Ecosystem-based adaptation (EbA) is the use of biodiversity and ecosystem services as part of an overall strategy to help people to adapt to the adverse effects of climate change and promote sustainable development. This report presents the results of using our Framework for Assessing EbA Effectiveness at the Adaptation, Vulnerability and Ecosystems (AVE) project, Costa Rica and Panama. The findings will be combined with those from 12 other sites in 11 other countries to help show climate change policymakers when and why EbA is effective.