top of page
  • Writer's pictureecoLogicStudio

Green VS Dark ecoCities

Last November Marco Poletto delivered a talk at the TEDxBucharest "Uncommon Sense" event, entitled "Uncommon Cities", focusing on a new approach to sustainability based on renewed interest in urban microorganisms such as Algae.

Here is the full transcript of the talk:

Let's make a little collective experiment.

If you close your eyes and think for a second about the concept of Nature, what images come to your mind first?

Who of you is picturing large tees or forests?

Who is picturing water, like mountain lakes or marine landscapes?

Who is picturing algae blooming, like the one in this picture taken by satellite over the Baltic Sea?

Who of you pictured in him mind mycelium networks; scientists believe it to be the largest living organism on earth.

You may wonder what does this have to do with cities, but I think that to be able to talk about future cities we need to start from Nature, or better the Modern notion of Nature that most of us share. One of the main ideas we inherited from modernity, and that has come to define the shape of our contemporary cities is that bacteria or microorganisms are dangerous. Modern master-planning and modern design has strong roots in the concept of sanitation. Even before industrialisation exploded wide boulevards where created, like in Haussmann's renovation of Paris, parks and other recreational areas, like in the Victorian East End of London. Modernism embraced that attitude and turned it into a style. White clean surfaces came to symbolize human's rational ability to frame nature and its darkest and uncontrollable aspects. Modern master-planning rationally separated all functions; zones of production and treatment of waste where moved further out of city centres, technically preventing possible contamination of living quarters. But also removing the by products of the urbanisation from our sight and from our consciousness at a very fundamental level. This was the origin of the modern, industrialized and metabolically linear city.  Resources go in on our side and waste goes out on the other. It is up to the Biosphere to close the loop.

Today we all know the impact that such model has on the Biosphere and since we surpassed 4 billion people living in dense urban environments we know it is only a matter of time before the Biosphere's ecosystems reach a tipping point. Nevertheless we fail to act, governments fail to reach agreements and even cities are failing to implement far reaching policies. Why?

I believe it involves our contemporary notion of Nature. Modernity not only has sanitised out cities but also Nature, or better, our concept of nature. We came to believe that such rationally organised environment that we consider our modern living habitat applies to the Biosphere as a whole. Today we have a machine like model of Nature dominated by the ideal of growth, prosperity and equilibrium. We talk about re-greening cities and re-naturalising forests as if such easy fixes would be at all logical. But this is not how the Biosphere actually works. In fact it is a non-linear system composed of billions of interlocking feedback loops. Destruction, death, decay, digestion, dissolution are some of the most fundamental processes of nature and a critical part of its circularity; these processes often take place in the dark, they generate strong odours. They trigger in us atavistic fears of contagion. They constitute the dark face of ecology that we have all but erased from our consciousness but that is critical to the functioning of ecosystems in the Biosphere. But microorganisms have exceptional properties that we keep discovering in Labs and that make them capable of turning what we consider pollution or waste into nutrient and raw material; they are the missing link to close urban metabolisms.

My team and I recently promoted this vision with the project Anthropocene Island, which investigates the urban future of Tallinn, the capital of Estonia. The project site is a unique Peninsula at the outskirts of Tallinn, it is a former Soviet Military Base that after Estonia became an independent country was abandoned. Nature and especially birds settled on it, as well as more recently the main wastewater treatment plant for Tallinn. Ever since a battle started among the plant management and birdwatchers / ecologists claiming the plant is contaminating their reserve. It is a case of green vs. dark ecology. But birds do not see it that way. They actually like the warm and nutritious water in the bio-digestion tanks and seem to play with its large machines. We decided to take the birds perspective, a non-anthropocentric perspective, and we developed it into a speculative project that became the main exhibition at this year Tallinn Architecture Biennale.  Which we conceived as a real Laboratory of future city making. Here we proposed a new city model that grows from the waste of Tallinn. It integrates microorganisms into the built environment and explores bio-digestion as founding principle for a new city.

We proposed new distributed habitats able to receive Tallinn's wastewater, process it, generate heath and nutrients, host new species, increase photosynthesis, grow biomass, extract biofuel and feed it back to the city of Tallinn. In this vision birds, microorganisms, machines and all other communication devices become, alongside human beings, bio-citizens, contributing to a sophisticated system of collective intelligence, the founding process of a new metabolically circular bioTallinn.

This notion is key to one of my practice longest running project, spanning a decade and called Urban Algae Farms. It is based on the idea of creating habitats for microalgae organisms as part of building envelopes. Within this framework microalgae are not only able to photosynthesize, but also to absorb emissions from the building itself.  This new active layer becomes part of both city and natural metabolic cycles. Green and Dark ecology are reconnected.

There are multiple interactions in buildings that can be activated by the intelligence of microalgae colonies. The microorganisms grow faster in our biomechanical environment than in the wild because they are very closely connected with the life of the building and that stimulates its biomass to grow; the biomass in turn can be used by the inhabitants of the building itself as source of energy or food. It is a new kind of symbiosis. This means we start seeing buildings as something not necessarily finished at the end of construction; we understand that it can keep evolving.

Our job is to imagine and design new urban typologies, new hybrid habitats for these emergent social groups.

We have just built one, in Astana, Kazakhstan, called Bio.TechHut, our first permanent biotechnological dwelling. The bio.TechHut is 180sqm in plan, It can host a large family and supports 1600L of living cultures of cyanobacteria in its lab grade glass photo-bioreactors.  In optimal conditions it produces approximately 1kg of dry algae per day. Green micro-algae can contain up to 60% oil from which 1kg of bio-fuel can be produced, releasing 10 KWh of energy. That is enough to power an average UK home which makes Bio.TechHut energetically self-sufficient. But this principle of urban symbiosis must extend to food and nutrients; these are a crucial cycles where important changes are required to feed a healthy diet to a growing urban population that is predicted to reach 5 billion in the next 15 years.

A micro-algae like Chlorella contains up to 60% vegetable proteins. Every day the BIO.techHUT produces up to 600g of proteins, This is enough to supply the recommended daily intake of 12 adults. This is the equivalent in meat based proteins of 8 cows!

And of course reducing farming also means reducing emissions of green house gasses. The living cultures of chlorella growing within the BIO.techHUT glass photobioreactors  in optimal conditions can absorb 2kg of CO2/day this is equivalent to the CO2 adsorbed by 32 large trees. This is equivalent to a family run urban forest. This numbers give us a spatial and material dimension of the efficiency of building integrated cultures and of this ability of the urban fabric to synthesize resources. It is a crucial transition; the urban environment stops being just a container of programmes or functions, like in the modern machine for living, and becomes itself a dynamic process of production, a living machine.

A living machine has an ability to harvest and process matter, information and energy in a way that differs radically from how we produce and distribute energy today, even renewable ones. The linear metabolism of the Modern city will evolve into the many interlocking circulars metabolisms of the bio-digital City. Centralized energy grids, like the ones connecting power stations, even large wind farms, to our houses, will evolve into distributed networks of emergent collective intelligence, where every building, every park or public space is both producer and consumer at the same time.

So how can we imagine this model at work?

With my team we began working with living Slime Mold as an urban simulation tool 4 years ago. You just saw an early experiment of a simulation sited in Arizona, while this time lapse video refers to Tallinn. Slime Mold is a protist, a single celled organism which contains hundreds of thousands of tiny nuclei. In the plasmodium phase, the nuclei are afloat and are able to interact with each other through bio-chemical reactions. They accumulate traces in the environment that form a distributed spatial memory of these interactions; this embedded memory is critical for collective intelligence to emerge in absence of a nervous system. It is thought billions of local direct 1:1 interactions that this behaviour and the overall morphology emerges. We developed an apparatus to capture this behaviour. As you can see there are remarkable similarities with urban networks, as seen from satellite. But what is fascinating here is that there is no master planner, or engineer to design it from the top. It is bottom-up emerging collective intelligence at work.

So after this journey in the world of urban microbiology I want to leave you with a little provocation, which paraphrases Donna Haraway.

Close your eyes and imagine you are now an ecological activist fighting to protect our planet from the catastrophes of climate change.

Who would you rather be,

a Tree Hugger?

or a Zombie ?

252 views0 comments

Recent Posts

See All


bottom of page