Unpacking Methods for Integrated Assessments of Nature-Based Solutions

The document outlines a five-step process for assessing nature-based solutions (NbS), moving from system mapping and climate analysis to the quantification of benefits and the identification of financing structures. It emphasizes the use of systems thinking to capture multifunctional co-benefits that traditional 'grey' infrastructure often overlooks. The guide provides a toolbox of quantification and risk assessment tools and illustrates the application of the SAVi methodology through case studies in the Netherlands, Burkina Faso, Italy, Greece, Belgium, and Colombia.

• Nature-based solutions (NbS) provide a multifunctional alternative to traditional 'grey' infrastructure by delivering a wide range of co-benefits, such as flood control, water purification, and climate regulation, which enhance long-term resilience and human well-being.
• The guide advocates for 'systems thinking' and 'system mapping' to understand the complex interdependencies and feedback loops within a municipality's environment, allowing planners to identify key leverage points where NbS can be most effective.
• A comprehensive NbS assessment follows a five-step process: identifying costs and benefits, analyzing the climate context, quantifying and monetizing costs and benefits, identifying financing structures, and communicating findings.
• Climate data analysis is essential for NbS planning to identify hazards and translate projections into economic inputs for CBA; the European Union's Copernicus Climate Change Service is highlighted as a primary open-access resource for this data.
• Quantifying NbS benefits requires translating physical impacts (e.g., carbon sequestered) into monetary values using methods such as avoided cost analysis, market pricing, willingness-to-pay studies, and hedonic pricing.
• Because NbS often lack direct revenue streams compared to traditional infrastructure, the guide suggests innovative financing instruments, including outcome-based models, carbon credits, and insurance-linked instruments like resilience bonds.
• Case studies demonstrate that NbS can outperform grey infrastructure in benefit-cost ratios (BCR). For example, in Greece, river restoration (NBI) achieved a BCR of 2.9, compared to 1.5 for grey infrastructure.
• In Medellín, Colombia, an urban green space project (Parques del Río Norte) was found to generate USD 1.67 in societal value for every dollar invested, with significant benefits in flood risk mitigation and public health.

APA

Contor, H. (2025). Unpacking Methods for Integrated Assessments of Nature-Based Solutions. International Institute for Sustainable Development. https://www.iisd.org/system/files/2025-04/integrated-assessments-nature-based-solutions.pdf

Chicago

Contor, Henri. Unpacking Methods for Integrated Assessments of Nature-Based Solutions. International Institute for Sustainable Development, 2025. https://www.iisd.org/system/files/2025-04/integrated-assessments-nature-based-solutions.pdf.

Wikipedia

{{cite report |last1=Contor |first1=Henri |title=Unpacking Methods for Integrated Assessments of Nature-Based Solutions |publisher=International Institute for Sustainable Development |date=March 2025 |url=https://www.iisd.org/system/files/2025-04/integrated-assessments-nature-based-solutions.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{contor2025unpacking, author = {Contor, Henri}, title = {{Unpacking Methods for Integrated Assessments of Nature-Based Solutions}}, institution = {International Institute for Sustainable Development}, year = {2025}, month = mar, url = {https://www.iisd.org/system/files/2025-04/integrated-assessments-nature-based-solutions.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }