Nature-based solutions (NBS) have risen in prominence as an alternative to high-cost engineering solutions, which can align with climate change adaptation and mitigation goals in cities. Green infrastructure (GI) is defined in a variety of ways, from planned networks of natural and seminatural areas with environmental features to deliver ecosystem services (EEA, 2017) to being cost-effective strategies for stormwater management with added community benefits (US, EPA). In a wider perspective, GI can play a significant role in improving the social and ecological resilience of urban landscapes. In the following, we will cover the key takeaways from this lecture series on GI planning.
Terminology
Matsler et al., found that urban ecology and stormwater management were the two most frequently cited terms in literature about GI (2021). Within urban ecology conceptualisations, the focus is on the benefits derived from implementation; this can be researched at a local level, therefore with consideration to inclusivity and environmental justice concerns, acknowledging the disservices received. GI, discussed as stormwater management, focuses on GI as a cost-effective strategy and is analysed by its ability to reduce combined sewer overflows (CSOS) and direct and indirect economic impacts of flooding (Matsler et al., 2021). Social and ecological benefits are often a secondary focus of GI centred on this objective.
Politics and Multifunctionality
There is an assumption that all ‘green’ is good; however, GI implementation is highly politicised and may not be accepted by all. We can evaluate GI effectiveness by considering the services and disservices produced by its design, social and geographical context, the maintenance it requires, and its functional performance criteria with consideration to the mitigative benefits. Consideration of disservices, such as between urban greening and gentrification and localised benefits and environmental justice, is especially important. The type of GI most suitable for one geographical and social context may vary dramatically for another, and therefore the assessment parameters used should alter depending on the features of the GI.
The politics of GI planning cover the processes by which we decide which infrastructure type we implement, at what scale, and with which objectives. GI is often promoted based on its multifunctionality; however at the design stage, this is reduced to much fewer benefits due to the policy drivers taking priority. GI often produces localised benefits and can result in environmental justice concerns rather than optimising its potential through considering social-ecological synergies across objectives and scales.
Landscape Ecology
GI should be carefully implemented to coexist with the landscape ecology in an area by connecting GI with existing green space to increase the spatial outreach of the benefits. The size and shape of the green spaces impact the types of habitats they can contain; some species thrive in core habitats, while others thrive in edge habitats. GI can be planned with local landscape ecology to create networks of nature throughout the urban space and improve biodiversity, maximising the ecological services provided. An example of this is in Izmir where they have implemented an ecological corridor natural area implementing NBs (Figure 1).
The corridor covers 26500m² with Mediterranean trees and bushes; it includes pollinator houses, fruit trees, and spaces for leisure and recreation. Through this, boasting several social ecological services such as reducing carbon emissions, increasing biodiversity, creating public space for activity and sports, protecting the river, creating permeable surfaces to increase groundwater infiltration, and reducing the urban heat island effect (Urban GreenUP).
Diagram showing a before and after of the Izmir ecological corridor implementation (Urban GreenUP).
Key Lessons
Key lessons on green infrastructure
Through this series of lectures, we have become aware of the oversimplification and overestimation of GI. Using accurate and coherent terminology and definitions will ensure understanding of the GI types, and objective, fragmented conceptualisation can lead to less effective outcomes derived from GI. It is important to be aware of objectives that are used to gather stakeholder and investor interest and not to overlook the potential of other services that could be provided. We must consider where synergies may appear, the maintenance costs, and potential disservices.
To improve GI’s potential to provide multifunctional uses and benefits, we must increase communication across sectors and stakeholders to foster collaboration with the overarching goal of increasing climate change resilience. With extensive planning, GI can increase community-level resilience by providing space for social activities and knowledge sharing empowering residents facing unpredictable climate change challenges. The limitations and complexities surrounding GI planning and implementation should not be disregarded; GI should be applied with specific objectives suitable to social, ecological, and economic contexts.
Bibliography
Matsler, A.M. et al. (2021) ‘A “green” chameleon: Exploring the many disciplinary definitions, goals, and forms of “green infrastructure”’, Landscape and Urban Planning, 214, p. 104145. doi: 10.1016/j.landurbplan.2021.104145.
An ecological corridor to reunite the city and nature (no date) Urban GreenUP. Available at: https://www.urbangreenup.eu/news–events/news/an-ecological-corridor-to-reunite-the-city-and-nature_1.kl (Accessed: 30 December 2024).
A reflective essay by Hana Hennin
Student at UIC Barcelona
Urban Resilience for Sustainability Transitions Master’s Programme (2024-2025)