The Case of Lisbon
The functional urban area (FUA) of the Case Study in Detroit
Lisbon is Portugal's most populous and dynamic urban center. The city sits at the core of the Lisbon Functional Urban Area (FUA), characterized by a dense urban fabric of high historical value and most of the region’s financial activity, administrative institutions and tourism. Lisbon’s central area is densely built and has few green areas, making it more susceptible to the effects of extreme heat. The wider FUA extends beyond the administrative boundaries of the city of Lisbon and comprises part of the complex network of urban, peri-urban, rural, riverside and coastal areas of the Lisbon Metropolitan Area. The Lisbon Metropolitan Area is made up of 18 municipalities and a population of around 2.8 million inhabitants, representing around 28% of Portugal's population. Today, the FUA faces interconnected sustainability challenges related to urban sprawl and land occupation, which continues to put pressure on natural and agricultural spaces. According to the Lisbon Metropolitan Area Adaptation Plan, the region is currently facing a combination of extreme heat events, flash floods, coastal overflows and increased frequency of droughts, and the most vulnerable areas are those along the Tagus estuary, the inland valleys and densely populated urban centers. For 2030 and beyond, the region expects to see an increase in the frequency and intensity of heat waves, rising sea levels, prolonged droughts and intensified urban and coastal flooding.
Environmental and urban issues in the Lisbon FUA have long been linked. Since the 1980s, the suburbs, or peri-urban areas, have experienced intense urban pressure and sprawl. Various types of nature-based solutions (NBS) have developed in response to these challenges in the Lisbon FUA, bringing multiple social and environmental benefits. These NBS range from municipal-led and community-led initiatives, to interventions covering parks along watercourses, green corridors on a municipal and inter-municipal scale, dune restoration, among others. While the FUA faces significant economic and environmental pressures, the area nevertheless continues to promote the active involvement of different groups and individuals, and actors in the public, private and community sectors have shown a commit to building a fairer urban future for Lisbon with strong connections to nature.
I personally really like the idea of thinking or dreaming or imagining possible futures. And if we didn't believe that yes, something different is possible, a different development model, we would have gotten into this because social activism, and now also political activism, requires such intense and voluntary work, without any remuneration, that if we weren't firmly convinced that yes, it is possible, we wouldn't be carrying out this work.
Three examples of nature-based solutions in Lisbon
URBEM Fast Forest – Parque Casal Vistoso
URBEM is a volunteer environmental NGO based in Lisbon and was launched in 2021 with a project on a hillside located in Vale da Montanha Park (Lisbon), a 300m² area provided by Lisbon City Council. Inspired by the Miyawaki Method, and with some key participants related to other projects like FCULresta, the NGO works closely with communities, municipalities and research institutions around Lisbon. The Forest has multiple functions, including volunteer planting and maintenance activities, and also provides a space for community activities, including yoga sessions, dance and music performances and school events. The NGO's mission is to contribute to mitigating the effects of climate change in increasing urbanized areas by reconnecting people to forests, land and each other. The NGO looks to mobilize volunteer efforts to plant mini-forests on empty urban lots, using native species, increasing urban biodiversity and community involvement. Today, the organization brings together various stakeholders, including companies, municipalities and civil society, to develop mini-forests of native species in vacant urban areas. Civil society and volunteers form the backbone of Urbem's operations, with the active participation of individuals from different countries, both from the Global South and the Global North. The NBS provides participants an opportunity to connect with nature and immerse themselves in climate action, along with the well-being benefits that come from learning and being part of a community. In addition, the diverse backgrounds of the volunteers also contribute to a broader exchange of ideas, bringing different environmental practices and cultural understandings of urban nature into the collective vision of the mini-forest.
Figure 1: Urbem Fast Forest. Photo source: Andresa Lêdo Marques
Figure 2: ReDuna Project. Photo source: Andresa Lêdo Marques
Figure 3: Alcântara Valley Structuring Green Corridor. Photo source: Andresa Lêdo Marques
ReDuna - Restoration of São João da Caparica Sand Dunes
The ReDuna Project is an NBS located in Almada, Portugal. The project is aimed at restoring and protecting the coastal dune ecosystem of São João da Caparica in response to the damage done by Storm Christina in 2014. The storm caused extensive coastal erosion and harm to the ecosystem, underlining the vulnerability of the coastline. The project utilized sand fences, native plant restoration and sediment retention techniques to rebuild the dunes, using seeds collected from local sources to maintain genetic integrity. More than 100,000 native plants were planted along 1.1 kilometers of coastline, ensuring resilience against future climate threats. These nature-based measure were used instead of traditional engineering solutions, such as artificial sand nourishment and gray infrastructure, which proved too expensive and largely unsustainable. In addition, the NBS is a community-oriented environmental management model. It has actively involved local residents, volunteers, schools and researchers in monitoring the dunes, engaging more than 1,000 volunteers in maintenance and ecological studies. The project's success has influenced the Portuguese Environment Agency (APA), which subsequently recognized dune restoration as a viable strategy for coastal protection. This shift aligned municipal strategies with both regional and EU policies, reinforcing the understanding of nature’s multifunctionality as an adaptive system capable of self-regeneration.
Alcântara Valley Structuring Green Corridor
Lisbon's Green Corridors Network is a central element of the city's urban and environmental planning, aimed at integrating ecological connectivity, climate resilience and urban well-being. The network is made up of nine green corridors that seek to reconcile urban growth with ecological restoration, promoting sustainable mobility and the preservation of natural and cultural heritage. Among them, the Alcântara Valley Structuring Corridor is a response to the historical inequalities in the organization of Lisbon's urban territory. It stands out for its strategic role in connecting two of Lisbon's main natural landmarks - the Monsanto Forest Park and the Tagus Estuary- as well as an important cultural symbol, the Águas Livres Aqueduct. The NBS project pays special attention to the issue of water, seeking to reintroduce this element into the territory while tackling wider challenges related to urban fragmentation, ecological connectivity and cultural preservation. The proposed interventions, especially on the Avenida de Ceuta stretch, illustrate the tensions between ecological restoration and urban infrastructure, making this corridor an emblematic example of the intersections between urbanization, sustainability and heritage conservation in Lisbon.