IUCN defines Nature-based Solutions as “actions to protect, sustainably manage, and restore natural or modified ecosystems, that address societal challenges effectively and adaptively, simultaneously providing human wellbeing and biodiversity benefits” (IUCN, 2016). This definition was adopted at the 2016 IUCN World Conservation Congress with the Resolution 6.069 (WCC-2016-Res-069).
The United Nations Environment Assembly (UNEA) Resolution 5/5 defines Nature-based Solutions as “actions to protect, conserve, restore, sustainably use and manage natural or modified terrestrial, freshwater, coastal and marine ecosystems which address social, economic and environmental challenges effectively and adaptively, while simultaneously providing human well-being, ecosystem services, resilience and biodiversity benefits”. This definition was adopted by UNEA in March 2022 with the Resolution 5/5 on “Nature-based solutions for supporting development”, together with other 14 resolutions to strengthen actions for nature to achieve the Sustainable Development Goals (SDGs) (UNEP, 2022).
NbS can be considered as an umbrella concept that covers a whole range of ecosystem-based approaches, all of which address societal challenges (Cohen-Shacham et al., 2016). As NbS use natural processes to address societal challenges, they are inherently dynamic and require adaptive management, ongoing iterative learning and targeted monitoring to support future adjustments and expansion amid future climate uncertainties.
Societal challenges
Societal challenges can be defined as “complex, multi-level, multi-dimensional problems impacting ecosystems, biodiversity and human wellbeing that require concerted efforts by various actors to be successfully addressed”. Societal challenges might include, among others, climate change disaster risk, biodiversity loss, environmental degradation, unsustainable resource use and pollution, as well as ensuring food security, water security, human health, and social and economic development (EC, 2021; IUCN, 2016b, 2020; UNDRR, 2020; UNEP, 2022).
Societal challenges are often interdependent and can manifest at all levels, from local to global (IPBES, 2024). For example, the impacts of climate change on urban areas in regions with increasing population growth and low economic performance might heighten the vulnerability to ill-health (poor physical or mental conditions) related to, for example, heat exposure, malnutrition and vector-borne diseases.
NbS have been regarded for their role in managing natural resources and enhancing ecosystem function to reduce habitat loss and increase the provision of ecosystem services. Today, NbS are formally considered capable of addressing a range of societal challenges beyond climate change (through mitigation and adaptation) and the reversal of biodiversity loss, to include social and economic related challenges such as urban development, poverty eradication, inequality and unemployment, sustainable consumption and production (Dunlop et al., 2024).
Nature-based Solutions contributing to global goals
Delivering NbS directly contributes to the following globally agreed goals:
The Sustainable Development Goals (SDGs)
There is today enough scientific evidence underscoring the critical role of NbS in achieving sustainable development goals (ENACT, 2024). For example, NbS can reduce vulnerability to climate change, particularly in the Global South (Woroniecki et al., 2023), they can enhance social-ecological community resilience by engaging local communities and respecting local values (Turner et al., 2022), and bring economic benefits, such as job creation and economic resilience, and increase resilience to economic shocks (Chausson et al., 2024; Gueye & Atallah, 2024).
The Rio Conventions
The “Rio conventions” arose from the 1992 United Nations Conference on Environment and Development (“the Earth Summit”) establishing a general framework for coordinating intergovernmental efforts in pursuit of shared environmental objectives. The Rio conventions address interdependent issues, are intrinsically linked and have interrelated objectives: the Convention on Biological Diversity (CBD) addresses the loss of biodiversity, the United Nations Convention to Combat Desertification (UNCCD) deals with desertification, drought and soil degradation, and the United Nations Framework Convention on Climate Change (UNFCCC) addresses global climate change. (UNFCCC) aims to check global climate change.
NbS are addressed in the Kunming-Montreal Global Biodiversity Framework (GBF) of the CBD, particularly in its mission for the period up to 2030, towards the 2050 vision (“To take urgent action to halt and reverse biodiversity loss to put nature on a path to recovery for the benefit of people and planet by conserving and sustainably using biodiversity and by ensuring the fair and equitable sharing of benefits from the use of genetic resources, while providing the necessary means of implementation”), in Goal A (protect and restore) and Goal B (prosper with nature) for 2050 related to the 2050 Vision for biodiversity, and Targets 8 (climate change) and 11 (nature’s contributions to people), which emphasise the role of NbS in minimizing the impacts of climate change on biodiversity, while restoring, maintaining and enhancing nature’s contributions to people, including ecosystems’ functions and services (CBD COP 15 Decision 15/4).
The UNFCCC, and the 2015 Paris Agreement, recognise the crucial role of NbS in tackling climate change and encourages their implementation, but also emphasizes the need for careful planning, robust social and environmental safeguards, and increased financial support to ensure NbS effectiveness and sustainability (UNFCCC COP 28 Decision 1/CMA.5). The 2022 Sharm-El-Sheikh Adaptation Agenda and the Implementation Plan, launched at the Conference of the Parties (COP) 27, call for collaboration and investments in NbS for their mitigation and adaptation action and the ability to deliver the integrity of natural ecosystems for climate, water, food, health and other biodiversity life supporting roles while ensuring relevant social and environmental safeguards. .
The UNCCD recognises the role of NbS in building resilience in areas expected to face the greatest increased risks of climate-driven floods and drought (UNCCD COP 15 Decision 8).
NbS can facilitate the harmonizing across these three Rio Conventions, helping countries and organisations optimize resource use and avoid duplication of efforts, ultimately leading to more effective conservation, restoration and climate adaptation and mitigation measures.
NbS are also recognised as scalable and effective solutions to address interconnected and systemic risks, build resilience and simultaneously provide human well-being, ecosystem services and biodiversity benefits by the 2030 Agenda for Sustainable Development, the Ramsar Convention on Wetlands, and the Sendai Framework for Disaster Risk Reduction 2015-2030.
From concept to operational framework: Development of the Global Standard for Nature-based Solutions
The IUCN Resolution 069, adopted at the 2016 Hawai’i World Conservation Congress (IUCN, 2016), presented the IUCN definition for NbS, as well as a list of eight principles for NbS to be considered in conjunction with the definition, written to help frame and understand NbS more in detail. The IUCN definitional framework for NbS was later complemented by a gap analysis and in-depth study on principles for ecosystem-based and ecosystem-related concepts (Cohen-Shacham et al., 2019).
The NbS definition, the eight principles, the gap analysis and a two-year public consultation process were the basis for shaping and developing an operational framework for NbS. The resulting IUCN Global Standard for Nature-based SolutionsTM was launched in 2020, with a list of 8 criteria and 28 underlying indicators (IUCN, 2020). The NbS-GS focuses on achieving major environmental, social, and economic goals in an integrated manner, as they have been expressed in the United Nations Environment Assembly (UNEA) 2022 Resolution 5/5.