Climate change is causing wide-ranging effects on ecosystem services critical to coastal communities and livelihoods, creating an urgent need to adapt. Most studies of climate change adaptation consist of narrative descriptions of individual cases or global synthesis, making it difficult to formulate and test locally rooted but generalizable hypotheses about adaptation processes. In contrast, researchers in this study analyzed key points in climate change adaptation derived from coordinated fieldwork in seven coastal communities around the world, including Arctic, temperate, and tropical areas on four continents. Study communities faced multiple challenges from sea level rise and warmer ocean temperatures, including coastal erosion, increasing salinity, and ecological changes. We analyzed how the communities adapted to climate effects and other co-occurring forces for change, focusing on most important changes to local livelihoods and societies, and barriers to and enablers of adaptation. Although many factors contributed to adaptation, communities with strong self-organized local institutions appeared better able to adapt without substantial loss of well-being than communities where these institutions were weak or absent. Key features of these institutions included setting and enforcing rules locally and communication across scales. Self-governing local institutions have been associated with sustainable management of natural resources. In our study communities, analogous institutions played a similar role to moderate adverse effects from climate-driven environmental change. The findings suggest that policies to strengthen, recognize, and accommodate local institutions could improve adaptation outcomes.