Climate scenarios serve a number of functions in helping society manage climate change—pedagogic, motivational or practical (for example, in engineering design, spatial planning and policy development). A variety of methodologies for scenario construction have been experimented with, all of them to a greater or lesser extent depending on the use of climate models. Yet the development of climate scenarios involves much more than climate modelling. The process of scenario development is one of negotiation between relevant stakeholders—funding agencies, policy communities, scientists, social actors and decision-makers in a variety of sectors. This process of negotiation is illustrated through an analysis of four generations of UK climate scenarios—published in 1991, 1996, 1998 and 2002. Using ideas from science and technology studies and the sociology of scientific knowledge to guide our analysis, we reveal complex relationships between the interests of UK science, policy and society. Negotiating climate scenarios involves compromise between the needs of policy, science and decision-maker in relation to, for example, the selection of the development pathway(s) and emissions scenario(s), the choice of climate model(s), the assessment and communication of uncertainty and the presentational devices used. These insights have a significant bearing on the way in which climate scenarios should be viewed and used in public discourse, strategic planning and policy development.