The concept of peak oil is well known, according to the Hubbert theory which I discussed in "Hubbert Peak Oil" a couple of days ago, wherein the amount of oil extractable from the ground is finite and accordingly its production is expected to peak at a point where about half the resource of it has been used up. All resources are finite and will ultimately be extracted only to the limit where it is feasible to do so, whereupon either financial costs or those of energy dictate that to proceed further only yields diminishing returns. The Hubbert theory was originally applied to oil, but there are potential and similar fits to gas and coal reserves too and a recent analysis has been made using the approach to a study of 57 different minerals, as reported by Ugo Burdi and Marco Pagini in a guest posting in the blog "The Oil Drum", which covers many aspects of Peak Oil and related matters.
These authors have fitted both logistic and Gaussian functions to mineral production data from the United States Geological Survey (USGS), and it is interesting that for mercury, lead, cadmium and selenium, there is good accord found between the "ultimate recoverable resources" URR determined from the curve-fitting to the data and those reported in the USGS tables + the amount of each already extracted. For tellurium, phosphorus, thallium, Zircon(ium) and rhenium, the agreement is quite close but tends to smaller values than are indicated from the figures for cumulative production plus the USGS reserves. For gallium, the figure obtained from the fitting analysis is significantly lower than the USGS estimate (by about a factor of seven).
Evidence of peaking is found for a number of the minerals, e.g. mercury around 1962; lead in 1986; Zircon in 1990; selenium in 1994; gallium in 2000. The results for gallium are significant, both in that the peak occurred seven years ago and in the size of its total reserve, which when compared with the amount used worldwide by the electronics industry implies that we may run short of gallium any time soon. Tellurium and selenium are two other minerals that underpin the semiconductor industry and it appears that their fall in production may also impact negatively on future technologies that are entirely reliant upon them, since there are no obvious substitute materials with precisely equivalent properties.
For vanadium, although a production peak is indicated in 2005, the data in the "mineral commodities handbook" show a later and sudden surge in production, which is not fully explained but thought may potentially relate to uncertainties in reporting from countries like China. So, there may be a real and ongoing upsurge in production from e.g. the Chinese economy which is quoted as being "out of sync" with the rest of the world, such is its massive expansion, or it might be a red herring.
Interestingly, copper, zinc, tin, nickel and platinum show an almost exponential increase in production; however, as I have noted previously, the stocks of some metals may be insufficient to supply the technological demands of the modern developed world into the far (or even near) future. There is also the issue of how quickly a rare and difficultly extractable metal such as platinum might be produced in comparison with an overall demand for it. Copper production can be fitted with an exponential function up to 2006, while a logistic function provides about the same quality of fit, yet indicates a peak in about 2040. The latter agrees reasonably well with the USGS estimated copper reserves of 0.5 - 1.0 Gigatons, while the fit gives 2 Gigatons. Notably, the world price of copper has skyrocketed during the past few years, which is again attributed to demand in China, as was the cost and shortage of wood earlier in the year.
Burdi and Pagini note that all of the above analyses rest upon the notion that the determined "peaks" represent actual global production maxima. Indeed, more reserves of all minerals may yet be found if we look assiduously enough for them; but herein lies the issue of underpinning costs, both in terms of finance and energy. It is the latter that may determine the real peaking and decline of minerals, which extend beyond the simple facts, say, of mining and refining a metal from its crude ore. There is also the cost-contribution from the energy needed to garner energy-materials such as oil, gas, coal and uranium, and thence to turn them into power and machinery; and since fossil fuels are being relentlessly depleted, it takes an inexorable amount energy to produce them, resulting in a cumulative and rising energy demand overall.
Saliently, the authors point out that the whole "extractive system" is interconnected through required underpinning supplies of fossil fuels, and it is perhaps this that explains why the production of so many minerals seems to be peaking during the period between the latter part of the 20th century and the start of the 21st, in a virtual mirror-image of the era when troubles in the production of fossil fuels were experienced across the globe. Hence, it may be the lack of the latter which determines the real amount of all other minerals that can be brought onto the world markets.
"Peak Minerals", By Ugo Bardi and Marco Pagani. http://www.theoildrum.com/node/3086.