source of loose sediment which would then leave the islands vulnerable. But again, there are no strong data links between dying reefs and the islands shrinking.
Regardless, the reality is that the Maldives along with the reef islands of the Pacific are not going to "wash" away any time soon. To assume so would be an awkward simplification of the problem, and be unhelpful in helping islanders actually adapt to rising sea levels. Because there are very real concerns. Let us start with flooding and freshwater.
Floods and Freshwater
The climate challenge the Maldivians will face in the coming years isn’t that the islands will vanish under sea. It is that the encroaching seas will flood the streets and homes of people, making the islands difficult to inhabit.
Higher sea levels mean higher waves. Not only from the waves of cyclones and tropical storms, but also from random swells. These waves are expected to be more likely to break over the reefs and reach the shoreline. There, they can do substantial damage to people's homes and, critically, their limited freshwater supply.
Many of these islands get substantial amounts of rain. That fresh rainwater gets trapped in a convex-shaped aquifer layer floating above the saltwater. This phenomena is called a freshwater lens, and it is often the islanders' primary water source.
Floods and rising sea levels can breach the freshwater lens and raise its salinity level to undrinkable levels. Plumes of saltwater from these floods can persist at the bottom of a water lens for months after the flood in question. In some cases, as long as a year. A succession of unusually strong floods can end up permanently impairing the freshwater lens.
Preventing Floods and Erosion at the Maldives
The most common mechanism that the Maldivians have employed to prevent floods is to build floodways. These would funnel rainwater from high-risk areas to the sea.
Residents would dig ditches where excess rain can flow out into the ocean. Sometimes they are lined with sand concrete bags or even concrete itself. Other times, they are just a simple grassy ditch.
Regular maintenance is needed to prevent debris stoppage and overflowing, no matter what the floodway is made of. But the grassy ditch ones require a lot more maintenance from the community as they tend to clog up and need to be dug out after a big rainstorm. But they are extremely effective so long they are well maintained.
Beach erosion is another effect of rising ocean levels. On the islands with beach erosion issues, the most common coastal erosion prevention measure in the Maldives is the sea wall.
Made of a variety of materials - sand cement bags, coral mounds, or boulders - they generally stand about 0.5 to 1 meter tall. Certain walls have "anchor rocks" that sit in front of them to provide additional protection.
Sometimes residents will also build breakwaters out in the ocean in front of the beach. These help dissipate the waves' energy before they hit the beach. Gentler waves mean less sand washed off the beach.
Coastal vegetation is also a very common traditional measure against beach erosion. Usually grasses or small bushes, they help hold onto land against wind and water. Sometimes these go right up to the ocean.
Vegetation is a natural way to prevent substantial land erosion. I see a lot of these on Taiwanese shores too.
Many of these flood and erosion prevention measures are basically ad hoc. Residents have used empty oil barrels, sand bags, corrugated sheet metal, and PVC piping for their sea walls.
Their creativity and resilience is admirable, but an ad hoc sea wall is more likely to fail and might make the erosion problem worse.
Land Reclamation and Raising
Raising the land itself is another possibility for combatting the rising oceans. As I mentioned earlier, the Maldives has been expanding their largest inhabited islands for a very long time.
This has had nothing to do with climate change. It is mostly due to population growth and the increasing density of their biggest cities.
In the late 1990s, the government decided to create a brand new island called Hulhumale next to their capital city Male. This was done by piling sand on top of an adjacent coral reef. The sand was dredged up from other parts of the atoll.
Phase I of the project started in 1997 involved the initial land reclamation. This would take about 5 years to complete, costing about $32 million in total. The first residents started moving there in 2004.
Phase II began in 2015. It would further expand the island and build new infrastructure on top of it. Then in 2018, a bridge was added to connect Hulhumale and Male itself. This greatly helped the flow of population from one to the other.
Hulhumale was initially built 1.8 meters above sea level and is protected with large sheet metal walls in the north, west, and south. Being higher than its neighbor Male, it has yet to experience serious floods.
That being said, the government has begun operations for raising the island another meter to accommodate future sea level rises. The ocean is not scheduled to go up that much until 2300 with the 95th percentile scenario. But raising an island that already has inhabitants on it can take decades.