It is morning, in a city of the future. Wafer-thin artificial leaves separate with the rising sun as buildings wake up. They continue to follow the sunlight over the course of the day, sucking dew and carbon dioxide out of the air. These substances are filtered into the fleshy fabric within the walls of our homes, not dead spaces but active processors, like stomachs packed with thriving microbial colonies. They generate heat, recycle grey water and filter effluents to produce rich, native soil that has a commercial value and is used to grow plants in green plots, or window boxes. We are now producers, not consumers.
There are no more infertile stretches of asphalt sprawled over our urban rooftops but an expanse of vegetation which processes the city’s rich chemical landscapes – and it is no longer possible to tell which of these vibrant structures are artificial, or natural.
Visionary ideas about our near-future cities are helping develop new approaches in human development without necessarily being constrained by the limits of what is currently possible.
Modern cities are run and populated by machines to such an extent that we no longer really notice them. And while machines are useful, they consume fossil fuels and transform them into energy, carbon dioxide and industrial pollutants – which, on an industrial scale, produces a world which Rachel Carson, author of the seminal environmental book Silent Spring, noted is "not quite fatal". In recent years we’ve looked to renewables to avoid the need for using fossil fuels – but the percentage of our energy provided by these alternatives remains small compared with our overall consumption.
Yet, there is an alternative technology available to us, which we have barely begun to apply to its full potential. Nature provides a rich portfolio of sometimes unlikely living technologies that may shape our near-future lifestyles in new ways. The practice of biomimicry already taps into nature’s ingenuity – for example, the famous hexagonal skin of Norman Foster’s "Gherkin" was inspired by the Venus Flower Basket sponge, which has a lattice exoskeleton.
These solutions are currently realised through industrial processes. But we have reached a point at the start of the 21st Century where we do not have to copy nature but can directly design and engineer her processes with such precision – and on a range of scales – that we can think of them as a new kind of technology.
Living technologies have unique properties that may enable us to imagine and realise our urban spaces in new ways, since they are adaptable, robust and have an incredible ability to transform one thing into another. Think of how trees share common technologies (leaves, trunk, roots) adapted to different kinds of environments and using a range of resources. For example, needle-leaved Canadian evergreens make the most of scant sunlight and their leaf litter feeds the acidic soils that nurture networks of microorganisms, such as nitrogen-fixing bacteria, which in turn, enriches the food for the trees.
In the near future, we will begin to tap into the technological potential of this "metabolic" diversity and strategically use it within the fabric of our cities.
While trees are complex organic structures that require substantial infrastructures and resources to nurture them, biotechnology has revealed that multicellular organisms can perform similar processes – but even more powerfully. Although these creatures cannot be seen with the naked eye, they are much easier to keep and much more vigorous than trees.
Indeed, architects are already proposing that micro-organisms may power our cities. For example, Alberto Estevez’s Genetic Barcelona proposes using synthetic biology techniques - which enables us to grow organisms that do not exist in nature by manipulating their DNA – to create trees that produce a natural light-producing protein usually found in jellyfish. So, not only would we be able to enjoy the mood-elevating wavelengths of the light emitted by these plants, but we would also benefit from not having to rely on fossil fuels and central power grids to provide street lighting.