Page - 73 - in Water, Energy, and Environment - A Primer

is depleted. This is common sense, applicable to all non- renewable resources, and not disputable. What is disputable is the shape of the production/depletion curve and the assumptions thatwent into identifying the resource tobeutilized and eventually depleted. Much of the public discussion that has ensued about the application of Hubbert’s Peak Oil theory to petroleum extraction has revolved about these two facets of his theory. It is important to clarify that Peak Oil is the point in time when oil extraction reaches its maximum rate but is not synonymous with oil depletion. Following a peak in extraction rate about half of the resource is still available for extraction, and the production rate decreases steadily thereafter. Much discussion has focused on the shape of the declining curve after PeakOil is reached (plateau? sharp decline? slow decline?) and the implications for the US and world economies that are dependent onoil supplies. Hubbert’s theory received great visibility when he correctly predicted, in his 1956 paper, that US domestic oil production Figure6.1 TheHubbertCurve(Source: ‘NuclearEenergyandthe Fossil Fuels’,M.K.Hubbert,March1956). Fossil fuels 73