Within the polarised and contentious debate over future oil supply a growing number of commentators are forecasting a near term peak and subsequent decline in production. But although liquid fuels form the foundation of modern industrial economies, the growing debate on ‘peak oil’ has relatively little influence on energy and climate policy. With this in mind, the UK Energy Research Centre (UKERC) has conducted an independent, thorough and systematic review of the evidence, with the aim of establishing the current state of knowledge, identifying key uncertainties and improving consensus. The study focuses upon the physical depletion of conventional oil in the period to 2030 and includes an in-depth literature review, analysis of industry databases and a detailed comparison of global supply forecasts. This Communication summarises the main findings of the UKERC study. A key conclusion is that a peak of conventional oil production before 2030 appears likely and there is a significant risk of a peak before 2020.