Pacific Island countries are increasingly investing in Nature-based Solutions (NbS) as part of their response to climate change. These approaches feature prominently in national adaptation plans, climate finance proposals and sectoral policies. As investment grows, a critical question remains: what does the evidence show about how effective these approaches are in island contexts?
Despite widespread implementation, decision-makers often lack consolidated and comparable evidence on how NbS perform across different ecosystems, climate hazards and socio-economic settings in Small Island Developing States (SIDS). This uncertainty makes it harder to prioritise investments, design robust monitoring frameworks and demonstrate results to climate finance partners.
A new systematic review led by Ms Zoe Brown, a PhD candidate at the University of Oxford, and co-supervised by the Pacific Community (SPC) through its Climate Change and Sustainability Division, including technical supervision from Mr Ludovic Branlant, Nature-based Solutions Mainstreaming Advisor, addresses this challenge by synthesising the available peer-reviewed evidence on NbS for climate adaptation in Small Island Developing States, with strong relevance for the Pacific.
NbS refer to actions that protect, restore or sustainably manage ecosystems to address societal challenges such as climate change, while delivering benefits for biodiversity and people. In island settings, this can include approaches such as mangrove restoration to reduce coastal flooding, agroforestry to support food security, or watershed management to protect water supplies.
Published in Frontiers in Environmental Science, the study systematically reviewed 49 peer-reviewed studies covering 53 interventions across 26 Small Island Developing States. It examined how these approaches have been implemented and evaluated, the climate hazards they address, and the outcomes reported across climate, social, ecological and economic dimensions.
The analysis found that most interventions reported positive climate adaptation outcomes, including reduced exposure to hazards such as soil erosion, flooding, declining agricultural productivity and economic vulnerability. In several cases, these approaches also delivered wider benefits for biodiversity and livelihoods, indicating that well-designed nature-based approaches can generate multiple co-benefits in island contexts.
Reflecting on these findings, Ms Brown noted that the overall direction of the evidence was encouraging.
“In many island settings, nature-based approaches have the potential to help communities reduce climate risks while supporting the ecosystems they depend on. That comes through in the evidence, though further research is needed.”
The review identified important weaknesses in the existing evidence base. Fewer than half of the studies used baselines or counterfactuals to assess effectiveness. Long-term monitoring was uncommon, reporting on equity outcomes was limited, and economic appraisal was rare.
Evidence was also unevenly distributed across regions and ecosystems, with a strong bias towards agriculture and relatively limited analysis of coastal and ocean-based approaches, despite their central importance for island states.
Ms Brown reflected that these gaps were familiar to many practitioners working on NbS.
“Across island countries, a lot of work is already happening on the ground. The challenge is that these experiences are not always documented or evaluated in a consistent way.”
She added that without clearer evidence, it will be difficult for governments to compare approaches, understand trade-offs and make confident decisions about scaling investments.
For SPC, the review provides an important synthesis to inform ongoing technical support to member countries. Mr Branlant said the findings highlighted both opportunity and responsibility.
“The evidence confirms that NbS can play a real role in reducing climate risks in island contexts. But it also shows that stronger monitoring, clearer equity considerations and better economic analysis are needed if these approaches are to be scaled responsibly in the Pacific.”
For Pacific Island countries, the findings are particularly relevant as NbS are increasingly integrated into Nationally Determined Contributions, National Adaptation Plans and adaptation investment pathways, and as governments seek to demonstrate results to climate finance partners.
Strengthening long-term monitoring, improving inclusion of local and Indigenous knowledge, and undertaking clearer economic appraisal would significantly enhance the credibility and policy relevance of these approaches.
Building on this review, Ms Brown will be conducting further research in the Pacific, working with regional institutions and partners to generate more context-specific evidence to support the design, implementation and evaluation of NbS in island settings. Her fieldwork will be carried out in Fiji, which will serve as the primary case study for this next phase of analysis.
For more information:
- Ludovic Branlant - Nature Based Solutions Mainstreaming Advisor, Climate Change and Sustainability Division, Pacific Community (SPC), [email protected]
- Zoe Brown – PhD Candidate, University of Oxford, [email protected]
