Encroaching seas in the far Pacific are raising the salt level in the wells of the Marshall Islands. Waves threaten to cut one sliver of an island in two.
"It is getting worse," said Kaminaga Kaminaga, the tiny nation's climate change coordinator.
The rising ocean raises questions, too: What happens if the 61,000 Marshallese must abandon their low-lying atolls? Would they still be a nation? With a United Nations seat? With control of their old fisheries and their undersea minerals?
Where would they live, and how would they make a living? Who, precisely, would they and their children become?
For years global negotiations to act on climate change have dragged on, with little to show. Parties to the 193-nation UN climate treaty recently met again in Cancun, but with no decisive action to roll back the industrial, agricultural and transport emissions blamed for global warming – and consequently for swelling seas.
From 11,000 kilometres away, the people of the Marshalls – and of Kiribati, Tuvalu and other atoll nations beyond – can only wonder how many more years they will be able to cope.
"People who built their homes close to the shore, all they can do is get more rocks to rebuild the seawall in front day by day," said Mr Kaminaga, who was in Cancun with the Marshallese delegation to the UN talks.
The Marshallese government is looking beyond today, however, to those ultimate questions of nationhood, displacement and rights.
"We are facing a set of issues unique in the history of the system of nation states," Dean Bialek, a New York-based adviser to the Marshall Islands, told Associated Press.
"We are confronting existential issues associated with climate impacts that are not adequately addressed in the international legal framework."
The Marshallese government took a first step to confront these issues by asking for advice from the centre for climate change law at New York's Columbia University.
The centre’s director, Michael B. Gerrard, in turn has asked legal scholars worldwide to assemble at Columbia next May to begin to piece together answers.
Nations have faded into history through secession – recently with the breakup of the former Yugoslavia, for example – or through conquest or ceding their territory to other countries.
But "no country has ever physically disappeared, and it is a real void in the law," Mr Gerrard said during an interview in New York.
The UN network of climate scientists projects that seas, expanding from heat and from the runoff of melting land ice, may rise by up to 0.59 metres by 2100, swamping much of the scarce land of coral atolls.
But the islands may become uninhabitable long before waves wash over them, because of the saline contamination of water supplies and ruining of crops, and because warming is expected to produce more threatening tropical storms.
"If a country like Tuvalu or Kiribati were to become uninhabitable, would the people be stateless? What's their position in international law?" asked Australian legal scholar Jane McAdam.
"The short answer is, it depends. It is complicated."
Ms McAdam, of the University of New South Wales, has travelled in the atoll nations and studied the legal history.
As far as islanders keeping their citizenship and sovereignty if they abandon their homelands is concerned, she said: "It is unclear when a state would end because of climate change. It would come down to what the international community was prepared to tolerate."
That is, whether the UN General Assembly would move to take a seat away from a displaced people.
The 1951 global treaty on refugees, mandating that nations shelter those fleeing because of persecution, does not cover the looming situation of those displaced by climate change. Some advocate negotiating a new international pact obliging similar treatment for environmental refugees.
In the case of the Marshallese, the picture is murkier
Under a compact with Washington, citizens of the former United States (US) trusteeship territory have the right to freely enter the US for study or work, but their right to permanent residency must be clarified, government advisers say.
The islanders worry, too, about their long-term economic rights. The wide scattering of the Marshalls' 29 atolls, 3,700 kilometres southwest of Hawaii, give them an exclusive economic zone of two million square kilometres of ocean, an area the size of Mexico.
The tuna coursing through those waters are the Marshalls' chief resource, exploited by selling licences to foreign fishing fleets.
"If their islands go underwater, what becomes of their fishing rights?" Mr Gerrard asked. Potentially just as important is revenue from magnesium and other sea-floor minerals that geologists have been exploring in recent years.
While lawyers at next May's New York conference begin to sort out the puzzle of disappeared nations, the Marshallese will grapple with the growing problems.
The "top priority," Mr Kaminaga said, is to save the isthmus linking the Marshalls' Jaluit island to its airport, a link now swept by high tides.
Meantime, a lingering drought this year led islanders to tap deeper into their wells, finding salty water that required them to deploy emergency desalination units.
And "parts of the islands are eroding away," Mr Kaminaga said, as undermined lines of coconut palms topple into the sea.
In the months to come, the Marshalls' representatives will seek international aid for climate adaptation. They envision such projects as a Jaluit causeway, replanting of protective vegetation on shorelines, and a 5km-long seawall protecting their capital, Majuro, from the Pacific's rising tides.
Islanders' hopes are fading, however, for quick, decisive action to slash global emissions and save their remote spits of land for the next century.
"If all these financial and diplomatic tools don't work, I think some countries are looking at some kind of legal measures," said Dessima Williams, Grenada's UN ambassador and chairperson of a group of small island nations.
Those measures might include appeals to the International Court of Justice or other forums for compensation, a difficult route at best.
In the end, islanders wonder, too, what will happen to their culture, their history, their identity with a homeland – even to their ancestors – if they must leave.
"Cemeteries along the coastline are being eroded. Grave sites are falling into the sea," Mr Kaminaga said. "Even in death we're affected."