Unpacking Methods for Integrated Assessments of Nature-Based Solutions

NbS are an innovative approach to addressing societal challenges by leveraging natural processes and ecosystems. They encompass interventions that protect, restore, and sustainably manage ecosystems to deliver multiple benefits. NbS offer a holistic alternative to traditional—often grey—infrastructure by blending infrastructure needs with ecological sustainability. This guideline emphasizes the critical role of NbS in addressing environmental challenges by harnessing the inherent functions of ecosystems to provide multiple societal benefits, such as flood control, water purification, and climate regulation.

Integrating NbS into project development requires a structured approach, starting with identifying societal challenges and evaluating if NbS can address them sustainably and cost-effectively. The guideline explains how to conduct a CBA for NbS through a five-step process:

1. identifying costs and benefits,
2. analyzing the climate context,
3. quantifying and monetizing costs and benefits,
4. identifying financing structures, and
5. communicating findings.

The guideline provides insights into systems thinking and system mapping for understanding the context of NbS. It also details how to collect and analyze climate data to inform NbS planning and implementation. Furthermore, it explores various methods for quantifying and monetizing the diverse benefits of NbS, including the use of tools like Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST). The guideline also discusses different financing structures for NbS projects, including public and private investments, grants and subsidies, and innovative financial instruments like carbon credits and resilience bonds. Finally, it highlights the importance of effectively communicating the value of NbS to various stakeholders through clear key indicators and tailored messaging.

The case studies throughout the guideline serve as real-world examples of NbS implementation and assessment, illustrating the practical application of the discussed methodologies. They showcase diverse NbS types in locations like the Netherlands (coastal protection), Burkina Faso (land restoration), and Colombia (urban green spaces). These examples highlight how to identify, analyze, quantify, finance, and communicate the value of NbS.