The UK food system, it is argued here, is not sustainable in that it is beset by vulnerabilities and lacks the resilience to overcome these. Focusing on the UK, and relying on earlier empirical data, the nature of these vulnerabilities is explained, as is their impact on the global, carbon-dependent, agro-food system. The earlier data were generated by scenarios of different food futures. These were employed as a research tool, as both their generation and their consideration involved stakeholders concerned with the supply chains for both dairy produce and wheat in the UK. The scenarios and their underpinning methodology are explained by reference to theories of systems' transitions. This article explains how scenarios of this kind can try and capture landscape pressures which might threaten the dominant paradigm and leave room for niche activity to challenge the mainstream. It will also warn, however, that the mainstream will seek to incorporate and marginalise the niche activity. The article concludes that the methodology adopted can draw out critical factors and, in the present case, tease out some early thinking about the nature of transitions towards a more sustainable and resilient system of production and consumption of food.