Circular Economy and the 2030 Agenda: Circular Cities

Week four of the UN Circular Economy course pushed me well out of my comfort zone. The focus was on circular cities, and the scale of what is involved feels genuinely daunting. At the same time, the opportunities for positive change are enormous.

Some quick numbers to set the scene: 55% of the world’s population live in urban areas, projected to reach 70% by 2050. Cities cover just 2% of the Earth’s surface yet account for 70 to 75% of global greenhouse gas emissions. With those figures in mind, shifting from linear to circular models in how we build and run cities is not optional. It is essential.

The concept of urban metabolism was one of the most useful lenses the course introduced. It treats cities as living systems with interacting environmental, social, and economic factors. By understanding how resources enter and exit a city, you can start to see where circular strategies might optimise flows of energy, materials, and waste. It is a powerful way to make sense of the complexity.

The built environment came up repeatedly. Modular construction, renewable materials, energy-efficient design. I found the analogy of designing buildings like Lego genuinely compelling: components that can be assembled, disassembled, recovered, and reused rather than sent to landfill. It shifts the mental model from buildings as permanent fixtures to buildings as material banks.

Mobility was another major theme. A circular city reimagines how people move, prioritising public transport, shared mobility, cycling, and walking. The course referenced Curitiba in Brazil, which tackled congestion and pollution by implementing a pioneering bus system that completely reshaped the city’s approach to transport. Reducing reliance on private vehicles alleviates congestion, improves air quality, and promotes healthier lifestyles.

Food systems also featured prominently. Cities need to transition from linear to circular models to address waste, pollution, and unsustainable consumption. Regenerative agriculture, localised food production, minimising food waste, and using organic waste to nourish soil and generate energy. Through circular strategies, cities can reduce environmental impact, improve food security, and support local economies.

Policy matters too. Many of the ideas behind circular cities require supportive frameworks that encourage innovation, facilitate collaboration, and ensure social equity. Cities have a unique opportunity to lead by example and implement policies that drive circularity at a local level. But policy alone is not enough. Citizens and communities are central to making this work. Grassroots movements, consumer awareness, and participatory governance all increase the impact of circular strategies.

We also had a fantastic live session with Esteban Munoz of UNEP and Maria Ferrer from the OECD, who covered the research available across many of these areas. The breadth of thinking required can be overwhelming, but building a foundational understanding of circular cities has been genuinely valuable. It has also reinforced something I keep coming back to: the need to operationalise sustainability efforts with the same rigour we apply to digital innovation and transformation.

You can read the other posts from this series: Circular Economy and the 2030 Agenda, Sustainable Lifestyles, and Developing a Circular Business Model.

Circular economy thinking shapes much of our sustainability work. If your organisation is exploring this territory, take a look at our Sustainability & Circular Economy work.

Further Reading

• Circular Economy and the 2030 Agenda.
• The Circular Economy.
• Developing a Circular Business Model.
• Circular Economy and the 2030 Agenda: Sustainable Lifestyles.
• A-Z of Sustainability.