As cities continue to grow in population and complexity, the question of whether urban development can proceed without further harming the planet has become increasingly urgent. A new study by the Institute of Environmental Science and Technology at the Universitat Autònoma de Barcelona (ICTA-UAB) explores this very dilemma. While it stops short of offering a universal answer—recognising that outcomes are highly contingent upon each city’s physical and socio-economic context—it firmly challenges the notion that all growth is inherently optimistic. Instead, the research calls for a fundamental reevaluation of urban development models, emphasising the need for integrated planning, thoughtful governance, and a willingness to challenge prevailing assumptions about growth and progress.
Cities are often portrayed as both culprits and saviours in the climate crisis. On one hand, they account for a significant share of global emissions and environmental degradation. On the other hand, they are hubs of innovation, density, and infrastructure that could mitigate these harms. However, the study notes that continued economic, demographic, and spatial expansion in urban areas is currently driving severe ecological consequences. These range from increased greenhouse gas emissions and resource depletion to loss of biodiversity and soil sealing. While approaches such as green growth, degrowth, and post-growth have gained prominence in policy circles, a striking lack of empirical evidence remains to support their practical effectiveness in urban contexts.
Published in Nature Cities, the study provides the first significant synthesis of how economic models intersect with environmental realities in the urban sphere. Drawing on fields as diverse as urban economics, sustainability science, environmental governance, and spatial planning, the researchers analyse three prominent paradigms. Green growth emphasises technological innovation and efficiency to reduce environmental impact without sacrificing economic output—degrowth advocates for deliberate reductions in production and consumption to protect ecosystems. Post-growth, meanwhile, rejects GDP as the dominant metric of success and calls instead for an emphasis on well-being and environmental limits. These frameworks are not merely theoretical; they offer diverging visions for the future of urban development.
The research evaluates these models across four dimensions of urban growth—economic, demographic, spatial, and environmental—highlighting how each approach impacts the city’s form and function. Lead author Charlotte Liotta notes that the study’s core contribution is a comparative framework for understanding how these dimensions interact. This model enables researchers and policymakers to evaluate the practical implications of various growth strategies. Real-world examples illustrate this, including Barcelona’s superblocks—which restrict car traffic to enhance liveability—and Amsterdam’s adoption of the doughnut model, which prioritises social and ecological boundaries over traditional economic goals.
Crucially, the study does not endorse any one model as a panacea. It takes a balanced view, pointing out the limitations of each approach. For instance, the evidence that green growth can truly decouple economic activity from environmental degradation is still scarce, raising doubts about its long-term feasibility. At the same time, the idea that cities should shrink—as some degrowth advocates propose—is challenged by the observation that high-density urban areas, if well-planned, can be more sustainable than sprawling ones. Urban density supports efficient public transport, lower per capita energy use, and more compact infrastructure, all of which can reduce environmental pressure if governance and design are effective.
In conclusion, the study urges a departure from simplistic narratives about growth—whether pro or anti—and instead calls for a more flexible, context-sensitive approach. Urban sustainability cannot be achieved solely through ideology; it requires a solid foundation in evidence and a willingness to adapt strategies to meet specific local needs. Growth is not inherently good or bad—it is a tool that must be wielded with care, precision, and foresight. The researchers emphasise that there is no single formula for balancing development and environmental stewardship. Still, by offering an analytical framework and real-world insights, they make a meaningful contribution to one of the most pressing debates of our time.
More information: Charlotte Liotta et al, The debate on growth versus environment at the urban scale, Nature Cities. DOI: 10.1038/s44284-025-00269-z
Journal information: Nature Cities Provided by Universitat Autonoma de Barcelona