Ever since we launched Blue21, we have been working on the opportunity that the oceans present to solve the most urgent global problems. These includes fundamental challenges such as climate change, urbanization, population growth and land scarcity. We call this shift of humanity to the oceans ‘the Blue Revolution’. It includes using the oceans in a sustainable way to make cities, produce food and energy, and create new ecosystems. A very comprehensive overview of all the opportunities the ocean gives to humanity is provided by the book Seasteading, written by Joe Quirk, director of the Seasteading Institute.

How the Blue Revolution can solve global land scarcity


In our research, we found that land scarcity will soon be a huge problem with a global lack of space of 22 million km2 (about the total land size of N. America) already in 2050. We also found that oceans provide the space we need and is capable of capturing huge amounts of CO2 by utilizing the potential of floating algae systems. Capturing CO2 is needed to achieve the Paris Climate Agreement that was signed two years ago. In fact only 1% of the oceans are needed for intensive algae cultivation to be able to capture the total required amount of CO2. We also studied what the Blue Revolution can do for cities. We found that cities can produce a substantial amount of their own food and energy on the water. These findings have been published in the scientific Journal of Cleaner Production.

Moreover, we found that cities can be at least 130 times as efficient in producing food and energy on the water than current agriculture on land. Think about this. One square meter of water can produce as much as 130 square metres of land. By saving these quantities of land, nature areas including the remaining rainforests, can be conserved by shifting production to the water. Only to 1% of the water is needed, the remaining 99% can be converted into a maritime reserve where aquatic ecology can be preserved.

Is it really a solution?

After 10 years of research only a few scientist would question our well-documented profound research findings. However, many people are still concerned that floating developments would make things worse rather than better. People are afraid that after the land we will also destroy the oceans. Is such a concern justified? Or do we risk destroying our planet by maintaining the status quo?

Much depends on how we will construct floating developments. This is partly a question of technology but also a matter of which values underpin the design and construction of floating developments. In the many lectures I have given about this topic, I often said that building floating cities the same way as we currently build cities on land will only make things worse, not better. So how should we do it then? How can floating development be a future perspective for the planet?

There are 7 key factors that need to be taken into account.

1. Think of a city as a living entity that should sustain itself

Current cities are based on the assumption that nature is an infinite source of resources which needs to be exploited for economic progress. Even worse, nature is considered a wastebin with infinite capacity. That’s why the floating city of the future will need to be based on the observation that nature’s resources are finite and that waste does not exist as such, but is a resource in itself. Moreover, the cyclic flows of resources should be used to achieve human and ecological progress. ‘Fine, but why not do the same thing on land?’Many people have asked me after presenting this. I fully agree that cities on land should transform to a cyclical metabolism. But if we look to one of the main ‘waste products’ of cities; CO2, it requires vast amounts of space to be able to capture it. Space that is lacking on land but is available at sea, and can be used with floating algae farms or floating seeweed farms. Therefore it is not a question of floating versus land based development but instead a symbiosis between cities on land and water. Waste products of cities on land, such as CO2 and wastewater, can be used in floating cities in a productive way by producing energy. For new floating developments it is key not to be a fossil-fuel dependent producer of waste but rather a renewables based producer of energy.

Figure 1: Key infrastructure to enable a floating city as a living entity (Source: Blue21)

2. Have a positive impact instead of reducing bad impact

Many environmentalists argue that we should not have any influence on nature, or at least reduce our influence as much as possible. That is neither realistic nor productive. Even in the hunter-gatherer age humans already had a large influence on nature. Today also beavers, ants and spiders have a large influence on their surrounding ecosystems. Therefore it is not a matter of reducing our impact but turn it into a positive impact by offering ecological services to other species.

We also need to make a mind switch considering our food systems. Today’s food systems are based on the idea that other species purely have an instrumental value only. This value is based on the services they can provide to humans. Future food systems should be based on the recognition of intrinsic value of all species and should focus on establishing symbiotic relations between species (including) humans in ecosystems.

Given the destructive influence of humans on nature in the past centuries it might be hard to believe this is possible. There is however no fundamental reason why humans could not have a symbiotic relation to the ecosystems of which they are part. Humans can be a source of CO2 and nutrients for plants and cultivated algae systems. Buildings can provide habitat for species. Floating buildings could enable new aquatic ecosystems and purify the seawater at the same time.

Figure 2. A symbiotic relation between humans and nature and floating ecological developments (source: Blue21)

3. Apply innovative environmental governance and monitoring


In the engineering and real estate sectors, cost-benefits, efficiency and ROI’s are still the main determinants for spatial decisions. While this believe system has created huge progress for humanity, the state of the planet is such that we will need to base our decisions on an adapted value system. Classical environmental impact assessments (EIA) assume that human development will have a negative influence on nature. The condition of nature is considered static. The human impacts need to be minimized or else compensated. While EIAs probably have slowed down environmental degradation they have not prevented it.

This is the reason why Blue21 is developing a new generation of EIA together with the Seasteading Institute and Blue Frontiers for the project in French Polynesia. Such a new system should focus more on encouraging positive impacts and recognizing the dynamic nature of ecosystems. New technologies such as sensors and aquatic drones enable real-time open sources environmental monitoring. Rather than static permitting based on EIA’s, this would enable dynamic permitting of floating developments.

With this process one would get a conditional permit to construct a floating building as long as the developer or building owner has a positive environmental impact. This process would be transparent and negative influences could be dealt with in a very simple way. The developer would get a warning to improve the environmental influence of the building or else the permit is withdrawn in a year. This type of dynamic conditional permits based on real time open source environmental monitoring would be a huge driver and incentive for ecological engineering and construction innovation by project developers.

Figure 3: Environmental monitoring under floating structures by underwater drones (Source: Indymo)

4. Make functional things PIMBY – Please In My backyard


Places where no people live are often selected as location for functional things that cause nuisance. Examples are waste incinerators, prisons, windmills and power plants. Places where no people live are also used as waste dump. Currently the ocean is such a place. It is used by humanity as a place to dump waste. Even in deepest place on earth, the Mariana Trench, toxic waste is found at 10 km depth.

One of the reasons why this happens is the absence of an ocean community. Because we only have a general interest in the ocean instead of a specific interest, the oceans end up as waste dump. Do you think this would happen if people were living on the oceans? It is not surprising that the Economist mentioned the presence of an ocean community invested in the upkeep of the oceans as one of the key factors for sustainable future oceans.

Ocean communities would create many aquatic backyards which would make it much harder to continue using the ocean as a waste dump because there would be much more resistance. The next step is then to design buildings and floating developments that people actually want in their backyard: the so called PIMBY (please in my backyard).


Figure 4: A PIMBY (Please in my backyard) floating development

5. Switch from rigid land ownership to a fluid symbiosis between land and water


Real estate development on land is mostly characterized by a rather conventional process of selling public land to private developers who subsequently develop the buildings and sell and rent it to their customers. This process has many disadvantages. It is susceptible to corruption as public officials can be bribed by project developers, it may lead to land speculation driving up costs and excluding vulnerable social groups, and it provides an incentive for governments to develop nature into urban areas.

On the water all of this can be entirely different. Floating city developers are not interested in ownership of the land or sea. Neither do they like to spend their money on land or water property because they might want to leave in the future. They just want to have the permit to be able to anchor their floating property at a certain place, preferably at no costs. They do pay a price for the right to stay at a certain location, but the price is delivered in environmental services. Floating developments can treat wastewater, absorb CO2, provide ecological habitat, reduce wave height and create jobs for the coastal cities where they are anchored. This is the symbiosis between the cities on land and water on which the concept of the Blue Revolution is based.

Floating developments should be based on costs/benefits, quality and total system impacts rather than costs/benefits only. For this purpose, it is key to start with having to build something with a positive ecological impact. We need buildings and infrastructure that 1) absorb CO2 and pollutants, 2) will create ecological habitat and 3) economic livelihood for local citizens at the same time. Then the next step is we need to use and develop technical innovations to make that affordable..


Figure 5: A symbiosis between cities on land and water (Source: Blue21)

 6. From consumers to independent co-producers


The main role we fulfill as citizens in Western civilization is the role of a passive consumer. Every day we are called to this role continuously by commercials, advertising and social media. One could even argue that our belief that consumption leads to happiness and general wellbeing -including economic growth- is so entrenched in our mental system, that Consumerism can be regarded the dominant religion in Western society today.

On the long term however, being a consumer only, is disappointing. People are capable of much more. To create floating developments that are not purely based on consumerism it is key that the functional use of these developments is not dominated only by consumer functions such as shopping, entertainment or tourism. Instead, there should be a focus on creating a new community and creating a sense-of place and livelihood for local people and visitors alike.

In a floating city, decentralized concepts for water supply, energy production and other utilities can be tested and applied. Citizens and groups of citizens have the opportunity to manage their own utilities and produce electricity and water instead of only being a passive consumer of large utility companies that are still dependent on fossil fuels. This will increase the influence of citizens in society and strengthen their independence compared to their fellow citizens in land-based cities. Citizens are better capable than ever before to take up such a role, since the level of education and access to technical information has never been as high as it is today.

Figure 6: Floating houses in Harnaschpolder Delft, a project initiated by the Municipality and DeltaSync and further developed entirely by the citizens themselves

7. Switch to a new way of working


Nowadays making a plan and launching it is easier than ever before. With a fancy picture and using buzzwords like sustainability, circular and biobased one can create a short term hype and get a lot of attention through social media. Achieving something in practice, however, is something totally different. So how does it work? How can you achieve tangible results?

For innovations such as floating cities it is important to do research first. With Blue21 we have established collaboration with universities and research institutes such as TU DelftRotterdam UniversityDeltares and Marin. This takes time but it is absolutely crucial. With this approach it is possible to base designs on numbers and scientific evidence rather than just another nice idea. Second, it is important always to work with policy makers, authorities and elected officials to understand their position and make them enthusiastic. We also give them influence on our designs. With this approach, stakeholder receptivity for innovations improves. We also invest time to capture floating construction knowledge and experience in construction legislation to enable municipalities to give permits for these innovative developments. Third, collaboration with many partners is key because great things are never achieved by a single company or single organisation.

Figure 7: the Floating Pavilion in Rotterdam: results of research driven interdisciplinary collaboration (Source: DeltaSync)

Dr. ir. Rutger de Graaf-van Dinther, co-founder/director of Blue21, DeltaSync and Indymo and Applied research professor of water innovation at Rotterdam University, the Netherlands