In April 2009 Richard Metcalfe presented Quintessa's TESLA decision support tool and QPAC systems modelling tool at the fourth meeting of the Risk Assessment Network concerned with capture of CO2 and its storage in deep rock formations. This international meeting was convened in Melbourne, Australia by the IEA's Greenhouse Gas R&D Programme and CO2CRC and was attended by more than 50 experts from a wide range organisations, including government agencies, insurance companies, hydrocarbons companies, research institutes and consultants. The TESLA tool implements Evidence Support Logic (ESL) and is used to ensure that decisions are made in a structured and transparent fashion. Decision trees have been developed to help decide upon the suitability of sites for CO2 storage, and for analysing the associated uncertainties. QPAC is used to develop systems models that aid understanding of overall system performance. The outputs from these models can be used together with information from other sources to derive inputs to the TESLA decision-support tool.