Purpose – A fully functioning carbon accounting system must be based on measurement that is materially accurate, consistent over space and time, and incorporates data uncertainty. However, achieving these goals is difficult because current carbon accounting efforts are spread across three distinct organisational fields, each prioritising different goals. This paper aims to address these issues. Design/methodology/approach – The authors identified three fields drawn together by the science of how carbon emissions can be measured, the social practices of carbon accounting, and accountability within the global carbon governance system. The authors hosted a workshop, and invited representatives participating in each of the organisational fields to highlight the contentious conversations within their field. The authors facilitated an across-field exploration of whether and how to achieve accuracy, consistency and certainty in carbon accounting. Findings – It was found that there are tensions between accuracy, consistency and certainty in carbon accounting both within and across organisational fields. Framing the evolution of carbon accounting as negotiation between these goals across fields yields powerful implications for addressing current challenges in carbon accounting. Practical implications – The authors provide guidance to policymakers on how to recognise legitimate uncertainty in carbon management science, manage the cost-benefits of policy and reporting mechanisms, and ensure actual greenhouse gas emissions reductions. Originality/value – This paper exploits the unusual approach of integrating carbon accounting across levels of analysis, from the molecular level through processes, organisations, industries and nations. This approach should help scientific, corporate and policy decision-makers move towards a more fully functioning carbon accounting system.