Regreening in Seestadt Aspern
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 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)
Färjenäs Agroforestry Garden
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]
Trees Plan
The "Plan Arbre" is a tool for ecological planning and renaturation aiming to plant 308,000 trees between 2023 and 2029, sourced from the municipal nursery with seeds purchased from local suppliers (Ref 1, Ref 2). In 2023, 14,922 trees were planted, with plans to double this number in 2024 (Ref 1). The project addresses the loss of 50% of Marseille's natural spaces over the past 75 years, aiming to reverse this trend and reintroduce nature into the urban environment (Ref 2). It also tackles issues like drought and heatwaves, particularly in summer, by using trees and shrubs to cool the air, restore biodiversity, reduce air pollution, and enhance public spaces while absorbing CO2 (Ref 2).
The plan is divided into two phases. Phase I focuses on planting in Marseille's 58 parks and 273 squares and gardens, as well as around childcare centres, schools, socio-cultural centres, and sports facilities (Ref 2, Ref 3). From 2020 to 2023, various improvements were made, including playground renovations, installation of misting systems, automatic watering, and the creation of a CrossFit area (Ref 3). Phase II will involve identifying major boulevards, avenues, and streets lacking trees to enhance the urban canopy (Ref 2).
A diverse range of tree species were selected for their drought resistance, water efficiency, and ability to attract biodiversity (Ref 2, Ref 3). The project also focuses on increasing biodiversity and managing invasive species through natural methods to protect trees from pests without chemicals (Ref 3). Furthermore, the initiative includes de-impermeabilizing soils and implementing a smart irrigation system with tensiometric sensors, developed with the start-up GreenCityZen, which has saved 66% of water in two years (Ref 3). The Plan Arbre also promotes citizen participation, with 23 parks selected for community gardening projects, where ten winning associations will receive plants from the municipal nursery (Ref 1).
The plan is divided into two phases. Phase I focuses on planting in Marseille's 58 parks and 273 squares and gardens, as well as around childcare centres, schools, socio-cultural centres, and sports facilities (Ref 2, Ref 3). From 2020 to 2023, various improvements were made, including playground renovations, installation of misting systems, automatic watering, and the creation of a CrossFit area (Ref 3). Phase II will involve identifying major boulevards, avenues, and streets lacking trees to enhance the urban canopy (Ref 2).
A diverse range of tree species were selected for their drought resistance, water efficiency, and ability to attract biodiversity (Ref 2, Ref 3). The project also focuses on increasing biodiversity and managing invasive species through natural methods to protect trees from pests without chemicals (Ref 3). Furthermore, the initiative includes de-impermeabilizing soils and implementing a smart irrigation system with tensiometric sensors, developed with the start-up GreenCityZen, which has saved 66% of water in two years (Ref 3). The Plan Arbre also promotes citizen participation, with 23 parks selected for community gardening projects, where ten winning associations will receive plants from the municipal nursery (Ref 1).
EPAL Stavroupoli Green roof
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 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).
Helmut Zilk park
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)
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)
North Bull Island
North Bull Island is a national nature reserve located in Dublin Bay on the north side of Dublin. Supporting both local and migratory wildlife, the area holds several nature conservation designations. It is designated as a special amenity area for its aesthetic and recreational value and forms an integral part of the Dublin Bay Biosphere. The Island, with its 5 km beach located within the capital city and close to the city center, serves as a unique and important public amenity. (1)
The Island is estimated to attract up to 1.4 million visitors annually, including walkers, swimmers, beachgoers, birdwatchers, nature enthusiasts, kite-surfers, and various other interest groups from the local area. Additionally, it is a popular destination for schools, universities, and visitors from Ireland and abroad who come to experience accessible examples of ecological succession across nationally and internationally significant habitats, and to learn about the intricate stories that make North Bull Island Nature Reserve central to a UNESCO Biosphere Reserve and part of a global network of Biosphere Reserves. (1)
The Island and Nature Reserve are managed by the Parks, Biodiversity, and Landscape Services of Dublin City Council in collaboration with the National Parks and Wildlife Service. Dublin City Council has prepared an Action Plan for North Bull Island for 2020-2025 to implement the objectives of the North Bull Island Management Plan 2020. The North Bull Island Oversight Forum, which represents a range of stakeholders, monitors the action plan’s implementation (2). The goal is to conserve the island's environmental qualities and scientific significance while balancing its recreational and amenity value for the benefit of the local community and visitors (8).
The Island is estimated to attract up to 1.4 million visitors annually, including walkers, swimmers, beachgoers, birdwatchers, nature enthusiasts, kite-surfers, and various other interest groups from the local area. Additionally, it is a popular destination for schools, universities, and visitors from Ireland and abroad who come to experience accessible examples of ecological succession across nationally and internationally significant habitats, and to learn about the intricate stories that make North Bull Island Nature Reserve central to a UNESCO Biosphere Reserve and part of a global network of Biosphere Reserves. (1)
The Island and Nature Reserve are managed by the Parks, Biodiversity, and Landscape Services of Dublin City Council in collaboration with the National Parks and Wildlife Service. Dublin City Council has prepared an Action Plan for North Bull Island for 2020-2025 to implement the objectives of the North Bull Island Management Plan 2020. The North Bull Island Oversight Forum, which represents a range of stakeholders, monitors the action plan’s implementation (2). The goal is to conserve the island's environmental qualities and scientific significance while balancing its recreational and amenity value for the benefit of the local community and visitors (8).
Phoenix's First Cool Corridor at Cesar Chavez Park
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)
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)
Teniente Paiva passage
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).
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).
Välen nature reserve
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 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].
Lake Dianchi Freshwater Biodiversity Restoration Project
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).
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).

