In the rush to come up with new, clean ways to produce electricity many people assumed that dirty old coal was a fuel of the past, a relic of the Industrial Revolution. However, coal's dominance of the market in electricity generation is actually increasing. China is building many new coal-fired power stations. The booming economies of Poland, Australia and South Africa are almost exclusively reliant on coal whilst even the Germans have turned back to the black stuff as they abandon nuclear power.

In 'Costing the Earth' Tom Heap investigates the dramatic revival of Old King Coal and asks if there are any realistic ways to turn our cheapest, most abundant fuel into a clean source of energy.

Producer: Martin Poyntz-Roberts.