The world’s leading Sustainable Cities: Built for long-term prosperity

The world has witnessed unprecedented urban growth in recent decades. In 2024, a third of the global population was represented by the 1,000 major cities considered in Oxford Economics’ Global Cities Service—a striking testament to the size and importance of these urban centres. But while urbanisation offers significant opportunities, such as economic development, innovation, and improved connectivity, it also presents challenges. These include mounting pressures on public services, increased demand for infrastructure, and in some cases, the proliferation of unplanned and/or unsafe urban expansion.

Given their scale and density, urban areas are also among the largest contributors to climate change. Cities produce up to 70% of global greenhouse gas emissions, despite covering only 2% of the Earth’s surface. This highlights their paradoxical position: they drive environmental degradation but are also among its most vulnerable victims, facing rising temperatures, air pollution, and more frequent climate-related disasters. For some, these issues are further compounded by the urban heat island effect, making cities even hotter and more hazardous.

In many parts of the world, especially in developing regions, these problems underscore the need for improved urban planning. Ensuring cities are inclusive, safe, resilient, and sustainable—economically, environmentally, and socially—is critical to achieving the Sustainable Development Goals (SDGs) and long-term prosperity.

Many cities are leading the sustainability charge, despite some national retreats

Sustainability and climate mitigation may appear to be indisputable issues requiring urgent action. However, some major national governments have recently deprioritised these matters.

Most notably, the United States—currently the world’s second-largest CO₂ emitter after China—has recently scaled back on climate and sustainability commitments. This retreat highlights a growing tension between long-term sustainability targets and short-term political or economic agendas. For some governments, the medium-term economic disruptions from addressing climate change and restructuring towards net zero are too great, despite the potentially devastating long-term implications of inaction that we have modelled as part of our City Climate Scenarios Service. As a result, there are rising concerns that the global effort required to achieve sustainable growth is losing momentum.

However, many cities remain committed to the cause. In numerous instances, local governments have bypassed national inertia to lead the charge on sustainable practices and climate resilience. As highlighted above, this leadership is driven largely by necessity, given the outsized role cities play in the global economy and their environmental footprint.

Identifying the world’s Sustainable Cities

A key question, therefore, is: which cities are currently on a sustainable path? Our latest update of the Global Cities Index—a comprehensive ranking of the 1,000 largest cities worldwide—helps shed light on this. The index evaluates city performance using five pillars: economics, human capital, quality of life, environment, and governance. But as part of our 2025 analysis, we have developed a typology of eight distinct city archetypes to identify common patterns and trajectories among major global cities. One of these archetypes is the Sustainable City.

We have assessed a range of quantifiable characteristics to evaluate this group, with Sustainable Cities distinguishing themselves across several metrics:

• Air quality—measured by a city’s mean PM2.5 concentration.
• Low emissions intensity—calculated as the total CO₂ emissions relative to a city’s GDP, reflecting the efficiency of economic output with respect to environmental impact.
• Political stability—crucial in enabling long-term planning, investment, and policy implementation.
• Industry share—a city’s economic reliance on carbon-intensive industrial sectors.

These indicators together provide a multidimensional view of what it means to be a sustainable city in today’s global context. We also cross-checked these findings using an OECD tool that measures the distance towards SDGs in cities and regions.

From Norway to Barbados: the diverse geography of the world’s Sustainable Cities

In our 2025 Global Cities Index, 63 cities stand out for sustainability performance. While mature European cities lead the way, sustainability leadership is also emerging in less expected places, with several island capitals—all facing acute climate threats—driving bold environmental initiatives.

Europe is the clear regional champion for sustainability. Countries such as France, Germany, Sweden, the Netherlands, Spain, and Italy have numerous cities that perform strongly on our sustainability metrics, spanning both major capitals and smaller urban centres. This dominance is partly driven by the mature policy environment shaped by binding EU initiatives like the European Green Deal, which sets ambitious climate targets and promotes sustainable urban development. European cities also benefit from coordinated local-level funding and strict environmental regulations, while generally having a lower economic reliance on carbon-intensive sectors.

Many European cities have also become leaders in establishing green transport and infrastructure networks. Cities such as Copenhagen and Zurich are globally renowned for their public transit systems, cycling networks, and pedestrian-friendly urban design—key in helping to reduce emissions and improve the quality of life for residents.

Nordic economies, such as Helsinki, Oslo, and Reykjavik, are well represented among our Sustainable Cities. This stems from their healthy renewable energy mix, political stability, and strong social welfare systems, alongside investments in energy-efficient buildings and green spaces to counteract the cold climate and increasing weather-related risks.

Interestingly, several remote island cities also feature on our list, despite not being traditional global city powerhouses—highlighting how assessing sustainability can reveal a distinctive and diverse mix of urban centres. Male (Maldives), Nassau (Bahamas), and Bridgetown (Barbados) have all emerged as examples of Sustainable Cities. These island cities face unique environmental vulnerabilities, such as rising sea levels, extreme weather events, and limited natural resources, which have prompted them to adopt aggressive climate adaptation and mitigation strategies. Their efforts include significant investments in renewable energy, water conservation technologies, and disaster preparedness. At the same time, these cities have attempted to balance environmental protection with tourism-driven economies, promoting eco-tourism as a way to preserve their natural beauty and support local commerce.

Australia and New Zealand also have cities meeting our sustainability thresholds, such as Canberra, Melbourne, Sydney, Auckland, and Wellington. Local governments in these cities have adopted progressive sustainability policies that have gone beyond the national directives. For example, the city of Sydney aims to achieve net zero by 2035, while the national government targets 2050.

North American cities are underrepresented when it comes to sustainability

Across mainland North America, it is only Vancouver (Canada) that earns a spot on our list of Sustainable Cities, reflecting its extensive Green Building Strategy and investment in renewable energy. Cities from the United States are noticeably absent, which is linked to significant challenges driven by political instability and fragmented climate policies at the federal level. This lack of cohesive national leadership is hampering progress on sustainability initiatives across many US cities, despite some encouraging recent signs at the state level.

It is also promising that cities like Montevideo (Uruguay) and San José (Costa Rica) are emerging as leaders in urban sustainability within Latin and South America, proving that even amid economic pressures, determined efforts toward sustainable development can be made.

The road ahead

Overall, as global urbanisation accelerates, cities are emerging not just as centres of population and commerce—but as critical arenas for sustainability leadership. While the 2025 Global Cities Index clearly shows that Europe is a stronghold for sustainability and climate, it is promising that new leaders are emerging around the world. And despite some national-level backsliding, particularly in the US, many cities are pushing ahead and proving that the future of sustainable development is being shaped at the local level.