Jonathan Rougier is a Reader in Statistics at the University of Bristol. He specialises in uncertainty assessment for complex systems, notably environmental systems such as climate and natural hazards. He has made several important contributions in the statistical field of computer experiments, including general approaches for representing model limitations, informal and formal approaches to model calibration and multivariate emulation for expensive models, such as climate models. Dr Rougier's recent and current collaborations include climate prediction and palaeo-climate reconstruction, ice-sheet modelling and sea-level rise, and inference for dynamical systems such as glacial cycles, avalanches and hydrocarbon reservoirs.

Steve Sparks is a Professorial Research Fellow at the University of Bristol. He is a volcanologist with interests in hazard and risk assessment, and his research includes the physics of volcanic eruptions and fluid dynamics of hazardous volcanic flows. He is the world's most highly cited scientist in volcanology and a former President of the International Association of Volcanology and Chemistry of the Earth's Interior. Professor Sparks has been involved in hazard and risk assessment with advice for governments for volcanic emergencies, including during the eruption of the Soufriere Hills Volcano, Montserrat, and the emergencies related to volcanic ash from Iceland in 2010. He was on the planning committee of the Integrated Research into Disasters Reduction programme of the International Council for Science (ICSU) and is currently joint leader of the Global Volcano Model project.