Mining for the Next Million Years
For many years, I've been pointing out that the entire mass of the earth, from the upper limits of its atmosphere 4,000 miles straight down to its core, consists of nothing but solidly packed chemical elements. There is not one cubic centimeter anywhere in the earth's mass that is not some chemical element or other, or some combination of chemical elements. This, I've said, is nature's contribution to the supply of natural resources, along with all of the enormous quantities of energy that go with it, from the energy contained in fossil fuels, uranium, wind, water, and the earth's core to the energy contained in thunderstorms and static electricity.
How much of this immense quantity of matter and energy can be transformed into the narrower category of natural resources that are economically useable by and accessible to man depends on the state of science, technology, and supply of capital equipment. In other words, it depends on the extent of man's knowledge of nature and the degree of his physical power over it. As man enlarges this knowledge and power, he increases the fraction of nature that constitutes economically useable, accessible natural resources. In the process, he transforms what had up to then been mere nature-given things into economic goods and wealth.
I've also always pointed out that up to now our power over nature—our ability to actually get at its contents and direct them to the satisfaction of our needs—has been measured in depths of feet rather than miles and has essentially been confined just to the thirty percent or so of the earth's surface that is land. The clear implication is that we are still at the very beginning of our ability extract economically useable natural resources from nature.
I've now gathered some empirical data that indicates just how modest man's mining activities actually are compared to the size of the earth. For example, total global production of petroleum is approximately 30 billion barrels per year. Each barrel of petroleum measures approximately .16 of a cubic meter. This means that in terms of cubic meters, the physical volume of all the petroleum extracted in the world in a year is .16 times 30 billion, which is 4.8 billion cubic meters. Since a thousand meters equals 1 kilometer, a billion cubic meters translates into a mere 1 cubic kilometer. So the physical volume of total annual global petroleum production is presently 4.8 cubic kilometers. And because 1 cubic mile equals approximately 4.17 cubic kilometers, this means that all of the world's petroleum production in a year represents about 1.15 cubic miles.
All by itself, this is enough to suggest that total global mining operations are extremely small relative to the size of the earth, which is 1.1 trillion cubic kilometers, or approximately 260 billion cubic miles. This conclusion is confirmed when one considers the global annual production of other important minerals, such as iron ore, coal, aluminum, and natural gas.
Global iron ore production was approximately 1.16 billion metric tons in 2003, the most recent year for which data are readily available. The density of iron ore varies between approximately 4 metric tons per cubic meter and 5 metric tons per cubic meter, depending on the type of ore. The smaller the number of metric tons per cubic meter, the larger the number of cubic meters required for any given tonnage. Using the lower figure of 4 metric tons per cubic meter, the total cubic volume of iron ore production in 2003 would be 291 million cubic meters, which is .291 cubic kilometers or .07 cubic miles. Because much of the iron ore extracted had a higher density, the actual physical volume of iron ore extracted was considerably less.
Global coal production in 2004 was 2.73 billion metric tons. Since the density of coal is roughly 1.3 metric tons per cubic meter, the physical volume of the coal extracted was about 2.1 cubic kilometers, or about .5 of a cubic mile.
Global aluminum production in 2001 was 32 million metric tons. The production of 1 ton of aluminum requires the mining of 4 to 6 tons of bauxite. Thus 32 million tons of aluminum production implies the mining of as much as 192 million tons of bauxite. Inasmuch as the density of bauxite is 1.28 metric tons per cubic meter, the cubic volume of the total amount of bauxite mined in 2001 was 150 million cubic meters. This in turn equals .15 cubic kilometers, or less than .04 of a cubic mile.
Global dry natural gas production in 2004 was approximately 98.62 trillion cubic feet, which equals 2,774 cubic kilometers. To put this figure in perspective, it should be realized that when liquefied, the volume of natural gas is reduced by a factor of 600. Thus the equivalent of this much gas in liquid form is 4.62 cubic kilometers, or little over 1.1 cubic miles. This, of course, is somewhat less than the cubic volume of petroleum production.
If we add up these numbers, they total 11.43 cubic kilometers or 2.86 cubic miles. To allow both for the mining of everything else and for any extractions we may have overlooked in connection with the items we've considered, let's just assume the nice round number of 100 cubic kilometers or roughly 24 cubic miles as representing all current mining operations combined on an annual basis for the world as a whole.
In a tolerably free, rational society, motivated human intelligence is easily capable not only of continuing man's ability to extract this volume of useful materials from the earth but also substantially to increase it. If the present annual volume of such extractions were merely to continue, it could do so at least for the next 100 million years. By that time, a total of 10 billion cubic kilometers or roughly 2.4 billion cubic miles of earth would have been extracted, which would represent a little less than 1 percent of the earth's total physical volume. If economic progress in coming centuries serves to increase the annual rate of extractions by a factor of 100, then mining operations could continue on that vastly larger scale for a million years, before 1 percent of the earth's volume had been extracted. The exhaustion of useable, accessible mineral deposits is simply not a problem for an economy as free as that of the United States was until a few generations ago.
Our growing problems in connection with the supply of natural resources are not caused by nature but by us. We have allowed ourselves to abandon our reason and give up our freedom. We have allowed ourselves to be led by people who would have us freeze and be immobilized rather than spill some oil on snow hardly any of us will ever see or disturb the habitat of wild animals that mean nothing to us. If we allow this to continue, then where we are headed is to a world describable by these terrible words of despair:
You must know that the world has grown old, and does not remain in its former vigour. It bears witness to its own decline. The rainfall and the sun's warmth are both diminishing; the metals are nearly exhausted; the husbandman is failing in the fields, the sailor on the seas, the soldier in the camp, honesty in the market, justice in the courts, concord in friendships, skill in the arts, discipline in morals. This is the sentence passed upon the world, that everything which has a beginning should perish, that things which have reached maturity should grow old, the strong weak, the great small, and that after weakness and shrinkage should come dissolution.
As I wrote in Capitalism, that passage is not a quotation from some contemporary ecologist or conservationist. It was written in the third century—long before the first chunk of coal, drop of oil, ounce of aluminum, or any significant quantity of any mineral whatever had been taken from the earth. Then as now, the problem was not physical, but philosophical and political. Then as now, men were turning away from reason and toward mysticism. Then as now, they were growing less free and falling ever more under the rule of physical force. That is why they believed, and that is why people in our culture are beginning to believe, that man is helpless before physical nature. There is no helplessness in fact. To men who use reason and are free to act, nature gives more and more. To those who turn away from reason or are not free, it gives less and less. Nothing else is involved.
 The passage quoted above appears In W. T. Jones, The Medieval Mind, vol. 2 of A History of Western Philosophy, 2d ed. (New York: Harcourt, Brace, and World, 1969), p. 6.
This article is copyright © 2006, by George Reisman. Permission is hereby granted to reproduce and distribute it electronically and in print, other than as part of a book and provided that mention of the author's web site www.capitalism.net is included. (Email notification is requested.) All other rights reserved. George Reisman is the author of Capitalism: A Treatise on Economics (Ottawa, Illinois: Jameson Books, 1996) and is Pepperdine University Professor Emeritus of Economics.