ClimateJust (www.climatejust.org.uk) is a web-based mapping tool that facilitates socially-aware decision-making by showing how, where and to what extent exposure to risk and social vulnerabilities intersect to produce ‘climate disadvantage’. Both the mapping tool and the key concept of climate disadvantage that underpins it have been widely used by a variety of policymakers and other public bodies both nationally and internationally, helping them to understand how climate change disproportionately affects vulnerable groups and informing planning decisions, adaptation strategies and practitioner guidance. Users include the UK government, the Town and Country Planning Association, Friends of the Earth, and public bodies in Liverpool, Hull, Glasgow, Staffordshire and Helsinki.