Environmental quality

The Anderson Road Quarry, once a vacant 40-hectare site is getting transformed into a sustainable residential neighbourhood while ensuring climate resiliency and low environmental impact in Hong Kong. The site will supply housing for 25,000 people. In addition to this, the city is employing a wide array of adaptive and resilient approaches including saving around 3,000 metric tons of CO2 annually, helping the city live up to its 65% to 75% carbon reduction goal by 2030 set in Hong Kong Climate Action Plan. [1]

Medellin is the second-largest city in Colombia. The city used to be one of the most dangerous in the world, as Pablo Escobar founded here the Medellin cartel. After the death of Escobar, the city's homicide rate has decreased by 95% and extreme poverty by 66%, thanks in part to a string of innovative mayors who laid out plans to integrate the poorest and most violent hillside neighbourhoods into the city centre in the valley below. The same innovative mayors realised that Columbia and its cities are very vulnerable to climate change being located in a tropical zone and is influenced by El Niño and the La Niña. In Medellin, the municipality has built upon a tradition of planning to become an urban lab for the construction of public life with the aim of inclusive, peaceful and sustainable development. As such starting in 2008 Medellin began implementing a green strategy whose goal was the creation of a green belt around the city as well as waste control. The intervention discussed in this case is one initiated in 2014 when the municipality carried out planting and reforestation projects for the protection of the eastern slopes of the city. (1,2,3)

Once empty paved area between the houses on Marat Street in St. Petersburg now has been turned into a cosy green garden [4, 5, 6]. The project was developed by a group of students and initiated by the Green Petersburg Foundation, Plants for Friends, "Vladimirsky" Municipal District and others [1, 3, 4, 5]. The square landscaping project contributes to the city's adaption to climate change, a need to increase urban green zones, reducing excessive heat and rainfall levels, and the creation of habitat for birds, among others [3]. The square acquired the concept of a harmonious combination of natural motives and the mood of the Russian landscape [4].

Touted as a long-term solution to flooding of Mandaue City, establishment of a mangrove eco-park has begun, having received funding from the Department of Budget and Management (DBM) (Ref. 1). Through establishment of mangroves, the eco-park will "perform a significant role in shoreline protection, acting as a buffer against strong winds and waves", which is considered particularly important in light of the anticipated effects of climate change (Ref. 6).

A total 17-hectare plot is to be rehabilitated, as identified in the Mandaue City Government's Comprehensive Land Use Plan (Ref. 3). At present, it is unclear whether nature-based solutions (including mangrove restoration) are to be implemented across the entire 17ha of the site, but initial efforts have been focused on the restoration of a 5-ha section of mangrove forest (Ref. 2). Due to the lack of data on how exactly the remainder of the 17-ha area will be restored, the total NBS area for this project has only been recorded as 5-ha (5000m2) within this case study, rather than the entire 17,000m2 which is encompassed within the site.

The site is situated at the outfall of the Butuanon River which frequently overtops as a result of heavy rain and has been considered "biologically dead" since 1992 (Ref. 7). The site itself comprises a former dumpsite which had been "left derelict and filled with piles of trash", hence in addition to reducing flood risk, its rehabilitation will serve as green space in which "the residents of Mandaue City [can] gather and enjoy a breath of fresh air" (Ref. 2). The eco-park is considered to bring the added benefit of filtering water as it enters the Mactan Channel, in addition to reducing greenhouse gas emissions through carbon dioxide absorption (Refs. 1 & 6).

The Porsuk Stream divides the city of Eskişehir into two with a green corridor running along the shores of the stream. The Porsuk Stream served provisioning services and acted as a recreational area in the first half of the 20th century, however with increased industrial activities discharging untreated wastewater into the river, rapid urbanisation in the city and other settlements, and increased fertilisers and pesticides in the groundwater originated from agricultural practices (upstream of the Porsuk River), it became highly polluted and its ecosystem degraded severely (1,2,4,5). The Organization for Security and Cooperation in Europe (OSCE) identified the stream as one of the highly dangerous rivers in terms of pollution and health, where no living beings except viruses live (1).
Within the framework of the 'Eskişehir Urban Development Project' the 'Natural Disaster Loss Reduction Project (Porsuk Project)' has been initiated focusing on the ecological restoration of the stream, improving water quality, increasing the resilience of the city against natural disasters (as earthquakes and floods) while also reestablishing the stream's environmental and social role in the city (1). A network of natural infrastructure was created along the Porsuk by expanding public green spaces and link the entire corridor with a sustainable public transport network. (4,5)

One of Valdivia's (in South Chile) southern peripheral neighbourhoods reaches the river of Angachilla which in time led to the creation of an urban wetland, a beautiful and large urban nature reserve of the city of Valdivia. The city of Valdivia is inserted in an extensive network of rivers and coastal wetlands, which penetrate the city through estuaries, hualves and meadows. The Angachilla estuary wetland is one of the most important, connecting the southern sector of the city with the Valdivia River estuary.
These urban wetlands provide important ecosystem functions that directly benefit citizens. Since 2007, the residents of Villa Claro de Luna (neighbourhood) together with various social organisations have worked on the recovery of the Angachilla Wetland, a natural space of great ecological and social value located in the city of Valdivia. Actions included carrying out cleaning, restoration and environmental education activities to recover a place that, abandoned and without any protection from the authorities, was converted into a clandestine garbage dump. (1,2,3)

From 1998-2002 Argentina went through an economic depression, which began after the Russian and Brazilian financial crises, caused widespread unemployment, riots, the fall of the government, and a default on the country's foreign debt. Rosario, the third-most populous city in the country, was not a stranger to the crisis' effects as many of its inhabitants were now living under the poverty line. Coupled with this, climate change was heating up the city and making rainfall more erratic, leading to both flooding in Rosario and fires in the nearby river delta. To tackle urban inequality and climate change the Municipality of Rosario developed a program called "Urban Agriculture Program" which aims to give low-income residents access to underutilized and abandoned public and private land to cultivate food. Over the years, the municipality evolved the program into a cornerstone of its inclusive climate action planning. (1)

The city of Algiers initiated in 2010 a project in order to establish a green belt around its areas and some northern municipalities. The project aims to create agro parks, allotment gardens as well as parks as a strategy for reintegrating the concept of the green belt into the Algerian territory. Through this intervention, the municipality aims to put into practice environmental values ​​linked to improved quality of life and social well-being, for the benefit of the local community. The intervention plans to introduce different species of trees and include for the first time in Africa agro parks as spaces which are designed to reconcile urban and agricultural functions in a win-win strategy. The action was thought to respond to the impacts of climate change in the country, which faces rain events that are less frequent but more intense, and droughts that are more common and longer. (1,2,3,4)

The Orbital Forest of Tirana is an innovative urban forest that as a green belt forms a natural growth boundary for the City. Tirana has experienced rapid development in the past decades that led to population growth challenging municipal services and infrastructure, while climate change also posed extensive pressures to the urban area with intense flooding, precipitation, urban heat and degrading environment (1, 4). The Orbital Forest is a ring on the periphery of the City that connects 14,000 ha of Tirana’s parks, agricultural fields, and forests, maintaining the ecosystem and supporting biodiversity. (3, 4) The NBS aims to increase urban greenery through the plantation of 2 million trees that fit well to the existing ecosystem while also creating a natural boundary to halt urban sprawl (1,4,5). The afforestation of the Orbital Forest has been done through the “Donate a Tree For Tirana” campaign started in 2017 where citizens, businesses and international organisations can plant a tree adding to the green belt. As of 2021, more than 440,700 trees in the framework of the "Donate a Tree" campaign are also bringing urban nature closer to residents (3).

Mauritius is a biodiversity hotspot, which has been declared by IUCN as a “Centre of Plant Diversity”. 39% of plants, 80% of non-marine birds, 80% of reptiles, and 40% of bat species on the islands are reported as endemic. (4) Nevertheless, human activity keeps threatening this endemicity in Port Louis, a port city and the capital of Mauritius. The city is surrounded by a semicircle of mountains on one side and the Indian Ocean on the other. In 2006 a local NGO started implementing an initiative that focused on restoring native vegetation to the hill that harbours the capital and it's also the place of an important historical heritage, the Fort Adelaide. (2)