Floating Our Concrete Jungles

Our shining cities can be saved from rising sea levels by floating concrete systems.

Atlantis will have New York City, Bangkok, Mumbai, and Miami as new neighbors under the sea due to global sea water rise. The rate of sea level rise is 0.15 inches per year (3.5 mm/year), and the rate has steadily increased over the past decade, which results in a projected 3-6.5 ft (1-2 meter) increase in sea water level by 2100.1  Efforts have been made to protect our cities; the Netherlands has the Delta Works, Tokyo recently built the River Super Levees, Venice has the MOSE Project to protect the lagoon, and New York has a Flood Prevention System comprised of flood walls, levees, and dams, but these efforts are designed to protect their cities against large in rushes of water from storms and floods.2  They will not be sufficient to address steady sea water rise.  LafargeHolcim is a concrete company that can help the world face the challenge of sea level rise to preserve our cities and heritage.

Over the past decade, ocean structural engineering has developed significant advances regarding floating concrete structures.  The most common uses for buoyant concrete include boat houses, large marine wave attenuators, and marina (mooring/docking) systems.  These engineering advances can be deployed to create a massive system of buoyant floats under cities the globe wants to preserve. As our land continues to sink into the sea, concrete will be a pertinent resource to float our existing cities and for new metropolises.  For ocean structure design, a lightweight, strong, water-resistant, and tough concrete is structurally supported with steel beams to hold the design shape, while light weight foam fills the structure to prevent flooding.  The structure is kept in place by a system of cables to resist lateral movement and allow vertical changes in water level.

LafargeHolcim is the largest concrete producer in the world.  Their team of engineers has provided solutions for transportation, mining, energy, and structural projects. One resulting solution is the Ultra High Performance Concrete (UHPC), and it has been utilized in several nuclear and hydropower projects.3 The LafargeHolcim emphasis on successful and sustainable projects is evident through their client partnerships and innovation. Their diverse concrete and cement portfolio and adept engineering teams are aptly capable of designing innovative materials for floatable structures.

Moving forward, LafargeHolcim faces two significant challenges: engineering a marine concrete and developing a business management team for the specialty concrete. It is quintessential to the project that the engineers develop a concrete that meets demands necessary for floating structures; the concrete needs to be strong to provide complimentary support to steel beams, it requires an adhesive property to stick to itself, steel, and potentially a foam filler, and it needs to be environmentally conscious pertaining to materials used, sustainability, deterioration, and waste. Beyond investing in the engineering team and efforts, LafargeHolcim should develop a strong business management team for the marine concrete.  This team would be charged with supply chain management, sales, potential project acquisitions, and environmentally conscious programs.  Supply chain concerns would be acquiring quarries and materials need for large scale production. Regarding the environment, as a global leader in the industry LafargeHolcim should welcome their position as a great opportunity to show the world how to responsibility source and create, while having a product that will be sustainable for future generations without negatively impacting the environment.  The business team of LafargeHolcim needs to acquire marine projects to test and apply the marine concrete.  First mover advantage will assist them in acquiring more projects and allow them to advance their technologies as they engage in more projects with larger scale.

Climate change and rising sea water level is a threat to our greatest coastal cities and low elevation nations.  A marine concrete product developed by LafargeHolcim will be a great asset to the world as we globally address the flooding of our homes.  Instead of saying goodbye to some our most precious treasures, buoyant concrete float systems could prevent the inevitable and allow us to preserve our beloved cities.  Going beyond urban preservation, a marine concrete could provide a utopian platform for which humanity can preserve the biodiversity of our landmasses.



  1. Henderson, Reinert, Dekhtyar, Migdal: Climate Change in 2016: Implications for Business
  2. Strauss, American Cities and the Rising Sea
  3. LafargeHolcim, Website: http://www.lafargeholcim.com/
  4. AT Design Collection. http://www.atdesignoffice.com/
  5. The Lilypad, Designed by Vincent Callebaut. http://inhabitat.com/lilypad-floating-cities-in-the-age-of-global-warming


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Student comments on Floating Our Concrete Jungles

  1. Very interesting concept Emma! You mentioned that the current solutions only suffice for larger rushes of water from storms or floods, but will not help for permanent sea rise. The floating city concept seems that it will face buy-in challenges, not just because of the capital investment needed to implement this at such a huge scale for a “distant future,” but also because the technology does not yet seem to be there. I’m sure these projects are stalling because companies are finding it hard to justify investment when it’ll take until 2100 to observe a 3-6.5 ft. rise in sea level. I wonder whether LafargeHolcim has already considered this project, but killed it early on due to a lack of observable and projected returns on investment.

  2. Thanks, Emma. This is super interesting. One of the takeaways I have from this is that it seems that concrete and related businesses would certainly benefit from the development of these floating cities. However, as the impact of climate change continues, it would obviously be impossible and actually undesirable for cities around the world to be floating. I wonder how these businesses can work towards limiting the impact through creative solutions in the production of concrete. In fact, according to the World Business Council for Sustainable Development, 5% of carbon emissions come from the concrete industry. So, their business actually helps create the problem that they would take advantage of with floating cities. While an attractive option, I would imagine most people would prefer to live on the mainland and for companies to work towards reversing rising sea levels to preserve our cities – the way they exist now – for future generations.

  3. I had no idea floating concrete existed! While this is a very interesting topic and there is a certainly a lot of potential for floating concrete in specific use-cases, I unfortunately cannot envision a scenario in which there is a large-scale transition to floating concrete across the world (or even within one individual city.) The amount of capital required and political coordination necessary to allow floating concrete to have a meaningful impact on climate change simply makes the task impossible.

    I also agree with Ranj that the technology does not seem to be perfected quite yet, making implementation even more difficult. Given the projected timelines for rising sea levels, I’d guess that we see large scale impact from climate change before floating concrete would be ready for large-scale deployment (not to mention the more practical implementation issues I mentioned above.) As much as I’d like to see a real-life Waterworld – but with floating cities – this seems like a conceptually good idea but simply impossible to implement.

  4. Great thought-starter Emma! It is indeed fun to postulate and imagine a future of floating cities. However, similar to other commenters, I can’t help but consider the immense practical obstacles that could prevent this from becoming a reality, and the reactionary essence of this solution that seemingly fails to address the root causes of climate change. Many of the above comments have touched on the practical implementation challenges, so I’ll leave that point aside. The other concern is the fact that floating cities appear to be a solution that reacts to the impacts of climate change that we can foresee today. However, given the impossibility of forecasting the future effects of climate change, and the fact that the pace of climate change has exceeded almost every prediction made by scientists, I’m concerned that by the time floating cities are near completion, new changes in the climate would have emerged (such as frequent tsunamis or earthquakes) that could render floating cities an incomplete or inadequate solution.

  5. Emma – this is wild! Very cool. I love Vincent Callebaut’s “Lilypad” concept, and I can understand how a buoyant marine concrete could play a large role in allowing the Lilypad and other similar designs become reality. Yet I suspect these floating mini-cities would most likely be financed to serve as resorts, casinos, private residential developments, or off-shore business and tax centers. Is it really feasible to believe that governments or private citizens would fund the creation of off-shore floating cities, or to somehow dig under and buoy existing highly populated areas? If rising sea levels are an inevitability, it seems that the path of least resistance, for most people, is to simply move inland.

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