In the early nineteenth century, political economists, politicians, and geologists debated the size and duration of the British coal supply. For mineral Malthusians, the argument about a dwindling supply sharpened anxieties about population pressure, fuel demand, and limited resources. They introduced a new sense of geological limits and long-term obligations into the theology of atonement. But for cornucopian liberals, the shift to a mineral energy regime supplied a powerful refutation to the Malthusian forecast. Inexhaustible coal promised growth without end.