As the ocean rose, they had to flee.
“The sea has started to come inland, it forced us to move up to the hilltop and rebuild our village there away from the sea,” said Sirilo Sutaroti, 94, a leader of the Paurata tribe, to a group of Australian environmental scientists. The scene of this rising sea is an archipelago of upthrust volcanoes and coral atolls, which dots the Pacific to the northeast of Australia: the Solomon Islands. There, a swollen sea is claiming the shoreline — and even, researchers say, entire masses of land.
In a recent paper in the journal Environmental Research Letters, the scientists link the destructive sea level rise to anthropogenic — that is, human-caused — climate change. The study marks the first time anyone has concretely analyzed the loss of Solomon Island shoreline in the context of global warming, they say.
Such work comes at a time when coastal villages — which might be inhabited by a few hundred people like Sutaroti, whose familial roots could stretch back a century — have scattered, reforming in smaller clusters where there is suitable higher ground. On the island of Nuatambu, the sea has claimed 11 houses. “Another 12 remain,” wrote Simon Albert, one of the study authors and a civil engineer at the University of Queensland, Australia, in an email to The Washington Post. “The families that have left have moved to the nearby large island of Choiseul.” What was once a single community has fractured into five smaller hamlets.
Taro Island, a populated atoll in the northwest Solomon Islands, may become the first provincial capital on the planet that people desert due to climate change, according to the Sydney Morning Herald. When Ban Ki-moon, the United Nations secretary general, visited the Solomon Islands and nearby Kiribati, he witnessed an entire population of a Taro Island town preparing to move. (His hotel room, he said in the same 2014 speech, came equipped with life preservers.)
The Solomon Islands, which consists of six main islands and nearly a thousand others, is one of the least densely populated Pacific island nations. Across 10,000 square miles live just over half a million people. Despite the low population density, finding a safe place to call home has become a challenge for some Solomon Islanders.
“There are large volcanic islands where people can relocate to,” wrote Albert. But such relocations can be fraught with tension. “The majority of land is tightly controlled by traditional owners — so moving one group of people onto other peoples’ lands has been the source of ethnic conflict.” Many who remain on Nuatambu would like to leave but cannot afford to.
Prior research indicated that although rising seas threaten shorelines, atolls and other islands appeared to resilient, at least in the short term. So-called dynamic atolls are in constant flux, according to one 2014 paper, able to keep their sandy tops above water. But Albert and his colleagues catalogued 11 drowned Solomon Islands — six that had “severe erosion” and five that sank completely.
When it comes to island erosion, several factors can mask or overpower the effects of climate change; Albert mentioned plate tectonics, hurricanes, waves, and human disturbances such as seawalls or reclamation projects. In the new paper, the researchers attempted to home in on the effects of climate change as much as possible.
“The study we conducted in the Solomon Islands is unique as the islands do not have human habitation,” Albert said, with Nuatambu Island being the one notable exception. (Those still living on Nuatambu are building basic stone walls by hand, the scientist said, which are “unlikely to help slow the erosion.”)
What’s more, the sea-level rise observed in this study — at about a fourth to two-fifths of an inch a year — is triple the global average. In most places, the added water from melting polar glaciers raises the sea level just slivers of an inch annually. But if the ice sheets that cover Greenland and Antarctica were to dissolve into the ocean, by 2100 the oceans could rise by as much as 49 feet.
Using historical evidence and satellite images of the Solomon Islands, the environmental scientists mapped the changes of a subset of 33 coral atolls over the years between 1947 and 2015. In the north, where the waves were strongest, islands were most likely to succumb to the sea. And these islands at risk, the researchers found, were far more than sterile humps of sand.
All five of the sunken islands once teemed with plant life, some of it estimated to be 300 years old. “The islands were densely vegetated with tropical forest,”Albert wrote. “Coconut palms, she-oaks, mangroves, pandanus.” Where the forests haven’t completely vanished along with the islands, all that now remains are the trunks of dead trees, stripped of greenery and left looking like skeletal fingers that point toward the heavens.
At the same time that the sea level rises, climate change has brought devastating floods to the Solomon Islands. A flood in April 2014 caused a total of 31 deaths, according to a scientific follow-up to the disaster. Twenty-ones lives were lost when intense rain burst riverbanks, and 10 children also died in the aftermath, falling ill to infectious diarrhea.
These islands are not the only Pacific Island nations facing a hungry sea. Strong tides have wreaked havoc over the Marshall Islands, where the United States once tested nuclear weapons. In 2014, refugees from the island of Tuvalu may have been the first to flee a country due to climate change. Beyond Pacific islands, coastal cities — such as Miami Beach, which now floods on a regular basis — are also vulnerable. If the Earth’s temperature increased by about 7 degrees Fahrenheit, as many as 760 million people could lose their homes to the ocean.
Over the past 20 years, the sea level rise around the Solomon Islands spiked dramatically, a trend that may not continue. “In the short term, things may stabilize,” Albert said. Even if the current water rise flags, however, the long-term prognosis is grim. “The rates we have recently seen in the Solomons will be experienced globally in the second half of this century.”
These sunken islands, he said, are a portent of things to come.
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