Highlights
- A structured review filters 117 coastal NbS studies to 35 CID-relevant and 14 implementation-informative cases
- Coastal NbS are evaluated through their implementation components under multiple climate impact drivers
- NbS foundational and measurement processes dominate reviewed NbS practices, while learning, governance, and economic processes remain weak
- Scalability emerges from processes completeness rather than ecosystem type or NbS intervention design
- Key implementation gaps are identified that limit the resilience, transferability, and policy uptake of coastal NbS
Abstract
Nature-based Solutions (NbS) are increasingly promoted for enhancing coastal resilience to climate change, yet most evaluations focus on biophysical outcomes while overlooking the project-level processes that influence long-term effectiveness and scalability. This study applies an implementation-based analytical framework to assess how coastal NbS respond to multiple Climate Impact Drivers (CIDs), including sea-level rise, ocean warming, storm intensity, precipitation variability, and ocean acidification.
A structured qualitative review of 117 coastal NbS studies was conducted, of which 35 were CID-relevant and only 14 contained sufficient process-level information for detailed analysis. Eight Implementation Components (ICs)—baseline assessment, stakeholder engagement, comparative analysis, economic analysis, performance indicators, monitoring, adaptive management, scalability and replicability—were identified and analysed using Jaccard similarity indices to quantify their co-occurrence. These ICs are related to implementation planning, governance, monitoring, learning, and scalability. The ICs were further mapped to the International Union for Conservation of Nature (IUCN) Global Standard for NbS to evaluate their conceptual alignment with recognised quality criteria.
Results show that ICs such as baseline assessment, monitoring, and performance indicators dominate current NbS practice, whereas learning-orientated and enabling processes—particularly comparative analysis, adaptive management, stakeholder engagement, and economic assessment—are weakly integrated. This structural imbalance limits cross-site learning, adaptive capacity, and scalability under interacting climate pressures. NbS interventions exhibiting more complete process architectures demonstrate greater alignment with IUCN criteria related to governance, feasibility, and long-term sustainability.
The study demonstrates that scalability is an emergent property of process completeness rather than a function of ecosystem type or intervention outcomes. This study establishes a quantitative-conceptual framework that integrates CIDs, ICs, and NbS standards, offering a transferable methodology for identifying implementation deficiencies and enhancing the design of resilient, policy-relevant coastal NbS.
Siddappanavara P. M. & Jaganathan A., 2026. Effectiveness and scalability of coastal nature-based solutions under climate impact drivers: a systematic review. Evolving Earth: 100108. doi: 10.1016/j.eve.2026.100108. Article.
