By century’s end, tens of millions of U.S. coastal property owners will face a decision embodied in the popular exhortation, "Move it or lose it."
But there’s an option for people who can’t imagine a home without an ocean view. It’s called "seasteading," and it could be a 21st-century antidote to the nation’s disappearing shorelines.
"Floating cities" could become climate havens for people whose lives and livelihoods are tethered to the sea or nearby coast, according to the San Francisco-based Seasteading Institute.
In many cases, floating colonies would be populated by people whose homes are rendered uninhabitable by rising seas and storm surges that chew away at the edge of the continent.
Residents would live in modern homes built atop modular platforms that rise and fall with the tides. Some communities could be linked to the mainland by bridges and utility lines. Others could exist miles offshore as semiautonomous cities or even independent nations.
"Nearly half the world’s surface is unclaimed by any nation-state, and many coastal nations can legislate seasteads in their territorial waters," says the Seasteading Institute, which has embraced floating cities with a near-religious fervor.
A few would occupy converted cruise ships flying under independent flags. Others would look like condominium complexes built atop ocean freighters or barges. All will provide offshore refuge from traditional seaside communities where climate hazards are becoming a part of daily life.
As an added benefit, floating cities could enjoy a limitless supply of desalinated water, while homes and businesses would be powered by microgrids pulsing with wind and solar energy.
Transportation would require little more than two feet or two wheels, and be entirely carbon-free. In deeper water, floating cities could rely on aquaculture, hydroponics and rooftop gardens. Other essentials could be delivered by barge or ship.
It’s a tough sell, often punctuated by eye rolls.
"The thing I usually hear when I first talk about this is, ‘Oh, you want to build ‘Waterworld,’" said landscape architect and seasteading advocate Greg Delaune, referring to the 1995 postapocalyptic film starring Kevin Costner as a kind of Mad Max of the sea.
"You know, that’s not really the image we want people to conjure up, but it’s often the first thing that comes to their minds. I get it," added Delaune, who recently co-founded the Deep Blue Institute, a Louisiana-based organization dedicated to building marine-based resilient communities.
Delaune is convinced that southeast Louisiana — one of the fastest-sinking coastlines in the world — could be a U.S. prototype for such a community, where floating structures — homes, businesses, parks and marinas — would offer a more stable life than a sinking marsh.
When hurricanes and storms threaten, as is increasingly common on the fast-warming Atlantic Ocean and Gulf of Mexico, modular floating cities could be partly disassembled and moved into safe harbor or to calmer waters, proponents say.
The details of how that would happen remain sketchy. But ship-based communities already have the luxury of movement, and back-bay communities would garner some protection from the ocean shore.
Futuristic as it sounds, seasteading is not new, and its adaptability to the United States is already being tested through other human-inhabited offshore infrastructure.
The Dutch model
Oil and gas platforms host hundreds of workers for months at a time. And as energy companies migrate into deeper water, floating platforms are becoming the norm. For proof, cross the Atlantic Ocean to the Netherlands, a climate-threatened country whose fate is tied to the sea.
"The Dutch have been doing this for 400 to 500 years. Now they’re selling their ideas around the world," Delaune said. "I see no reason why we can’t design and build sustainable, resilient sea-based communities right here, borrowing on some of the same marine-resilient infrastructure that made the United States a leader in these other offshore activities."
Experts say the origins of floating cities also lie in the Netherlands, where Dutch engineers have spent centuries adapting to life at the ocean’s doorstep. Much of the western half of the country is below sea level, and Amsterdam, with a population of 1.1 million, is nearly 7 feet below the adjoining North Sea.
The Dutch way of coastal adaptation, distilled in the phrase "living with water," has informed urban planning in waterfront cities around the world, notably its use of highly engineered infrastructure like dikes, dams and floodgates. The Army Corps of Engineers incorporated such approaches into the redesigned Southeast Louisiana Urban Flood Control Project built after Hurricane Katrina.
Lesser known but gaining notoriety are the floating homes developed over the last two decades around Amsterdam, one of the lowest-lying cities in the world. They include IJburg, a planned residential district east of Amsterdam where more than 120 floating homes will make up "Waterbuurt West," a floating suburb on an inland bay called the IJ. When fully developed, IJburg will support 18,000 floating homes for 45,000 people.
But what of the United States, where cities like Boston, New York, Miami, Houston and New Orleans are equally threatened by storm surges and rising seas? Experts say it’s a slow process, in part because much of the coastal adaptation conversation has focused on shoreline protection, home elevations and coastal retreat.
"The Dutch have this mentality that we can experiment. The U.S. mentality is we can’t change anything," said Dale Morris, director of strategic partnerships at the Water Institute of the Gulf, a national nonprofit based in Baton Rouge, La., that provides research and technical support to communities preparing for sea-level rise and other climate change impacts.
For eight years after Katrina, Morris worked for the Dutch government as a liaison to Louisiana and other coastal states facing challenges around water management, flood control and climate adaptation.
Morris is an advocate for floating cities in the United States, but he is also a realist. In an interview, he said floating cities are impeded by social, political, economic and cultural barriers. Among them are the long-standing American ideals of abundant land and natural resources, and the notion that people can spread out as cities become denser, dirtier and more expensive.
That hasn’t happened. Today, 95 million Americans, nearly 30% of the U.S. population, live in coastline counties, according to the Census Bureau, compared with roughly 80 million people in 2000.
Coastal cities also experience some of the most disruptive and costly climate change impacts, as evidenced by the frequency of tropical storms like Superstorm Sandy and Hurricane Harvey, which hit two of the nation’s largest urban areas. Other hazards include peak rain events, or "rainbombs," that quickly overwhelm urban infrastructure.
And while storm surge flooding from hurricanes is catastrophic and occasional, king tides and sunny-day flooding can occur daily and are equally damaging to low-lying cities, experts say.
"There are visionaries who are investing in these important ideas, and the technology that allows us to do innovative things is improving all the time," Morris said. "But the economic components of these ideas have to be addressed. There’s an iterative process between vision and reality."
But, Morris noted, "it’s also true that without inspiration or vision, there is no progress."
Big ideas, big failures
That’s where advocates have their work cut out for them.
In the United States, much of the enthusiasm for floating cities is channeled through the Seasteading Institute, which was founded by Patri Friedman, an entrepreneur and grandson of the Nobel Memorial Prize-winning economist Milton Friedman, also a libertarian.
Friedman and colleague Joe Quirk, the institute’s president, wrote the bible of floating cities, titled "Seasteading: How Floating Nations Will Restore the Environment, Enrich the Poor, Cure the Sick, and Liberate Humanity from Politicians." In it, they say "seasteaders are radically misunderstood by landlubbers."
Quirk did not make himself available for an interview, but in an email to E&E News, he said, "Not only is seasteading the quickest, cheapest solution to sea-level rise, we will increase the amount of life on the ocean with every seastead we build."
While not a developer, the institute is a portal for information and advocacy materials, including research papers, blogs, podcasts and YouTube videos explaining and extolling the virtues of floating human habitation. Its website also provides a list of "active" seasteading projects.
Quick also co-created Blue Frontiers, a company that worked with French Polynesia in 2017 to establish a semiautonomous floating city off the Pacific island nation. With pilot costs estimated at between $30 million and $50 million, the project gained significant momentum before it was postponed indefinitely by the government for political reasons, according to the firm.
Most floating cities are overseas, but the institute’s list includes Delaune’s effort — called the "Louisiana Opportunity Zone Initiative," or "Blue Tech Delta" — as well as several projects that remain under development or did not materialize.
One in California called Ventive SeaTech aims "to build permanent ocean communities for the masses, using modular structures designed to make ocean living safe, comfortable and affordable."
Its primary product, the "floathouse," is shaped like a capsule with windows. It’s described as "a finished home, ready to move in, and is intended to be a year-round home for individuals or a family" by Ventive SeaTech.
Another long-awaited project, conceived in 2011 by a California firm called Blueseed, would establish a floating city on a cruise ship parked in international waters about 12 miles offshore from San Francisco.
Its developers describe it an "entrepreneurial incubator" and "the Googleplex of the sea," where international tech startups could collaborate on projects near Silicon Valley without obtaining visas to enter the United States. It raised several million dollars in seed money, including from the well-known tech financier Peter Thiel, but it has been mothballed for six years.
Where Blueseed stumbled early, another cruise ship city that was set to sail this month imploded days before leaving dry dock. The MS Satoshi, conceived as a Bitcoin-based technology hub anchored in the Gulf of Panama, was rerouted to a scrap yard in India after its owner, Ocean Builders, could not find an insurer to underwrite the floating city.
In a statement, Ocean Builders said it had "hit the roadblock of having no insurance company willing to insure the MS Satoshi upon dropping anchor in the Gulf of Panama. The closest we came was a company toying with us with a million dollar premium for a maximum of $5 million in coverage, nothing close to the coverage we would need to be legally compliant."
The company said it will issue refunds for 100 cabins it auctioned last month for between $50,000 and $100,000 each.
For U.S.-based seasteaders like Delaune, the bridge to a floating city could be years, or even decades, away. But he is not discouraged.
Since arriving in New Orleans, he has been canvassing the region for receptive audiences. He has found a few, including at the Tulane University School of Architecture, where a primary research effort is focused on implementing ideas that emerged a decade ago through the city’s water management planning process called the "Dutch Dialogues."
"I have my pitch deck, and I’ve been rolling it out down here over the last few months," Delaune said. "The big spin is the dying wetlands east of New Orleans, the buffer areas, the barrier islands: People cannot live in these places anymore."
Delaune says the project could take years to materialize. But as Louisiana undergoes a multibillion-dollar restoration of its coastline, floating communities can be a part of the solution.
"These people don’t want a Silicon Valley or NASA project to drop into their backyards," he said. "But when your people are leaving and your economy is dying, there is no plan B except to move away."