Countries everywhere are facing increasingly complex climate-related challenges that, in combination with unplanned growth and nature loss, are making them less resilient to climate shocks and more vulnerable to disasters. Nature-based solutions (NBS) for climate resilience are integrative strategies to reduce climate risks while at the same time enhancing biodiversity and ecosystem services. They include the protection or restoration of mangroves, urban green space, rivers and floodplains, reef ecosystems, and wetlands.
Despite growing interest in NBS, one of the key barriers to scaling up investment in these solutions for climate resilience is the limited understanding of their benefits at the project level. A better understanding of methods and approaches to value NBS may enable further uptake of NBS by articulating their contribution to disaster risk reduction, climate resilience, and important co-benefits for other sectors and, thereby, pave the way for additional financing options.
In consultation with over 20 leading NBS experts, a technical team from GFDRR and the World Bank developed the report Assessing the Benefits and Costs of Nature-Based Solutions for Climate Resilience: A Guideline for Project Developers. This report provides practical guidance for valuing NBS for climate resilience; it also considers other benefits such as food production, tourism, recreation, biodiversity, health, and water quality.
The report outlines six steps that should be part of every NBS valuation: scoping the benefits, defining the decision support framework, hazard and risk assessment, risk reduction benefits valuation, other benefits valuation, and cost valuation. Moreover, the report outlines four guiding principles for all assessments:
1. Value both risk reduction and other benefits. NBS are multi-benefit and therefore multistakeholder approaches. The other benefits—such as biodiversity, climate regulation, and ecosystem services supporting local livelihoods—are a crucial part of their value proposition.
2. Engage stakeholders to scope locally relevant benefits of NBS. It is critical to consult and engage stakeholders to identify the relevant benefits to consider in project identification to ensure community buy-in and engagement.
3. Address uncertainty. Uncertainties driven by both climate and socioeconomic conditions play an important role in the assessment of the benefits and costs of NBS.
4. NBS cost-benefit assessment should inform project identification, design, implementation, and impact evaluation. Such an assessment should be an integral part of NBS project identification and preparation to raise awareness, engage stakeholders, assess economic viability on investments, and evaluate the impact of the NBS.
Building on these principles, the report presents a tiered decision framework that guides study design, considering the project context as well as time and budget constraints. The framework also connects valuation methods to the different phases in NBS investment projects, from upstream analytics to impact evaluation.
Eight case studies on the valuation of NBS for climate resilience that have informed World Bank projects are included in the report. For example, in Sri Lanka, the economic case was made for wetland conservation in the capital city of Colombo, showing that the benefits of flood management and recreation outweigh the opportunity cost of land development. In Indonesia, a national-level cost-benefit analysis revealed the economic viability of mangrove conservation and restoration and helped identify priority areas for a $400 million investment, offering coastal protection and ecosystem services supporting the livelihoods of local communities.
View more results stories from fiscal year 2023 in GFDRR's Annual Report 2023.