The focus of this paper is on scale dilemmas in environmental decision-making, particularly those dilemmas posed in space and time by the challenges of societal adaptation to climate change impacts. The analysis draws insights from a case study of strategic coastal management and decision-making at Christchurch Bay in southern England, where communities face long term threats of increased coastal erosion and coastal flooding. In terms of spatial scale, the paper exposes a mismatch between the broad geographical scale at which strategic planning takes place in the UK and the narrower spatial scale of decision-making on coastal management interventions. In terms of temporal scale, it finds that the time horizons of coastal planning are generally too short to mandate consideration of climate change impacts. Both sets of scale issues inhibit anticipatory response capacity of institutions, and the barriers to adaptation are particularly evident at the local decision-making scale in the context of local political, financial and technical constraints. Together, they point to a 'problem of fit' between the climate change threat and local capacity to take advance action to address that threat, under conditions of long term change and scientific uncertainty.