Compound this with the upcoming economic, technological and ecological challenges we’re likely to face as a species and the picture becomes even more urgent.
So how do we go about creating a system of places and spaces that not only address all of these factors, but at the same time maintains an urban environment that’s appealing, fair to all, productive and efficient and ultimately, one that’s livable?
It turns out that the answer to these pressing questions may lie in the concepts behind the circular economy.
An Introduction to Circular Cities
Ultimately, the idea behind the circular city is a green one and the reason for this is incredibly straight forward – as with the principles of a circular economy, using nature as a template for urban development allows the implementation of infrastructure that replicates natural processes and systems to help address the most pressing issues facing the built environment.
The driving principles of a circular economy approach are a focus on the regeneration of natural systems, keeping products and materials in use and designing in a way that minimises and mitigates the adverse effects of design – things like pollution and waste.
All of these of course, can in theory by translated to the urban scale, informing everything from architecture and spatial planning direction to the implementation and operation of transportation systems, infrastructure and public services.
From overcrowding and inequality, through to climate change mitigation, resilience and adaptation, a green approach to designing and planning the built environment around a circular city concept could be the solution to some of the biggest problems our cities are likely to face over the coming decades.
The concept of circular urban planning is one being actively explored in cities from Berlin and Amsterdam to Malmö and Helsinki.
Bringing Circular Thinking into the Built Environment
As with the underlying principles behind circular economic thinking (sharing, renting, reusing and recycling), the circular city is one in which the focus is shifted from the unsustainable to the sustainable, promoting environmental and equitable outcomes and ultimately, minimising the adverse effect of externalities that result from activities associated with the built environment.
At the most basic level, this requires a change in the way that planners, designers and stakeholders at almost every level, think about the urban landscape, it’s byproducts, and the forces which act upon it.
Incorporating natural systems as well as physical materials and surfaces into the urban makeup of cities is one of the best ways to rapidly encourage the development of the urban landscape built around circular processes.
Greening of buildings is one such example of this and looks to replace exterior surfaces with naturally complemented replacements such as green roofs and green facades.
Deploying this kind of structural greening can significantly extend the lifespan of surfaces due to the additional protection offered against weathering effects of sunlight and temperature – there are examples of green roofs in Berlin which trace their heritage back up to a century.
One of the key elements in achieving a transition to a circular city is the mitigation of waste at all levels.
From the implementation of green infrastructure that reduces waste from construction industry processes to policies which promote the reduction of waste at the individual level.
A central element of any circular system is maintaining balance through managing consumption of resources.
In the case of the circular city, this can take several forms but perhaps the most obvious is the reduction in energy consumption that can be realised through a transition to green infrastructure.
It’s estimated that as much as 40% of the total energy consumed in the EU is attributable to the built environment and this is a figure which is undoubtedly going to rise as demographic and ecological disruptions continue.
As well as providing consumption benefits through increased insulation (and subsequent lower year-round energy usage), green surfaces such as roofs and external facades also offer the potential to cut out significant amounts of energy otherwise consumed in the construction process associated with alternate materials and fabrication processes.
Viewing water as a critical resource in any circular system will become increasingly prevalent to many cities over the coming decades.
Indeed, rapidly changing climatic conditions will make water conservation and utilisation the primary consideration in many places where water security is already the predominant threat and is a matter of not just the viability of a city, but of its very survival as environmental pressures steadily increase.
Adversely, episodes of heavy rainfall present a different set of challenges to urban infrastructure planners with runoff from storm water often overwhelming not only drainage infrastructure (leading to severe flooding), but also water treatement plants further ‘downstream’ and the subsequent adverse pollutant effects this has on natural bodies of water such as rivers.
Nature of course, already has a perfectly finessed circular system of dealing with excess water and mimicking these natural systems at the urban scale (as is already being trialed in the US and China) will be key to ensuring cities adapt to the water challenges of tomorrow.
Green infrastructure as a tool for water management has a crucial role to play in the future of all cities, and the ability to effectively utilise and control every drop that reaches buildings, streets and spaces will take on increasing importance for increasing the resilience of cities against the growing unpredictability of shifting climate patterns worldwide.