With the world’s population nearing 7.9 billion, and estimates projecting that it will reach 9.7 by 2050, architects and urban planners naturally speculate about cities of the future.

In the 1960s, the visionary architect Yona Friedman imagined Spatial City (Ville Spatiale), a city raised on stilts that could straddle existing cities. Around the same time, the influential British architecture collective Archigram drew up Plug-In City, a computer-controlled, adaptable megastructure of a city with removable units. And just this year, the speculative architect and film director Liam Young proposed Planet City, in which the Earth's entire population could live in one hyper-dense city the size of Tokyo, devoting the rest of the planet to rewilding.

But what if the most promising model for a future city wasn't on land?

Floating cities—with modern amenities and commercially-viable real-estate—have long been a dream of utopias, from Buckminster Fuller’s unrealized proposal for a floating city in Tokyo Bay in the 1960s, to the entrepreneur Lazarus Long’s quest for a new island nation on an unclaimed Caribbean shoal in 1999. But with the number of people displaced as a result of the climate crisis reaching 40.5 million in 2020, and sea-level rise continuing to threaten the future of coastal cities, offshore living is beginning to sound less like a whimsical proposal and more like a credible alternative. At least that is what the founders of Oceanix, a company invested in designing and building floating cities, believe.

In the Face of Rising Seas, Are Floating Cities a Real Possibility?
Oceanix is developing a hurricane-resistant, zero-waste city. BIG - Bjarke Ingels Group

In 2019, the UN-Habitat—a United Nations program that advocates for sustainable urban development—convened a roundtable of architects, designers, academics and entrepreneurs who discussed the viability of floating cities as a solution to climate change and affordable housing. Hosted together with Oceanix, the MIT Center for Ocean Engineering and the U.S.-based Explorers Club, the day-long conference introduced the idea of Oceanix City.

This hurricane-resistant, zero-waste city would be comprised of 4.5-acre hexagonal floating islands that each house 300 people. Six of these islands would form a ring-shaped village articulated around a sheltered harbor. And six of these villages would form a small city of 10,800 people. Hypothetically, the numbers could add up indefinitely.

Designed by Danish starchitect Bjarke Ingels Group (BIG), in collaboration with Oceanix, the city may seem like something out of a science-fiction novel, but Oceanix is now gearing up to build a prototype of a 5-acre city for 300 residents (that’s the equivalent of one Manhattan block, but with over half the density) in a yet-to-be determined location.

“The cities we’re talking to are incredibly keen to leverage this technology to prepare for their own future,” says Oceanix CEO Marc Collins.

A 4.5-acre hexagonal floating island could house 300 people. BIG - Bjarke Ingels Group
Six of these islands would form a ring-shaped village. BIG - Bjarke Ingels Group
Six of these villages would form a small city of 10,800 people. BIG - Bjarke Ingels Group
The numbers could add up indefinitely. Oceanix's 5-acre prototype for 300 residents is the equivalent of one Manhattan block, but with over half the density. BIG - Bjarke Ingels Group

Oceanix at the Smithsonian

A scale model of Oceanix City will be featured in the upcoming exhibition, “Futures,” at Smithsonian’s Arts & Industries Building (AIB) in Washington, D.C. Opening in November, the show seeks to explore what lies ahead for humanity through the lens of art and technology. Balancing futuristic concepts like flying cars with problem-solving technological innovations like biodegradable burial urns, the exhibit will present a multifaceted look into what's next.

"What we really wanted to demonstrate is there isn't a singular pathway to a specific kind of future," explains Ashley Molese, the exhibition’s curator. "And there are multiple pathways and multiple futures that emerge out of these pathways."

The exhibit is organized into four themes that will unfold across AIB’s four monumental halls. In Futures Past, visitors can explore past visions of the future, through artifacts like an experimental Alexander Graham Bell telephone, early androids and the Bakelizer—a machine that was used to create an early form of brittle plastic called Bakelite. “You can’t understand the future until you understand the past,” says Molese. Futures that Unite showcases visions for how we can relate to one another and create a peaceful, inclusive world, from a Covid-friendly support robot that tackles loneliness to a video game that can be played using the eyes. Futures that Work focuses on problem solving, with an algae bioreactor that cleans as much air as a 400-acre forest and a sustainable brick made from mushrooms on display. And in Futures that Inspire, museumgoers will see bold, seemingly impossible visions that could one day prove possible.

This last section is where the model of Oceanix will live. Measuring 5.5 by 5.5 feet, it will present a bird’s eye view of a city that can support more than 10,000 residents.

"You see a model and you can start to imagine it in your own backyard," says Molese.

And perhaps you should start to imagine it, because Oceanix is now fully funded by a private (and at this point, secret) venture capital firm. And with French company Bouygues Construction already on the team, a prototype of a 300-person city, still seeking an exact location, is ready to be built in just three years.

How It All Started

Oceanix was dreamed up by Polynesian entrepreneur Marc Collins Chen, who first saw floating cities as a solution to climate adaptation while he was minister of tourism in French Polynesia. In this role from 2007 to 2008, Collins Chen was tasked with assessing the long-term effects of sea level rise on the islands. Six years later, a 2013 study published in the journal Nature Conservation confirmed what Polynesians already suspected: about a third of French Polynesia’s 118 islands were projected to be submerged by rising seas over the next 60 years.

If seawalls are too costly, thought Collins Chen, do you start thinking about managed retreat?

The idea of moving people, buildings and other assets from areas deemed vulnerable to sea-level rise has garnered mixed reviews. While some recognize its inevitability, others still see it as a last resort. With Oceanix, Collins Chen and his cofounder Itai Madamombe are hoping to flip perceptions: "We would advance instead of retreat," he says. Instead of running away to high grounds, people and cities themselves would push beyond the edge of the water.

In 2014, Kiribati, a neighboring cluster of islands in the South Pacific, purchased nearly eight square miles on a Fiji island, marking the world’s first international land purchase intended for climate refugees. And in 2019, Indonesia’s president Joko Widodo announced plans to move its capital from the ever-sinking city of Jakarta to Borneo, citing rising sea levels and the chronic flooding of Jakarta as reasons.

According to a paper authored by University of Delaware's disaster researcher A.R. Siders and published in Science this June, managed retreat could involve advancing onto floating infrastructure. A self-prescribed "advocate for audacious climate adaptation,” Siders argues that long-term adaptation will involve some form of managed retreat, like "building floating neighborhoods or cities," or "turning roads into canals in an effort to live with the water."

BIG - Bjarke Ingels Group
BIG - Bjarke Ingels Group
Designed by Dutch starchitect Bjarke Ingels Group (BIG), in collaboration with Oceanix, the city may seem like something out of a science-fiction novel. BIG - Bjarke Ingels Group
BIG - Bjarke Ingels Group
BIG - Bjarke Ingels Group
BIG - Bjarke Ingels Group

Retro Visions of Future Cities

Iterations of floating cities, both fictional and real, have captured the human imagination for centuries. In Jules Verne’s science fiction novel Propeller Island, published in 1895, a French string quartet sails on a floating city designed to travel the waters of the Pacific Ocean. And in the much-derided, 1995 action film Waterworld, Kevin Costner, who has developed gills, fights for survival in a post-apocalyptic world where most of the globe is underwater after the melting of the polar ice caps.

In the early 1960s—in the real world—a wealthy Japanese developer commissioned Buckminster Fuller, the architect who popularized the geodesic dome, to build Triton City on the water in Tokyo Bay. Designed as a series of floating city blocks with permanent connections to mainland Tokyo, the city was to hold apartments, schools, parks and stores. Triton City was never built—the developer died and the concept died with him—but many other floating cities, of varying scales, have seen the light of day. More than 13,000 people live on stilted houses connected by a 23-mile boardwalk in Brunei’s Kampong Ayer, a floating settlement that dates back more than 600 years. In Lagos, Nigeria, the community of Makoko sits on precarious stilts hovering over a fetid lagoon, with little access to electricity and clean sanitation. And on the Peruvian side of Lake Titicaca, the indigenous Uros people have lived on floating islands (62 of them!) for over 4,000 years. For some like the Makoko community, migration to water was a desperate measure driven by the sheer lack of adequate infrastructure and affordable housing on land. For others, it was triggered by political unrest; as the Inca Empire expanded, it pushed the Uros people to evacuate onto the lake.

Living with the water, be it on floating structures or in extremely close proximity, can also be simply a natural consequence of topography. In the low-lying country of Denmark, for example, about 80 percent of the population lives in urban areas near the coast. "It's very much a part of the Danish DNA," says Kai-Uwe Bergmann, a partner at BIG, the Danish architecture studio behind Oceanix City.

In 2016, BIG stacked upcycled shipping containers on floating platforms to create buoyant student housing in the Copenhagen Harbor. Dubbed Urban Rigger, the community currently houses about 100 students, with room for a green courtyard, a roof terrace and an underwater community room. Urban Rigger was a sort of prelude to Oceanix, or as Bergmann calls it, "a proof of concept." With its monumental scale, Oceanix is a whole other beast, with a certain set of challenges.

The Challenges to Building a Floating City

"Whenever you're doing something that floats you have to start thinking about ballast, and wave action and how the energy that is built into the waves will start to work with whatever floating structure," says Bergmann.

So BIG started looking at floating pods: how to support them, how to connect them, and how to protect them from wave forces. The end-result is a modular city designed to facilitate a man-made ecosystem with a circular economy. Anchored in the UN Sustainable Development Goals, a 17-point blueprint for “better and more sustainable future for all,” it features technologies like Biorock, which can be used to make robust artificial reefs for corals to grow. The city also challenges the take-make-waste economy through partnerships with the Center for Zero Waste Design. For example, food waste would be converted to energy and compost in community gardens, single-use packaging would be eliminated, and sewage would be treated in algae ponds.

“What we hope is to truly start thinking about a different model, a future model that is structured differently,” says Bergmann. “Some people could view this as very provocative because it would start to question their systems, and maybe there would be a reluctance to try something out that might start to impact the way business is actually done.”

Reluctance to the project does exist. Oceanix has been vilified as a “vanity project for the rich,” and a “moonshot response to climate change” that would barely make a dent in cities like Jakarta, where as many as 5 million people could need to evacuate from the sinking city. The city’s first location will either confirm or dispel these concerns.

Communities experiencing the effects of sea-level rise could be prime candidates, as could places with already established floating communities that can help “push and support these ideas,” Bergmann explains. He cites Singapore is a potential contender. “Here’s a country that is finite,” he says. Through unremitting land reclamation, Singapore has grown in size by almost a quarter, but the process has its limits. And since it involves dumping sand, rock, soil and cement into the water, land reclamation has a strong impact on marine ecosystems, too. “What if you just accept that you could build on floating platforms as opposed to semi-land?” says Bergmann.

Singapore, of course, is just a guess at this stage. Collins Chen, the Oceanix CEO, says the company is in conversation with 12 different countries. Africa, Southeast Asia, the Middle East, and "both coasts" of the U.S. are being considered, but the exact location is yet to be confirmed. What is known is that Oceanix City belongs near the shore, where geological features would keep it sheltered and "where coastal cities need to grow," says Collins Chen.

As the climate crisis escalates, more than 1 billion people will live in countries with insufficient infrastructure to withstand sea-level rise by 2050, according to The Institute for Economics and Peace. At this rate, it would take over 9,000 Oceanix cities to rehome these projected climate refugees.

While floating cities alone can’t solve climate change, for Molese, the “Futures” exhibition curator, such projects have a lot to contribute to the discourse.

“What we're trying to say is: we've got real problems and we need to problem-solve for them, but we can’t do that if we’re so disenfranchised and disinterested in creating a better scenario," she says. "Most radical experiences don't have a precedent."