Local wildlife (e.g., birds, pollinators)

Phoenix is America’s fifth largest and hottest city, a sprawling urban heat island which has expanded without adequate consideration to climate and environmental factors like water scarcity and extreme heat (1). ​Multiple heat records were broken in 2023 including 133 days over 100F (37.7C), and 55 days topping 110F (43C) (1). Only around 9% of Phoenix is protected by tree canopies, yet this citywide figure masks vast inequities between wealthy, majority-white neighborhoods (1). As a response, the City of Phoenix has adopted an equity-driven heat mitigation plan to create a shadier, more livable environment amid rising temperatures and hundreds of heat-related deaths (1). Part of this plan created the Community Canopy Grant program, which offers public schools, churches and homes in qualifying census tracts – low-income neighborhoods with little shade funds for tree planting projects (1). One neighborhood, Grant Park is one of the city’s oldest neighborhoods – and one of the most neglected (1). It is a red lined neighborhood with higher pollution levels, less vegetation, more noise pollution and higher temperatures (1). To change the inequity and create enough shade to provide residents and passersby reprieve from the heat, the city planted around 40 trees in the Grant Park neighborhood within household yards (1-2). Residents can choose from a list of 19 native and desert-adapted trees including the Texas olive, Chinese red pistache and Chilean mesquites (1). The trees, which are a couple of years old and pretty heavy, are planted by contracted arborists (1). Following the planting process, each household was provided with a tree kit – a hose, irrigation timer and instrument to measure the soil pH and moisture, as well as written care instructions (1). This is the fourth tree planting effort by this city and the hope with this initiative is that it lasts (1).

Two stages of a project called "Flowering roadsides" have been created along a bike road stretch measuring 6,5 km between the areas of Gunnilse and Bergum in the eastern part of the City of Gothenburg. The projects came to be through citizens' initiatives and are carried out in cooperation between the City of Gothenburg and two local NGOs: The Bergum-Gunnilse Development Association and the Gothenburg branch of the Swedish Society for Nature Conservation (Gunnilse-Bergum utveckling & Göteborgs naturskyddsförening). The first stage of the project was carried out in 2021 and focused on taking inventory of species and ecosystems along the stretch and suggesting management options to promote biodiversity. The second stage is carried out from 2022 to 2024 and focuses on implementing and evaluating alternative management options to today's conventional management. Mowing and scraping are carried out to disturb weeds and benefit meadow flowers. Sand has been placed to create a habitat for wild bees. Signs were put up along the stretch to inform the public of the initiative, and benches will be renovated to create opportunities for recreation. The project receives funding from the Swedish Environmental Protection Agency through their local nature conservation investment, LONA. The project falls under the umbrella project of "the world's longest meadow", organised nationally by the Swedish Society for Nature Conservation [Ref. 1, 3, 4]. The goal of that project is to transform 1000 km of Swedish roadsides into flowering meadows with high biodiversity richness [Ref. 2].

‘Grün macht Schule’ has been informing, advising, and supporting schools and school initiatives in Berlin since 1983 in the planning and realization of schoolyard projects. The program focuses on improving school playgrounds by creating child-friendly, natural habitats and ecological learning spaces, making schoolyards better equipped to address climate change. In 2012, the program expanded with the launch of the ‘Grün macht Schule - KinderGARTEN’ funding initiative, which extended support to kindergartens.
Over the past four decades, with the program’s assistance, Berlin has seen the transformation of large, unstructured schoolyards into smaller, creative playgrounds. These spaces now feature imaginative and artistic objects alongside facilities for play, exercise, and communication. Additionally, many school gardens and biotopes have been established or restored, turning school grounds into vibrant ecological and educational environments .
The projects are largely driven by schools’ self-initiatives, with ‘Grün macht Schule’ offering support throughout. This grassroots approach fosters pride and a sense of ownership among school communities, strengthening their identification with the results. The collaborative effort also enriches educational practices, promoting inclusion, integration, and democratic participation. Such initiatives offer a hands-on experience with sustainable climate protection projects, making these efforts tangible and impactful in everyday school life.
In addition to its project-based support, ‘Grün macht Schule’ provides training for school teams, organizes regional and national conferences, and hosts seminars and lectures to share best practices and inspire further action .
The program is a cooperative effort between the Senate Department for Education, Youth and Family and the association Freilandlabor Britz e.V., operating under the guidance of the Senate Department. (Ref. 1-4, 6)

As heat waves and high temperatures intensify due to climate change and urbanization, the City of Phoenix is exploring how to reintroduce tree shade into urban spaces to create a more equitable, livable environment. In 2014, the city set a goal to shade at least 25% of Phoenix by 2030, known as the Tree and Shade Master Plan. Achieving this ambitious target requires substantial resources and active community participation.
A key player in this initiative is Trees Matter, an environmental nonprofit dedicated to helping Phoenix reach its shade goals. Trees Matter not only works to expand and sustain the city’s tree canopy but also aims to foster environmental equity. Among its initiatives, the Trees for Schools program promotes tree planting in schools while educating staff and students about the significance of trees and tree care.
Silvestre Herrera Elementary School is one example where the Trees for Schools program has made a direct impact. As part of this program, 30 trees were planted on the school grounds, involving students, staff, and community volunteers in the process. These new trees offer critical environmental benefits, including shade, air purification, dust reduction, food production, and carbon sequestration. Additionally, tree presence has been linked to improved physical and mental health outcomes.
Beyond the immediate environmental gains, the project also offers educational value by involving students, staff, and maintenance crews in hands-on learning about tree care and environmental stewardship. This approach ensures that participants are equipped with the knowledge and skills needed to care for the trees long term, reinforcing both sustainability and community resilience.
Through these combined efforts, Phoenix is making strides toward a greener, more shaded future—one that benefits not only the environment but also the well-being and health of its residents. (1-5)

The Grand Parc des Aygalades project involves the creation of a 14-hectare metropolitan park (connecting Aygalades Park with Bougainville Park and François Billoux Park) that will connect the northern neighbourhoods of Marseille to the port located further south (Ref 1). This project is part of the green conversion of Marseille's northern districts, historically among the most disadvantaged areas in France (Ref 1). The Grand Parc des Aygalades project will enhance the city's greenery, reduce flood risks, create cool zones, restore and develop biodiversity, and significantly improve residents' quality of life and air quality (Ref 1, Ref 2). The environmental and social challenges include reconnecting the populations of these neighborhoods to green spaces, services, education, sports opportunities (Ref 2).
The park project includes redesigning urban infrastructure to improve rainwater absorption and reduce flood risks, addressing the issue of impermeable and artificialized soils that exacerbate flooding during heavy rainfall (Ref 1). It also involves renaturing a 17-kilometre-long stream currently buried under railway tracks, improving flood management and rainwater drainage (Ref 1, Ref 4). The project will also convert a heavily degraded former industrial site, requiring the rehabilitation of polluted soils (Ref 1). Additionally, creating green corridors aims to mitigate the heat island effect, particularly severe in these northern districts due to the high concentration of buildings and concrete surfaces, and the lack of green spaces. Public participation will be encouraged through information meetings, thematic workshops, and an online platform for submitting ideas and feedback (Ref 4).

The Oxygen Alley project, developed by the NGO Arboretum Detroit, is a green space located in the Poletown East neighborhood of Detroit. Spanning four formerly abandoned lots, the project, completed in 2023, serves as a significant environmental and community initiative aimed at improving local resilience and promoting environmental justice. Named in recognition of the closure of the Detroit waste incinerator—a major source of pollution for over 30 years—the project replaces a long-abused landscape with a thriving greenway that enhances both the ecological health and social well-being of the area.
Key features of Oxygen Alley include the planting of air-filtering trees and the creation of a shaded greenway lined with wildflowers, benches, and walking paths. This new green space not only provides a recreational area for residents but also functions as a natural air conditioner, stormwater sponge, and wildlife habitat. It addresses the neighborhood’s lack of tree cover, offering shade and cleaner air while helping mitigate the effects of climate change.
The project also underscores the neighborhood's longstanding struggle for environmental justice. The removal of 400 feet of asphalt and the remediation of a polluted landscape highlight the community’s efforts to reclaim and revitalize their environment. Oxygen Alley serves as both a functional green space and a monument to the residents’ victories over the waste industry, symbolizing their continued fight for clean air and livable spaces.
Supported by grants from the City of Detroit, Michigan Department of Natural Resources, and DTE Energy Foundation, among others, the project was brought to life through over 300 hours of volunteer labor. The creation of this greenway not only improves the neighborhood’s walkability but also offers a vision for a more sustainable and equitable future, serving as a model for urban revitalization projects across Detroit and beyond.
(Ref.1,2,3)

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 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).