This thesis focuses on community-based adaptation to climate change (CBA) in a rural, Pacific islands context. It is informed by a case study of Mota Lava, a small island in northern Vanuatu. Climate change poses particular challenges for Pacific island communities, who, in general, are largely natural resource dependent, coastal dwelling and experience high climate variability and extremes. This thesis responds to the lack of critical attention paid to dominant understandings of how to implement adaptation to climate change in a way that best serves the needs of local people. The research addresses the dearth of Pacific local voices in mainstream international adaptation knowledge, therefore contributing to more effective CBA projects and programmes in the region. The features that distinguish effective CBA are that it: reduces vulnerability; is participatory; is based on local knowledge, needs and priorities, and; empowers communities to help themselves in adapting to climate change. Situated in critical human geography, the study examines mainstream international discourses of vulnerability and adaptation, and the implications of these for effective CBA implementation in a Pacific island community context. Qualitative research drawing from participatory and postcolonial theories provides a platform for community voices in Vanuatu. A combination of semi-structured interviews, unstructured interviews, participatory techniques and participant observation were used to investigate the ways in which people construct their vulnerability and adaptation needs in the community of Mota Lava. The research revealed tensions between local and mainstream constructions of vulnerability and therefore, adaptation needs. Local people construct vulnerability to climate change as caused by predominantly social factors and processes. Mechanisms for minimising the negative implications of a range of climate stresses and uncertainties are integrated into livelihoods, society and culture. However, this (considerable) adaptive capacity is threatened by aspects of social change stemming from non-local processes of (under)development. Effective CBA requires community-led development initiatives, targeting social processes at the core of increasing community vulnerability. However, in mainstream international discourse, vulnerability to climate change is constructed as being caused by specific climate stimuli, their biophysical impacts and the ability to directly respond to these. As a result, CBA implementation in the region is characterized by technical measures that reactively respond to particular climate impacts rather than proactively reducing vulnerability. The mainstream adaptation discourse limits the effectiveness of CBA for communities like Mota Lava, where the causes of vulnerability are primarily social.