WHEN SEA LEVEL ATTACKS!

Which cities might flood when.
______________________________________________________
  

  
The map shows a few world cities based on their lowest elevations above sea level, set against predicted sea level rise in coming 100-year cycles. Based on IPCC predictions. Major icy contributors to sea-level rise on right. Click for larger version.
  
Via InformationIsBeautiful.net | ©© David McCandless 2009.

A GLOBAL WARMING REFUGE AT EQUATORIAL ISLANDS

Some islands in the bulls'-eye of climate change may dodge the worst thanks to heretofore unknown dynamics between deep currents, upwelling, and rising temperatures.
⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏

Gilbert Island archipelago in the Pacific island nation of Kiribati. Credit: NASA/Aqua Satellite.

  
A new paper in Nature Climate Change reports on an unexpected refuge of cooler water around the equatorial Gilbert Islands—one of three archipelagos of the Pacific island nation of Kiribati (say: KEER-uh-bus).
  
This is good news at a time when when scientists predict that rising ocean temperatures in the equatorial Pacific will wreak havoc (coral bleaching, coral disease) on coral reef ecosystems by the end of the century. 
  
The new study shows that climate change could cause ocean currents to operate in a surprising way to mitigate warming near a handful of islands on the equator... which may then become isolated refuges for corals and fish.
    

The three archipelagos of the Pacific island nation of Kiribati straddle the Equator. Map based on: TUBS via Wikimedia Commons.

  
The dynamics of this cooler-water refuge include:
  

1. Equatorial trade winds pushing a surface current, the Equatorial Countercurrent, from east to west
2. A swift Equatorial Undercurrent flowing below the Equatorial Countercurrent in the opposite direction, west to east, at 100-200 meters (328-656 feet)

Where the Equatorial Undercurrent encounters an island, its flow is deflected upward on the island's western flank, carrying its cooler nutrient-rich water to the sunlit surface and creating localized areas of greater ocean productivity.

You can see the dynamics of this in the map and graph below showing chlorophyll levels—a marker of phytoplankton and hence marine productivity—across the equatorial Pacific. The red in the map view indicates highest chlorophyll / phytoplankton / marine productivity.

Credit: Kristopher B. Karnauskas and Anne L. Cohen. Nature Climate Change. DOI:10.1038/nclimate1499.

    
Clearly, the most productive waters occur in the eastern tropical Pacific, where the Equatorial Undercurrent drives up against the Galapagos Islands to create huge upwelling.
  
Chlorophyll quantities then dwindle rapidly as you move west... until the anomalous red signature marking the outlines of the Gilbert Islands of Kiribati seen inside the white-dotted rectangle. The islands are not shown in the map view, just their chlorophyll signatures.
  
Co-author Anne Cohen at WHOI says:
  

"Global models predict significant temperature increases in the central tropical Pacific over the next few decades, but in truth conditions can be highly variable across and around a coral reef island. To predict what the coral reef will experience in global climate change, we have to use high-resolution models, not global models."

Coral reef of the equatorial Pacific. Credit: USFWS.

The models predict:
  

• That as air temperatures rise and equatorial trade winds weaken, the Pacific surface current will also weaken by 15 percent by the end of the century.
• But the then-weaker surface current will also impose less friction and drag on the EUC, so this deeper current will actually strengthen by 14 percent.

 
The high-resolution models developed by  Kristopher Karnauskas, also at WHOI, and Cohen, suggest the amount of upwelling will actually increase by about 50 percent around the Gilbert Islands, to reduce the rate of warming waters there by about 0.7°C (1.25°F) per century.
  
From the paper:

In the central Pacific, home to one of the largest marine protected areas and fishery regions in the global tropics, sea surface temperatures are projected to increase by 2.8 °C by the end of this century. Of critical concern is that marine protected areas may not provide refuge from the anticipated rate of large-scale warming, which could exceed the evolutionary capacity of coral and their symbionts to adapt. Combining high-resolution satellite measurements, an ensemble of global climate models and an eddy-resolving regional ocean circulation model, we show that warming and productivity decline around select Pacific islands will be mitigated by enhanced upwelling associated with a strengthening of the equatorial undercurrent. Enhanced topographic upwelling will act as a negative feedback, locally mitigating the surface warming. At the Gilbert Islands, the rate of warming will be reduced by 0.7±0.3 °C or 25 ± 9% per century, or an overall cooling effect comparable to the local anomaly for a typical El Niño, by the end of this century. As the equatorial undercurrent is dynamically constrained to the Equator, only a handful of coral reefs stand to benefit from this equatorial island effect. Nevertheless, those that do face a lower rate of warming, conferring a significant advantage over neighbouring reef systems. If realized, these predictions help to identify potential refuges for coral reef communities from anticipated climate changes of the twenty-first century.

  

A bathymetric view of the Phoenix Islands group of the Pacific islands nation of Kiribati. Credit: Phoenix Islands Protected Area.

    
As an interesting aside, in 2006 Kiribati created the Phoenix Islands Protected Area (PIPA) to the east of the Gilbert Islands. In 2008 they doubled its size to make it the world's largest marine protected area. (Since then the Chagos Marine Reserve in the Indian Ocean has surpassed PIPA in size.)

At 410,500 square kilometers (158,453 square miles), about the size of California, PIPA preserves one of the Earth's last intact oceanic coral archipelago ecosystems, complete with eight coral atolls, two submerged reef systems, underwater sea mounts, and abundant marine and bird life.
 
This is a truly phenomenal accomplishment. 
  
But if the Gilbert Islands are destined to become one of the few places where coral reef biodiversity is able to hang on in the coming century, then maybe we should begin thinking about giving those waters stronger protections too.

 

An atoll of Kiribati. Via Flickr.

The paper:
   

• Kristopher B. Karnauskas & Anne L. Cohen. Equatorial refuge amid tropical warming. Nature Climate Change (2012) DOI:10.1038/nclimate1499

  

TITANIC DISASTERS

Created by Jean Galvão at JeanBlog.

THE FATE OF OLD SEA ICE

A few years ago sea ice covered a quarter of the Arctic Ocean. Now: 2 percent.
⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏⸏

Aerial view of the edge of the sea ice in Nunavut, Canada. Credit: Doc Searls via Wikimedia Commons .

  
The latest stats on 2012's sea ice in the Arctic are out from the National Snow and Ice Data Center (NSIDC). The winter of 2012 was not the lowest year since satellite monitoring began 34 years ago—but it was well below the average.
  
And the trend continues downward... as you can see in the graph below showing March sea ice extent since 1979.
  

Credit: National Snow and Ice Data Center.

  
Worse is the fate of old sea ice. 
  
Ice older than four years used to make up about a quarter of the wintertime sea ice cover in the Arctic. It now constitutes only 2 percent. From the NSIDC page:
  

Ice age data this year show that the ice cover remains much thinner than it was in the past, with a high proportion of first-year ice, which is thin and vulnerable to summer melt. After the record low minimum of 2007 the Arctic lost a significant amount of older, thicker ice, both from melting and from movement of ice out of the Arctic the following winter. In the last few years, the melt and export of old ice was less extreme than in 2007 and 2008, and multiyear ice started to re-grow, with second and third-year ice increasing over the last three years.

 

Arctic sea ice. Credit: Pink floyd88 a via Wikimedia Commons.

  
After the near-record summertime melt of 2011 there was a decline in two-year-old ice. And although some thicker three- and four-year-old ice managed to survive, the oldest, thickest ice—the stuff more than four years old—continued to decline. 

   

Credit: National Snow and Ice Data Center courtesy J. Maslanik and M. Tschudi, University of Colorado.

  
In the map above you can see how much of 2012's winter sea ice was new ice—just formed this year (purple). And how there's virtually nothing left of the old sea ice that was born five or more years ago (white).
  

Credit: National Snow and Ice Data Center courtesy J. Maslanik and M. Tschudi, University of Colorado.

  
The graph above shows the trend since 1983... how much old ice there used to be and what an endangered species it is now.

CRAB GETS CRAFTY

Hermit crab with anemone n shell. Credit: mirtai via Flickr.

My recent hermit crab post included a video of hermits trying on new homes, and included the the way some defend their shells with stinging anemones (above).
  
But I also found myself wondering what will become of hermit crabs in a world of increasing ocean acidity and dwindling seashells? (You can read more about that in my latest article in OnEarth magazine.)
  

Credit: Courtesy of the NOAA Pacific Marine Environmental Laboratory. 

In the above image you can see the fate of a shell dissolving over 45 days in acidified water. 

   

Now via Discover Magazine I see this interesting photo (below) of a nude hermit crab donning an anemone: 

Greg Rouse and colleagues found this critter during an expedition off the coast of Costa Rica in 2010. The area is lacking in large snail shells, says Dr. Rouse, and there has been a previous report of this species, Parapagurus foraminosus, covered by an anemone.

  

Credit: Greg Rouse, Scripps Institution of Oceanography at UC San Diego.

Crabs—survivors since at least the early Jurassic—are crafty!

NORTHWEST PASSAGE OPENS FOR BOWHEAD WHALES

Bowhead whale. Via.

  
A new paper in Biology Letters reports on two satellite-tagged bowhead whales from different oceans meeting in the ice-free waters of the Northwest Passage in September 2010. 
  
One whale was from West Greenland. The other from Alaska. Their paths crossed in the Parry Channel in the Canadian Arctic Archipelago (maps, below). 
  
From the paper:
  

It is not known what attracted the whales to this area, given the region has relatively low marine production in autumn compared with other known bowhead whale feeding areas.

   

Bowhead whale bones on ceremonial ground, Point Hope, Alaska. Credit: rnoblin via Flickr.

This was not the first times whales from different waters have met in an ice-free Northwest Passage. From the paper:
  

During the commercial whaling period (i.e. pre-1900), several harpoon heads of Atlantic origin were discovered in bowhead whales harvested in the Chukchi Sea/western Arctic, but this information was largely dismissed as anecdotal by scientists. 

  
Further evidence appears in the genetic record:
  

Recent genetic studies compared DNA of whales from Foxe Basin, Canada to whales from Alaska and suggest genetic mixing, although results are based on a small sample size from a highly segregated population. The lack of genetic differentiation between whales in the Pacific and the Atlantic, acknowledging that samples are taken several thousand years apart, suggests that some exchange of individuals occurred between whales in Svalbard and Alaska. 

  

Credit: Mads Peter Heide-Jørgensen, et al. Biol Lett. DOI:100.1098/rsbl.2011.0731. 

The maps show the individual tracks of the two whales from late spring through early autumn. The inset map shows where they overlapped. From the paper:
  

The Northwest Passage with tracks of four bowhead whales and extent of sea ice with greater than 50% concentration (white fields). (a) Track of a whale tagged on 4 May 2002 in West Greenland and ice extent on 20 September 2002. (b) Track of a whale tagged in Alaska on 12 May 2006 and sea ice extent on 8 August 2006. (c) Track of a whale tagged on 24 May 2010 in Alaska, one tagged on 15 April 2010 in West Greenland, and sea ice extent on 14 September 2010. The insert shows the area where whales occurred together in 2010. The whale from Alaska was present in Viscount Melville Sound between 19 August and 18 September while the whale from Greenland was present from 11 to 28 September.

  

1980: Sea ice coverage 1 Nov-31 Jan. Credit: NASA Earth Observatory.

2012: Sea ice coverage 1 Nov-31 Jan. Red star marks approximately where the two whales met in 2010. Credit: NASA Earth Observatory.

These latest images posted by NASA's Earth Observatory give you a sense of how the passage has opened up in the last three decades for whales... and presumably for others too. I marked (red star) approximately where the two whales met in 2010.
  
The authors conclude:
  

Given recent rates of sea ice loss, climate change may eliminate geographical divisions between stocks of bowhead whales and open new areas that have not been inhabited by bowhead whales for millennia (e.g. North of Greenland and north of the Canadian Archipelago).

The documented movements of bowhead whales in the Northwest Passage are perhaps an early sign that other marine organisms have begun exchanges between the Pacific and the Atlantic Oceans across the Arctic. Some of these exchanges may be harder to detect than bowhead whales, but the ecological impacts could be more significant should the ice-free Arctic become a dispersal corridor between the two oceans.

Foxe Basin Bowhead Whales from Stephen Ambruzs on Vimeo.

The open-access ♥ paper:
  

• Mads Peter Heide-Jørgensen, Kristin L. Laidre, Lori T. Quakenbush, and John J. Citta. The Northwest Passage opens for bowhead whales. Biol Lett. DOI:10.1098/rsbl.2011.0731.

SATELLITE VIEW OF GLOBAL ICE MELT

Bear Glacier, Alaska. Via.

 
A new paper in Nature calculates that total global ice mass lost from Greenland, Antarctica, and all Earth's glaciers and ice caps between 2003 and 2010 was about 4.3 trillion tons (1,000 cubic miles).
  
That's enough melted ice to drive up global sea level by 0.5 inches (12 millimeters).
  
And that's enough water to cover the US to 1.5 feet deep (0.5 meters deep).

Glacier melt tunnel. Credit: Dook Cook | DougAK via Flickr.

  
The research was based on satellite measurements of ice loss from all Earth's land ice collected over eight years—with attention paid to rarely-observed glaciers and ice caps outside of Greenland and Antarctica.
  
The findings:

• About a quarter of the average annual ice loss came from glaciers and ice caps outside of Greenland and Antarctica (roughly 148 billion tons, or 39 cubic miles). 
• Ice loss from Greenland and Antarctica and their peripheral ice caps and glaciers averaged 385 billion tons (100 cubic miles) a year.

Glacier Bay, Alaska. Credit: NPS.

  
Traditional estimates of Earth's ice caps and glaciers have been made using ground measurements from only a few hundred of the roughly 200,000 glaciers worldwide.
  
This video explains some of those traditional ground-based measurement techniques.
  


  
This video describes how the GRACE satellite measurements work.
  

  
One positive finding of the satellite study was that ice loss from high the high Asian ranges—from the Himalaya, Pamir, and Tien Shan mountains—was only about 4 billion tons of ice a year. Previous ground-based estimates ranged as high as 50 billion tons a year.
  
From NASA News:

"This study finds that the world's small glaciers and ice caps in places like Alaska, South America and the Himalayas contribute about 0.02 inches per year to sea level rise," said Tom Wagner, cryosphere program scientist at NASA Headquarters in Washington. "While this is lower than previous estimates, it confirms that ice is being lost from around the globe, with just a few areas in precarious balance. The results sharpen our view of land-ice melting, which poses the biggest, most threatening factor in future sea level rise." 

Bering Glacier, Alaska. Credit: NASA.

The paper:

• Thomas Jacob, John Wahr, W. Tad Pfeffer & Sean Swenson. Recent contributions of glaciers and ice caps to sea level rise. Nature. DOI:10.1038/nature10847

CALIFORNIA COAST MOST SUSCEPTIBLE TO PACIFIC WARMING

Big Sur coast, California. Credit: Calilover via Wikimedia Commons.

A new paper in PLoS ONE finds that marine life in the coastal waters of Northern California may be among the most vulnerable to warming in the North Pacific.

This on top of evidence the Northeast Pacific may be more vulnerable to warming than the Northwest Pacific.

And this on top of earlier evidence the North Pacific is warming 2 to 3 times faster than the South Pacific.

Temperate North Pacific realm, and the 16 MEOW ecoregions included in this paper. Credit: Meredith C. Payne, et al. PLOS. DOI:10.1371/journal.pone.0030105

The researchers assembled a picture of monthly sea surface temperatures (SSTs) over 29 years for waters within 20 km/12 miles of shore for 16 North Pacific ecoregions (map). 

All their data are courtesy of satellite-borne Advanced Very High Resolution Radiometer instruments.

Cape Promontory, Aleutian Islands, Alaska. Credit: USFWS via Wikimedia Commons.

Their results suggest the flora and fauna of the Aleutian ecoregion will also be highly susceptible to rising SSTs. 

Why? Because the two areas are already adapted to low variation in SSTs... with the least yearly variation found off California, and the least monthly off the Aleutians. 

From the paper:

[I]t is possible to speculate which ecoregions might be most susceptible to temperature increases, assuming that, in general, organisms living in areas with smaller temperature variations would be more susceptible to temperature increases.

Kelp, California. Credit: NOAA via Flickr.

They conclude:

This speculation needs to be evaluated both by comparing the actual temperature ranges of organisms from field surveys and by evaluating temperature tolerances with experimental studies. Nonetheless, we suggest that analyses of existing temperature regimes can provide insights into what organisms and regions will be at the greatest risk from this aspect of climate change.

The ☺pen-access paper:

• Payne MC, Brown CA, Reusser DA, Lee H II (2012) Ecoregional Analysis of Nearshore Sea-Surface Temperature in the North Pacific. PLoS ONE 7(1): e30105. doi:10.1371/journal.pone.0030105

GREENLAND'S ICE IS DARKENING

Greenland melt map by NOAA’s climate.gov team, based on NASA satellite data processed by Jason Box, Byrd Polar Research Center, the Ohio State University.

  
Not only is Greenland's ice melting, it's also become darker and therefore more absorbent of light—accelerating its own thaw. 

From NASA's Earth Observatory page:

The map above shows the difference between the amount of sunlight Greenland reflected in the summer of 2011 versus the average percent it reflected between 2000 to 2006. Virtually the entire ice sheet shows some change, with some areas reflecting close to 20 percent less light than a decade ago.

Melting atop the Greenland ice sheet. Image via The Big Picture.

  

As expected, rising temperatures melt snow and ice to uncover water, vegetation, and bare ground. These darker substrates absorb more sunlight. 

As predicted, the loss of reflectiveness amplifies the initial warming.

Greenland glacier. Credit: Ville Miettinen via Wikimedia Commons.

Most of the melt patterns on the map (top) fit these expectations. 

But what's unexpected here is that the reflectivity of Greenland's ice is diminishing not just at the coasts but far inland as well. 

Even at the highest point of the ice sheet, nearly two miles above sea level, where there's no visible summertime melting, the ice is darkening.

Smaller, colder snow crystals, left. Warmed ice crystals, right. Credit: NASA Earth Observatory.

So what's going on?

Well, according to Jason Box at Ohio State University the inland darkening is a result of changes in the ice crystals themselves.

As temperatures rise, the snow grains clump together, reflecting less light than the many-faceted smaller crystals (above left). 

The warmed—but not melted—crystals become rounded (above right), and these shapes absorb more sunlight than jagged crystals.

Greenland glacier from the air. Credit: Mila Zinkova via Wikimedia Commons.

  

Another chapter in Ooops: A history of Homo sapiens.

A HISTORY OF THE SKY

A History of the Sky from Ken Murphy on Vimeo.

HAIR O' THE SEAL

Antarctic fur seal (right), Weddell seal (left), Penguin Island, South Shetland Islands, Antarctica. Credit: © Julia Whitty.

   

How do you assess the health of a marine invertebrate—namely Antarctic krill—when there's no historical baseline to measure it against? 

In an intriguing piece of detective work reported in PLoS ONE a team of researchers from China and the US turned to analyzing old seal hairs to determine changes in abundance of krill in the past century.

Antarctic krill. Credit: Uwe Kils via Wikimedia Commons.

Antarctic krill, Euphausia superba, is a keystone species in the Southern Ocean and the primary consumer in a foodweb supporting fish, penguins, seabirds, seals, and whales. 

They school in swarms of up to of 30,000 individuals per cubic meter and are perhaps the most abundant animal on Earth, with a total biomass estimated at ~379 million metric tons.

In the video below (starting at 00:01), you can see humpback whales bubble feeding on krill in Antarctic waters.

 

There's evidence of a decline in krill biomass in parts of Antarctica in the past 30 years—but when did it begin?

To look deeper into history, the authors analyzed core samples from lake sediments near an Antarctic fur seal colony on King George Island in the South Shetland Islands off the Antarctic Peninsula.They dated the fur in the cores via stable carbon (δ¹³C) in the samples. They inferred the abundance of krill in the seals' diet via the nitrogen (δ¹⁵N) isotopes in the fur. From the paper:

Since Antarctic fur seals feed preferentially on krill, the variation of [nitrogen] in seal hair indicates a change in the proportion of krill in the seal's diets and thus the krill availability in local seawater.

  

Antarctic krill grazing on algae living on the underside of sea ice. Credit: Uwe Kils via Wikimedia Commons.

  
Their results indicate that krill began to decline in the diet of fur seals in this part of Antarctica nearly a century ago. That time frame correlates with increasing sea surface temperatures and dwindling sea ice. (See my post Life Inside the Sea Ice more about the relationship between krill and sea ice.) 

From the PLoS ONE paper:

In this region for the past decades, the sea ice shows a decline trend, and this is in coincidence with the decline trend in krill populations. Like the seal [nitrogen] values, the sea surface temperature anomaly in Southern Ocean (50°S) also shows an obvious increasing trend for the 20th century, and the significant correlation between them... suggests that the inferred decreasing krill population is linked with warming ocean and declining sea ice extent.

 

The paper: 

• Huang T, Sun L, Stark J, Wang Y, Cheng Z, et al.Relative Changes in Krill Abundance Inferred from Antarctic Fur Seal.PLoS ONE. 2011.DOI:10.1371/journal.pone.0027331.

TINY TUVALU RUNS DRY

Funafuti Atoll, Tuvalu. Credit: Stefan Lins via Wikimedia Commons.

 

The tiny Pacific nation of Tuvalu—already suffering from rising sea levels—has declared a state of emergency as water supplies on some islands ran dry today. 

The Telegraph reports that Tuvalu's state of emergency was declared after existing desalination plants broke, exacerbating an already dire drought:

The Tuvalu Red Cross said it had not rained properly in the country for more than six months. Meteorologists have forecast a lack of run until December. Typically it gets between 200mm to 400mm [~8 to 16 inches] of rainfall per month... [New Zealand] was working with the Red Cross to deliver aid workers and supplies as quickly as possible.  

  

Location of the Pacific island nation of Tuvalu. Credit: TUBS via Wikimedia Commons, modified by Julia Whitty.

 

I wrote about the troubles facing Tuvalu's nine tiny islands in my 2003 Mother Jones article All the Disappearing Islands. At that time Tuvalu was threatening to sue Earth's gassiest nations for emitting enough CO2 to sink Tuvalu for good:

Tuvalu is among the smallest and most remote countries on Earth, with a total land mass comprising only 10 square miles/26 square kilometers, less than half the size of Manhattan and scattered over 347,400 square miles/899,000 sq km of ocean—an area larger than California, Oregon, and Washington combined... At no point is the sandy island of Funafuti higher than 13 feet above sea level, as is the case throughout the nine coral atolls of this South Pacific nation of Tuvalu. Surrounded by the sea, the people here have been shaped by it as few others on earth. Every afternoon, rain or shine, Tuvaluan children romp in its unsupervised playground... Inescapably, this is a nation of waterfront property; even the plywood and corrugated-tin houses standing 'inland' a block or two enjoy the ambiance of the ocean. No one here has ever lived a moment without hearing the thunder of surf.

Credit: © Julia Whitty.

Now Tuvalu's freshwater aquifers may be contaminated, reports the BBC:

Secretary General Tataua Pefe advised people against drinking water from wells. "It's not safe for consumption," he told Radio Australia. "Some animals have died recently and we think it's because of subterranean water."

In The Fragile Edge I wrote how Tuvalu's problem with freshwater contamination could render its islands uninhabitable long before rising sea levels irrevocably sink them:

Floods and rogue waves raise the saltwater table underlying the atolls, poisoning the Tuvaluans' staple crops. Already some farmers have been forced to grow their [crops] in tin containers, and already some of the smaller motus [islands] have lost their coconut palms to saltwater intrusion. Nor are storms a prerequisite for disaster. "Last August," Prime Minister Saufatu Sopoanga tells me, "on a clear, calm day, a sudden wave surge rolled in from the sea and washed across Funafuti into the lagoon, flooding houses." There was no apparent reason for it, and during my stay on the atoll, I find the sensation of threat to be ever present—the sea on both sides, the constant drumroll of surf, a thin strip of land between—like living on a liquid fault line.

Funafuti Atoll, Tuvalu. Credit: Davidarfonjones via Wikimedia Commons.

   
Meanwhile 3 News New Zealand reports the drought is affecting other Pacific islands too:

The latest place to declare a state of emergency is Tokelau, a New Zealand territory of fewer than 1,500 people on three coral atolls in the central Pacific.

And The Taiwan News reports a possible cholera outbreak in Tuvalu.

A wedding party on Funafuti. Credit: © Julia Whitty.

  
Inundated by ills from afar, more and more Tuvaluans are leaving their home islands—and not because they want to. From All the Disappearing Islands:

Within the coming decades, the atolls of Tuvalu and elsewhere will almost certainly revert to sandbars and then nothing. Although the people themselves will not go extinct, without their home islands to anchor them, their beliefs and identity probably will, scattered person by person across the rising waters... until, like Atlantis, the name of Tuvalu fades into myth.