Underground coal gasification (UCG) opens up the prospect of accessing trillions of tonnes of otherwise unmineable coal. When combined with carbon capture and storage (CCS), UCG offers some attractive new low-carbon solutions on a vast scale. This paper has several aims: to review key developments in technologies for UCG, CCS and CO₂ storage in coal seam voids; to quantify the scale of the opportunity that these technologies open up; to examine the scope for linking these developments to other more familiar plans for decarbonising the fossil fuel power generation industry and other carbon-intensive industries; to identify the main hurdles to be overcome in taking forward any large-scale UCG–CCS proposition; and to propose a basis on which UCG-CCS can sit at the heart of plans to decarbonise present day industry in a way that dove-tails with longer-term ambitions for an economy based on renewable energy.