Research shows that community-based adaptation (CBA) can empower grassroots agents to determine their preferred responses to climate change. After two decades of practice, recent analysis is highlighting that CBA has its limits, which we argue is in part because it is predicated on an idea of ‘the communal’ as being local, static, and spatially distinct. We investigate the relationship between the nature of community and the successful implementation of CBA through an ethnographic longitudinal study in Namdrik in the Republic of the Marshall Islands. We show that the Namdrik community is best understood as a spatially dynamic network of actors whose sense of shared purpose and capacity to act varies over time in response to demographic, economic and political circumstances. These processes at times weaken the shared commitment necessary for collective action on adaptation, especially as the material support and leadership that initiated CBA in Namdrik has waned. In such circumstances, the success of CBA is spatiotemporally contingent, and depends heavily on the persistence of factors that sustain shared commitment to the task, which most often means ongoing financial and technical support for activities and for community leaders.

研究表明，基于社区的适应 (CBA) 可以使基层代理人确定他们对气候变化的首选反应。经过二十年的实践，最近的分析强调了 CBA 有其局限性，我们认为这部分是因为它基于“公共”的概念，即本地、静态和空间上的独特性。我们通过在马绍尔群岛共和国 Namdrik 进行的民族志纵向研究来调查社区性质与 CBA 成功实施之间的关系。我们表明，Namdrik 社区最好被理解为一个空间动态的参与者网络，他们的共同目标感和行动能力随着时间的推移而变化，以响应人口、经济和政治环境。这些过程有时会削弱集体适应行动所必需的共同承诺，尤其是当在 Namdrik 启动 CBA 的物质支持和领导力减弱时。在这种情况下，CBA 的成功取决于时空，并且在很大程度上取决于维持对任务的共同承诺的因素的持久性，这通常意味着对活动和社区领导者的持续财务和技术支持。