Cities and the circular economy
This topic area looks at the role cities play in the transition to a circular economy.
Architect and key thought leader in sustainable design, William McDonough, summarises in his book, Cradle to Cradle: Remaking The Way We Make Things: “As long as human beings are regarded as ‘bad’, zero is a good goal … This is the ultimate failure of the ‘be less bad’ approach: a failure of the imagination. From our perspective, this is a depressing vision of our species' roles in the world. What about an entirely different model? What would it mean to be 100% good?”
‘100% good’ is the mindset shift needed for a regenerative economy. The goal must be moved from mitigating negative impacts to generating a positive impact for people and planet. A would do just that by intentionally redesigning products and materials that mimic natural systems and produce no waste. It also goes beyond product design to consider business models and opportunities for regeneration – in other words, it would redefine an entire system.
There are many challenges, and the industry that faces perhaps the greatest and most far reaching challenges when it comes to regeneration is the built environment, which generates more waste and consumes more virgin materials than any other sector.
It’s no mean feat, but despite the challenges, nature-positive buildings and infrastructure aren’t just a fantasy anymore. In fact, they’re cropping up all around the world.
In the next 40 years, a further 230 billion square metres of buildings are expected to be constructed, adding an area roughly equivalent to the size of Paris to the global building stock each week. The projected material, energy and resource requirements – as well as the pollution and carbon emissions associated – are eye-watering.
But by following circular design principles, the negative impact on the planet could not only be reduced but replaced by a positive impact – one that is founded on a reciprocal and mutualistic relationship with nature.
It lies at the heart of nature-inspired design approaches like biomimicry, biophilia and ecosystem thinking – all of which take a holistic view that the human and natural world are interconnected and can thrive through mutually beneficial exchanges. Resource efficiency and pollution reduction are still paramount, but the end goal moves beyond zero harm towards the higher ambition of restoration and flourishing.
Around the world, almost 300,000 sq km of coral reefs absorb about 80 million tonnes of carbon dioxide every year to form their calcareous skeleton. Though predominantly made of the same material (limestone, which forms concrete) and sharing similarities in the busyness and diversity of life contained within them, cities on the other hand emit more than two billion tonnes of CO2 annually.
But could our cities be designed to sequester carbon dioxide, rather than emit it?
US start-up Blue Planet Systems is showing that this can become a reality by developing concrete that sequesters carbon dioxide during the manufacturing process. Concrete containing 50% or more of Blue Planet’s synthetic aggregate and sand can then be used for a variety of building projects with no loss in strength or performance.
They are already implementing it in different projects: the construction of a new boarding area of San Francisco International airport as well as a section of California’s coastal highway.
Brent Constantz, CEO of Blue Planet, believes that in a plausible mid-term scenario his company’s technology could reduce 35 times more carbon dioxide than Tesla’s electric cars.
The pinnacle of an effective built environment is one that is functionally indistinguishable from the natural environment it replaced. “Nature is our only reference point for regeneration,” Biomimicry 3.8 CEO Nicole Miller says. By looking at the positive impacts that natural environments have on an area, we can create a set of ecological performance standards that built environments should strive for.
The positive impacts of regenerative built environments are not just felt by the planet. People also reap enormous rewards when we start designing the buildings that we live, work and exist in to do good, and on the flipside are also adversely affected by built environments that aren’t created with their impact in mind.
Particulate air pollution is the largest environmental health risk across the world, responsible for an estimated 60,000 premature deaths in the UK and contributing to over half a million child deaths per year. A 2019 study by Greenpeace and AirVisual revealed that globally, over 60% of cities have dangerous levels of pollution.
Trees and plants have long been seen as the ‘lungs’ of a planet, but according to Italian plant physiologist Rita Baraldi, they can also act like a ‘liver’ by filtering out unhealthy gases and particulate matter (PM) to clean the air around them.
Using plants to purify the air is being put into practice in the design of the Venlo City Hall in the Netherlands, where the entire northern face of the building is a vertical garden, containing over 100 plant species and covering a 2,000 square metre surface. As well as providing a habitat for insects and birds, the green facade also absorbs nitrogen, sulphur dioxide and particulates from the surrounding air and roads.
But it’s not just plants that can do this – it's the buildings themselves, too. In New York, the 55-storey Bank of America has two sets of large air-intake openings near the base and roofline. These openings are akin to gills; they take in the air from the city and purify it with filters designed to remove 95% of particulates, as well as ozone and volatile organic compounds. The clean air is distributed through the building and then filtered once more before it is exhaled into the city, creating widespread benefits in the surrounding areas.
Built environments also have the potential to impact entire communities in a positive way. On the eastern edge of Kolkata in India, a vast, seemingly natural wetland plays a critical role in supporting the nearly 15 million strong population of the city. The massive patchwork of channels, lagoons, farms and bheris (flat-bottomed shallow fish ponds) that make up East Kolkata’s wetlands is a unique example of indigenous infrastructure.
The wetlands are simultaneously a fishery, waste-management system, wildlife zone, farming and grazing area, community hub and heritage site. In total the East Kolkata wetlands treat 700 million tonnes of wastewater per day, as well as providing flood protection, natural water storage and groundwater recharge. In addition, each year it produces 13,000 tonnes of fish, 16,000 tonnes of ice, 156 tonnes of vegetables and provides 80,000 people with livelihoods. It is the largest waste-water fed agriculture system in the world.
The East Kolkata wetlands have evolved over one hundred years on a foundation of traditional knowledge. It is a highly effective green infrastructure asset and represents a unique indigenous innovation that the world should look to for guidance on creating resilient urban infrastructure systems.
Regenerative built environments are undeniably beneficial for the planet and for people. But they also make business sense, and are far from a pipedream for many organisations – in many industries, a regenerative economy is already a reality.
The food and fashion industries are implementing methods like no-till, intercropping or agroforestry. Many of these methods are built on millenia-old indigenous practices that prove that it is possible to produce abundant food and clothing while maintaining the health of the planet.
French food company Danone works with 50,000 farms to regenerate soils across the world, while US fashion brand Timberland has started using leather produced in a way that improves grasslands in its new walking-boot collections.
And it's possible to take it further by incorporating regenerative built environments into manufacturing and production processes. In the mid-1990s, Swiss textiles company Rohner achieved something incredible: their factory mimicked the function of a forest.
Through manufacturing a fully compostable line of textiles, the quality of the wastewater flowing out of the Rohner factory was of a higher quality than the incoming supply – in other words the factory purified the water. The waste trimmings from the manufacturing process, which previously was transported out of the country for ‘specialist incineration’, could now be sold to farmers and gardeners for use as mulch or ground cover, improving local soil conditions.
A decade after deciding to develop the first 100% biodegradable synthetic upholstery fabric, Rohner was generating one third of their revenue with their fully compostable product line, while also reducing operational costs.
In the aftermath of Covid, our perception of physical space has been altered. We have the opportunity to reimagine our relationship with cities and the role that they play on our planet.
Buildings that breathe clean air, factories with waste streams that support healthy farming systems, wetlands that nurture whole cities – all of these and more constitute a positive vision for the future that companies and citizens can rally behind.
Cities need to be a key driver and adopter of regenerative practices and outcomes. And it's not just good for the planet and surrounding communities – it's also good for the bottom line. The saved resources, improvement to staff wellbeing and retention and increase in productivity that result from regenerative design are significant.
We are now in the era of the anthropocene, where human actions have the greatest impact on the planet. We can choose which kind of future we want to build: one that drains the precious and finite resources of our planet, or one that sees people, cities, communities and the natural world flourish within a harmonious cycle of use and regeneration. The choice is ours.