A. All stakeholders benefit fairly from the project

In Phoenix, many residents live in dead zones with little or no access to fresh food. These zones are called 'food deserts,' which represent a low-income area with low access to a grocery store (3). Out of the 43 food deserts identified by the city, 18 are fully or partly in south Phoenix (2-3). In 2017, Two researchers from Arizona State University’s School of Sustainability and Leuphana University Lüneburg in Germany began exploring the idea of creating a sustainable food forest cooperative in Phoenix to provide fresh, healthy food, supporting local entrepreneurs, and promote environmental sustainability (1). The project's development team spent months immersing themselves in the world of food forests, by exploring different types of community gardens, discussing preferred characteristics, anticipating local challenges, and identifying potential collaborators (1). As a result, The Food Forest Cooperative was established and planted roots in a 0.5 acre (0.20 ha) plot within the Spaces of Opportunity Community Garden in 2022 (1). This food forest engages the local community by offering educational opportunities around the value of culturally relevant, whole fruits and vegetables, medicine making, and learning about the many uses of edible/medicinal plants (4). The Food Forest Cooperative as a multi-generational project that members preserve for their children, and their children’s children (2). The intention behind the project is to address food insecurity in south Phoenix and empowering the community to take ownership of it and reconnect with their ancestors through the land and food (2). Through the Cooperative, members can contribute different skills, from administrative work to manual labor to community education and traditional medicine (2). It was created to empower community members and challenge the patterns of our food system through the blending of environmental, social and economic goals (4).

The regreening project is located in Seestadt Aspern, a newly developed urban area in Vienna's Donaustadt district. Two years after the completion of buildings, streets, and squares, the ground was reopened in 2022 to address the challenges posed by urban heat islands. Pavement was removed, and trees and shrubs were planted to provide shade, create insect habitats, and open seepage areas for rainwater. Additional features like benches, a water station, and water jets were installed to enhance the area's livability. These measures improve the overall quality of life, offering residents green spaces to relax and opportunities to cool down through water play.
The project spans three connecting squares in Seestadt: Wangari Maathai Square, Simone de Beauvoir Square, and Eva Maria Mazzucco Square. In 2022, Wangari-Maathai-Platz and Simone-de-Beauvoir-Platz underwent intensive regreening. By 2023, Eva-Maria-Mazzucco-Platz in the Seeparkquartier was similarly transformed with additional greenery and cooling features. Under the slogan "Out of the Asphalt," one of Europe's largest and most innovative urban development projects took a significant step toward improving quality of life.
In 2023, over 1,100 square meters of asphalt were removed and greened. This effort included the creation of 12 new green beds planted with grasses, perennials, and shrubs. The design also introduced two square-like recreation areas with existing seating elements surrounded by green beds, providing shaded, pleasant spaces for relaxation.
The Eva-Maria-Mazzucco square was designed by a local NGO specializing in citizen engagement in urban development, while the project's overall initiation and implementation were led by the City of Vienna, the Donaustadt district, and Wien 3420 Aspern Development AG. This collaborative effort demonstrates how regreening initiatives can mitigate heat islands, foster urban biodiversity, and create more attractive, livable spaces. (Ref. 1-3)

The initiative involved the creation of three educational spaces in social service centers for children (Bucium, Ion Holban, Bogdanesti) in Iasi and its peri-urban area that included urban gardens, the development of green spaces, and facilities for sports activities. In the urban gardens, raised and arranged in a circular design, various orchards and food-producing plants were planted, along with bushes and perennial plants introduced in the new green spaces. Additionally, benches, workshop stations, a volleyball court, and a ping-pong table were constructed alongside the green areas.
The initiative was implemented by the NGO "Asociatia Outventure" and financed through the "In stare de Bine" program, funded by Kaufland Romania and managed by the Fundatia Pentru Dezvoltarea Societatii Civile (Foundation for the Development of Civil Society). The project also included training for permanent volunteers involved in the initiative and conducted 16 thematic workshops on healthy living and ecological behaviors.
The primary target group for the initiative was children and young people at risk of social exclusion, whose circumstances worsened after the COVID-19 pandemic. The objective was to provide them with "an alternative space to develop their personalities, as well as the necessary tools to adopt a healthy lifestyle in harmony with the surrounding environment." The project had a budget of 22,127 euros and was implemented over the span of six months. (1-5)

The Färjenäs Agroforestry Garden started in 2013 in the Färjenäs park in Hisingen, Gothenburg. A group of people interested in agroforestry started a study circle on the topic the year before and then formed an association to apply their knowledge in practice. The City of Gothenburg helped the project get started by providing some funding and finding a 2000 sqm spot for the garden on land owned by the city. The Färjenäs agroforestry garden association is run by volunteers, who have planted about 200 different species of trees, bushes and herbs that produce produce. The planting and management of the garden aims to promote soil health and biodiversity. The association received funding from the Swedish Environmental Protection Agency in 2020 and partnered with the Natural History Museum in Gothenburg to further promote biodiversity and wild pollinators, and has partnered with a local beekeeping association to establish a beehive in the garden. The garden is open to the public and invites the public to educational activities and working events such as planting. The association aims to be a meeting place for locals and visitors from all over the city, with different cultural backgrounds and generations. Several courses and educational programs within agroforestry, agriculture and gardening have been held at the garden. [Ref. 1-7]

In 2024, Ozanam (a housing private company) and the French Development Agency (AFD) formalized a partnership to modernize an ecological wastewater treatment plant in Saint-Joseph, a neighborhood in Fort de France. The project focuses on replacing an outdated 30-year-old installation that no longer meets current standards with a plant-based water filtration system based on the ‘Rhizosph’air’ patent. This innovative treatment process utilizes "filter gardens," which combine mechanical systems, a gravity network, and a phytoremediation approach. The system employs filters made of gravel and the roots of local plants, specifically Strelitzia reginae and Cyperus alternifolius, to naturally and effectively filter wastewater without odor (Refs 2, 3, 4).
The nature-based system purifies wastewater over an area of 2,000 square meters, with a capacity equivalent to serving 900 residents. This approach offers several advantages, including reduced maintenance costs due to its simplicity, decreased energy consumption compared to traditional treatment methods, and improved water quality released back into the environment (Ref 2). Beyond its technical efficiency, the filter gardens enhance biodiversity (Ref 2) by improving the quality of water discharged into the environment and providing habitats for various species. The solution also integrates seamlessly into the landscape, showcasing vibrant flowers native to the area (Ref 1).
Additionally, the project implementers plan to construct a walking path, provide recreational equipment, and install benches to encourage residents to utilize the area as a public green space (Refs 2, 5).

Minimizing heat stress is a critical priority for Phoenix, the hottest major city in the U.S., where heat-related deaths reached at least 359 across Maricopa County last year. The city's expansive urban layout and infrastructure exacerbate the urban heat island effect, making an already scorching climate even more hazardous. In addition, heat impacts communities unequally, with some neighborhoods up to 10 degrees hotter than others. Lower-income and predominantly Hispanic neighborhoods often have less canopy cover and fewer resources to combat rising temperatures, making them more vulnerable to extreme heat.
To address this, the City of Phoenix launched the Cool Corridors Program in 2020, a key initiative in its broader climate resilience strategy. This program, a partnership with American Forests and the Phoenix Street Transportation Department, aims to establish a network of shaded pathways that connect communities across the city. These corridors enable residents to travel safely to schools, public transit, and other city hubs, promoting environmental sustainability and public health.
The program prioritizes investment in low-income, heat-sensitive neighborhoods to improve tree equity and create green spaces where they’re most needed. The first Cool Corridor was developed in 2022 at Cesar Chavez Park, where over 250 trees were planted with the support of more than 100 volunteers, setting a strong example for future initiatives. By 2030, Phoenix plans to complete 100 Cool Corridors citywide, building a more resilient and livable urban environment for all residents. (1-5, 7-8, 10)

Over the past 10 years, Lima's population has grown from 8.2 to 9.6 million people. As the city's urban sprawl and population density have increased, green spaces have been replaced by grey infrastructure. Consequently, it has become challenging to ensure that residents enjoy a good quality of life (1, 2, 3). In December 2019, Lima City Hall launched "Limeños al Bicentenario," an initiative to revitalise the city's public spaces (1, 3). This program seeks to transform public areas through low-cost interventions, based on criteria such as vulnerability, citizen participation, and catalytic potential, among others (3). It also aims to foster social cohesion by involving residents in the maintenance of these newly renovated areas, while improving the city's resilience to climate change (1, 2, 3). Since its inception, the project has reclaimed 17 public spaces, covering an area of 41,000 m² (3). 430 trees have been planted, and the project has benefited from the collaboration of civil society and private sector partners (3). The programme also focuses on addressing climate change. Heat waves, droughts, floods and mass migration are the main climate-related risks affecting the city. In particular, the expansion of grey infrastructure at the expense of green spaces has exacerbated the risk of heat waves, causing temperatures to rise by up to 3.5 °C in certain areas of Lima (3).
One of the projects involved the recovery of public spaces in Teniente Pavia. For many years, the space was used as a public parking lot, and at night it accumulated garbage, there was alcohol consumption, drug use, and other problematic issues. There was no vegetation, benches or infrastructure for recreation. The neighbours, especially children, did not have access to green areas or recreational spaces (5). For this reason, in 2020 the project was initiated to repair sidewalks, plant vegetation, create gardens, and install infrastructure for play, rest, and exercise (3, 4).

D-Town Farm, located within Detroit’s River Rouge Park, is a landmark urban agriculture initiative led by the Detroit Black Community Food Security Network (DBCFSN). Since its establishment in 2008, this seven-acre farm—the largest in Detroit—has embodied the organization’s commitment to food sovereignty, justice, and security for the city’s African American community. Each year, the farm cultivates over 30 varieties of fruits, vegetables, and herbs using sustainable and regenerative practices. Key operations include large-scale composting, rainwater retention, solar energy generation, and beekeeping, all of which support its ecological and educational missions.
Beyond production, D-Town Farm serves as a community hub. From May through September, it hosts public events that offer educational and recreational opportunities for children and families. The farm also provides hands-on training for aspiring growers through internships and volunteer programs, fostering community engagement and agricultural skill development. Volunteers play a crucial role in daily operations, with ongoing opportunities available throughout the growing season.
D-Town Farm’s mission extends beyond agriculture, serving as a platform for broader advocacy. By challenging barriers to food access, it addresses food deserts with a focus on empowerment and education. The farm supports the local economy by supplying fresh produce to restaurants, farmers markets, and residents, while its health-focused initiatives, such as the youth-centered Food Warriors Development Program, aim to reduce health disparities within the community.
The DBCFSN’s work at D-Town Farm exemplifies a model of community cooperation and self-determination, promoting equity and justice in the food system. By engaging with both local and broader urban communities, D-Town Farm not only strengthens Detroit’s leadership in urban agriculture but also contributes to food justice movements nationwide.
(Ref.1,2,3,4)

Situated in the southern suburbs of Kunming City, Dianchi is one of the largest freshwater lakes in Yunnan and the sixth largest in China (Refs 1, 2). However, due to rapid industrial development, agricultural activities around the lake, land reclamation, and population growth, Dianchi Lake became severely polluted, ranking among the most contaminated lakes in China. This pollution threatened biodiversity and degraded natural habitats (Refs 1, 2, 3). The introduction of exotic species further disrupted the lake’s ecological balance (Ref 1).
In response, the Kunming Institute of Zoology (KIZ), with funding from the Chinese Government, World Bank and the Global Environment Facility (GEF) launched the Lake Dianchi Freshwater Biodiversity Restoration Project. This initiative aimed to restore natural habitats, improve water quality through biological means, and foster community engagement and institutional capacity, creating a sustainable framework for the long-term conservation of Dianchi's unique freshwater biodiversity (Refs 1, 4).
The project was implemented across four key components: Wetland Management and Restoration, Surveys and Monitoring of Species Conservation, Capacity Building and Training, and Public Awareness (ibid.). The project was rated 'Satisfactory' in terms of outcomes, sustainability, and execution under a comprehensive evaluation framework that employed multiple indicators (Refs 4, 5).

The Parco della Musica in Cagliari, inaugurated in 2011 by the municipality of Cagliari, blends modern urban design with a focus on green spaces, music, and culture. Spanning approximately five hectares, the park features a small, winding artificial river that flows from north to south, creating a micro-habitat for various bird species. This waterway, lined with benches on the western side and open green spaces on the eastern side, offers a peaceful setting for both wildlife and visitors. The use of native plants, trees, and shrubs further enhances the biodiversity.

In terms of construction, the use of sustainable materials like marble paving and wooden platforms reflects a commitment to modern design. This makes the Parco della Musica an ideal venue for hosting events and fostering social interaction where culture can thrive, and people can relax and enjoy fresh, calm spaces. Overall, the Parco della Musica serves as an example of how modern urban spaces can be designed to promote ecological balance while offering cultural and recreational benefits to the community (Refs. 1, 2, 3, 4 & 5).