Increased property prices

The Mobile Tree Trail is a nature-based solutions (NBS) initiative aimed at preserving Mobile, Alabama’s urban forest while celebrating its cultural and ecological heritage (Ref 1, Ref 2). First established in the early 1990s by volunteers, the original trail featured 24 iconic trees, selected for their historical significance, environmental value, and beauty (Ref 1, Ref 2). Over the years, some trees were lost to development and storms, and the trail faded into obscurity (Ref 1, Ref 4).
From 2021, the Mobile Tree Commission, with support from The Nature Conservancy, is leading efforts to revive the trail (Ref 3, Ref 6). Activities include reviewing past entries, opening public nominations, and selecting new trees that best represent Mobile’s identity (Ref 3, Ref 4). The project emphasises inclusivity and public participation, welcoming volunteers and local input to shape a trail that evolves with the city (Ref 4, Ref 6).
Mobile faces environmental threats such as hurricanes, urban expansion, and loss of native tree cover (Ref 1, Ref 6). The revitalised trail helps address these challenges by promoting awareness, conserving old-growth specimens like the 300-year-old Duffie Oak, and maintaining vital green spaces (Ref 4, Ref 6).
The Mobile Tree Trail blends education, tourism, and conservation, enhancing urban resilience while telling the city’s story through its trees (Ref 3, Ref 6).

The Mediterranean climate in Lisbon, already characterised by low precipitation, has been further exacerbated by climate change. The city faces challenges related to biodiversity loss, urban loneliness, and climate anxiety (1). To address these issues, Lisbon's urban development plans have prioritised the re-naturalisation of urban spaces and the integration of ecological networks. Urban nature is now a central component of the city's Master Plan (2012) and other strategic agendas (1).
It is being developed by the LISGREEN project, which aims to enhance ecological connectivity and mitigate the effects of urban heat islands in Lisbon. By establishing nature-based solutions, it aims to restore forests within the city (1, 2, 3). This project encompasses different strategies, such as the RENATURA pilot project. It is a collaboration with the NGO URBEM and involves active public participation in tree planting and forest maintenance. This initiative aims to educate the community about nature, promote well-being, and mitigate extreme climate events (1), through the creation of urban forests.
The main strategy is to create fast forests using the Miyawaki method, which involves dense planting of native trees, removal of invasive plants, and intensive initial care. This approach accelerates the growth of natural forests within a short period, using native species and reducing the need for watering (1)
The first fast forest was developed in Parque Casal Vistoso within Bela Vista Park, within the Eastern Green Corridor of Lisbon. The park is being underutilised because of the lack of shade (1). Thus, this initiative encouraged volunteers to participate in tree planting and forest maintenance activities (3). The NbS intervention began with a 300m² experimental plot near the Vale da Montanha pedestrian bridge and has since expanded to a new 1,500m² plot on the opposite side of the bridge (2). Over 500 volunteers joined the effort, planting more than 3,800 trees (1)

The stretch of the Great Lakes basin ecosystem from southern Lake Huron through western Lake Erie forms a unique urban refuge where life thrives with beauty and resilience. Known as Metropolitan Detroit, this region is where the Community Foundation for Southeast Michigan and many partners are working to create The Great Lakes Way by connecting 160 miles of greenways and 156 miles of water trails (1).
The vision for the Great Lakes Way project is to ensure that all residents and visitors of southeast Michigan—people of all ages, backgrounds, ethnicities, abilities, and interests—feel connected to the water resources, welcomed on its trails, and able to enjoy the benefits and opportunities these access points provide (1). To bring this vision to life, the project plans to link 160 miles of greenways and 156 miles of blueways, connecting people to a range of world-class freshwater, wildlife, and recreational opportunities. These include fishing areas, bird migration pathways, parks, working waterways, preserved woodlands, and restored wetlands (2).
The Great Lakes Way project connects existing assets, supports accessibility and equity, and promotes the Great Lakes Way to both residents and visitors through marketing and communication efforts (2). There are 26 points of interest that will serve as connection hubs along the Great Lakes Way (2). In Detroit specifically, the focus is on connecting 13 culturally or historically significant destinations, as well as locations known for their environmental and ecological importance or as regional landmarks (2).
Rich in world-class fisheries, migratory flyways, parks, urban centers, small towns, preserved old-growth woodlands, and restored wetlands, the Great Lakes Way offers unique experiences that can only be found here. By uniting the natural and cultural assets the Great Lakes Way designation aims to emphasize and expand the essential linkages needed to further connect this remarkable region. (2,3)

Sri Lanka faces multiple natural hazards, including tropical storms, flash floods, and landslides. As the country's urban population has grown, development projects have encroached on wetlands, compromising their natural flood protection, air and water purification, and carbon storage capabilities. Additionally, hilly regions are at risk of landslides, particularly during the monsoon season, posing significant threats to vulnerable communities (4).
To address these challenges, the World Bank and the Sri Lankan government collaborated on the Metro Colombo Urban Development Project. This initiative focused on nature-based solutions (NBS) as cost-effective and sustainable approaches to risk management (4). By strengthening natural processes and ecosystem services, the project aimed to mitigate hazards such as floods, erosion, and landslides (4). Technical assessments by the World Bank highlighted the importance of wetlands in flood protection, leading to efforts to protect and restore 20 square kilometres of freshwater lakes, wetlands, and swamps (1, 4).
The project supported the Sri Lankan government in reducing flooding in the Colombo Water Basin and enhanced local authorities' capacity to manage infrastructure and services. It prioritised metropolitan investments to mitigate the physical and socioeconomic impacts of flooding and aimed to build long-term capacity for urban management and local service delivery (6).

The Cagliari Canal project is an initiative aimed at revitalizing and transforming the urban and natural landscape of the Cagliari Metropolitan Area in Sardinia. The project is rooted in the city's strategic metropolitan plan and seeks to restore and enhance the navigability of the Terramaini-La Palma canal, which had become disused and neglected over time​ (3,4). The primary goal of the Cagliari Canal project is to develop a connected, innovative, and sustainable urban environment by re-establishing the canal as a green and blue infrastructure​ (2). It aims to provide alternative, sustainable mobility options, improve connectivity between municipalities, and enhance the natural and urban environments. It strives to foster a sense of community by creating a shared space for residents and integrating modern amenities that align with environmental sustainability (1,4). It involved a highly participatory process, emphasizing community involvement from the initial planning stages. The Metropolitan Authority of Cagliari, in collaboration with local stakeholders, launched a series of consultations to gather public input on the canal's design and function​(3). These consultations were part of a broader initiative called LabMet, the Metropolitan Laboratory for Innovation, which facilitated the collection of ideas and feedback (1). The project was partly developed in response to the increasing environmental challenges faced by Cagliari, including the need to adapt to climate change. The canal's revitalization is seen as a key measure for enhancing the city's resilience to climate-related risks, such as flooding and heat waves​(1). By restoring the canal and its surrounding areas, the project aims to mitigate these risks through improved water management, reducing pollution, and the creation of green spaces that can absorb excess rainwater and provide cooling effects​ (2)

The Fenkell Stormwater Project in the Brightmoor neighborhood of Detroit is an initiative led by the Detroit Water and Sewerage Department (DWSD) to mitigate the impact of heavy rain events on the local sewer system. By transforming 92 Detroit Land Bank Authority (DLBA) parcels into 24 bioretention gardens, the project aims to significantly reduce street flooding and basement backups in the area. These gardens, spread across approximately 50 acres of mostly vacant land, utilize permeable soils and landscaping techniques to absorb excess rainfall, which helps prevent the overloading of the city’s combined sewer system. This is particularly important in reducing combined sewer overflows (CSOs), which occur when the system's capacity is exceeded during heavy rains, leading to untreated stormwater and sewage being discharged into the Rouge River.
The project is expected to manage and treat about nine million gallons of stormwater annually, making a significant impact on both the neighborhood’s infrastructure and the environment. In addition to the bioretention gardens, the project includes the partial removal of Blackstone Street between Keeler and Midland streets to further enhance stormwater management.
Community engagement has been a critical component of the project, with residents of Brightmoor and Minock Park participating in meetings to share their preferences for the types of trees, plantings, and other features. The DWSD will maintain the gardens under its Green Stormwater Infrastructure (GSI) program, which already includes 19 other similar projects across the city. The project is currently in the construction phase and is expected to be completed by the end of 2024, modernizing Brightmoor’s stormwater infrastructure and providing long-term environmental and community benefits.
(Ref.1-3)

The Santa Gilla lagoon, a crucial wetland in the Cagliari metropolitan area of Sardinia, has been the focus of several interventions aimed at restoring and preserving its natural and socio-economic functions. The overarching goal of these projects is to rehabilitate the lagoon's ecosystems, improve public accessibility, and promote sustainable economic activities such as eco-tourism and fishing. One significant intervention is the restoration of pedestrian and cycling paths around the lagoon, managed by CACIP (Consorzio Industriale Provinciale di Cagliari) in collaboration with the Metropolitan City of Cagliari. With over two million euros in funding, this project aimed to recover the original profiles of the lagoon's embankments, while removing waste from the area and enhancing the paths for non-motorized mobility (2). Another crucial development was the legal action taken by the Corpo Forestale (Forestry Corps) in 2020 to address illegal constructions and pollution along the lagoon's eastern shores. This action included the sequestration of areas used for illegal fishing activities, where hazardous materials and waste were improperly disposed of, leading to environmental degradation​ (1). Furthermore, environmental groups have made continuous efforts to address illegal dumping near the lagoon, particularly along the SS 195 highway. These groups have actively sought the intervention of local authorities to initiate cleanup operations and enforce regulations against illegal waste disposal​ (4). The projects were implemented primarily to address the significant environmental hazards facing the Santa Gilla lagoon, including pollution from illegal dumping, habitat degradation due to unauthorized constructions, and the overall loss of biodiversity. These activities also aimed to mitigate the socio-economic risks posed by the deteriorating environmental conditions, such as the decline in tourism and sustainable fishing practices (1,2,4).

In an architecturally important area of Berlin, situated between the Landwehr Canal, the Kulturforum (the Berliner Philharmonie and the Berlin State Library) and the new construction on Potsdamer Platz, a combination of green and grey infrastructure has been realised to minimise the burden on Berlin’s existing water infrastructure.
Green and non-green roofs harvest annual rain, which flows through the site’s buildings and is used for toilet flushing, irrigation, and fire systems. The roofs retain and then release water to the large on-site buffer pond, which has five underground storage tanks. Next to the roofs, a series of urban ponds and connecting canals have been implemented, with a combined area of approximately 1.2 hectares. They are filled with rainwater, creating an oasis for urban life. Vegetated biotopes are integrated into the overland landscape and serve to filter and circulate the water that runs along streets and walkways. The lake’s water quality is excellent, forming a natural habitat for animals and cooling the surroundings, while fresh water usage in the buildings has been reduced. (Ref. 1; Ref. 2; Ref. 3; Ref. 6)
The project was implemented in the 1990s as part of the development of Potsdamer Platz in the wake of the reunification of Germany. Several architects collaborated on the implementation that was completely privately funded. Beyond its ecological and technical features, the site is a blue natural site in the heavily built city centre of Berlin and allows people to linger and enjoy natural features. The drainage system won several sustainability prices and is considered a successful integration of nature and technology-based mechanisms to foster climate change adaptation. As the rainwater system stores rainwater in underground tanks and ponds, the urban sewage system is relieved during heavy rain, and water can evaporate. Therefore, the small water circle is closed, and the microclimate is cooled. (Ref. 2; Ref. 6)

The Metropolitan Linear Park is a project initiated by the national government of Bolivia, funded by the Inter-American Development Bank (IDB) (1-8). The proposed park will be located along a disused railway corridor between the cities of La Paz and El Alto, spanning 18.2 km (8, p. 8). The project involves the construction of a linear park, divided into five sections, each with distinct objectives, uses, and designs (8, p. 9). This large-scale initiative aims to improve access to public spaces in La Paz and El Alto, enhance connectivity between the two cities, protect surrounding biodiversity and natural spaces, and strengthen resilience to and mitigate the effects of climate change (3 & 8, pp. 11-12).
To achieve these goals, the project design includes outdoor sports and recreational facilities, pedestrian and cycling circuits, as well as the restoration of parks, squares, and public spaces adjacent to the park corridor (8, p. 9). Some features include balcony corridors, flower and food-producing urban gardens, and viewpoints (5). The project also plans for the re-vegetation of the area with native species and aims to stop the environmental degradation of surrounding natural environments, such as the Pura Pura forest, which has been suffering from ongoing deforestation and waste dumping (8, p. 9). These efforts are expected to increase and support biodiversity in the area (7 & 8, p. 12).
Additionally, the project emphasizes social inclusion, with policies designed to incorporate women, indigenous populations, and persons with disabilities (8, pp. 7-8). The park is intended to raise awareness about climate change and biodiversity, ultimately improving the quality of life and health of nearby residents and the citizens of La Paz and El Alto (8, p. 13).

The Stora Amundö and Billdal archipelago nature reserve is in the southernmost part of the City of Gothenburg. The proximity to the city makes it a popular recreational destination, with about 73000 visitors each year. In 2018, the area was protected as a nature reserve to preserve its recreational, natural and historical values. The status as a nature reserve prohibits any exploitation and other harmful activities in the area. The area of the reserve is 1103 ha, of which 259 ha is land area and the rest is water [Ref. 1-3]. The management of the reserve includes promoting recreational and educational activities by creating new entrances, paths and signs, as well as holding guided tours. The management also includes restoring and improving terrestrial ecosystems such as grasslands through mowing and grazing and deciduous forests through selective clearing. A wetland has been restored to promote biodiversity further [Ref. 2, 4]. The reserve was created and is managed by the City of Gothenburg, the process of creating it involved consultation of stakeholders such as land owners, government agencies and NGO's [Ref. 1]. Some local landowners disagreed with the borders of the nature reserve having an impact on their land, leading to an appeal that was ultimately denied [Ref. 5, 6]