NbS Triple Win Toolkit: Principles 17 While the ideas behind NbS have existed for decades in scientific and local or indigenous knowledge, there remains an opportunity to increase the knowledge base around technical intervention effectiveness and cost-effectiveness4. The use of an umbrella term such as NbS presents the opportunity to compare approaches, better understand linkages between ecosystems or sectors, test indicators, and understand limitations or barriers10. To strengthen the evidence base and enable adaptive management (see Principle ‘Emphasise an adaptive management approach’), projects need robust monitoring and evaluation systems carried out during and after the project life cycle. Models of community-based monitoring (see Principle ‘Engage local communities in a participatory approach’) are most successful forlong-term adoption and positive outcomes for people and nature4. Long-term monitoring and maintenance are especially important asthe benefits – or unintended negative impacts (see Principles ‘Put in place social and environmental safeguards’ and ‘Consider trade-offs and synergies across multiple scales’ ) – of NbS may not be realised until after a project’s activity or life-cycle has ended. Evaluating intervention effectiveness or conducting extended cost-benefit analyses (See Economics and Finance), which reflect local value systems, develop trust in local projects and help to mainstream approaches Build robust, long-term monitoring systems into policy10. Project objectives and indicators should be specific to the triple win of enhancing biodiversity, mitigating or adapting to the effects of climate change and reducing poverty, whilst also being appropriate to the scale of an intervention. There is added benefit in aligning with existent ICF Key Performance Indicators or indicator frameworks relevant to the project’s investor or overarching programme (see Biodiversity Indicators in Context chapter). Assessment frameworks should establish appropriate baselines and targets, be adaptive to change, and disaggregate data (such as for gender) where possible24. Evaluations and reporting should acknowledge uncertainty and complexity, communicate all benefits and costs clearly, and be openly accessible and shared, especially with local communities5,9. View examples: > Silvopastoral systems in Colombia > Mangrove restoration in Viet Nam Return to Principles