Lowered local temperature

The 'Step Garden' is a 14-tier green roof atop the Asian Cross Roads Over the Sea (ACROS) Fukuoka Prefectural International Hall in Fukuoka, Japan (Ref. 2). The Hall itself is a centre of international, cultural and information exchange, and sits amidst the Tenjin Central Park (Ref. 3). As the building displaced a plaza, the architect, Emilio Ambasz, created the “image of a mountain" through the design and installation of the roof terrace (Ref. 2), "want[ing] to give back to Fukuoka’s citizens all the land the building would subtract from the city" (Ref. 3). In combination with the Central Park, the rooftop garden is considered to be the only open green space in the city centre (Ref. 4), and since its inauguration in 1995, has been open to the public, accessible via two entrances on the park side of the building (Ref. 1).

Having been awarded the LEED Gold certification, the President Place building is considered the greenest building in the city. The building has been designed to create an exceptional balance between work, life and the environment. The 9th and 13th levels of the building have green roofs and terraces. President Place selected climate-tolerant plants that can survive on natural rainfall, and thus the green roof system does not require a permanent irrigation system. Effective practices were considered during the installation of the green roof, such as mulch for trees to conserve moisture, choosing plant species that can easily adapt to the site and need less irrigation. Trees have also been planted on the ground level. Additionally, the building is surrounded by permeable paving to help rainwater percolate easily. The aim was to create a visually appealing office building that leads the way in environmental, design-led construction in Saigon. [1, 2]

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 green roof pilot project is part of eThekwini Municipality's Climate Protection Programme, initiated in 2004, it was focused initially on understanding the vulnerability of the city of Durban to the impacts of climate change. A strong emphasis has been placed on identifying climate change adaption projects that will improve the resilience of the city to future developmental, social and environmental challenges. Basically, the green roof pilot project is a response to the higher temperatures and increase in the frequency and severity of floods and droughts that are expected as a result of climate change. From an urban environment perspective, these changes will exacerbate the already high temperatures experienced as a result of the Urban Heat Island effect and the high levels of surface run-off and flooding that result from the hardening of permeable surfaces. (1,3)

In 2018, a new annexe building to the Parliament of Victoria was built to host the increased number of municipal employees. The new building is located in the heritage garden that surrounds the parliament precinct of which one hundred per cent of the footprint has been crowned with two new flourishing rooftop gardens that merge the building into its extraordinary landscape setting (1). The new garden is one of the biggest rooftop gardens in Melbourne and accommodates 300 mostly native plant species that characterise the Australian meadows with wildflowers, grasses and shrubs (2). During the construction of the annexe building and the landscaping of the rooftop garden and the connected sunken courtyard key elements of the heritage garden were protected as touchstones for example a Federal Oak planted in 1890, a Norfolk Island Pine and a camphor laurel ( 7). The garden encourages greater biodiversity within the dense urban context, provides thermal insulation to the new building and creates social spaces for events, announcements and contemplation (2).

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 Fund (UFF) was launched in May 2017 by the City of Melbourne to provide financial support to new greening projects that otherwise would not be able to be funded. Such projects include green spaces, tree planting, vertical greening or green roofs on private land" (1 p20). The City of Melbourne has multiple strategies and programs in place to increase the quantity and quality of green space in the city. The UFF aims to support such sustainability lead initiatives by providing match-funding grants to green projects in the private realm. The UFF is a key initiative in tackling sustainability challenges in the entire city, as 75% of its land is privately owned (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 Xochimilco borough of Mexico City is a World Heritage and Globally Important Agricultural Heritage System wetland site, with significant cultural and ecological importance in food cultivation and water ecosystem (1). Due to the deterioration of the area and lack of top-down initiatives for the restoration and conservation of the area, a number of grassroots initiatives trying to revive the traditional chinampa cultivation and restore the natural state of the ecosystem function and its native species such as the Xochimilco axolotl through reinvigorating sustainable practices that produce quality food and foster water supply. This NBS introduces 3 such grassroot intiatives: (a) Cooperativa Chinampayolo (b) Restauración Ecológica y Desarrollo A.C. (REDES) with its EcoQuilitl producer-consumer network and (c) Umbral Axochiatl A.C. (local community organisation). (1)