6 . POLICY PERSPECTIVES: NATURE-BASED SOLUTIONS FOR ADAPTING TO WATER-RELATED CLIMATE RISKS
All NbS have an impact on biodiversity2, and conversely, the functionality of an NbS itself can be impacted by biodiversity. While some NbS actively aim to enhance biodiversity so as to enhance the ecosystem service provided, such as the restoration of diverse oyster reefs for flood protection benefits, others may prioritise a different ecosystem function over biodiversity, such as the planting of non-native monocultures that enhance carbon sequestration, but that have a negative impact on local biodiversity (Seddon et al., 2018[10]). However, NbS that do not support biodiversity may be more susceptible to environmental change in the long term, and therefore less resilient. Ensuring an NbS supports biodiversity, such as functional diversity, can serve to bolster ecosystem functioning, and therefore provide stability against disturbances (Isbell et al., 2017[11]). NbS can be considered as an ‘umbrella concept’ for other approaches such as ecosystem-based adaptation (EbA), eco-disaster risk reduction (eco-DRR), green infrastructure (GI) and natural climate solutions (NCS). While each approach differs slightly, (see Table 2.2), a commonality across these concepts is that they are often defined in contrast to grey infrastructure3. In the context of flooding, for example, grey infrastructure refers to built structures such as dams, dikes, channels and storm surge defences. Different terms tend to be used by
different users, and there is no one set definition used by countries. The Government of Canada, for example, tends to include clean energy in their definition of green infrastructure, and often uses the term living green infrastructure to cover concepts similar to NbS (Canada, 2016[12]). The European Union uses a variety of terms in their policy documents, and the Flood Directive refers to “Natural Flood Retention Measures” (NFRM), whereas The EU Strategy on Adaptation to Climate Change (2013) calls on Member States to make Europe more climate resilient by deploying ecosystem-based approaches to adaptation. NbS encompass a wide range of actions, such as the protection and management of the natural environment, the incorporation of green infrastructure in urban areas and the application of ecosystem-based principles to agricultural systems (Eggermont et al., 2015[17]). Interventions range from minimal or no interventions, including protection and conservation, and monitoring strategies; to management approaches to develop ecosystems and optimise the generation of chosen ecosystem services, such as planning agricultural landscapes to minimise drought; and finally highly intensive management approaches, including those aimed at the creation of entirely new ecosystems, such as greening buildings or creating new green spaces (Eggermont et al., 2015[17]).
TABLE 2.2. Comparing similar concepts to NbS Concept
Definition*
Link to the concept of NbS
Green infrastructure (GI)
“A strategically planned network of natural and semi-natural areas with other environmental features designed and managed to deliver a wide range of ecosystem services such as water purification, air quality, space for recreation and climate mitigation and adaptation” (EC, 2019[13]).
GI is a type of NbS. Although GI can be used in a rural context, it is most frequently associated with urban areas.
Ecosystem-based adaptation (EbA) and disaster risk reduction (Eco-DRR)
“Physical measures or management actions that EbA/Eco-DRR are NbS that primarily focus on utilise natural or ecosystem-like processes to adapt to reducing vulnerability and build resilience to the a variety of climate hazards” (EC, 2017[14]). impacts of climate change.
Natural climate solutions
“Conservation, restoration, and improved land management actions that increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, and agricultural lands” (Griscom et al., 2017[15])
Natural climate solutions are NbS that focus on nature conservation and management actions that reduce greenhouse gas emissions from ecosystems and harness their potential to store carbon
Natural Capital and natural assets
“The world’s stocks of natural assets which include geology, soil, air, water and all living things. It is from this natural capital that humans derive a wide range of services, often called ecosystem services, which make human life possible” (Natural Capital Coalition, n.d.[16]),
Natural capital can be considered the “asset base” on which NbS are built.
Note: *None of the concepts listed has a single uncontested definition, therefore definitions that are frequently cited or used in policy documents were selected as a proxy.
