Do you remember Peak Oil? This was the theory, driven by research originally conducted by petroleum geologist M.K. Hubbert in the 1950s, that oil production inevitably followed a bell curve, with supply eventually peaking as easier reserves were exhausted, leading to an inflexion point in production and a long tailing off. Originally Hubbert was talking solely about US oil production, and he seemed to have been borne out by the evidence. But a lack of discoveries of new large fields in the 1990s led to a revision of the theory that predicted a global production peak in 2005-6, potentially leading to rapidly rising oil prices until demand destruction occurred.