Community-based adaptation, in principle, leverages existing local knowledge, capabilities, and priorities.Although there is an increase in adaptation activities in the Pacific region, it remains uncertain whether these are effectively promoting long-term adaptive capacity. Here we evaluate the performance of 32 community-based adaptation initiatives across 20 rural communities in the Pacific Islands. We find that initiative appropriateness was a strength while sustainability was a consistent issue; locally-funded initiatives and those implemented by non-governmental organisations were more likely to perform better; climate-awareness raising initiatives and those integrated with ecosystem-based adaptation performed best. We also identify four interdependent optimization points for future community-based adaptation initiatives: local approval and ownership; shared access to and benefit from initiatives; integration of local realities; and systems-thinking and forward planning. Our analysis suggests a need for a praxis shift whereby adaptation is locally-led, communities drive their own agendas, and donors and implementers become facilitators that resource the diverse capacities of communities.The Pacific Islands are highly vulnerable to climate change impacts, despite having contributed little to its causes 1 . With projections showing that island communities will continue to face worsening climate change impacts over the remainder of this century and beyond, understanding what successful adaptation looks like for the Pacific Islands is urgent 2,3 . Significant donor-funded adaptation investment means efforts have already been carried out, with the Pacific receiving the highest per capita climate aid globally 2 , a focus likely to be maintained at least in the short term 3 .With growing understanding of diminishing returns resulting from top-down climate change responses, assistance is increasingly being delivered at the local scale through bottom-up responses such as community-based adaptation (CBA) 4,5 . CBA is an approach that is small-scale, place-based and grassroots driven, while also having synergies with broader development aspirations 6 . In principle, the local scale focus of CBA provides an opportunity for adaptation to better acknowledge and integrate existing local knowledge, capabilities, priorities and context of the community, and for impacts to be addressed at the scale at which they are experienced 7,8 . Effective and sustainable adaptation that fosters reflective engagement with the community (i.e. ideal CBA) 9 , however, is not as straightforward as often implied 10 .Negative impacts can occur if CBA fails to adequately represent vulnerable populations and generate long-term social resilience 11,12 .Despite the increasing number of CBA activities across the Pacific region, uncertainty remains around whether these communities are becoming better prepared to cope in the long-term 13,14 . Bottom-up approaches such as CBA are important in Pacific Islands as they can support and utilize traditional ...
