Increase or improve urban vegetation cover to help reduce outdoor temperature

The Chulalongkorn University (CU) Centenary Park was created to provide a green space for the city and celebrate Chulalongkorn University’s 100th anniversary. Located in the centre of shopping and commerce, the park is designed as a multi-functional “urban forest”, which serves as an oasis for the residents and visitors of Bangkok, who can spend quality leisure time in a lush and pleasant environment. The park includes constructed wetlands with rain gardens, retention ponds, an underground water drainage system and green roof areas. Opened in 2017, Chulalongkorn Centenary Park is the first critical piece of green infrastructure in Bangkok to mitigate detrimental ecological issues and disaster risk reduction. Unlike other public parks around the city, this one is the first in Thailand to demonstrate how a park can help reduce urban flood risks and help the city confront climate change, all while offering city dwellers a place to reconnect with nature. Designed with various ecological design components, the park reminds the city of ways to live with water rather than fear it. [1, 2, 4]

The Ras Mekonnen Urban Park is part of a larger intervention developed by ICLEI (an international NGO focused on the promotion of sustainable development) with the Addis Ababa municipality alongside the Shega river that crosses a nearby neighbourhood. The location of the park was initially used by locals as a dumping site affecting not only the quality of life of the inhabitants but also contributing to the environmental degradation of the area. As more and more people discarded their waste here, the small river running through the site, a tributary of the Shega River, became increasingly overgrown and inaccessible, resulting in a derelict, run-down space in an otherwise vibrant urban area. As such, action was needed, which eventually resulted in the rehabilitation of the river and the creation of the park, which now can be enjoyed by all the inhabitants of the Ras Makonnen neighbourhood. (1,2)

The construction of "the biggest vertical garden in Uruguay" was completed in 2014 (Ref. 1). The vertical garden has an area of 300m2 and contains over 6,000 plants, of which most are endemic, comprising 35 species and 10 different families (Ref. 2). In addition to being aesthetically pleasing, the garden is intended to reduce temperature, produce oxygen and offset greenhouse gas emissions. It is thought to "contribute...to the filtration of approximately 165 tons of gases per year and [be] capable of producing the necessary oxygen for 255 people, in addition to trapping 130 kilos of dust" (Refs. 2 & 3).

The main rivers that cross Lilongwe are the Lilongwe, Lingadzi, Nankhaka and Chankhandwe Rivers, of which the Lilongwe River is the biggest and longest river and the primary source of water for Lilongwe city's residents. At 200 km long, besides its primary function, the river also supports several informal settlements and provides ecological, recreational, cultural and economic benefits. Despite these important functions that the river offers, it is still facing threats such as pollution, urban agriculture, sand mining, climate change effects, and a loss in the biodiversity of fauna and flora that this watercourse hosts. As it sustains a population of approx. 1 mil. inhabitants, the local authorities were interested in finding solutions to address the above threats. As early as 2016, ICLEI ( Local Governments for Sustainability), an international NGO that promotes sustainable development, worked alongside Lilongwe City Council and other stakeholders to protect the river as well as the people depending on it and implemented several actions, with the help of the local community. Eventually, this collaboration led to the issuing of a strategic plan for a sustainable and functional ecological corridor system in the heart of Lilongwe City. The Ecological Corridor aims to transform Lilongwe into a green, clean, prosperous, and resilient city, by ensuring the protection of its urban natural assets, and advancing complementary nature-based solutions. 1,2,3)

The project has seen the "installation of rock structures to reduce the energy of the water that is drained by conventional rainwater galleries and the strategic planting of certain plant species that, through phytoremediation, can mitigate the diffuse pollution that affects the body of the river" (Ref. 1). In combination, "these solutions aim to prevent erosion and landslides on the banks, stop the siltation of the river, improve water quality and strengthen the linear park as a leisure space increasingly demanded by the population in its surroundings" (Ref. 1). A demonstration project which occurred under ICLEI's INTERACT-Bio project, the implementation of NBS has also been accompanied by other measures which saw Lake Cabrinha be de-silted, a walking path, benches, and playground be built and LED lighting be installed" (Ref. 1).

Located in the Eastern part of Tanzania's mainland, the city of Dar es Salaam has been a fast urbanising centre in Sub Saharan Africa. A steady population increase represents implications related to increased human activities, such as encroachment of hazardous land, poor urban planning, as well as lack of infrastructure, placing considerable pressure on the good functioning of the city and causing a rapid loss of green areas and of trees. In counterbalancing these aspects, peri-urban agriculture, artisanal fishing, and nature-based tourism contribute substantially to the well being and livelihoods of the inhabitants of Dar es Salaam. Understanding that nature plays a significant role in the sustainable development of the city and to address the issues above, the municipality of Dar es Salaam, alongside several stakeholders, elaborated a so-called "Thematic Atlas of Nature’s Benefits to Dar es Salaam", tailored specifically for the city. One of the aims of the atlas is to tackle climate change effects that are threatening Dar es Salaam by keeping urban and peri-urban ecosystems intact while implementing nature-based solutions. It is a balancing act coupled with the fact that Dar es Salaam is located in a globally important biodiversity hotspot, the ‘East African Coastal Forest’. (1,2,3)

The municipal government of the Yiwu city in China has launched the Green Lungs of the City Project (GLCP) in 2019. The overarching goal was to build a green lung, which will create more green spaces for residents in Yiwu, mitigate environmental pressures and improve the city's resilience to climate change. Under the project, a green corridor was created to reconnect the roads, rivers, ponds and lakes where different tree species were planted. Additionally, wetlands were constructed and restored to improve resilience against climate change disasters. The project is still in the ongoing phase, and a forest-wetland ecological park is under development in the city's central area. The GLCP aims to use different types of NBS elements to promote sustainable urban development and to provide multiple ecosystem services to the citizens in a highly urbanised area. [1]

The marshes in southern Iraq, formed by the Tigris and Euphrates Rivers, are home to one of humanity’s oldest cultures, once the third-largest wetlands in the world. The Eden In Iraq wastewater garden project started as a humanitarian project that has developed as a necessity for the people of Al Chibaish and the localities surrounding the town. This water remediation project holistically looks at wastewater, trying to include this type of water and its nutrients in a sustainable form by using it to create green spaces. The Eden project in Iraq regards human waste as a valuable source of nutrients and freshwater, which can add to local greenery and landscape beauty if properly treated close to its source. From a climate change point of view, the project focuses on the creation of a wetland with wastewater that can support a garden within the marshes of Iraq. Marsh restoration is a powerful tool against warming temperatures and loss of vegetation, especially in arid areas such as Iraq. From a biodiversity point of view, the project bares a great deal of significance as marshes support a myriad of rare wildlife and rich biodiversity. (1,2,3)

Al Shaheed Park is the largest park in the country. The park was designed to include besides its green spaces, several buildings (museums, parking) populated with green roofs and an artificial lake. The size of the park with all the mentioned grey and green elements stands at 20 ha. The park is viewed as an encompassing part of a green belt that surrounds the city of Kuwait. From an environmental point of view, the park was built to protect the city from sandstorms and to reduce air pollution. From a cultural point of view, the park and the museums are providing the public with high-quality programs, events and spaces, and part of their mission is to spread awareness and educate the public on the importance of the country’s land, history and environment, in addition to the encouragement of international and regional exchange of arts. In addition, the park is meant to commemorate the victims of the first Gulf War. (1,2,3)

To mitigate environmental pressures, including air pollution and urban heat island effects and to improve urban resilience, the municipal government in Beijing has launched the largest afforestation Programme in 2012, Beijing Plain Area Afforestation Programme (BPAP). The aim was to create huge forest patches, develop urban forest park clusters and optimise the large-scale forest patterns. By 2015, BPAP has created green strategies with nine green wedges, multiple green belts, and green corridors around Beijing's old city centre. More than 70,000 hectares of forest (more than 54 million trees) have been planted, and the survival rate has exceeded 95%. BPAP has been considered one of the most ambitious projects for a high-density urbanised area like Beijing. [1, 5]