This paper reflects on lessons from a study undertaken by the Stockholm Environment Institute and World Wildlife Fund (WWF) that focused on adaptation needs in Belize, Nepal and Tanzania, with an emphasis on the value of participatory and collaborative processes. It finds that current interventions are fragmented across many sectors and institutions both public and private. Moreover, the interventions themselves tend to be narrowly defined and assessed. The paper argues that this makes it difficult, if not impossible, to tackle large-scale systemic challenges such as poverty, biodiversity loss and climate change effectively. Collaborative action is, therefore, a critical need. The key lessons covered by the paper provide ways to strengthen governance and support effective decision-making to address climate change; lessons specific to Belize, Nepal and Tanzania; and lessons about how to facilitate a participatory process of collective learning to support more integrated approaches.