338 PETROLEUM GEOLOGY/Reserves Figure 11 Discovery volumes and world oil production, 1900 2000 mmbbl, billion barrels Figure 12 The effect of changing the resource base on the timing of peak oil bnbbl, billion barrels; mmbopd, million barrels oil per day on the total resource base of oil, but also on dynamic variables, such as price, infrastructure, and technology The level of peak production will also increase if recoverable reserves rise and, as a consequence, the timing of peak oil will be pushed further into the future (Figure 12) Economists argue that oil reserves are not a ‘fixed stock’ and that energy has not been getting scarcer in basic economic terms, but rather has been getting more plentiful The fall in the long run cost of oil production has been used in support of this argument It is also argued that there is no such thing as an exhaustible natural resource and that the total petroleum reserves in the Earth are an irrelevant non-binding constraint If oil becomes uneconomic to produce, the industry will disappear and whatever is left in the ground will remain unknown: a geological fact of no economic interest On the demand side, it has been proven wrong to project current rates of growth well into the future For example, in the late 1970s, the history of nearly 30 years of an average 7% per annum rate of growth in oil demand still played a powerful role in determining attitudes to the longevity of oil resources This was at a time when growth rates had already fallen to around 1% per annum and when most