Joint implementation (e.g. tree planting)

Alexandria is one of the vulnerable cities facing climate change (1). From rising sea levels, pollution, extreme rise and fall in temperature and the urban heat island effect, Alexandria is battling significant challenges (1). The city is also worldly renowned for it beaches and gardens that act as the lungs through which the city breathes, and are considered a haven for its people (1). Unfortunately, in the last ten years, there has been a decrease in parks and green areas, which is a cause for concern (1). This shrinkage comes at the expense of urban expansion and the establishment of Commercial and profitable projects, which is a challenge facing the environmental balance and cultural heritage of the city (1). To address the nature of the challenges and climate changes and their effects in Egypt, the president launched the "The 100 Million Trees Initiative" was brought into action in 2022 as part of the Egypt 2030 Vision (2-3). The campaign is meant to double the per capita share of green spaces across the country, improve air quality and people’s health, and reduce greenhouse gases. It will also aim to recoup economic benefits from the trees, including wood and olive oil (3). As part of this initiative, the governor of Alexandria was tasked with taking care of the green spaces and improving the aesthetic and civilizational level, within the scope of Alexandria's neighborhoods and centers (4). In 2023, the gardens department carried out the planting of 812 trees and shrubs of various types within the scope of Al-Muntazah 2 Neighborhood during Week 25 to continue the work of the presidential initiative to plant 100 million trees in the governorate's neighborhoods (4).

Tirana's urban development has set a new record in 2022, when more than 1.8 million square meters of new buildings were constructed (Ref. 5). This rapid development increased the need for accessible urban green areas. At the Tulla Urban Farm, a wide audience is trained to create those green areas in their yards, balconies and roofs with the added benefit of growing produce for their own needs (Ref. 1,2,5). This practice of food autonomy is deeply rooted in Albanian culture but has been lost in urban settings where concrete has taken over the city (Ref. 1). Tulla Urban Farm addresses this issue by providing an inclusive space for people of diverse backgrounds to come together and experience urban gardening first hand under the guidance of professionals from the Agricultural University of Tirana (Ref. 2,3). In these "urban agricultural schools", workshops, seminars and discussions are held to re-cultivate traditional agro-cultural practices and knowledge that will benefit the participants, many of which are from marginalised backgrounds (Ref. 1, 4). All these activities are facilitated through the rooftop greenhouse of the Tulla Cultural Center, which harbours over 300 plants (Ref.1). As such, Tulla Urban Farm not only provides a space for experiencing and learning about plants but also for social interaction and building a community that also addresses more serious issues such as mental health in a society that faces high rates of unemployment (Ref. 1).
The project had received inital funding from the German GIZ in 2022 and won the Cultures of Resistance Award through which it financed the first two years of its programme and enabled free participation at the urban agricultural school for all participants (Ref. 2,4).

The Pantanos de Villa Wildlife Refuge is a natural oasis in the heart of Lima. It is considered a marsh of international Ramsar importance, as it is home to a large number of species of flora and fauna. It includes 5 bodies of water with about 210 species of birds, 13 species of fish, and 5 species of amphibians and reptiles, among others (1). It was created in 2006, by Supreme Decree N°055-2006-AG, which established the definitive category for the Pantanos de Villa, under the name of The Pantanos de Villa Wildlife Refuge (2). This protected area was established over an area of 263.27 ha, and its main goal is to conserve a representative sample of the Marshes of the Subtropical Pacific Desert, including important plant communities, as well as migratory and resident avifauna, focusing mainly on species with some degree of threat (1, 2, 6).
In 2016, a Master Plan was approved aimed at strengthening the conservation of the biological diversity of this coastal marsh and ensuring conditions to promote inter-institutional cooperation and participatory management, including neighbours, authorities, municipalities and interested institutions (2).
This Master Plan establishes environmental, economic and cultural indicators defined to be met over 5 years. These are focused on protecting water resources, conserving migratory and resident bird species, ensuring the conservation of the cattail, promoting tourism and recreational activities, fostering environmental awareness activities and engaging citizens in the management of the Refuge (2)
This plan seeks to confront a series of threats that endanger the conservation of this ecosystem. Among the main problems are the illegal extraction of natural resources, such as cattail; the improper use of the space for activities such as bonfires, consumption of illicit substances and pet walks; the change in land use due to urban expansion; pollution from effluent discharges and solid waste disposal; and illegal fishing (2)

The urban farm of Lak'a Uta is an initiative launched by the NGO Fundación Alternativas, which established the first community garden in Bolivia, located in the city of La Paz at an altitude of 3,600 meters above sea level (1-3). The initial plan was to develop the garden on private land, but since the goal was to create an open space accessible to all citizens, the project eventually sought a public location (3). The subdistrict of Cotahuma granted them permission to use the Lak'a Uta park, an abandoned area rendered unusable by two landslides in the previous year (3). Through voluntary efforts and an investment of 2,800 euros, the land was transformed over three years to accommodate 40 plots of 16m² each, with individual families cultivating a variety of vegetables (3).
Now celebrating its 10-year anniversary, the project adheres to many principles of organic agriculture in an urban setting (5). The area has become a biodiversity hotspot, featuring an artificial pond, 16 wild plant species, and 39 fauna species, including 34 bird species, two types of frogs that provide natural pest control, and three bee species (3-5). Compost is produced naturally using waste management practices and worms (4-5). In addition to edible vegetables, the garden produces medicinal plants, some of which help stabilize the soil and prevent further landslides (3-4). The infrastructure also includes a rainwater collection system (3-5).
Originally, the project aimed to improve access to food, particularly in response to the growing urban population (1-3). Over time, it has also fostered a strong sense of community, while promoting urban gardening through educational workshops and disseminating information nationwide (1-5). It is estimated that 20,000 people have been educated on urban agriculture, healthy eating, and reconnecting with nature (5). The project has also contributed to shaping a local government law supporting urban gardening within the municipality (3).

In 2021-2022, the fenced grassy area beside the Ballyfermot Community Civic Centre was transformed into a welcoming 'people’s park'—an open green space for the community (2). Designed by Dublin City Council’s Parks, Biodiversity, and Landscape Services, the park reflects ideas from local residents gathered over eight months of on-site conversations and two community consultation events.
The new park features a winding perimeter path, earth mounds planted with a variety of trees and plants for seasonal color, and infrastructure to support small community gatherings. An open pergola and a designated market space for food, plant, and craft markets provide inviting spots for social events. Along the park’s edge, a movement trail with playable elements for exercise and play adds a dynamic feature to the space.
Furthermore, a Jackstraws See-Saw is ideal for older children to play in groups and learn about movement whilst also being a tremendous informal seating area for them to gather and chat. Trees cover the See-Saw, offering shade and shelter from the weather, making it a great social space all year round. A Rope Course provides a physical challenge for older children to climb and balance at height while exploring the area. Informal play opportunities are found throughout the park to, with trees, fallen logs, benches and planting that create sensory, imaginative and physical play experiences. (5-7)
Additionally, an edible garden is planned to be developed collaboratively with local residents over the next 2-3 years (4).

Thessaloniki, Greece's second-largest urban center, is a key hub for economic growth and outward trade in the Balkans. The city hosts the country’s second-largest export port, which plays a crucial role in connecting European trade routes with Asia and China. However, until 2014, Thessaloniki's waterfront was poorly maintained, largely inaccessible, and unattractive. Moreover, major flooding events, connected to extreme weather events, exposed significant deficiencies in the city's flood mitigation infrastructure, leading to damage to housing and critical services. (5, 10, 11)
To address these issues, the Municipality of Thessaloniki launched an International Architectural Competition for the redevelopment of the New Waterfront. From 2006 to 2014, Thessaloniki's waterfront underwent a significant regeneration aimed at benefiting the city's population of 1.1 million and stimulating the local economy. The revitalized waterfront now stretches 3 kilometers between land and sea, featuring 58,000 acres of green space an playgrounds.. In total, 2,353 new trees and 118,432 plants were added across an area of 238,800 m² (Refs 1, 3, 4).
The project also introduced walking routes, sports and recreational facilities, seating areas, and scenic viewing points. The waterfront now has a bicycle path along the entire walkway, and an arbour of 660 umbrella pine trees, serving as shade from the midday sun. Completed in 2014, the New Waterfront has already become a vibrant urban green space, enjoyed by both Thessaloniki's citizens and visitors alike (Ref 4).

In Phoenix, access to native, traditional foods prepared by Indigenous communities is scarce. This disconnection is rooted in the legacy of colonization and the forced assimilation of Indigenous peoples through practices such as mandatory residential schools. The Phoenix Indian School, which operated until 1990, is a stark reminder of these injustices, and deep-rooted systemic inequalities continue to persist today. In response, Indigenous food activists have worked tirelessly to promote traditional foodways and advocate for food sovereignty.
One such initiative is led by Native Health, an urban Indian health program that provides primary medical, dental, behavioral health, WIC, and wellness services in Phoenix. In 2019, Native Health launched a community-based garden initiative to reconnect urban Indigenous communities with their traditional life ways. The Native Health Traditional Garden was initially established on a 15-acre plot of vacant land, which sat atop the remnants of a notorious boarding school. However, when an investment firm purchased the land, the garden was displaced and forced to relocate. It downsized to less than an acre of space within a larger community garden project known as the "KeepPhoenixBeautiful Garden."
Despite these challenges, the Traditional Garden continues to thrive, drawing from Indigenous agricultural techniques such as Akimel O’odham canal irrigation, Zuni waffle beds, and Diné dry farming. The garden focuses on cultivating traditional, Indigenous, and desert-adapted plants, including corn, beans, squash, gourds, peppers, sunflowers, melons, and medicinal plants. In addition to growing these vital crops, the garden provides interactive learning opportunities for all ages, including workshops, youth clubs, pick-your-own events, and monthly community workdays.
The goal of the Traditional Garden project is to offer the urban Indigenous community opportunities for hands-on learning, and increased access to harvested produce. (1, 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 Vale da Ameixoeira Urban Park is a key part of Lisbon's Peripheral Green Corridor, covering 20 hectares and aiming to enhance the city's ecological and social resilience. It includes pedestrian and cycling paths, rest areas, picnic spots, skate parks, and playgrounds, enabling recreational activities while providing scenic views (Ref 1). The park has undergone several requalification initiatives, including the tree planting project in 2018, which saw the community and municipal bodies plant over 130 native trees and shrubs, promoting biodiversity and environmental sustainability (Ref 3). Additionally, the park supports community-based vegetable gardens, integrating horticultural practices to promote local engagement and foster social inclusion (Ref 3). More recently, as part of the Life Lungs project, another 600 drought-resistant trees were planted to mitigate climate change impacts, such as urban heating and water scarcity (Ref 5). The Lisbon Participatory Budget funds the project and reflects the community’s demand for sustainable urban development (Ref 2).