Unequal availability and access to public green spaces

Lima is the capital of the region with the lowest coverage of green spaces. According to the World Health Organisation (WHO), a city should have at least 9m2 of green space per inhabitant. Lima is just over 3m2 square metres, which means a deficit of almost 60 million square metres. In this context, actions from the public and private sectors are essential to add this type of space to the city. In response to this need, Grupo Centenario carried out a green project on one of its plots of land in San Isidro, where real estate projects will be developed (1, 2, 3, 4).
A square was built with a green area with wild and low-consumption species, knocking down the walls that surrounded the land for years, turning it into a place for everyone to see and use (1, 2, 3, 4). The Choquehuanca Square was built to contribute to the community and make it a better place to live. It is located on a plot of land that was previously enclosed by walls, converting it into an area of 3,945 m2 with a green space that occupies 70% of the square (1, 2, 3). This is a temporary project, as the green space was opened while projects are being developed on this land (1, 2, 3).

Biotope City Wienerberg is located in the southern part of Vienna on a 5.4-hectare site that once housed a Coca-Cola factory. It lies at the edge of the Wienerberg recreational area, surrounded by business parks and tower blocks to the west and predominantly detached houses to the east (Ref. 1).
The project embodies the concept of an "urban biotope" (Ref. 2), grounded in the principle that nature's mechanisms of self-regeneration are essential for mitigating the challenges of urban living and climate change. By integrating urban and natural spaces, Biotope City fosters both human-nature connections and social interactions through activities like community gardening. The project’s centerpiece is its extensive green infrastructure, including trees and green roofs, which serve to cool the microclimate, purify the air, enhance water retention, and create carbon sinks while providing habitats for local wildlife. These green spaces aim to improve physical health through cooling effects on hot days and support mental well-being with their calming influence (Ref. 1; Ref. 2).
Biotope City encompasses:
Around 980 flats, including 400 subsidized flats and 200 SMART flats
A school, a kindergarten, and 2,000 square meters of children's and youth playgrounds
600 square meters of community gardens and 3,850 square meters of ground-floor gardens
250 trees, 8,900 square meters of meadows, and 13,600 square meters of green roofs
2,200 square meters of façade greening
The inner courtyards and roof areas are designed for gardening, while façades are greened, and balconies are equipped with integrated plant troughs. Even the spaces between buildings are climate-effective, featuring unsealed catchment and seepage areas to manage water sustainably (Ref. 1).
The project’s implementation took 18 years and involved collaboration among various stakeholders. The concept was initiated by the Biotope City Foundation and funded by eight different investors (Ref. 2).

The project La Ruée Verte aims to create a green corridor connecting two emblematic locations for social and environmental justice: La Base Marseille and L’Après M. The route spans over 7 km and passes through La Friche de La Belle de Mai and aims to bring more nature into the city on a larger scale in a fair and equitable way (Ref 2).
Given the challenges of climate change—rising temperatures, urban heat islands, fewer trees in Marseille, and increasing urbanization—the green corridor will offer a solution to combat the suffocating effects of the city’s concrete sprawl (Ref 2). Additionally, it aims to reduce pollution peaks and improve air quality (Ref 2), increase biodiversity (Ref 2), and provide access to green spaces and places for social interaction (Ref 2).
The project also addresses the broader social crisis, with rising costs of food, housing, and transportation (Ref 2). Local solidarity is key, ensuring that all green initiatives foster community interaction and consider the urgent needs of residents, such as precarious living conditions and isolation (Ref 2). Collective participation is central to the project, ensuring that it is designed by and for residents of different neighborhoods, reflecting their realities. The project, called “La Ruée Verte,” aims to unite various citizen groups, social centers, and associations to amplify their voices (Ref 2).
The project's first phase, “La Petite Ruée,” will launch in October 2024, following a year of preparation. It will start with neighbourhood micro-projects and shared advocacy, including events and gatherings (Ref 2). The goal is to collectively think about social and climate justice and begin taking concrete actions towards popular ecology in each neighbourhood (Ref 2).

Minimizing heat stress is a top priority for Phoenix, the hottest major city in the U.S. In 2023, extreme heat contributed to at least 359 deaths across Maricopa County. Phoenix is particularly vulnerable to climate change, with extensive concrete and asphalt, increased pollution, higher population densities, and concentrated infrastructure that exacerbate the urban heat island effect, drought, and extreme weather. Moreover, the heat disproportionately impacts lower-income and Hispanic neighborhoods, which tend to have less tree canopy and fewer resources to cope with rising temperatures.
To address these challenges and promote tree equity in underserved neighborhoods, the City of Phoenix, along with the Office of Heat Response and Mitigation, launched the Community Canopy Grant Program in 2023. The concept of tree equity refers to identifying areas with low tree coverage and high social need, then prioritizing investments in these areas. By improving tree equity, the program aims to assist neighborhood associations and community members in areas that need it most.
The Community Canopy Grant Program targets neighborhoods within Qualifying Census Tracts across Phoenix, and one of the first neighborhoods to benefit was Westwood. In early 2024, community members gathered to plant 200 box trees for residents who received grants, marking the largest City-sponsored neighborhood tree planting event of the season. These tree plantings aim to provide much-needed shade for homes while fostering community engagement, helping to mitigate heat stress and build stronger, more resilient neighborhoods. (1-5)

The 28th of October Street (28ης Οκτωβρίου) was one of the most neglected streets on the eastern side of Thessaloniki, completely devoid of trees despite its central importance. Additionally, the street suffered from severe flooding during heavy rainfall. In 2011, the Municipality of Thessaloniki, in collaboration with Konstantinos Zervas, the Deputy Mayor for the Environment, Quality of Life, and Free Space, proposed a redevelopment project aimed at transforming the street through the planting of trees and the installation of flower beds that would function as rain gardens (Refs 3, 5). This initiative was part of the "Integrated Green Cities" action, which falls under the European territorial cooperation program Greece-Bulgaria 2007-2013 (Refs 1, 2, 3, 6).

To achieve the dual goals of sustainable rainwater management and urban beautification, decorative trees were planted in specially constructed bioretention tree stands. These stands, along with the flower beds, were designed to collect rainwater, which would then be used to irrigate the trees along the road and the plants forming the rain gardens. Rainwater was gathered from the road surface, pavements, and the gutters of apartment buildings through these bioretention systems (Refs 1, 2). This sustainable water management solution significantly reduced rainwater runoff, improved water quality, and enhanced the area’s aesthetic appeal (Refs 2, 6, 7).

The project aims to restore green spaces in the neighbourhoods of San Francisco and 7 de Agosto. Led by Aguas de Cartagena, in partnership with other organizations, the initiative focused on environmental recovery, social integration, and reducing inequality through the revitalization of community spaces. Activities included planting native species, maintaining community infrastructure, and promoting environmental education, contributing to climate change mitigation and fostering a healthier, more sustainable environment​ (ref 4). As part of a collaborative effort between Aguas de Cartagena and SACSA, a synthetic grass sports field named El Wio was constructed with an investment of around 60 million pesos. The project aimed to foster community integration and provide safe spaces for sports and recreation, and it also included improving drainage systems, installing solar-powered lighting, and creating green spaces around the field (ref 5). Additionally, the Biblioparque, a community library and park in San Francisco, was rehabilitated to restore the library infrastructure, including terraces, reading rooms, and green spaces. The initiative provides a vital cultural and educational space for the community, especially for children, youth, and the elderly, fostering a culture of reading and community engagement. It also addresses previous safety concerns after a fire incident and aims to promote arts and cultural activities​( ref 3). In parallel, a long-term initiative, in collaboration with the local government, provided educational tools and resources to over 1,000 children and youth in San Francisco (ref 2).

This mega-project is part of the Agenda for the Commemoration of the Bicentenary of the Independence of Peru (3). It is the new ecological lung of Ventanilla where families have free access to a meeting point where they can carry out sports, recreational, leisure and cultural activities (1, 2, 3). This park is the largest emblematic work carried out in Callao and one of the largest in extension at the national level, built in commemoration of the 200 years of independence (1, 2, 3). It was built on vacant land, where there was no possibility of meeting or recreation for the neighbours (1).
In addition to offering recreational spaces, it is a cultural work that seeks to teach the population about the history of independence, making the public space a commitment to a citizen-centred public policy with an intercultural approach (3). In addition, its financing was part of the second phase of the economic reactivation plan for public investment, encouraging local economic development and generating more than 1,300 direct and indirect jobs (3). This work is an investment of the Executive together with the Regional Government of Callao and the labour force of the municipality of Ventanilla (1, 2). Its facilities are freely accessible and will contribute to the social development and well-being of the citizens (3).
Inaugurated in 2022, it has cultural components, such as squares and amphitheatres, playgrounds, campsites and more than 30,000 m2 of green and blue areas (1).

Masthuggsparken is a planned park in the Masthuggskajen district, which is undergoing development and construction. The park will measure about 2000 m2, and serve as a green oasis and meeting place for locals. It will have ameneties such as benches and areas for play, and a noise barrier against a large nearby road. The park will connect to the adjacent square and street, making it accessible to visit. The street will be renovated to have more trees and plants, increasing green connectivity in the district. The park will be surrounded by trees and other plants, which are planted to promote biodiversity and be adapted to a changing climate [Ref. 1-5, 7]. The park is at a low point, where up to 800 m3 of stormwater will flow during heavy rainfall, reducing flood risk in the surroundings [Ref. 1, 2, 6]. The Masthuggskajen district has a sustainability program, establishing goals for green environments which the park will contribute to. Green areas should be accessible to the entire district and provide ecosystem services such as rainwater management, climate adaptation, biodiversity and recreation. The program was created by the City of Gothenburg in collaboration with construction companies active in the area and was supported by Citylab Action, a national competence program in sustainable urban development [Ref. 7]. The City of Gothenburg is the primary responsible for the park, which will be constructed between 2025 and 2026 [Ref. 1, 2, 4].

The Hellenic Park by Farka Lake stands as a symbol of the growing relationship between Albania and Greece (Ref. 1,2,3). The project was designed and implemented by the Municipality of Tirana in partnership with the Greek Embassy and supported by Greek companies operating in Albania. Its inaugurated was attended by the mayors of both capitals and the Greek Ambassador to Albania (Ref. 3,4). The opening ceremony marked three significant milestones: the 200th anniversary of the Greek Revolution, the 50th anniversary of the restoration of diplomatic relations between Greece and Albania, and the 40th anniversary of Greece's membership in the European Union (Ref. 4). The park reflects bilateral unity through emblematic vegetation, such as olive trees, which hold cultural significance in both countries. Beyond enhancing diplomatic ties, Hellenic Park fosters inclusive sports and cultural activities and provides a space for recreation (Ref. 1,3,4).

The project to revitalize the Huveaune River and its biodiversity is taking place in Aubagne, a city within the Marseille Metropolitan area. For a long time, the river received little attention, constrained by urbanization, and was even covered for several hundred meters. Urbanization and the construction of a road have made the floodplain more susceptible to flooding (Ref 2). The initiative aims not only to restore the Huveaune and its environment but also to strengthen the connection between residents and the river (Ref 1) while reducing flood risk as a critical objective (Ref 1).
The challenge is transforming the area into a higher-quality environmental space with resilient ecosystems. A diagnostic conducted during the project's design phase revealed the site's degraded state, including the presence of invasive species, steep banks unsuitable for riparian vegetation, poor waterway conservation, and disrupted ecological continuity (Ref 2).
Key actions include revitalizing the river and its biodiversity, removing artificial banks, and creating new meanders to give the river a more natural shape. Diversifying flow patterns will create habitats for aquatic and fish species by varying water heights and flow speeds. This involves increasing the river's sinuosity and varying the width of the minor riverbed (Ref 2). Additional steps include planting trees and shrubs adapted to the Mediterranean climate with low water needs (Ref 2). To bring residents closer to the river, plans include creating walking and cycling routes, sports equipment, educational panels, and useful visitor facilities such as benches, water points, and restrooms (Ref 3).