Cities need to rethink their traditional supply chains.
Cities account for only three per cent of the Earth’s land surface area but they punch well above their weight by hosting the majority of humans, accounting for 80 per cent of the world’s GDP and contributing up to 70 per cent of global waste and the majority of greenhouse gas emissions.
Naturally, cities contain a vast amount of assets and products within their urban boundaries. They are home to a large number of residential and commercial buildings, comprising office and living spaces with so many items in them such as furniture, office supplies, etc. Furthermore, cities are connected by infrastructure such as roads, bridges, water and energy networks. And residents of cities consume a large variety of products such as textiles, cars, household items and appliances. Additionally, city residents enjoy various skills and knowledge which are intangible assets.
Historically, we humans have adopted a simple approach in our consumption of these city assets and products. Basically, we consume them for a certain amount of time and then throw them away. It is a straightforward linear approach: i.e. consume and dispose. However, given the enormous amount of assets and products we consume, this is not a sustainable approach for cities as we keep piling things in waste while concomitantly causing adverse impacts on the environment.
Do we have an alternative to linear cities? The good news is we certainly do, by feeding back our consumed assets and products back into the economy and society through various means, the so-called circular city. The challenge is that our existing systems and supply chains are not yet completely geared up for it.
So, what are these alternative means that enable us to better consume and not dispose city assets and products to waste? Stated simply, we can either extend their usage and lifespans or even create a new life for them. Some tricks in the form of targeted actions can be applied to city assets and products to achieve this.
The lifetimes of household items and appliances can be extended by refurbishing them if they break down, as opposed to disposing them immediately. City infrastructures such as roads, bridges and underground infrastructures can be refurbished and maintained to extend their lifetimes.
Similarly, our household and personal items can be reused by selling them as second-hand items or donating them to the needy residents in the city, a means of social circularity. Cars and other transportation items such as trucks, scooters, bicycles and motorcycles can be shared for mobility purposes leading to improved usage as personal mobility items tend to be idle for a large majority of their lifetimes. Sharing applies not only to mobility but to a large number of city assets and products whether they are household items or appliances.
City infrastructures such as roads, bridges and underground infrastructures can be refurbished and maintained to extend their lifetimes.
Similarly, sharing knowledge and skills can be done either on a commercial basis, through the likes of economic activity, or via non-commercial means such as social volunteering, assistance, etc. There is a significant potential to explore and implement city residents’ volunteering activities when it comes to assisting others in a city, another example of social circularity in action.
Recycling has enormous potential for circular cities. The obvious example is households segregating waste into different categories and then recycling it. But there are several other very interesting examples emerging globally. Roads can be built from recycled plastic. Today, we demolish buildings at the end of their lifetimes and dispose them as waste. We have an enormous opportunity to assemble homes from their constituent parts, disassemble those parts at the end of their lifetimes and reuse them in different buildings with even different designs.
Recycling has enormous potential for circular cities.
A similar concept can in fact be applied to almost any city asset or product. For example, a company’s product can be recycled either as is, or broken down into its constituent parts and then used as a raw material by another company. This creates an enormous potential among businesses to recycle and reuse their products or constituent parts, commonly referred to as industrial symbiosis. We have barely scratched the surface of such circularity potentials across the globe.
Digitising is another action item that can be applied to certain tangible products, circumventing the need for the usage of physical products. Items such as books and music today are to a large extent digitally available and sold or streamed for consumption, extending their lifespans compared to their physical formats and enabling their higher shelf-life. The pandemic has contributed significantly to digitising various physical processes and avoided the need for physical interactions such as meetings, customer support, teaching, medical consultations, etc.
Cities can pick and choose from various circularity methods according to their priorities from a global innovation landscape and learning from their peers. This landscape provides cities with a large number of options. The United Nations’ United for Smart Sustainable Cities initiative has produced a pragmatic guide for cities to use in implementing their circularity initiatives1. It also provides a list of enablers to support and accelerate implementation efforts and presents 17 global case studies.
Circular cities not only stimulate economic growth but also create a positive social and environmental impact. Circularity provides immense innovation opportunities for cities and encourages entrepreneurship for new businesses, the creation of new industries, as well as social and environmental entrepreneurship.