Green densification model

Phoenix is one of the hottest cities in the United States, with temperatures regularly exceeding 40°C (104°F) for more than 90 days each year. The urban heat island effect is severe here, posing a significant health risk. Many communities in Phoenix lack equal access to shade cover—often, the impact of extreme heat disproportionately affects low-income neighborhoods that lack resources for tree planting and maintenance. In contrast, wealthier areas tend to have more trees and are visibly greener, which helps reduce the heat residents experience.
To address these disparities, the City of Phoenix partnered with SRP, a not-for-profit public power utility, to launch the "Right Tree, Right Place" program in 2018. This initiative aims to bring shade relief to areas most in need, such as parks, public transit stops, and schools, while replacing older trees that interfere with SRP power lines. SRP and the city work together to identify trees that pose risks to overhead power lines, and for each tree removed, three new trees are planted—either in a different location or with a species better suited to coexist with power lines.
One of the program’s notable projects took place in West Phoenix’s Cortez Park, where 24 drought-tolerant trees from four different species were planted. This diversity helps protect the trees against pests and other natural threats, ensuring their longevity and resilience. Through initiatives like these, the "Right Tree, Right Place" program contributes to Phoenix’s larger goal of developing a robust, biodiverse urban forest. By expanding green infrastructure, the city aims to reduce local temperatures, improve air quality, and create cooler, healthier neighborhoods for all residents. (1-8)

Parque Lácides Segovia is an urban park located on Isla de Manga in Cartagena, Colombia. The park was inaugurated and revitalizated in June 2014 to serve as a multifunctional green space promoting cultural, social, and environmental activities. Named after General Lácides Segovia, a notable figure in Cartagena's history, the park aimed to provide a family-friendly and culturally enriching environment (ref 1). The primary goal was to transform a neglected urban area into a dynamic public space that fosters community interaction and enhances local culture. The park aimed to create a safe, inclusive, and accessible environment for residents of all ages, promoting social integration and cultural activities. Additionally, the project sought to establish a green area contributing to the ecological health of the city through urban greenery (ref 1, 2).
The first revitalization in 2014 involved facilities, planting native trees, and setting up public amenities such as Wi-Fi, seating, and cultural spaces(1, 2, 3).
This new revitalization in 2024, led by the local government of Cartagena, will focus on enhancing the infrastructure of both the park and the surrounding sports area in Manga to improve sustainability. The project has an estimated budget of approximately USD 675,000. The improvement works to provide better facilities and infrastructure to support recreational and sports activities, benefiting the community and promoting a healthier urban environment (ref 6). The park is essential for the community; it was recently the subject of several citizen science projects led by the Montessori School, including research identifying the park's ecosystem services (ref 3).

The intervention of the Ecological Park of La Molina is an urban-landscape design project developed between the San Martín de Porres University, through the IVUC, the Institute of Housing, Urban Planning and Construction, and the Municipality of La Molina (7). This is the first ecological park in the city of Lima, located in a characteristic ecosystem such as Las Lomas, between 600-1000 m.a.s.l. (1). It is a natural area that is part of the hill system of Villa María del Triunfo, located in the Subtropical Coastal Desert ecoregion, and is part of the Regional Conservation Area ‘Sistema de Lomas de Lima’ (7). The City Council decided to open this space in 2022 to the public, as a 200-hectare area, designed to bring people closer to nature, through outdoor activities and environmental education about its fauna, flora and microclimates (1). Thus, citizens can enjoy a recreational area with multi-purpose spaces and sports circuits; a cultural area where workshops and an open-air amphitheatre are held; an ecological interpretation area with exhibition galleries and an interpretative route; and an administrative and control area (1). The park also envisages reforestation efforts in areas that are currently arid and infertile to convert them into green areas for the enjoyment of citizens (1). In 2023, conservation efforts were reinforced for an additional 50 hectares, due to the danger posed by encroachment and land trafficking (4).

The Olive Garden ("Jardim das Oliveiras") is a green roof created in the Centro Cultural de Belém (CCB) in Lisbon, as a green space that blends natural elements with the surrounding cultural area and building. Situated by the Tagus River, the garden features a lawn, olive trees, and small lakes, offering a quiet place for people to relax and enjoy nature (Ref 1, Ref 2). It is a popular spot for families, young people, and children who use the space (Ref 1). The garden also hosts cultural events, such as concerts and DJ performances, adding to its appeal as a community gathering place (Ref 3, Ref 4).

Maskinparken is a new park covering 3700 m2 in the Lindholmen district, a new neighbourhood in a previous industrial/harbour area [Ref. 5]. The park is described as a well-needed green oasis or green lung in the developing area. The park finished construction in 2022 and is intended to provide access to green space for people living and working nearby. It is also designed as a blue-green stormwater management solution, where about 500 m3 of rainwater can be stored in the lower areas during heavy rainfall. Stormwater will be leaked from surrounding grey areas to the park to protect them from flooding. The Swedish National Board of Housing, Building and Planning (Boverket) has highlighted the park as a good example of climate adaptation in urban planning. The park has a variety of plants such as different tree species and flowering meadows, and plants that can withstand being soaked in the lower areas. Plants can grow in different landscape structures, such as hills and a pergola. The park also has amenities such as benches and lights, which are designed to mirror the style of the surrounding, older industrial brick buildings [Ref. 1-4].

The last large-scale park in Iași was opened in 1923, and since then, the city has lacked any significant new green spaces. With the European Union recommending at least 26 square meters of green space per resident and the city's increasing urban density, the need for a new park is undeniable.
To address this, the Municipality of Iași is launching its first major park project in over a century. The project aims to transform the current CTP depot (tram station) into a 4.5-hectare, accessible green space in a densely populated area with strong development potential. This new park is envisioned as a green oasis that will enhance residents' quality of life while promoting environmental sustainability and urban renewal.
The initiative has received widespread public support, with citizens proposing the creation of a local museum to honor the tram station’s historical significance—one of the oldest in the city, with over 100 years of history. A consultation process has been established, involving local residents, NGOs, and a group of experts, including urban planners, architects, and mobility and environment officials, all contributing to the planning stage. Public suggestions for the park include underground parking, recreational and exercise facilities, and a diverse range of vegetation. Ensuring accessibility for all citizens and visitors is also a key priority in the park's design.
The municipality has allocated 300,000 euros for a solutions contest to finalize the approach to redeveloping the tram station. (1, 2, 3, 4, 5, 8, 9)

The Cartagena-Barranquilla Road Corridor project, led by the National Infrastructure Agency (Agencia Nacional de Infraestructura (ANI)), covers 146.7 km to enhance connectivity between Cartagena and Barranquilla (ref 2). While primarily a transportation initiative, the project stands out for its focus on environmental conservation and community development. A major goal is the restoration of ecosystems and biodiversity protection. To this end, over 40,000 mangrove seedlings have been planted in the 34.13-hectare Ciénaga de la Virgen, a vital coastal wetland in Cartagena. These mangroves play a crucial role in restoring habitats, capturing carbon, and acting as natural flood barriers, thereby safeguarding nearby communities (ref 1,4,6). The project also tackles hazards like wildlife-vehicle collisions and habitat fragmentation. Seven wildlife crossings have been built to facilitate the safe movement of species, including the endangered Blue Crab (Cardisoma guanhumi) in the Ciénaga de Mallorquín. These crossings are essential for preserving local wildlife (ref 1,7).
In terms of socio-economic impact, the project has created over 9,000 jobs and established six bioclimatic nurseries, which provide sustainable livelihoods for communities in La Boquilla, Villa Gloria, Tierra Baja, and Puerto Rey. These nurseries support mangrove restoration and offer local people opportunities to participate in planting, monitoring, and maintenance activities. This approach fosters a circular economy, empowering community members, both men and women, to engage in sustainable economic practices (ref 1,2,6).
Overall, the Cartagena-Barranquilla Road Corridor is more than a transport project; it acts as a green corridor with a comprehensive approach that combines environmental conservation, hazard mitigation, and socio-economic development.

Rike Park, centrally located on the riverbank of the Kura River, is one of the most recently developed Parks in Tbilisi. It was announced by the city hall in 2009 with the aim to increase the amount of accessible green space in the densely developed city center and stretches over an area of 7.5 ha (Ref. 1). Being the only location in the city where such a project could have been developed, it also serves as a pedestrian-friendly way to cross from the newer part of the city towards the old town via the adjacent "Peace Bridge" (Ref. 1,3). Next to its various amenities for recreation, the park has become a symbol of national identity through its design (Ref. 2). From above, one can identify the grid abstraction of the map of Georgia while in the center of the park lies a large Rose shaped mosaic, making a symbolic reference to the Rose Revolution (Ref. 3,5). Furthermore, Rike Park hosts several cultural festivities and artistic performances that invite the public to interact and socialize (Ref. 4).
Despite the park's success, its development has been criticised due to the city hall's exclusion of public consultations and transparency (Ref. 1).

San Borja has 1,347,000 square metres of green areas, equivalent to 12 square metres of green space per inhabitant, one of the highest ratios in the capital (1, 2). In total, there are 75 parks within its jurisdiction (1, 3). However, in recent years it has consolidated its role as a metropolitan urban centre and has become denser with new multi-family construction projects replacing traditional single-family homes with gardens (2). As a result, tree cover has decreased, affecting the creation of shaded areas and air quality, putting the health of residents at risk (2). Nevertheless, this municipality has reaffirmed its participation in the Global Covenant of Mayors for Climate and Energy, committing to implement policies and take measures to reduce (or limit where appropriate) greenhouse gas emissions and prepare for the impacts of climate change, as it is vulnerable to heat waves and droughts, as well as high wind and thunderstorm hazards and fires (1). Thus, since 2014, 56,000 trees have been planted, which is one tree for every two residents in the district (2). The mitigation programme includes 40 measures, including the creation and conservation of green areas, which involve planting trees to create urban forests to help regulate temperature, prevent heat waves, improve CO2 absorption, and preserve endemic species (1). In addition, the programme promotes the use of organic farming practices and the propagation of plants using natural methods (1).
One of the sectors where there has been the most progress is Sector 12, with 31% of the green areas created (3). Within this sector, the district is planting and creating an urban forest within the premises of the Army Headquarters, better known as ‘Pentagonito’. Its objective is to educate neighbours and promote greater environmental awareness (3, 4, 5).

Phoenix is grappling with severe urban heat problems. As the city continues to grow, it is expected to experience a rise in temperatures of three to five degrees on average in the coming years. This makes urban heat a significant concern, especially for vulnerable populations. Phoenix’s extensive urban sprawl, combined with a lack of green space, has exacerbated the urban heat island effect, where cities become significantly hotter than surrounding rural areas due to the high concentration of concrete, asphalt, and infrastructure. In 2022, Nick Lodato, the principal of Emerson Elementary School, wanted to mark the school's 100th anniversary in a meaningful way. He decided that planting trees would be the perfect way to celebrate this milestone while also benefiting the community. The tree planting event not only symbolized the school's strong sense of community but also represented an investment in its sustainable future. Prior to the project, Emerson had only 9% tree canopy cover, which was far below what is necessary to address some of the pressing environmental challenges Phoenix faces.
Tree cover has become critical infrastructure for heat mitigation. Trees provide natural shade and help cool the environment by reducing surface temperatures, which in turn lowers energy consumption and promotes better public health. In addition to offering shade, the native, drought-tolerant trees and plants planted at Emerson will also contribute to carbon sequestration, purify the air, and improve mental health by creating more green spaces for relaxation and outdoor activities.
To complete this project, Emerson Elementary partnered with the Arizona Sustainability Alliance (ASA), a local nonprofit. Together, they planted over 100 trees and plants across the school’s campus, with approximately 125 people attending the event. Volunteers included students and their parents, Tau Psi Omega fraternity members, APS employees, neighbors, former Emerson students and teachers. (1-3)