Organic waste management is one of the most urgent urban sustainability challenges. Rapid population growth, global food waste and methane emissions demand scalable, innovative approaches that go beyond traditional composting and energy recovery, while also improving existing practices. This theme sets the tone for circularity at the city scale. It establishes organic waste as both a climate challenge and an opportunity for value creation, food system resilience, and social engagement.

As cities densify, waste collection becomes an increasingly visible and complex operational challenge. Waste prevention remains the highest ambition, yet has its limits in current societal and economic realities. As waste streams become valuable resources, separate collection by product type or material puts growing pressure on urban space and governance, while also creating local employment opportunities. Sustainable systems must therefore embrace innovation, efficiency, digitalisation, and behavioural change.

This theme also addresses the transition away from waste mismanagement through stronger basic infrastructure, collection coverage, and inclusive service design. Ending practices such as open dumping and open burning requires accessible and reliable collection and sorting systems, supported by enforcement. Capacity building for municipalities, integration of informal sectors where relevant, and community engagement remain essential to resilient and equitable urban systems that enable circularity from the first step in the chain.

A significant share of residual waste remains unavoidable as regulations, incentives, and markets continue to evolve towards a circular economy. This theme explores how residual waste can be managed responsibly through technological innovation, regulatory adaptation, governance, and planning. It addresses the role of Waste-to-Energy, energy recovery, and landfilling within climate and resource goals, provided they meet high environmental and operational standards.

It also covers safe final disposal, landfill rehabilitation, environmental monitoring, hazardous materials, lithium-ion batteries, fire safety, and the protection of workers and public health. The aim is to ensure that waste which cannot be prevented or recycled is managed in a controlled, transparent, and environmentally sound way.

Effective waste and resource management is fundamentally a governance challenge. Clear roles, responsibilities, and standards are essential across planning, operations, enforcement, and service delivery. This theme explores the policy, regulatory, and institutional frameworks needed to accelerate circularity, decarbonisation, and decontamination at city scale. It addresses obligations, incentives, taxes, and Extended Producer Responsibility schemes, as well as the financing of infrastructure and services.

It also examines fair cost-recovery models, risk allocation, and investment in innovation and long-term resilience, bringing governance, legal instruments, and financial mechanisms together to make circular ambitions scalable and accountable.

The transition to circular and climate-aligned urban systems is not only technical or economic, but also ethical. Waste and resource decisions directly affect workers, communities, and future generations. This theme explores ethical dilemmas such as affordability versus ambition, enforcement versus fairness, and rapid transition versus social impact. A central focus is Diversity, Equity and Inclusion (DEI), ensuring that communities are represented, benefits and burdens are shared fairly, and no group is left behind.

It also addresses transparency, integrity, responsible leadership, human rights, safe working conditions, and the protection of vulnerable and informal workers. These principles are essential to building trust, legitimacy, and lasting system change.

Cities are vast “urban mines” rich in materials embedded in buildings, infrastructure, electronics, and textiles. As global waste shipment rules tighten, domestic recovery capacity must expand. Best practices of ecodesign, transparency and traceability in production of consumer goods and innovative usage models are covered. This theme looks ahead: designing cities where materials are continuously cycled, operational risks are reduced, and local economies benefit from resource retention.