Diversity of both social networks and livelihood sources plays a central role in determining the sustainability of natural resource use and resilience of social–ecological systems, not least in resource-dependent economies. Yet the types of social capital and characteristics of diversity are not well understood. Here we examine social capital and livelihood diversification strategies in dynamic lakeshore social–ecological systems in Uganda adapting to climate variability and change. Water and land use data are used to explain lake system variations and lakeshore people's livelihood responses in terms of adaptive cycles and examine how system resilience changes over time in response to climatic and other stresses. Interview and household survey data are used to explain household adaptations to climate variability based on livelihood diversification and social capital and to determine which adaptations were dominant during different stages of adaptive cycles. Results show that households adapt to climate variability using concurrent, spatial, and temporal diversification of livelihoods and by drawing on social capital, but these sources of resilience are not sufficient in all circumstances. The availability of adaptation options varies according to the different stages in the adaptive cycle of the lakeshore's dynamic, coupled human–ecological system; to the degree and nature of the climatic stress; and to differences in household access to assets and adaptation options. This implies a need to maintain multiple sources of resilience for use in times of system collapse or crisis.