Despite gradual sea level rise, the most low-lying island nations on the planet are growing in land area.
Are Low-Lying Islands Helpless in the Face of Sea Level Rise?
“Buy land; they’re not making it anymore.”— attributed to Mark Twain
A repeated fear—and political football—in the climate change conversation is the plight of small island nations. When the United Nation’s climate summits roll around, these nations, consisting of islands and atolls barely a few feet above sea level, are, like clockwork, made out to be victims of an ever-encroaching ocean.
Because seawater level rises have accelerated in recent decades and low-lying islands are supposedly the most vulnerable, we’d expect at least some of them to have lost land area to the sea. Even stock market brokers advertise property funds using Twain’s old quip, spiced up for a modern age with claims that because the land area is shrinking as sea levels rise, the remaining land will become more valuable.
In 2019, the Washington Post’s editorial board warned that rapid glacier melting could lead to a six-and-a-half foot increase in sea levels by 2100: “That would swamp roughly as much territory as is contained in all of Western Europe and make 187 million people homeless.”
In the middle of the pandemic, the New York Times Magazine also trotted out the extraordinary claim that the Great Climate Migration had already begun, estimating that 150 million people would be “displaced from their homes by rising sea levels alone by 2050.”
In a piece on the Antarctic ice sheet earlier this year, National Geographic concluded that “Two feet [of sea level rise] would submerge much of the Maldives and other small island nations.”
Stories like these make a lot of sense: Low-lying islands in the Pacific and Indian Oceans are small and scattered, with long and shallow coastlines, and most habitations situated only a few feet above sea level. With rising sea levels of even a few millimeters a year, the waves will eventually swamp the ground on which these developing nations’ inhabitants live. With no high land to retreat to, an avalanche of “climate refugees” seems inevitable.
However, that story is incomplete.
First off, we know that sea levels are rising at about 3–3.6 millimeters per year, rather than the runaway rate of 25 millimeters implied by the 6.5 ft figure above. Plus, the original scientific article that arrived at 187 million refugees explicitly assumed that the outcome was absent any kind of adaptive behavior. Buried in a portion of the paper that the editorial boards, climate advocates, and policymakers probably didn’t read was the much more sober assessment:
Assuming no or failed adaptation, this exposure translates into catastrophic impacts with tens of millions or even more people being turned into environmental refugees owing to sea-level rise.
In contrast, a protection response suggests that most of the threatened population would be protected, and the main consequence of a large rise in sea level is a larger investment in protection infrastructure. This analysis shows that it is incorrect to automatically assume a global-scale population displacement owing to a large rise in sea level, and coastal populations may have more choices than widely assumed [emphasis added].
The authors hypothesized that the most likely outcome from gradually rising sea levels was not millions of destitute and homeless refugees but increased spending on protective infrastructure.
In recent decades, reality has painted a very different picture from the desperate claims seen in major news outlets and at climate conferences. Globally speaking, the world is reclaiming more area from the oceans than the rising tides swallow. As Matt Ridley, an advisory board member of HumanProgress.org, writes:
Countries like the Netherlands and Vietnam show that it is possible to gain land from the sea even in a world where sea levels are rising. The land area of the planet is actually increasing, not shrinking, thanks to siltation and reclamation.
Since 1980 global sea levels have risen by about 100 mm, but the low-lying islands and atolls of Tuvalu have increased in size. According to a University of Auckland study, hundreds of islands in the Pacific are accumulating enough sediment to increase in land area even as sea level rise threatens the region. The focus of the study, Jeh Island, (one of the Marshall Islands, which are routinely held as “most at risk of disappearing due to sea level rise“) grew 13 percent over the last 80 years.
And Jeh Island doesn’t seem to be a one-off: according to one of the authors of the study, Paul Kench, the majority of the islands that were studied gained land area or stayed the same—with only about one-tenth shrinking in size.
Another island-nation at risk from sea level rise is the Maldives, which in the 1990s began constructing the two-square kilometer island of Hulhumalé by pumping sand from the sea floor. Since then, the island has doubled in size, becoming the Maldives’ fourth-largest island with 50,000 inhabitants. The changes to the main Maldivian isles over the last 20 years are nothing short of astonishing, with human ingenuity reclaiming land from the sea rather than passively being inundated by a slow-moving sea level rise.
One academic survey of low-lying islands across the Pacific and Indian Oceans concluded:
Over the past decades, atoll islands exhibited no widespread sign of physical destabilization in the face of sea-level rise. A reanalysis of available data, which cover 30 Pacific and Indian Ocean atolls including 709 islands, reveals that no atoll lost land area.
Like other places on Earth that are next to an unruly ocean, such as the Netherlands, “land reclamation has become a simple fact of Maldivian life,” reported the BBC’s The World of Tomorrow series. Humans are not passive observers of a changing climate but active participants in mounting their defenses, shaping their environment, and taming a nature that isn’t naturally nice.
Strangely enough, we’ve been here before. The Associated Press ran a story in June 1989 where Noel Brown of the UN Environment Programme gave humanity a 10-year window to solve the greenhouse problem:
As the warming melts polar icecaps, ocean levels will rise by up to three feet, enough to cover the Maldives and other flat island nations … Coastal regions will be inundated; one-sixth of Bangladesh could be flooded, displacing a fourth of its 90 million people.
Brown concluded that “ecological refugees will become a major concern.” They weren’t, and the New York Times Magazine instead began writing about another impending climate migration that would take place 20 years hence (i.e., after it was supposed to have been all over). Contrary to Brown’s catastrophizing comment, no flat island nations have been covered by the ocean.
If theoretical presumptions and modeling outcomes indicate a devastating change in one direction, but reality produces a shift in the opposite direction, some portion of that theory and the modeling assumption need to be revisited. In some static sense, low-lying islands might be the areas most threatened by climate change because they are vulnerable to rising sea levels. But that also makes the people living on those islands highly attuned to reality and keen on practically countering such a predictable threat to their lives and homes.
The solutions, both natural and manmade, have no shortage of problems. Land reclamation can disrupt ocean ecosystems, and though many atoll islands are growing, sea level rise still threatens their freshwater resources and sanitation. But these problems are solvable, and much less dire than the existential scenarios so aggressively promoted.
Despite gradual sea level rise, the most low-lying island nations on the planet are growing—they are adapting to rising sea levels and overcoming the changes that their natural environment presents to them.