Joint implementation (e.g. tree planting)

A combination of green and grey coastal infrastructure is being developed off the coast of Semarang, Indonesia in response to the increased risk of coastal flooding as a result of sea-level rise (Ref. 1). Due to its geography as a coastal city, "Semarang deals with various physical challenges...such as tidal flooding, erosion, land subsidence and rising sea levels" (Ref. 1). Tidal flooding is becoming increasingly worse as a result of climate-induced sea-level rise and increasingly extreme weather events (Ref. 1 and 3). Coastal protection which was historically afforded by naturally occurring mangrove systems has been reduced as a result of the mangroves being largely lost to urbanisation, fish farming and other forms of agriculture (Ref. 2). One proposed sub-project of the Integrated Protective Coastal Zone, Coastal Balance Project 01: Coastal Balance Pilot in Genuk/Sayung, will focus on the northeast of Semarang. Using the 'Building with Nature' approach, it will leverage nature-based solutions through the deployment of green infrastructure, primarily focusing on mangrove restoration (Ref. 3). Mangrove restoration is hoped to stabilise the coastline, therein reducing erosion, encouraging sedimentation and increasing resilience against sea-level rise (Ref. 3).

The Million Trees project was a programme launched by Auckland Mayor Phil Goff in 2017 to plant a million predominantly native trees and shrubs over a period of three years (Ref. 1,2,3,4). It aimed to make Auckland a greener, more beautiful place while creating carbon sinks, protecting the city’s waterways and improving the city’s living environment (Ref. 2,4). The programme engaged a variety of actors in the planting activities, including local boards, iwi, schools, service and social sector groups, private entities, the council group, the New Zealand Transport Association (Ref. 1). Particularly notable partnerships included those with the Department of Corrections and the Trees that Count Trust (Ref. 2,4,6).
The initial goal was met in 2019, and the project has been renewed for 2019-2022 (Ref. 1,7).

The Green Urban Infrastructure in the municipality of Beira project aims to increase Beira’s resilience to climate change and flooding (Ref. 2). It is a two-part project that consists of rehabilitating the Chiveve River and constructing a public park along the river (Ref. 1). The river rehabilitation was completed at the end of 2016 and restored the natural flow of the river, enabling better flood control (Ref. 5,6). The public park was completed at the end of 2020 and serves as a recreation, catchment and overflow area through three basins of the river (Ref. 1,2).

The Nyashishi wetland is located on the western side of Lake Victoria some 15 km from Mwanza, a port city of the lake. The area is characterized by a double maxima rainfall, with heavy rains occurring during October to December. The wetland is traversed by the Nyashishi River, which is an intermittent river draining stormy waters and domestic waste water into Lake Victoria. Increased human socio-economic activities in Mwanza, such as horticulture, overgrazing and discharge of industrial effluents, have degraded the Nyashishi wetland. As a result, vegetation specifically elephantiasis and papyrus that used to flourish in the wetland and provide fish breeding grounds have disappeared. The crocodiles, large lizards and a host of other creatures that used to populate those areas cannot be seen today. Since the wetland and the river are part of the Lake Victoria Basin, both have been subjected to floods and droughts, impacting livelihoods, public health and the environment. The root causes of floods are irregular seasonal and year to year variability in rainfall patterns, combined with mismanagement of land and water resources, leading to soil erosion and increased run-off. Therefore restoration efforts in the area are much needed. (1, 5)

In 2015 an innovative project called the "Sweet City" (Ciudad Dulce) was launched in Curridabat. Its main goal was to bring wild spaces into 21 urban neighbourhoods of Curridabat ("spaces of sweetness") and eight corridors ("transitions") and thus linking neighbourhoods and parks through a participatory re-design approach with local stakeholders [3]. The main objective of the Sweet City model is to reintroduce biodiversity into the urban space by focusing on five fundamental dimensions: Biodiversity, Infrastructure, Habitat, Co-existence and Productivity. The interventions of this project included park improvements, sustainable drainage systems, the protection of wetlands, spring water recovery, promoting organic farming practices, and many strategies that help improve biodiversity and motivate citizen participation, finally, as ecosystem-based disaster risk reduction measures and climate change adaptation actions [1].

The Water Forest region covering around 250,000 hectares in the hinterland of Mexico City provides 70% of the city's urban water demand through the aquifers located below the forest. It consists of forest fragments and grasslands, encompasses four mountain ranges, and two adjacent Mexican states – Morelos and Mexico State with national parks (2). However, as native grasses are replaced by human settlements and poorly sited tree-planting projects, water available to recharge the aquifers declines and their loss contributes to flooding in densely populated urban areas downstream (1, 2). The Water Forest Initiative initiated by a non-governmental NGO aims to develop and implement "a regional conservation strategy to provide water and other ecosystem services to Mexico City (CDMX), Mexico State, and Morelos through the protection and rehabilitation of the Water Forest Area" (1 p6).

The City of Melbourne, through its Urban Forest Strategy, has a comprehensive plan for greening major streets and precincts, but not the smaller laneways. Across the municipality, laneways occupy a ground area of 60 hectares, with a further 150 hectares of space on the walls in these laneways (3). "The City of Melbourne has established the GYL program in 2016 with the vision to help transform the city’s smaller laneways into leafy, green and better usable spaces for the residents and other visitors to enjoy while addressing the city’s sustainability challenges." (1 p27). So far, a pilot project has been carried our including the transformation of 4 laneways: Coromandel Place, Guildford Lane, Meyers Place and Katherine Place (1,3). The intervention included an intensive planning process with the involvement of stakeholders from the private and public sectors and the creation of an interactive map of laneways ideal for greening. (1,2). The GYL program aims to address the issues of urban heat islands, climate change impacts of flood mitigation while also improving local aesthetics, amenity and creating opportunities for recreation (1).

"The Urban forest strategy (UFS) is a central part of an innovative overarching policy framework of the City of Melbourne underpinning the city's aim to create healthy ecosystems for people and nature" in the period between 2012-2040 (1 p9). The UFS outlines a scientifically-vetted long-term process to re-nature the city with a diverse selection of urban trees and open space for and with the citizens, combining elements of an eco-managerial governance arrangement with an open and reflexive co-governance approach. (1 p11). The Strategy concentrates on 6 areas to achieve its goals: canopy cover, forest diversity, vegetation health, water quality and soil moisture, urban ecology and environmental stewardship among citizens. (1)

The Mary Ellen Welch Greenway (previously East Boston Greenway) is a mixed-use pathway and linear park built on a former rail corridor" linking several parks in the neighbourhood and also connecting the East Boston district to the beachfront (1, p23). In the 1950s after the Consolidated Rail Corporation stopped using the railways, it became a derelict dumping ground. To the initiation of a local community organisation with the collaboration of governmental authorities, the redevelopment of the area has started as a rail-to-trail conversion program. When completed, the Greenway will link several important open green spaces in the East Boston neighbourhood, increase the acres of park per resident in the area, provide a place for recreational activities and direct greenway to the Boston Harbor (1). Furthermore, with water management amenities the area would serve as a buffer zone in case of flooding by barricading the waterfront. (1)

This project started as a grassroots movement by Hunter’s Bar Infant School (HBIS) in Sheffield when they were seeking to actively help to protect children from air pollution. HBIS led a fundraising campaign that, in collaboration with the University of Sheffield, provided the base to create a green barrier in their playground. The NBS is part of a bigger study called BREATHE that provides the science behind the project, which involves the design of the green barrier, the assessment of its impacts and a feasibility evaluation for installing green barriers in other schools in Sheffield and in Buenos Aires. (1)