Climate change mitigation

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 revitalization and conservation of the Butuah Wetlands work started in 2020 by a Ghanian NGO, called Friends of the Nations, in collaboration with some public institutions and an American charitable foundation that makes small grants to grassroots environmental causes around the world. In the past, the wetland has been a major flood reservoir that channelled excess water from different parts of the metropolis into the sea as well as a beacon of biodiversity. The weak monitoring regime of this wetland has led to massive encroachments by both private and industrial developers, therefore, causing biodiversity depletion and contributing negatively to climate change. (1)

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 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 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)

In 2014 a counselling office of the NGO Green City was established, entitled The Greening Office (Begrünungsbüro), with the objective of better engaging citizens in green adaptation measures, such as green roofs, green façades, green walls or green courtyards (Reference 1, 5). Financed by the City’s Department of Health and Environment, the project addresses climate change adaptation through greening private properties, achieved through counselling citizens and companies, with diverse outreach and networking activities. The NBS recognised the potential of the many unused private spaces, such as south-facing facades and flat roofs to better adapt to climate change across the entire city (Reference 1).

Parc Marianne is an ecodistrict that aims to address multiple challenges such as climate action for adaptation, environmental quality, flooding, and in response to the high population growth in Montpellier. Parc Marianne is connected to public transportation, has bicycle lanes and car parks, and the sidewalk is shared between pedestrians and bicyclists and structured with trees and other greenery. The park was certified with the ecodistrict label in 2015 following requirements like environmental sustainability, thermal performance, quality of life, nature and biodiversity, and mobility (Ref. 1). Parc Marianne is a mixed neighbourhood with an ability to combine city and nature, quality of life and centrality (Ref. 2).

The 16-storey EnBW Administrative Complex and planned office district in Stuttgart's industrial area of Fasanenhof has three wings and a high-rise for about 2,000 employees on the 35,000 square meter sites, with many extensive green roofs and usable intensive roofs over underground parking. With the new office complex, EnBW wanted to create a modern and pioneering work environment for its employees. Different green system solutions were used on the project including a "Natural Roof", "Garden Roof", "Public Roof" and "Landscape Roof", with both extensive as well as walk-intensive plantings. The resulting green roofs offer respite and recreation for employees and visitors. [ref 1, 2]