Increased number of species present

The city of Thessaloniki is tackling the energy crisis and climate change risks by prioritizing the installation of green roofs and green walls on school and municipal buildings as part of its resilience strategy, Thessaloniki 2030 (Ref 1, 2). One key project under this strategy has been implemented at EPAL Stavroupoli, one of the largest school complexes in the metropolitan area. The school, with a total built area of 11,918 sq.m and roof surfaces covering 6,042 sq.m, now includes a green roof covering 3,087 sq.m with 25,000 ground-cover plants, along with a vertical garden on three walls at the entrance, covering 100 sq.m and featuring 3,098 plants (ibid.).
The project is expected to yield multiple environmental benefits, such as reduced energy losses, improved thermal performance, enhanced sound insulation, better rainwater management, decreased runoff, and retention of harmful particles, all of which contribute to upgrading the area's green infrastructure (Ref 1). This initiative also strengthens the green fabric of western Thessaloniki and improves the local microclimate while addressing rainwater management issues (Ref 3, 4).

The project aims to protect seagrass meadows, which are vital habitats for the prey of resident dolphins and essential to the local fishing economy. The initiative involves local fisherwomen, called "Keepers of the Sea," in activities such as marine education, awareness campaigns, and monitoring the health of the seagrass meadows (Ref 1). Founded in 2015, Ocean Alive aligns with several UN Sustainable Development Goals, including ocean conservation, gender equality, quality education, and climate action (Ref 4). The project is supported by partnerships with UNESCO and other organizations, and it extends its efforts to Portuguese-speaking African countries. Ocean Alive’s activities also include advocacy for blue carbon ecosystems and programs that involve community engagement and social innovation (Ref 2, Ref 5).
One of several implementation projects targeted safeguarding the young seagrass meadow at Cambalhão Bay, at the entrance of the Sado estuary, as an Ocean Alive’s initiative in partnership with SeaTrees by Sustainable Surf (Ref. 2). The Cambalhão meadow is made up of 202 patches of seagrass. Unregulated shipping is one of the factors in the degradation of the prairie, and to protect it, Ocean Alive is running a campaign to raise awareness about recreational boating (Ref. 6).

The Helmut Zilk Park, named after the late Mayor of Vienna, is located in the heart of the city, near the central train station. Surrounded by newly constructed residential and office buildings, the park serves as a vital green space, offering a variety of amenities. From playgrounds and sports fields to a community garden and cafés, it provides a space for social interaction and recreation. The park is characterized by large open meadows, which function as rainwater seepage areas, and features over 500 trees along its pathways., as well as community gardens. Flower groves enhance the park’s visual appeal while also providing habitats for local wildlife. The natural edges of the park create a diverse urban biotope that supports various plant and animal species. Grass and meadow communities have been carefully planned to enhance biodiversity and provide wet, humid habitats that help infiltrate rainwater from the surrounding paved areas. Already in its first year, the park has become home to insects, small animals, and even larger species like rabbits and snakes, contributing to its rich ecosystem.
The park was developed by the local municipality of Vienna on a site that was once part of the city's railway track system. It is the largest park the city has created in the past 40 years, designed to serve as a recreational area for both local residents and travelers using the nearby train station.
This project is part of a broader urban development initiative around the former Southern Railway station, led by Austria’s Federal Railways Company (ÖBB) and the City of Vienna. The plans included residential housing, office spaces, social infrastructure, and the creation of the Helmut Zilk Park.
Spanning approximately 70,000 square meters, the park stands as the largest public green space created in Vienna in four decades. The central area of the park features a large lawn, perfect for picnics, ball games, and recreational activities. (Ref. 1, 2, 3, 8)

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).

The Museum of Art, Architecture and Technology (MAAT) features a 2,920-square-meter green roof (Ref 8). Located on the riverfront of the historic Belém area in Lisbon, MAAT, inaugurated in 2017, comprises the repurposing of a thermoelectric power station built in 1908 (MAAT Central), a contemporary museum building (MAAT Gallery), connected by a garden that stretches along the Tagus River (MAAT Garden) (Ref. 3).
Blending structure into landscape, MAAT was designed to allow visitors to walk over and under its building, in which "the roof becomes an outdoor room, a physical and conceptual reconnection of the river to the city’s heart – where visitors can turn away from the river and enjoy the vista of the cityscape, and at night, watch a film with Lisbon as a backdrop sitting on the bank of steps" (Ref. 1). This roof, part of AL_A’s (design company) architectural vision, offers panoramic views of Lisbon and the Tagus River (Ref 1), and complementing the green roof is a 225-meter-long garden designed by Vladimir Djurovic, which connects MAAT to the Central Tejo power station. This garden features diverse vegetation (Ref 2, Ref 3, Ref 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)

Välen is a natural area 8 km south of central Gothenburg, established as a protected nature reserve in 2013. Prior to the establishment of the nature reserve, Välen was an agricultural area that experienced environmental degradation due to pollution from a nearby sewage treatment plant. Västra Frölunda Nature Conservation Association leased the land in 1985 in order to allow cattle to graze through the overgrown meadows as a form of landscaping approach [Ref. 5].
The City of Gothenburg took the initiative to protect and manage the area as a protected reserve [Ref. 1, 2]. It is formed of wet meadows and deciduous forests and has a total area of about 68 hectares, of which 52 ha are land and 16 ha are water. Välen is situated by the sea and the mouth of a small river, and protects some of the coastal waters. Residential areas surround the nature reserve and are a popular destination for recreation [Ref. 1-3]. In creating the nature reserve, efforts were made to make the area more accessible to visit and to provide learning opportunities. New paths, entrances and signs were established [Ref. 3-4]. The nature reserve is described as contributing to several national environmental goals, particularly goals related to biodiversity [Ref. 2].

The Adana Urban Park was created in 2024, replacing an aged sports stadium (Ref. 6). The park, located in a densely populated part of the city, was designed to enable access to a place for socializing and recreation in the city centre (Ref. 1,2,5). Especially families, youth, and the elderly will benefit from the installed amenities - they include a large public coffeehouse of about 850m², diverse playgrounds, walking, running and cycling paths, as well as several gardens hosting orchards, aromatic plants and other local vegetation (Ref. 1,3,4,5). The park has a total area of ca. 4.8 ha and was approved by the Government of Türkiye - Ministry of Environment, Urbanization and Climate Change (Ref. 3,6). Beyond its social benefits, Adana Urban Park is expected to aid in alleviating the pressure of air pollution in the city (Ref. 4).

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).