Measurements of biophysical aspects of the NBS (e.g. temperature, water flow)

Penang is a state located in north-western Peninsular Malaysia with an area of 1,049 km2. It comprises two local authorities, Penang Island and the mainland. The former is further divided into five administrative districts which are further divided into mukims (sub-districts). Two urban mukims located on the island – George Town and Bayan Lepas – are the focus of the proposed nature-based solutions (NBS) climate adaptation programme. The programme was launched in 2022 by UN-Habitat in collaboration with the Ministry of Environment and Water (KASA) of Malaysia, Penang Island City Council (Majlis Bandaraya Pulau Pinang - MBPP), Department of Irrigation and Drainage (Jabatan Pengairan Dan Saliran - JPS) and Think City (a wholly-owned subsidiary of Khazanah Nasional Berhad (the sovereign wealth fund of the Government of Malaysia)). (Ref 1)

The implementation of the project responds to several challenges posed by climate change including heatwaves and flooding (Ref 4). The main goal of the programme is to enhance urban resilience and reduce human and ecosystem health vulnerability to climate change impacts and extreme weather events by implementing nature-based solutions (NBS) such as tree-lined streets, pocket parks, green parking spaces, green facades and rooftops, urban agriculture and blue-green corridors to reduce surface temperatures and stormwater runoff, as well as to increase social resilience and build institutional capacity (Ref 1, 3).

Pirojshanagar Township is an industrial and residential establishment of the company Godrej & Boyce Mfg. Co Ltd (G&B), located in the Vikhroli suburb of Mumbai city along Thane creek, with diverse natural and human-made habitats (1,2). Of the 16 km2 area of the Township, approximately 12 km2 is occupied by the mangrove ecosystem and its associated habitats (1,2). Upon recognizing the importance of this ecosystem, G&B decided to prioritize the conservation of the mangroves that grew along the banks of the newly acquired land (along the Thane Creek west bank) (1,2). Pirojshanagar, with its biodiverse mangrove forest, is sandwiched between two solid waste dumping grounds of the Brihanmumbai Municipal Corporation (BMC), which only increases its importance in the landscape and makes it a green oasis that acts as a carbon sink (1). It was a research-based project and the first successful mangrove conservation project in Mumbai, now serving as the Mumbai Metropolitan's green lung (1,2).

Neknampur Lake, also known as Ibrahim Bagh Cheruvu, located in Hyderabad, Telangana State of India, has historical importance and was part of a water reservoir network for irrigation and drinking as well as an inalienable part of the rural ecology of the village (1,2). Due to urbanization, the lake underwent drastic changes in ecology, land use and management in the past decade. Scientific investigations conducted by the Telangana State Biodiversity Board on Neknampur Lake highlighted that the water body was full of sludge and extremely eutrophicated, showing elevated algal growth (2). This was mainly because of the unabated entry of sewage and other waste over an extended period into the lake (1,2). In June 2016, The NGO named 'Dhruvansh' decided to adopt Neknampur Lake and thus began a series of interventions that incorporated bioremediation and phytoremediation techniques, regular cleanup drives of plastic removal and recycling campaigns into a restoration plan for the lake (1,2). With the support of the government institutions, 'Dhruvansh' began the revival of the lake across two phases: (1) the revival of the lake periphery and the lake body, followed by (2) the revival of the lake ecosystem (1,2). The ecological restoration of Neknampur Lake has improved the ecological services it provides and restores the glory of this historically significant lake, now known as a biodiversity hotspot (1,2,3,4).

The Upper Kinta River Basin covers an area of about 31,470 hectares above Ipoh City, and it is the main water catchment resource for the residents of the city and its surrounding areas. The Kinta river basin is now threatened by land erosion, land development, improper sewage treatment and irresponsible waste discharges (Ref 1). In 2021, a pilot project was implemented near the city of Ipoh along the SimpangPulai Highway and experimented with river bio-engineering techniques to reduce soil erosion and subsequently prevent sedimentation downstream (Ref 3). The pilot site was established as part of the Mainstreaming Biodiversity Conservation into River Management project, which focused on applying nature-based solutions for mainstreaming biodiversity into riverine landscape planning and watershed management in Malaysia. To provide seedlings for the bio-engineering project and also other related initiatives, a nursery was established in the indigenous Pawong Orang Asli Village. The nursery also provided additional income for communities (Ref 4). The pilot was developed with the expectation to be upscaled and replicated in other parts of the UKB, especially along the SimpangPulai Highway. (Ref. 6)

The International Cultural Garden Park (IC Park) is a comprehensive, private-sector-led, green development project in Yarmag, Ulaanbaatar, Mongolia. Initiated in 2021 by the Ikh Uilsiin Ereld Group LLC on its own property land as part of its social responsibility, the planned area covers a 35 hectares (86 acres) site. First, an international design competition was announced to plan the project. As a result of this competition, a contemporary park concept was developed for Ulaanbaatar's New Center to convey an international concept, with designs of significant cultural and historical elements from over ten different nations. The IC Park will also serve as a venue for a variety of international events, including conferences, sporting competitions, cultural festivals, and more. Green technology is being used with particular attention throughout the park's construction, and more than 90 species of trees and about 50 species of natural perennials growing in Mongolia are planned to be planted with the cooperation of professional tree planting and gardening organizations, specialists, researchers, and scientists. As of today, more than 7,000 trees have been planted in the project area, and professional personnel are diligently working on their care and pruning. The project is expected to reduce the negative consequences of global warming, create a greener environment, and secure long-term employment. (Ref. 1, 2, 4, 7)

The project “Enhancing climate resilience of Gorakhpur by buffering floods through climate-resilient peri-urban agriculture” is part of the Asian Cities Climate Change Resilience Network (ACCCRN) and financed by The Rockefeller Foundation. It was implemented by the Gorakhpur Environmental Action Group (GEAG) from June 2012 to May 2016 to demonstrate how ecosystem services generated by peri-urban agriculture can positively address the impacts of climate change in Gorakhpur, a city located in eastern Uttar Pradesh, India (Ref 1, 2). To be more specific, it was set out to “demonstrate flood risk mitigation through the preservation and improved management of open spaces by strengthening agriculture-based livelihoods in peri-urban areas” (Ref 1, 2). The main project outcomes were focused on conserving peri-urban agricultural land areas as they serve to climate-proof cities and build resilience, enhance the livelihood and food security of vulnerable groups in peri-urban areas, as well as establish sustainable and climate-resilient models (Ref 1). Activities like baseline surveys, field interventions, climate resilient extension systems, the adaptation of practices and research and advocacy were carried out to achieve the project outcomes (Ref 1). Additionally, the project has successfully improved the soil and water quality and developed special measures for waste management (Ref 1, 2, 3).

Iloilo River Esplanade is a promenade and linear park along the Iloilo River, created as part of the Iloilo River Rehabilitation Project. It is the largest linear park in the Philippines and was designed by the landscape architect Paulo Alcazaren. The esplanade is one of a kind in the country that aims to foster biodiversity, store carbon by mangroves and provide protection from possible flood damages. Furthermore, the project aspires to build a lifestyle hub for the locals and promotes educational eco-tourism. The site was an existing dike road devoid of shade and originally built just as a flood control measure. The redesign has showcased its effect on public amenities, received several recognitions and has become a magnet for tourists in this city. [1, 3, 6, 7]

Mérida city developed a Municipal Green Infrastructure Plan (Plan Municipal de Infraestructura Verde), in order to "strengthen the green infrastructure system through planning, design and implementation of urban strategies at different scales of actions and projects that contribute to enriching ecosystem services in the public and private space of the Municipality of Mérida" (Ref. 1). The plan has four axes, providing a comprehensive and transdisciplinary approach to integrating nature-based solutions into city planning and the design of public spaces in order to provide climate change adaptation and mitigation benefits (Ref. 1).
The Mérida Green Infrastructure Plan shares strong ties with a state-wide strategy, 'Arborizando Yucatán', which promotes reforestation efforts across the 106 municipalities of the state in order to "help reduce the effects of climate change, have more areas green and a better climate for the benefit of current and future generations of Yucatecans" (Refs. 3 & 4). At both the municipal and state level, the relevant administrations (Mérida City Council and the State Government, respectively) have signed an agreement (Declaration for Mérida 2050), whereby both pledged to plant at least 200,000 native trees in the City of Merida, running alongside both the Mérida Municipal Green Infrastructure Plan and the Aborising Yucatán Strategy (Ref. 2).

"Siargao It Up" is the mangrove conservation programme in Del Carmen, Siargao Islands of the Philippines. The municipality of Del Carmen hosts the largest mangrove forest in the Philippines – consisting of 4,871 hectares as of 2018. This mangrove forest is the habitat of rare and endangered species of flora and fauna both in marine, wetland and terrestrial areas. This ecosystem helps maintain the island's ecological balance by providing rich breeding grounds for aquatic lives. Furthermore, the forest plays a key role in capturing and storing carbon and helps the Philippines to meet its goal of carbon emission reduction. In addition to creating habitats and storing carbon, the forest also protects the community from the inevitable effects of climate change disasters. Recently, in December 2021, it was able to protect the residents from the onslaught of Typhoon Odette. [1, 2, 3]

South Africa is struggling to provide services to the millions of poor people migrating to the major centres and living in informal settlements (shanty towns), built on land that was formerly used for agriculture or pasturage. Vegetation is sparse and the open spaces between the houses are generally of beaten earth. These areas face persistent challenges that undermine health and everyday well-being and increased disaster risk due to their poor design and lack of green infrastructure. Moreover, informal settlements are very vulnerable to flooding events, which affect the quality of life of the people living in them. Such a case is Diepsloot, a settlement in Johannesburg, where a team of researchers implemented a sustainable urban drainage system with the purpose of alleviating poor water infrastructure and addressing issues related to land erosion and environmental degradation. This research has been benefiting from the support of the local population through adaptive co-management and joint implementation of the intervention. (1,2)