Almost all growth of the human population this century will be accounted for by a growing number of city dwellers1. This demographic reality has elevated political attention to urban issues. Between 2012 and 2015, a dialogue on urban issues within the United Nations (UN) General Assembly resulted in the inclusion of a dedicated Sustainable Development Goal (SDG) on cities and human settlements within the 2030 Agenda. SDG 11 committed national governments to “make cities and human settlements inclusive, safe, resilient and sustainable”2. This goal is of major significance. By including a commitment focused on cities within a nationally determined agenda, countries recognized both the importance of a place-based approach to development and the unique nature of the challenges facing urban communities of all shapes and sizes3.

Before 2015, cities and urban areas had been neglected, with their only forum for international dialogue the UN Conferences on Housing and Urban Development in 1976 and 1996 and the biennial World Urban Forum4. While these conferences helped focus collective attention on issues of urban poverty and infrastructure, they did not acknowledge the importance of cities as the drivers of economic growth and climate-resilient development5,6. The dedicated SDG gave urban practitioners, policymakers and local government representatives a formalized space in policy dialogues that acknowledged varied roles for local, national and multilateral actors in urban governance.

Beyond SDG 11, the commitment to localize the 2030 Agenda and “work closely on implementation [of the goals] with regional and local authorities” opened up opportunities for local governments to engage across the spectrum of national planning processes2. In 2016, the parallel but complementary Habitat III conference attempted to highlight further the urban imperative and while it did not succeed in gaining high-level international traction, it did provide a normative and operational framework for global urban policy7. Furthermore, in 2020, six international organizations (including the European Union, the Organisation for Economic Co-operation and Development and the World Bank) agreed upon a harmonized definition of urban settlements, following a decades-long and hotly contested debate8.

Together these agreements have helped to shape a ‘Global Urban Agenda’, which has continued to gain ground among technical audiences, exemplified by the Intergovernmental Panel on Climate Change’s commitment to issue a Special Report on Cities and Climate Change in its 7th Assessment cycle and recent discussion of urban challenges in the reports of Working Groups II and III6,9. However, the turbulence of recent world events and the need for post-pandemic reconstruction is limiting the political and fiscal space for upscaling and even maintaining global urban deliberations. This is despite the fact that the pandemic revealed opportunities for more systemic interventions to reduce future pandemic and climate change risk in cities and towns6.

A close look at the outcomes of the major global macroeconomic and political meetings of the past decade, such as the G20 or G7, show that issues of urban development have been consistently undervalued in national discussions10. Cities and many subnational governments were on the front line of the COVID-19 pandemic, but the disproportionate burden they face was not acknowledged in the outcome statement from the extraordinary G20 summit on COVID-19 (ref. 11). This is in spite of evidence suggesting that most cities are financially ill-equipped to cope with post-pandemic challenges; “lower exports, a decline in tourism revenues and remittances, and an acute contraction of economic activities are translating into a precipitous drop in tax revenues” for local authorities, making it incredibly hard to cope with increased vulnerability and service demand12.

Furthermore, urban governance challenges were ignored in the Declaration from the 75th General Assembly of the UN in 2020, which specifically discussed the necessity for a reinvigoration of multilateralism to help deal with modern social, economic and environmental crises. The 2021 report of the UN Secretary General did shine some light on the role of local governments and call for the creation of an Advisory Group on Local and Regional Governments to help Member States engage local government in recovery efforts, but this is not enough13.

Creating a new urban narrative

To prevent political backsliding and to keep the spotlight on how to govern complex urban dynamics, urban stakeholders need to organize themselves into a coherent epistemic community, with clear political messaging. New bridges need to be built, such as with long-term investors, both public and private, to avoid the risks of geopolitical fragmentation. During the period 2012–2015, the urban community demonstrated unprecedented coordination, mobilizing in support of an Urban SDG and orchestrating a related campaign (#UrbanSDG), as well as establishing a Global Taskforce: a common platform for local and regional government associations. Now, halfway through the SDG project, this community needs to regroup, reignite these platforms and call for a renewed focus on urban and place-based development, with clear ambitions for the next 5–10 years.

First, this community needs to coalesce around a new narrative of what urban sustainable development really is, building on recent literature that foregrounds complexity and systems thinking. Complexity in urban environments has a long academic tradition, with inputs from biology, computational sciences and physics, among others14,15,16,17. Complexity theory has also spawned new models and planning tools, which are increasingly being used by cities and their service operators to better understand spatial organization and governance systems18. The fact that urban planning embraces complexity head on makes it a highly practical and pertinent approach to implement a global, interdependent and complex sustainable development agenda.

Second, the new narrative needs to address emergent challenges; for instance, the necessity to foster resilient and equitable social systems rather than focusing only on economic development, better integrating the climate change, health and well-being, and biodiversity agendas, and ensuring disaster-resilient infrastructure6,19. Urban inequality also constitutes a series of pressing challenges, including the inequities exposed by the COVID-19 pandemic, such as healthcare coverage, but also socio-economic inequalities in housing and labour markets and differentiated climate vulnerabilities20. It is crucial to respond to the failure of existing urban development models that have resulted in unplanned, informal urban expansion in many cities in the Global South.

Third, this community needs to engage meaningfully with policy experts and social scientists who are immersed in the complex architecture of the international governance system and can help place key messages at the top of political agendas21. Engaging at this level is essential to garner political commitment and to help change power dynamics within countries that might otherwise be reluctant to empower local government leaders. It is clear from the limited attention to local and regional government in international dialogues that current modes of engagement (for example, via the Major Groups to the UN) are insufficient. Similarly, the vast reservoir of expertise that exists in the field of south–south cooperation too often remains untapped. Urban stakeholders need to capitalize on the techniques that proved so effective during the SDG deliberations and focus on delivering unified, concise messaging, framed in ways that resonate with political decision-makers and communicated by partners who can access the various organs of the international system.

But it is not just about smarter lobbying. We need to embrace a new and changing political geography, which, alongside global governance hubs such as New York or Geneva, or Washington DC, includes regional fora such as the UN Economic and Social Commission for Asia and the Pacific (UNESCAP), the UN Economic Commission for Latin America and the Caribbean (ECLAC), the UN Economic Commission for Africa (UNECA) or the UN Economic Commission for Europe (UNECE), major macroeconomic fora such as the G20, and regional unions, such as the African Union, the Association of Southeast Asian Nations and others22. According to the Deputy Secretary General of the UN, these regional entities must play a key role in helping countries to achieve their sustainable development objectives, acting as ‘think-tanks’ and hubs for regional partnership23. Engaging with countries in their own regional context is particularly important to address the regionalized nature of urban concerns and governance.

Cities as sites of international decision-making

The struggle to secure a global focus on cities began nearly a decade ago and culminated in a commitment to localization, place-based development and a dedicated Urban SDG. Since then, the world has been torn asunder and the focus on cities as sites of sustainable development action has eroded. Given the complexity of sustainable development, a place-based approach to development is imperative.

Urban stakeholders need to once again come together and articulate a coherent narrative that can be used to galvanize attention to cities as key international decision-making spaces. Yet, the lessons of the past decade — from financial, economic, health and environmental crises — show that urban stakeholders need to join forces at a wider scale than ever before. It is not just about looking back to the epic narrative of SDG 11. Recoupling urbanization with social progress, and within planetary boundaries, depends on our shared ability to articulate these interconnections, to galvanize attention and to create a larger political space for cities as key sites of international decision-making.