Barcelona Metropolis

On a steadily warming planet, it is essential to plan cities and territories to reduce risk and prepare for inevitable impacts. Urban planning must adopt mitigation, prevention, adaptation and resilience strategies in a multiscalar, systemic and integrated manner. Furthermore, decision-making must incorporate a long-term vision to ensure the efficiency of investments.

Since the Industrial Revolution, human activity has had a profound impact on the planet, affecting biodiversity, ecosystems and the climate on a global scale. The unchecked transformation and exploitation of land have disrupted the entire environmental system, triggering a crisis in many of the processes that regulate resilience and sustain the planet’s habitability.[1]

Climate change is expected to bring about multiple consequences that, although varying in position and intensity, will have both direct and indirect effects on urban settlements. The city, historically a place of refuge, is now becoming a place of risk. The population density in urban areas,[2] the fact that more than half of humanity resides in coastal zones, and the impacts of global warming, particularly significant in cities due to their emissions and characteristics such as the heat island effect and runoff—,[3] compel us to reconsider how we plan and renew our urban environments. In Catalonia, the quantified and projected effects of climate change on territories and cities are clear, and they leave no doubt that the time to act has come.[4]

Planning with risks in mind

Since the 20th century, urban planning has shaped the growth, redevelopment and evolution of cities in a collective, interdisciplinary and global manner. Initially, the focus was on health, later shifting to growth. Today’s systemic crisis demands a new perspective, and our generation has the responsibility to lead this change. Urban planning, with its tangible impact on health and quality of life in largely consolidated cities, must be grounded in reality, not just ideology. Incorporating new strategies and actions will be key to achieving this. But within a holistic vision of the city, where multiple factors come into play, what strategies and actions can help steer and adapt urban planning in the context of climate change? How can we limit its effects and strengthen the resilience of cities and territories to withstand its impacts?

The scale and severity of climate-related disasters will depend largely on how well we understand the risks, their consequences and the possible ways to respond. The Intergovernmental Panel on Climate Change (IPCC) identifies three key factors that, combined, determine overall risk: hazard (extreme weather events that may have negative impacts), vulnerability (the degree to which a community is susceptible to harm) and exposure (the extent to which a location is at risk from adverse weather events).

On a planet that will continue to warm, it is essential to plan cities and territories in a way that reduces risks, prepares us for inevitable impacts and minimises vulnerability to change. This can be achieved by planning measures based on four key strategies: mitigation, to reduce greenhouse gas and CO₂ emissions; prevention, to limit exposure to direct hazards and minimise disruptions to existing resources; adaptation, to protect and adjust systems, reducing exposure and damage; and finally, resilience, which enables us to accept change and plan to withstand, absorb and swiftly recover from disruptions.

Urban planning that responds to climate change must incorporate all these strategies in a multiscalar, systemic and integrated way, ensuring that decision-making takes a long-term perspective – looking ahead to 2100 – while guaranteeing the effectiveness of investments.

Multiple actions, one plan

In the face of global warming – its effects similar yet distinct – the (urban development) Plan, conceived as a tool for identifying, guiding and fostering opportunities for positive transformation within the city’s overall strategy, must incorporate both direct and complementary lines of action to ensure variability and built-in safeguards within the planned framework. Within the previously outlined strategies, it is essential to introduce both strategic and binding criteria and instruments to guide and regulate urban expansion and renewal. These must also provide new conceptual foundations for redevelopment, infrastructure renewal and construction, all of which are key to driving transformation. The following key lines of action are proposed:

Balanced territorial planning and management. Taking a territorial approach to addressing urban challenges is essential. Aligning social, economic and environmental demands with territorial dynamics is paramount. Public policies must ensure balanced development models through territorial and metropolitan-scale planning tools – such as territorial master plans, Catalonia’s urban planning directives or Singapore’s Concept Plan 2030. It is essential to consolidate polycentric, nodal systems and improve the distribution of economic activity and employment to ensure the efficiency of urban structures, enhance quality of life through proximity-based environments, facilitate public transport access and reduce reliance on private vehicles and CO₂ emissions.

Mobility planning. Redesigning the mobility model so that spaces traditionally reserved for private vehicles are repurposed as assets for environmental improvement, enhanced liveability and the recovery of public space is also a strategy for reducing CO₂ emissions. This can be complemented by traffic restrictions based on tolls or emissions criteria, as already implemented in many cities. Reshaping mobility requires first reinforcing metropolitan and regional intermodal networks and their surrounding infrastructure. This includes measures such as the Pla Director Urbanístic (PDU) [Territorial Master Plan] for park-and-ride facilities within the integrated system of the Autoritat del Transport Metropolità (ATM) [Metropolitan Transport Authority], as well as initiatives outlined in urban plans like the Pla d’Ordenació Urbanística Municipal (POUM) [Municipal Urban Development Plan] of Vic. At the same time, strategies must be put in place to strengthen urban cycling networks, with initiatives such as Copenhagen’s Bicycle Strategy or the so-called metropolitan avenues of the Pla Director Urbanístic Metropolità (PDUM) [Metropolitan Urban Master Plan], currently in progress. Parking regulations must also be revised or made more flexible, incorporating allocated parking spaces in buildings for other forms of mobility, such as bicycles.

Planning for energy efficiency and transition. The role of renewable energy and reducing energy consumption is, in turn, fundamental. Regulations must be adjusted or introduced to facilitate the deployment of renewable energy sources, thermal energy recovery, energy retrofitting and efficiency improvements in the built environment. However, new developments – both buildings and public spaces – must comply with zero-emission standards through applicable regulations, with the possibility of imposing binding restrictions on public buildings. Moreover, urban land use and zoning must be adapted to accommodate the infrastructure needs of emerging energy sources. This includes initiatives such as Barcelona’s Special Plan for the Installation of Charging Stations for Motor Vehicles (electric vehicle charging points) and special regulatory plans for photovoltaic plants, which are already being rolled out in various parts of the region.

Planning for direct risk. Avoiding exposure to hazardous events and preparing for their impacts is essential. Through zonal regulations (in addition to sectoral ones), new developments can be prevented in areas at risk of flooding and landslides, while existing activities in these zones can be regulated. Similarly, better land management can help reduce wildfire risks, particularly in urban-forest environments and between infrastructure and forested areas. Regulations must also be introduced to protect environments that provide ecosystem services[5] and safeguard water resources, as outlined in the PDUM.

Redefining the relationship with the coast. Urban planning must address the challenges facing coastal areas by assessing and managing the need for retreat, adaptation or protection. This includes regulating the design of public coastal spaces through strategies that enhance resilience and tolerance, reinforcing their ability to withstand flooding and coastal retreat. At the same time, measures must ensure the restoration of these spaces’ natural functions.

Planning public spaces, green areas and public facilities as catalysts for change. In urban areas, restoring geographical memory and reconfiguring public spaces offer significant opportunities in the context of climate change. These efforts focus on three key areas of action:

Reurbanisation. Establishing regulations and guidelines for reurbanisation that incorporate cool materials for paving and building surfaces (those with high reflectivity, lower heat capacity and controlled emissivity and albedo), as well as greater permeability, will help reduce heat retention. Manuals such as Ghent’s Comprehensive Plan for a Climate-Resilient Public Space or regulations set out in the PDUM, which mandate minimum soil permeability in public spaces, are essential. In addition, planning and creating shaded areas – whether through trees or artificial structures – along with evaporative cooling measures and the integration of water features will help lower temperatures and improve thermal comfort in public spaces, where it will also be necessary to focus on optimising the life cycle of the materials used and required. Currently, 72% of Barcelona’s ground is impermeable.

Urban greening and naturalisation. Planning an interconnected urban vegetation network is also key to mitigating heat through evapotranspiration, while simultaneously capturing CO₂, improving drainage and facilitating airflow to cool the city. Such networks also serve as infiltration and evaporation surfaces, helping to maintain hydrological balance and fostering naturalisation. Initiatives like Barcelona’s Green and Biodiversity Plan, its Superblocks project in the Eixample with green streets and squares and tree-planting programmes help strengthen these structures. Likewise, the planning of green and blue infrastructure – integrating vegetated open spaces and water systems – helps connect the urban fabric with the wider territorial green network. This approach, as seen in Stuttgart, not only improves access to cooler spaces but also supports the establishment of ventilation corridors linked to nearby large natural areas. A systemic approach to planning is necessary to strengthen green infrastructure while also adapting urban regulations with updated criteria for the design and implementation of public spaces, including mandatory minimum vegetation coverage and specific guidelines for plant selection. Given current resources, these changes will require embracing a new, wilder urban green landscape with different maintenance needs, as proposed in Girona’s La Vora project.

Reutilisation. Another key policy is repurposing certain public facilities or spaces to create a network of naturalised, protective spaces for periods of heightened vulnerability. This approach is reflected in climate shelter programmes and initiatives such as Oasis in Paris or Barcelona’s school greening projects.

Planning for bioclimatic improvements in the built environment. Regulations must ensure adequate conditions for sunlight exposure, natural ventilation and both surface and subsurface land use while allowing flexibility in building volumes to improve the bioclimatic performance of existing urban areas. They should also facilitate enhancements in energy efficiency and climate control in buildings, encouraging construction solutions such as green roofs and façades that contribute to thermal comfort and reduce energy demand. At the same time, it is essential to promote energy self-sufficiency, water and material reuse, and regulatory frameworks that ensure new developments and the regeneration of both public and private spaces integrate environmental improvement criteria. These efforts should support the ecological restoration and improvement of urban areas through tools such as the Índex de Devolució Ecològica de l’Espai Urbà (IDEEU) [Ecological Return Index for Urban Space], introduced in the Modificació del Pla General Metropolità (MPGM) [Amendment to the Metropolitan General Plan] for Gràcia.