How can cities become circular?

Cities, as dense hubs of consumption, production, and waste generation, possess "tremendous power to drive change toward more circular, closed-loop systems". Their role is pivotal in accelerating the transition to a circular economy, as they can implement systemic changes that influence infrastructure, policy, business, and citizen behavior. The shift from linear to circular in urban environments allows cities to enhance efficiency, improve quality of life, and drastically reduce their environmental footprint.

Here are key strategies and actions for cities to become circular:

1. Policy Leadership and Regulatory Frameworks:

   • Enact Bold Policies: Governments and municipal authorities must implement robust policies and regulations that actively steer markets from linear to circular models. This includes integrating circular economy measures into national climate plans (Nationally Determined Contributions - NDCs) and National Biodiversity Strategies and Action Plans (NBSAPs), which serve as investment plans to lower emissions and restore ecosystems.
   • Extended Producer Responsibility (EPR): Implement regulatory instruments like EPR, which hold manufacturers accountable for the entire lifecycle of their products, including post-consumer waste. This incentivizes companies to design products that are durable, repairable, recyclable, and safe from the outset. Viet Nam, for example, has integrated eco-design and EPR mechanisms for electronics, plastics, and textiles into national policies.
   • Standards for Circularity: Develop and enforce standards to ensure products are durable, repairable, and recyclable.
   • Support Circular Business Models: Create policy environments that incentivize and reward circular business models, from bio-based materials to reverse logistics. This includes offering grants to innovative ideas, such as Serbia’s ‘Circular Communities’ project supporting initiatives from waste glass interior design to involving informal waste pickers in film industry waste management.

2. Infrastructure for Circular Ecosystems:

   • Advanced Waste Management Facilities: Cities need significant investment in infrastructure for more reliable waste collection and sorting facilities, and safer, more effective recycling plants. This transforms municipal solid waste into valuable resources. India's Plastic Waste Management initiative offers a replicable model for cities, integrating innovation and social inclusion to establish closed-loop recycling systems through Material Recovery Facilities.
   • Reuse, Refill, and Repair Logistics: Invest in convenient logistics and physical systems to support reuse, refill, and repair. Without this infrastructure, circular principles remain theoretical.
   • Renewable Energy Systems: Transition to and invest in renewable energy systems. This includes utilizing bioenergy that can be recycled from food and other organic waste. Amsterdam, for instance, found that incorporating biorefineries, waste separation, and return logistics could generate substantial added value, material savings, and job creation in various sectors.
   • Water Conservation and Treatment: Improve urban water conservation and treatment systems. Innovative approaches, like Biopolus's modular urban water treatment system, can harness clean water, energy, nutrients, and minerals from wastewater and organic waste, potentially offsetting the energy required for treatment.

3. Circular Built Environment:

   • Regenerative Building Practices: Adopt circular economy principles in building construction. This can dramatically reduce carbon emissions—potentially by as much as 75% by 2050—by minimizing waste, maximizing material reuse, and extending the lifespan of structures.
   • Deconstruction and Material Recovery: Implement strategies that favor deconstruction over demolition, allowing for the recovery and reuse of valuable building materials. The Circular Building Toolkit recommends strategies like "build nothing, build long-term value, build efficiently and build with the right materials".
   • Multifunctional Design: Encourage building designs that are multifunctional, transforming structures from serving a single housing function to also being energy producers and consumers, and even food producers. This inherent multifunctionality creates more resilient and self-sufficient urban systems.

4. Sustainable Transportation and Mobility:

   • Improved Public Transportation and Cycling Infrastructure: Reduce the need for private vehicles by enhancing public transportation networks and promoting bicycle infrastructure within cities. When vehicles are necessary, shift towards electric-powered ones. This increases the efficient use of resources and reduces pollution.
   • Alternative Ownership Models: Support alternative ownership models like car-sharing services, which increase the efficient use of existing resources (fewer cars needed per capita).

5. Data, Metrics, and Innovation Incentives:

   • Robust Data Collection: Cities need better quality data—more robust, complete, and consistent—to track progress, align incentives, and inform policy decisions for circular interventions. Projects like the Dominican Republic’s "Rescue the Ozama" demonstrate how collecting data on waste types and volumes can support informed decision-making.
   • Reward Circular Innovation: Incentivize financial systems to recognize and reward circular business models. This could include grants, investment funds, and other financial mechanisms to support the development of bio-based materials, reverse logistics, and other circular innovations.
   • Embrace Technology: Utilize modern manufacturing and waste technologies like 3D printing, the Internet of Things (IoT), and big data analytics to accelerate the circular economy. Digital platforms can track and optimize resource use, strengthening connections between supply chain actors.

6. Cultural Shift and Citizen Engagement:

   • Education and Awareness: Foster a cultural shift toward regenerative consumption by educating citizens about the circular economy and empowering them to make informed choices. Awareness campaigns can highlight the impact of individual consumption habits, encouraging practices like buying less, reusing more, and proper recycling.
   • Transparency and Traceability: Advocate for greater transparency about product contents and traceability of materials, which empowers both policymakers and consumers to make more sustainable decisions.
   • Active Agents of Change: Encourage citizens to become active agents of change, recognizing that their choices collectively contribute to a larger, positive movement.

7. Systems Thinking and Collaboration:

   • Holistic Approach: Cities must adopt a systems thinking approach, understanding that the circular economy is not about individual products but about changing the organization of whole systems. This requires interconnecting different urban systems to create synergies and harness diversity.
   • Partnerships: Building a circular city requires strong partnerships between individuals, businesses, and different levels of government. This involves collaboration throughout the supply chain, within organizations, and with the public sector and communities to increase transparency and create joint value.

Examples of cities already embracing these principles include Amsterdam, Bilbao, Berlin, and Malmö, which are leading the way as "emerging circular cities". Amsterdam’s roadmap, for instance, has identified opportunities for added value and job creation in the building, agriculture, and food processing industries through circular strategies. By implementing these interconnected changes, cities can transition from being contributors to the linear "take-make-waste" problem to becoming powerful engines for a resilient, prosperous, and sustainable future within planetary limits.