Barcelona is a vibrant city, welcoming around 12 million visitors a year (pre-Covid09 statistics from 2019) and home to 5 million (metropolitan area). Mass tourism and the city’s thriving economy stand behind rocketing property prices that are forcing residents to move out to urban fringes. Barcelona city is also dealing with increasing intensity and prolonged duration of heat waves that affect the most vulnerable – the poor in urban areas with insufficient green and blue infrastructure – as well as forest fires in the nearby Collserola natural park due to summer droughts. With the packed streets, unaffordable housing, social inequalities, pressure on urban parks, and slowly diminishing natural sites – the resilience of the socio-ecological system is disputed.
Ecosystem Services (ES) from urban green and blue infrastructure (GBI) provide cities and their citizens with benefits necessary to cope with present and future sustainability challenges.
Most urban policies fail to address the challenges described above due to their short-term and narrowed agency. The GBI objectives must be integrated in cross-boundary urban policies. But, which policy sectors are the most important? How do these policies reflect on ecosystem resilience? And what should sustainability policies look like? To this end, we need to understand the dynamics behind urban systems in terms of ecosystem provisioning capacity, the social demand of diverse beneficiaries, their shifting needs and preferences, and how institutions interfere with these processes. The system model helps us to visualise relational flows among them.
Researchers and experts from the Barcelona city departments established a transdisciplinary collaboration to develop sustainability policies. A long-term process involving policy and document analysis, a series of iterative stakeholder meetings, future scenarios and ES assessments exercises, or exploration of policy trajectories has produced valuable insights for policy-making. Stakeholders had the opportunity to explore and reflect on local and global challenges and the resilience of ES flows. The three filters – perceptions, institutions and infrastructures – provided lenses through which we viewed linkages between the identified policy clusters, ES resilience principles and finally ES supply and demand flows.
Stakeholders in Barcelona assessed particular ES for their capacity-demand mismatch (meaning, where the ES capacity is unlikely to satisfy the high demand). Mental well-being, regulation of microclimate, social cohesion, air purification, physical recreation, runoff control and soil permeability, were considered by stakeholders as ES with the widest capacity-demand mismatch. Policy exploration exercise reflected on these mismatches. Finally, urban planning, climate and greening, housing, education, mobility, tourism, and health were considered as the most critical policy sectors, while stressing the need to deliver intersectoral policies.
While the best fit for particular policies may vary from city to city, the stakeholder process showed that collaborative work leads to critical thinking in terms of socio-ecological resilience and sustainability. It allows us to recognise and assess future disturbances and changes. It helps us to understand the diversity of socio-ecological systems. And it reveals how we think about futures and what policy tools we have on hand to shape our cities and societies.