The purpose of this handbook is to provide a tool to guide the planning and implementation of ecosystembased adaptation (EbA) in developing countries to help address the growing impacts of climate change. The handbook provides practical guidance for EbA in drylands, mountains and coastal zones, since these ecosystems and the people living in them are particularly vulnerable to climate change. For each type of ecosystem, it sets out the steps to take when planning and implementing EbA interventions, in order to increase the resilience of vulnerable people through ecosystem management and biodiversity conservation. Healthy ecosystems are more resilient and can better resist the negative impacts of climate change, thus supporting the people who depend on them. The handbook promotes a bottom-up, community-centred approach to ensure the needs of vulnerable people are addressed and to foster local ownership and sustainability of the EbA process. The first part of the handbook (Part I) introduces the concept of EbA and is intended for a broad audience, including policymakers. Part II introduces the ecosystems and Part III provides general protocols for EbA planning and implementation in drylands, mountains and coastal zones. These sections are intended for project managers, practitioners and technical specialists in different organisations and sectors – including government, civil society and private-sector organisations, in climate change, natural resources, agriculture, land use, poverty reduction and disaster risk reduction (DRR) sectors.