Urban Green and Blue Infrastructure: What Can Cities Learn about Integrating GBI Solutions for Tackling Global Environmental Crises?
By adopting Green and Blue Infrastructure, urban areas can mitigate climate risks, strengthen resilience, and protect biodiversity. Join Laura Valente de Macedo and José Puppim de Oliveira as they take us on a journey around the world to inspiring projects that implement GBI.
Environmental crises are increasingly threatening urban populations worldwide, particularly in the Global South. Cities are now actively addressing climate change and biodiversity loss by implementing Green and Blue Infrastructure (GBI) in collaboration with all levels of government, civil society, international organisations, and the private sector.
GBI refers to interconnected natural and semi-natural landscapes that offer ecosystem services such as temperature regulation, improved health and nutrition, and recreational spaces. By integrating GBI, cities can mitigate climate risks, build resilience, and safeguard biodiversity. Local governments are well-positioned to lead collaborative governance, engaging diverse stakeholders in climate-responsive urban planning.
Navigating the Complex Challenges of Urban Growth
The rapid expansion of urban centres, especially in developing regions, imposes unprecedented demands on urban services, often lacking planning and equitable distribution. These areas also suffer from severe social and economic inequalities, escalating risks for their most vulnerable populations. Urban leaders now face not only longstanding challenges like housing shortages, limited mobility, and inadequate public health infrastructure but also the intensifying impacts of climate change, such as extreme weather events. Scarce resources often leave urban poor communities most exposed to these threats.
Innovative Approaches to Urban GBI
Innovative GBI strategies can help reconnect urban areas with surrounding natural systems, enhancing climate resilience in cost-effective ways. Integrating GBI into broader urban development plans ensures it supports housing, transportation, and economic objectives. For example, parks can serve as stormwater management spaces, while green roofs, urban farms, and rain gardens can alleviate urban heat islands and reduce flooding risks. By blending ecological infrastructure with urban development, cities can create multi-functional, resilient landscapes that meet today’s environmental challenges.
Mapping GBI Initiatives Across the Global South
From 2018 to 2023, the “Understanding Innovative Governance for Food, Water, and Energy Nexus in Cities (IFWEN)” project mapped Green and Blue Infrastructure (GBI) initiatives across the Global South to explore how they linked food, water, and energy security in urban areas. This study, covering cities in Africa, Asia, and Latin America, identified 82 GBI initiatives, classified into six types: green spaces, street trees, green roofs, urban forests, urban agriculture, and water bodies, including wetlands. Results showed that 49 per cent of these projects involved green spaces, 44 per cent were water bodies, whereas green roofs were the least common at 7 per cent.
Deployment of GBI varied across regions. Urban agriculture was most prevalent in lower-income areas, with 41 per cent of such projects concentrated in Africa. Water-body initiatives were notably concentrated in Asia, while green spaces predominated in Latin America and the Caribbean. Asian cities, particularly high-density areas, used GBI elements like parks, rooftops, and vertical gardens to combat urban heat and provide recreational spaces. In 2014, China launched the “Sponge City” programme to address urban flooding and water scarcity; pilot projects have since demonstrated effective stormwater management and reduced heat island effect.
Creative Adaptation of Existing Resources
In regions with limited access to resources and technology, creatively adapting existing assets can be effective. For example, cities in India, Brazil, and Kenya have enhanced wetlands near rivers, canals, or lakes to treat wastewater, restore native vegetation, and improve water quality. In Nairobi, Kenya, constructed wetlands near informal settlements treat wastewater before it enters rivers. São Paulo, Brazil, employs wetlands around water bodies to manage stormwater and restore vegetation, offering multiple ecosystem services such as urban cooling, biodiversity enhancement, and air quality improvement. These wetlands also serve as recreational and educational spaces, showcasing how natural features can support urban resilience affordably.
How Do Local Governments Innovate in GBI?
Transformative GBI innovations often come from sources external to local bureaucracies, while internal learning tends to drive incremental change. For example, Gangtok in India collaborated with ICLEI and other international organisations to introduce a composting machine that processes waste from local markets for use in nearby farms and forests.
In Florianopolis, Brazil, a community urban agriculture and composting project reduced waste sent to distant landfills, enhancing local nutrition, health, and water quality. The “Bucket Revolution” partnered with a local institute and the university to develop the programme. The municipality then expanded this initiative, establishing a policy to support agroecology and urban agriculture citywide.
Globally, GBI projects demonstrate the potential to boost urban ecosystem services. For instance, the city of Durban in South Africa transformed a former landfill into a carbon-sequestering urban forest that generates income for local communities, while Medellín, in Colombia, developed a greenbelt that provides environmental and landscape benefits despite social justice challenges.
Implementing GBI strengthens the connection between people and nature, fosters resilience, and promotes sustainable urban development. These projects often require collaboration between local governments and other stakeholders, which is essential for building knowledge and capacity. Encouraging these learning mechanisms can accelerate the adoption of GBI, particularly in the Global South, creating stronger, more resilient cities worldwide.