Lack of social acceptance

Sri Lanka, particularly its low-lying coastal areas, faces recurring flooding challenges exacerbated by climate change, coastal erosion, and urbanization (1). Wetlands have emerged as crucial ecosystems in mitigating these risks, acting as natural sponges during heavy rainfall and releasing water gradually as flood levels subside (1). Beyond flood control, wetlands play a vital role in environmental quality. Their biodiversity helps filter pollutants and chemicals from the air and water, creating a healthier environment for both humans and wildlife (1). In 2018, Colombo was designated as a Global Wetland City under the Ramsar Convention, becoming the first and only capital city to receive this recognition (1). Recognizing the significance of wetlands as nature-based solutions, international institutions have prioritized their conservation through financing programs (1), and the city has developed projects to raise awareness and involve its citizens in their protection (1). These efforts have resulted in the creation of four wetland parks in the city, that comparing to a wetland, the wetland parks have more human intervention. Thus, they are focused on different topics and activities (2): Diyasaru Park, Beddagana Wetland Park (managed by the Urban Development Authority), Kotte Rampart Wetland Park (managed by the Urban Development Authority), and the Gothatuwa Wetland Park (managed by the Sri Lanka Land Development Corporation) (2). Gothatuwa Park is the newest wetland park and it is located in the flood-prone Gothatuwa neighbourhood (1). Inaugurated in 2024, It has a recreational focus, with trails for cyclists and hikers, and together with the other wetland complex, this park is designed to make the wetlands a cornerstone of local people's lives (1). Currently, environmental education activities are carried out in the park, focusing on managing aquatic invasive plants, tree planting and solid waste collection (3).

Ballymun is a suburban area on the north side of Dublin, Ireland. Originally developed in the 1960s, Ballymun was built to address Dublin’s post-war housing shortages, with iconic high-rise towers and flat complexes. However, over the years, the area faced social and economic challenges, leading to a reputation for issues such as poverty, unemployment, and lack of services.
In response, the Irish government launched the Ballymun Regeneration Project in the late 1990s. As part of the Ballymun Regeneration, Poppintree Park has been transformed into a 45-acre public space at the heart of Ireland’s celebrated urban renewal project in Ballymun Town Centre. This redevelopment followed an extensive public consultation process, incorporating input from local residents, sports clubs, community groups, and youth organizations.
Poppintree Park now offers a range of upgraded amenities, including a Tree Trail featuring 15 native tree species, enhanced biodiversity, extensive wetlands, sustainable drainage systems, and spaces for passive and active recreation. The park also features a 1.25-acre playground for children aged 0-12, an amphitheater with a permanent pond, and a fully accessible pathway network with abundant seating and viewing areas. Over 50,000 plants have been added to enhance the park’s natural beauty.
The park’s transformation, led by Ballymun Regeneration Ltd., involved significant engineering and landscaping efforts. Mitchell + Associates provided the detailed landscape design, construction drawings, and supervised the landscape works.
Completed in 2010, Phase 1 of Poppintree Park’s redevelopment represents an investment exceeding €6 million. The project includes substantial earthworks, drainage systems, gabion walls, three limestone-paved entrance plazas, structural retaining walls, a cantilevered pond walkway, diverse path surfaces, and high-quality playground construction. (1-7, 10)

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).

Masthuggsparken is a planned park in the Masthuggskajen district, which is undergoing development and construction. The park will measure about 2000 m2, and serve as a green oasis and meeting place for locals. It will have ameneties such as benches and areas for play, and a noise barrier against a large nearby road. The park will connect to the adjacent square and street, making it accessible to visit. The street will be renovated to have more trees and plants, increasing green connectivity in the district. The park will be surrounded by trees and other plants, which are planted to promote biodiversity and be adapted to a changing climate [Ref. 1-5, 7]. The park is at a low point, where up to 800 m3 of stormwater will flow during heavy rainfall, reducing flood risk in the surroundings [Ref. 1, 2, 6]. The Masthuggskajen district has a sustainability program, establishing goals for green environments which the park will contribute to. Green areas should be accessible to the entire district and provide ecosystem services such as rainwater management, climate adaptation, biodiversity and recreation. The program was created by the City of Gothenburg in collaboration with construction companies active in the area and was supported by Citylab Action, a national competence program in sustainable urban development [Ref. 7]. The City of Gothenburg is the primary responsible for the park, which will be constructed between 2025 and 2026 [Ref. 1, 2, 4].

Coastal erosion is a well-known consequence of climate change, driven by rising sea levels, extreme storms, and powerful coastal surges. Dollymount Strand, a popular spot for bathing and water sports in Dublin, is particularly vulnerable. Located on North Bull Island and managed by Dublin City Council, the area is part of several protected zones, including a Special Area of Amenity, a Special Area of Conservation, a Special Protection Area, a Ramsar Wetland, a Natura 2000 site, and the UNESCO Dublin Bay Biosphere. To help mitigate this issue, Dublin City Council has implemented a solution that works with, rather than against, natural processes.
During late summer and autumn—particularly following high tides, warm weather, and storms—a type of seaweed called Ectocarpus siliculosis naturally accumulates along Dublin Bay’s beaches. Instead of removing it, the council allows the seaweed to remain, recognizing its essential role in maintaining the beach’s rich biodiversity. Ectocarpus contributes to the health of the coastal ecosystem, supporting marine life and enhancing the natural resilience of Dublin Bay. (1.2)

The Avas Tomato Community Garden, located in a formerly neglected area of the Avas hill of Miskolc, has transformed from an overgrown, rat-infested, and litter-strewn space into a thriving community garden. Just a few years ago, this site was a source of concern for local residents, plagued by issues such as homelessness and illegal dumping. Today, however, it stands as a flourishing green space with fresh garden beds, composting boxes, a pavilion offering shade to gardeners, and a renewed sense of community spirit.
The seeds of the Avas Tomato Community Garden project were planted in the fall of 2014, led by Zsolt Jakab and Ákos Káli-Nagy. The initiative began with the establishment of the "Panelkertész" club, and by 2016, with the support of a local representative, the garden began to take shape. The gardening community that blossomed in the spring of 2017 was built upon the strong relationships within the established Avas neighborhood. Working together, members constructed the garden beds according to a precise schedule and, through frequent discussions, developed a close-knit community. The garden now consists of 20 large and 6 smaller beds, with 18 families actively growing vegetables, herbs, and spices, alongside raspberry and strawberry plants by the fence.
The community has greatly benefited from both the professional support and supply donations provided by the Miskolc Ecological Institute Foundation. Additionally, the Dialóg Association has played a key role in organizing the garden users and fostering collaboration. Initially, Dialóg appointed a coordinator for the garden, but this responsibility has since been handed over to the gardeners themselves. Owned by the Municipality of Miskolc, the Avas Tomato Community Garden continues to thrive as a model of successful urban gardening, uniting people with a shared passion for gardening and a commitment to building a strong, supportive community.
(Ref.1,2,3)

The Miraflores Bicentennial Park has been built on the Malecón de la Reserva and the Quebrada de Armendáriz. It was inaugurated in June 2022 as one of the created projects within the framework of the commemorations of the 200 years of Independence celebrations (1). It is considered a new green lung of Lima (2), as it has a green area of 30,400 square metres and stands on one of the cliffs of the Costa Verde (1). It has a system of terraces that replicates the construction model of the Incas, which has made it possible to additionally reinforce the soil and the slopes with the use of retaining walls up to 10 metres high, with horizontal geogrids and vertical geocells (1, 2). It was structured on a stabilised slope in order to mitigate the risk of landslides (4), and an irrigation system was implemented to stabilise the soil (4).
This space was built as a biodiversity garden with more than 160,000 xerophilic coastal species with low water consumption, 300 trees and 80 palm trees. It also offers places for tourism, such as viewpoints and squares, where cultural events, open-air activities and rest areas are held (1). It also aims to connect aspects of landscape conservation, preservation of biodiversity in the city, and the construction of a cultural landscape in which human action is complementary and friendly to the natural environment (9). Finally, it seeks to contribute to the reduction of the municipality's carbon footprint by reducing the harmful effects of urban expansion on the Lima cliff ecosystem, such as deforestation, water pollution and loss of biodiversity (9).

In 2022, the municipality of Cagliari launched a project to revitalize Viale Trieste, one of its avenues, by redesigning its roads and pedestrian areas and adding new green spaces. The project covers approximately 1,300 meters and 36,500 square meters, and will be completed in two phases, each focusing on different sections of the avenue. With a budget of 12 million euros, funded by municipal, national, and EU resources, the aim is to transform Viale Trieste into a vibrant, accessible, and attractive space for everyone.

The renewal will introduce new green spaces and improved drainage systems to enhance soil permeability. As part of this, some trees will be relocated to other areas of the city to address root issues and improve survival rates. Dead or unstable ficus trees will be removed, while 79 new trees will be planted. Older ficus trees will be relocated to city parks, with younger ones planted along the avenue to prevent pavement damage and promote sustainability. The project also includes upgrading water supply and drainage systems to manage stormwater more effectively, reducing the risk of flooding and improving sustainability. Public lighting will be modernized, with new street lamps and dedicated lighting for pedestrian and bicycle paths to make the area safer and more welcoming after dark.

However, the community has expressed concerns about the project, citing safety issues, delays, disruptions, and poor communication from officials. There is also significant opposition to replacing the historic ficus trees, valued for their environmental and historical significance, with Chinese pear trees and younger ficus (Refs. 1, 2, 3, 4, 5, 6, 11, 16).

The Green Corridor Südpanke is a transformative restoration project that unveiled 700 meters of the river Südpanke, connecting Invalidenpark and Südpankepark in the heart of Berlin. This initiative, part of Berlin's broader mission to restore the Panke River, was spearheaded by the state of Berlin with a focus on ecological restoration, biodiversity enhancement, microclimate cooling, and creating recreational spaces to improve the quality of life for residents (Ref. 2; Ref. 3).
Historically, the river in this area was channeled underground. The project brought the Südpanke back to the surface, integrating ecological principles and landscape planning into the design. The restored section of the river now flows openly in a natural watercourse bed, making it accessible to the public (Ref. 5). The restoration was completed in 2021, transforming the area with features such as playgrounds, lawns, benches, and a continuous biking and walking path that weaves through the green spaces.
Work on the project began in 2010 but was interrupted by the construction of the neighboring headquarters of the Federal Intelligence Service. As a result, parts of the green corridor were opened to the public in 2012, with the full restoration completed nearly a decade later, in 2021 (Ref. 3; Ref. 6).
The project established a seamless connection for cyclists and pedestrians from Invalidenpark in the south to Südpankepark in the north. The new open water section cools the microclimate in Berlin's densely built-up center while providing a critical habitat for plants and animals. Embankments and meadows near the Federal Intelligence Service's property support wild bees and other pollinators, fostering biodiversity. The Green Corridor Südpanke is a vibrant example of how urban ecological restoration can contribute to sustainability, quality of life, and resilience in a growing city. (Ref. 2)

Cagliari's waterfront is currently characterized by extensive soil sealing, which has rendered the soil impermeable, leading to a loss of biodiversity and contributing to the urban heat island effect. Additionally, the waterfront is disconnected from the city due to heavy traffic. In 2023, the Municipality of Cagliari launched the "Green Promenade for Cagliari’s Seafront" project, aimed at revitalizing the waterfront and reconnecting the city with its coastal heritage. Led by Stefano Boeri Architetti, the project seeks to transform the area into a continuous green space that integrates pedestrian pathways with shaded public areas, functioning as a "green lung" to mitigate urban heat and enhance biodiversity.
The initiative will introduce over 200 new trees and 5,700 square meters of green space, creating a park that beautifies the area, improves air quality, and lowers local temperatures. A key focus of the project is fostering cultural and social inclusion by developing new community hubs that encourage diverse activities and strengthen social cohesion. Additional features include recreational areas, sports fields, and outdoor seating. (Ref. 1, 2,3)
The project also aims to enhance social inclusion, environmental sustainability, and urban connectivity, ultimately transforming the waterfront into a vibrant public space that reflects Cagliari’s identity.
However, the lengthy construction process has disrupted local businesses and reduced foot traffic, making the area less attractive during the redevelopment phase. (Refs. 10, 11, 12 & 13).