NBS has emerged more widely in the climate change adaptation context as an umbrella concept encompassing different related approaches, including ecosystem-based adaptation, ecosystem services and blue-green infrastructure. Some concepts, such as ecosystem services can be criticised for viewing nature mainly as a resource or service provider for humans. For NBS, it is part of the definition that they also need to benefit nature and biodiversity.
NBS aim to holistically address climate change or other societal challenges while simultaneously providing economic, environmental and social benefits. This is based on a recognition that healthy and well-managed ecosystems are providing a range of benefits to humans, including resilience to the effects of climate change, but also that nature is threatened by human pressures and has an intrinsic value. The basis of NBS is in many ways to create a more balanced relationship between humans and the environment such that both benefit.
NBS are multifunctional, which means they can be effective ways of solving several fundamental challenges at the same time. For example, green spaces in cities can, in addition to improving recreational areas, mitigate effects of climate change by providing shade and water retention and improving biodiversity as habitats for different species.
NBS can take different forms and scales. To differentiate between them, different types of NBS have been proposed and used since 2015 (Eggermont et al., 2015; European Commission, 2021a). One way of categorising NBS is to look at the degree of ecosystem intervention. This can broadly be divided into categories from minimal intervention to the most engineered solutions (combinations of solutions are also possible):
Improved use of ecosystems (such as establishment of protected areas and conservation efforts)
Management approaches for multifunctional ecosystems (such as integrated water resource management and innovative design of agricultural landscapes)
Creation and management of new ecosystems (such as green roofs, bioswales, restoration of heavily degraded/polluted ecosystems)
Several NBS definitions have been developed over the years, including by the European Commission (n.d.b). The International Union for Conservation of Nature (IUCN)’s definition of the concept in 2016 has been widely influential (Cohen-Shacham et al., 2016). In 2022, a definition was multilaterally agreed at the United Nations Environmental Assembly (UNEP 2022). The UN resolution clearly puts NBS in the context of ecosystems, thus strengthening the biodiversity and integrity aspects. Biodiversity loss, degradation of ecosystems and poor conservation of habitats pose risks to the delivery of ecosystem services and the impacts of climate change are more visible and costly (European Commission, 2021b). That is why there is great potential in NBS as they are largely associated with delivery of ecosystem services (Maes et al., 2020) and benefits for improving the state of ecosystems (EEA, 2020) which is also highlighted in the UN resolution. Different NBS can support the ecosystem services (EEA, 2021):
Provisioning services are benefits that are extracted from ecosystems (e.g., water and food supply);
Regulating services arise from the ability of ecosystems to regulate their physical, biological, chemical and other processes (e.g., air quality, carbon sequestration, flood regulation);
Cultural services include the non-material benefits provided by nature (e.g., tourism, recreation);
Supporting services are those sustaining the natural processes and integrity of ecosystems (e.g., pollination, nutrient cycling).
More action is needed to protect and restore the ecosystems in EU as well as for meeting the ambitions targets of EU Biodiversity Strategy to 2030 (European Commission, 2021c). The benefits of using NBS for addressing the challenges associated with climate change in different ecosystems (e.g., urban, wetland, forest) has been recognised at different levels. Nature, climate and environment focused frameworks at the global and EU levels are increasingly incorporating NBS in their agenda with the most prominent examples being the European Green Deal (European Commission, n.d.c), EU Biodiversity Strategy to 2030, EU Strategy on Adaptation to Climate Change (European Commission, 2021b) and UN Decade on Ecosystem Restoration (n.d.). To streamline their use, the first major pursuit of standardising the development and use of NBS was developed by IUCN in their Global Standard for NBS in 2020 (IUCN, 2020a). The IUCN Global Standard sets the framework for design and implementation of NBS as well as their upscaling and it is a good starting point for anyone working with NBS. IUCN also provides a guidance for using the standard including a self-assessment tool (IUCN, 2020b).
Common definitions and criteria are especially important when working with NBS to ensure that they have the quality and functionality needed to solve the societal challenges as intended (Sowińska-Świerkosz & García, 2022). Concerns have been raised regarding the potential for misusing the NBS term to ‘greenwash’ climate emissions and actions not benefitting biodiversity (Nature-based Solutions Initiative, 2021; NetworkNature, 2021; Gałecka-Drozda et al., 2021). There is clear evidence that NBS can significantly contribute to solving societal challenges, including those exacerbated by climate change, when properly designed and implemented. However, using NBS is not an alternative to drastic cuts in climate emissions or other harmful activities – both needs to happen at the same time (Mercer et al., 2022; Seddon, 2022).
3.2 What are policies and policy instruments in the context of NBS?
There are various options for engaging actors into implementing NBS more extensively and at greater scales. To make environment-focused targets a reality, a policy needs to be operationalised using policy instruments. In the context of A-DVICE, a policy is defined as “a set of requirements and their objectives, targets and measures that regulate the behaviour of entities (public authorities, business and individuals) towards a desired state” and multiple instruments in addition to regulatory measures can serve the purpose of changing attitudes and behaviours (Davis, Cuevas & Gvein, 2024).
Regulatory measures such as regulations and laws that legally require meeting goals and targets, are the most direct way of ensuring the implementation of solutions targeting climate change adaptation as well as mitigation. However, in practice the development of multiple policies targeting different goals is difficult to achieve as coordination and horizontal and vertical alignment of policies are necessary to avoid contradictory requirements. Evidence-based policy making through stakeholder consultations is increasingly regarded as key to design effective policies (OECD, 2021).
On different governance levels, market-based and economic instruments such as financing mechanisms, incentives for business and diversifying funding sources can provide clear mechanisms for action especially for smaller municipalities and the private sector. Softer policy instruments such as establishing cooperation, knowledge and awareness-raising instruments (cooperation, innovation and awareness raising) benefits all governance levels and actors by generating the prerequisites for any climate action – knowledge and awareness of nature and benefits of ecosystems. Different barriers such as the competition over land use and lack of knowledge and resources prevent wider implementation of NBS and its mainstreaming. Policies are key instruments to achieving sustainability transitions and wider sustainability goals (Van Der Jagt et al., 2022) and they should be developed based on evidence and best available practice (European Commission, n.d.d). The NBS policy handbook does not go into resources and recommendations for policy development in general but provides information and examples that are specifically relevant for NBS.