1. NBS Knowledge Databases

Nature-based solutions knowledge gaps

Explore the nature-based knowledge gap analysis below to help identify future avenues for research.

The knowledge gap database compiles an evidence base for nature-based solutions, to support defining research and innovation avenues, bolster policy and practitioners’ knowledge and knowledge-implementation. The database gathers 'gaps' collected through desk study and online consultations from August to October 2021 (see the NetworkNature report on practical, research and innovation needs for more information). 171 knowledge gaps were collected and categorized into 30 broad gap topics. This database will be updated during the course of the NetworkNature.


Displaying 1 - 20 of 169
Gap Description Origin of source Source Resource Broad topic

Thus, there is a significant lack of understanding regarding the conditions under which nature-based solutions achieve impacts, and especially social and health impacts.

 Desk Study Academic literature

Dumitru, A., Frantzeskaki, N., Collier, M., 2020. Identifying principles for the design of robust impact evaluation frameworks for nature-based solutions in cities. Environmental Science & Policy 112, 107–116. https://doi.org/10.1016/j.envsci.2020.05.026
  • Cost/benefit evaluations
  • Impacts for health and well-being

A better understanding of the relationships between biodiversity, ecosystem functions and ecosystem services is required to develop Nature-based Solutions. Here research should focus more than previously on efficiency and resilience properties of systems. Genetic resources and species and community diversity should be explored as a toolbox for Nature-based Solutions, promoting adaptation and sustainability.

 Desk Study Institutional publication

Eggermont, H., Le Roux, X., Tannerfeldt, M., Enfedaque, J., Zaunberger, K., Biodiversa+ partners, 2021. Strategic Research & Innnovation Agenda : Horizon Europe Partnership on Biodiversity.
  • Relationship between biodiversity, ecosystem functions and ecosystem services

A major challenge in estimating market potential is the lack of national and EU wide data and market analysis on emerging market sectors and limited data availability on more mature markets. This lack of market information could inhibit investment interest in emerging market sectors in particular.

 Desk Study Grey literature

McQuaid, Siobhán, Rhodes, Mary-Lee, Andersson, Thomas, Croci, Edoardo, Feichtinger-Hofer, Marianne, Grosjean, Matthieu, Lueck, Alina, Kooijman, Esmee, Lucchitta, Benedetta, Rizzi, Daniela, Reil, Alice, Schante, Joanne, 2021. From Nature-based Solutions to the Nature-based Economy - Delivering the Green Deal for Europe. Draft White Paper for consultation. Nature-based Economy Working Group of EC Task Force III on Nature-based Solutions. https://doi.org/10.5281/ZENODO.5055607
  • Knowledge base

A major difficulty comes in identifying appropriate indicators and metrics for the social–ecological effectiveness of nature-based interventions.

 Desk Study Academic literature

Seddon, N., Chausson, A., Berry, P., Girardin, C.A.J., Smith, A., Turner, B., 2020. Understanding the value and limits of nature-based solutions to climate change and other global challenges. Phil. Trans. R. Soc. B 375, 20190120. https://doi.org/10.1098/rstb.2019.0121
  • Methodologies and tools for systematic evaluation

A plethora of indicators and frameworks is available, but cities and regions rarely have capacity and skills to consistently evaluate impacts and adapt projects or implementation strategies based on this.

 Online public consulation University / Higher Education / Public research institute sector

Carmen, R., Jacobs, S., Leone, M., Palliwoda, J., Pinto, L., Misiune, I., Priess, J.A., Pereira, P., Wanner, S., Ferreira, C.S., Ferreira, A., 2020. Keep it real: selecting realistic sets of urban green space indicators. Environ. Res. Lett. 15, 095001. https://doi.org/10.1088/1748-9326/ab9465
  • Awareness and capacity building

A possibly even more important issue here is to evaluate the effectiveness of various Nature-based Solutions through science-based assessment of their economic, social and environmental benefits and costs while also addressing the timescale and geographical scale of both costs and benefits.

 Desk Study Institutional publication

Eggermont, H., Le Roux, X., Tannerfeldt, M., Enfedaque, J., Zaunberger, K., Biodiversa+ partners, 2021. Strategic Research & Innnovation Agenda : Horizon Europe Partnership on Biodiversity.
  • Cost/benefit evaluations
  • Effectivennes at different geographical scales
  • Effectivennes at different time scales

Adapt the monitoring of the effectiveness of NbS over time and readapt the NbS management accordingly.

 Desk Study Grey literature

Raymond, C.M., Centre for Ecology and Hydrology (Great Britain), 2017. An impact evaluation framework to support planning and evaluation of nature-based solutions projects: prepared by the EKLIPSE Expert Working Group on nature-based solutions to promote climate resilience in urban areas.
  • Monitoring tools

Adequate indicators and data on the effectiveness and multiple benefits of NbS for CCA and DRR are needed to guide the broader implementation of NbS and better quantification of the net effectiveness of NbS in terms of their environmental, socio-cultural and economic benefits (including potential negative consequences) is needed (e.g. multi-criteria analysis).

 Desk Study Institutional publication

European Environment Agency., 2021. Nature-based solutions in Europe policy, knowledge and practice for climate change adaptation and disaster risk reduction. Publications Office, LU.
  • Cost/benefit evaluations

Also, for NbS to effectively serve as an umbrella framework, it will be critical to incorporate key identified gaps (e.g., need for adaptive management and governance, refer more clearly to ecosystem complexity, temporal scale, effectiveness, and uncertainty) in operational documents.

 Desk Study Academic literature

Cohen-Shacham, E., Andrade, A., Dalton, J., Dudley, N., Jones, M., Kumar, C., Maginnis, S., Maynard, S., Nelson, C.R., Renaud, F.G., Welling, R., Walters, G., 2019. Core principles for successfully implementing and upscaling Nature-based Solutions. Environmental Science & Policy 98, 20–29. https://doi.org/10.1016/j.envsci.2019.04.014
  • Approaches and governance systems for implementation
  • Effectivennes at different time scales

Also, to support efforts for wider uptake of NbS it is necessary to advance the methodologies and tools for systematic evaluation of benefits and co-benefits

 Desk Study Institutional publication

European Commission. Directorate General for Research and Innovation., 2020. Nature-based solutions: state of the art in EU funded projects. Publications Office, LU.
  • Methodologies and tools for systematic evaluation

Analysis of what are the synergies and trade-offs between social, environmental and economic goals associated with Nature-based Solutions.

 Desk Study Institutional publication

Eggermont, H., Le Roux, X., Tannerfeldt, M., Enfedaque, J., Zaunberger, K., Biodiversa+ partners, 2021. Strategic Research & Innnovation Agenda : Horizon Europe Partnership on Biodiversity.
  • Synergies and trade-offs between goals

And third, inflexible and highly sectoralized forms of governance hinder uptake of NbS, with grey, engineered interventions still being the default approach for many climate adaptation and mitigation barriers

 Desk Study Academic literature

Seddon, N., Chausson, A., Berry, P., Girardin, C.A.J., Smith, A., Turner, B., 2020. Understanding the value and limits of nature-based solutions to climate change and other global challenges. Phil. Trans. R. Soc. B 375, 20190120. https://doi.org/10.1098/rstb.2019.0126
  • Approaches and governance systems for implementation

Another key knowledge gap of importance to policy, relating to performance measures, is the analysis of the timescales, and physical/ecological/socio-economic con- ditions under which EbA may or may not be successful.

 Desk Study Academic literature

Doswald, N., Munroe, R., Roe, D., Giuliani, A., Castelli, I., Stephens, J., Möller, I., Spencer, T., Vira, B., Reid, H., 2014. Effectiveness of ecosystem-based approaches for adaptation: review of the evidence-base. Climate and Development 6, 185–201. https://doi.org/10.1080/17565529.2013.867248
  • Cost/benefit evaluations
  • Effectivennes at different time scales

Assesment of ecosystem capacity (Assesing ecosystem capacity to maintain services over long period of time, long term monitoring and evaluation of ecosystem performance and function before and after the disaster)

 Desk Study Academic literature

Ruangpan, L., Vojinovic, Z., Di Sabatino, S., Leo, L.S., Capobianco, V., Oen, A.M.P., McClain, M.E., Lopez-Gunn, E., 2020. Nature-based solutions for hydro-meteorological risk reduction: a state-of-the-art review of the research area. Natural Hazards and Earth System Sciences 20, 243–270. https://doi.org/10.5194/nhess-20-243-2024
  • Relationship between biodiversity, ecosystem functions and ecosystem services

Assess the adaptability and flexibility of NbS actions to new stressors, such as climate change.

 Desk Study Grey literature

Raymond, C.M., Centre for Ecology and Hydrology (Great Britain), 2017. An impact evaluation framework to support planning and evaluation of nature-based solutions projects: prepared by the EKLIPSE Expert Working Group on nature-based solutions to promote climate resilience in urban areas.
  • Risks from slow-onset events

Assessment of multiple benefits of NBSs (quantification of co-benefits partiulary for human well-being)

 Desk Study Academic literature

Ruangpan, L., Vojinovic, Z., Di Sabatino, S., Leo, L.S., Capobianco, V., Oen, A.M.P., McClain, M.E., Lopez-Gunn, E., 2020. Nature-based solutions for hydro-meteorological risk reduction: a state-of-the-art review of the research area. Natural Hazards and Earth System Sciences 20, 243–270. https://doi.org/10.5194/nhess-20-243-2023
  • Cost/benefit evaluations

Average citizens are not aware at all about basic principles of soil preservation/restoration, of relatable differences in the quality of the air/soil environment in different urban contexts, or have a clear idea to what extent NbS can impact positively their daily life. The gap is in the opportunities for collecting transparent information from trusted/institutional sources

 Online public consulation Private company (SME) sector
  • Awareness and capacity building

Can a NbS address more than one different type of urban challenges in a city? How to measure the positive impact on these different dimensions?

 Desk Study Academic literature

Grace, M., Balzan, M., Collier, M., Geneletti, D., Tomaskinova, J., Abela, R., Borg, D., Buhagiar, G., Camilleri, L., Cardona, M., Cassar, N., Cassar, R., Cattafi, I., Cauchi, D., Galea, C., La Rosa, D., Malekkidou, E., Masini, M., Portelli, P., Pungetti, G., Spagnol, M., Zahra, J., Zammit, A., Dicks, L.V., 2021. Priority knowledge needs for implementing nature-based solutions in the Mediterranean islands. Environmental Science & Policy 116, 56–68. https://doi.org/10.1016/j.envsci.2020.10.011
  • Methodologies and tools for systematic evaluation

Climate change and biodiversity loss are key drivers of demand for NbS but uncertainty around changing climate change conditions and challenges measuring the impact of NbS, both positive and negative, have been identified as a barrier.

 Desk Study Grey literature

McQuaid, Siobhán, Rhodes, Mary-Lee, Andersson, Thomas, Croci, Edoardo, Feichtinger-Hofer, Marianne, Grosjean, Matthieu, Lueck, Alina, Kooijman, Esmee, Lucchitta, Benedetta, Rizzi, Daniela, Reil, Alice, Schante, Joanne, 2021. From Nature-based Solutions to the Nature-based Economy - Delivering the Green Deal for Europe. Draft White Paper for consultation. Nature-based Economy Working Group of EC Task Force III on Nature-based Solutions. https://doi.org/10.5281/ZENODO.5055613
  • Risks from slow-onset events

Combination of NbS with grey infrastructure

 Desk Study Academic literature

Ruangpan, L., Vojinovic, Z., Di Sabatino, S., Leo, L.S., Capobianco, V., Oen, A.M.P., McClain, M.E., Lopez-Gunn, E., 2020. Nature-based solutions for hydro-meteorological risk reduction: a state-of-the-art review of the research area. Natural Hazards and Earth System Sciences 20, 243–270. https://doi.org/10.5194/nhess-20-243-2021
  • Effectiveness of hybrid solutions