Independent: When burnt, coal is the dirtiest of all fossil fuels but a range of methods – called clean coal technology (CCT) – is being developed to reduce environmental impact of coal-fired power stations. The most important of these is carbon capture and storage (CCS), a process designed to trap carbon dioxide, preventing greenhouse gases entering the atmosphere, and storing it deep underground. A range of methods have proved technically feasible but have yet to be shown to be economically …