“Has the Earth ever run out of a natural resource?” This intriguing question was posed to me nearly two years ago by producer Niall McGee of Canada’s Business News Network (BNN).
Many of you are aware that I am a frequent guest on BNN speaking about supply and demand fundamentals of commodities and evaluation of junior resource companies. At the time I was scheduled to be interviewed on a BNN show, and Niall was working on a special film project concerning natural resources, which unfortunately never made the airwaves. When he asked the question, I said, “Let me think about this and I’ll get back to you soon.” I had an idea but wanted to do some research before sticking my neck out.
The answer that immediately popped into my brain was this:
Throughout human-kind’s history on Earth, we have never exhausted the supply of any mineral or energy commodity, with one notable exception.
But before I make my case, let’s cover some historic background:
Beginning about 10,000 years ago, Modern Mankind evolved from nomadic hunter-gatherer societies into permanent settlements supplied by subsistence farming and made possible by domestication of animals and the use of metal tools.
Man initially exploited the highest grade, simplest to extract, and most easily processed of any given metallic commodity. Nine metals were known and mined during prehistoric times including iron, copper, zinc, silver, tin, gold, mercury, lead, and bismuth. As easily obtained metal supplies were depleted, civilizations have progressively mined lower grades, at greater depths, in more remote areas, and/or from minerals requiring more complex processing.
If there is an inherent demand for a particular commodity, humans have repeatedly discovered a way to supply that demand. Demand provides the incentive for new technological advances that lead to increased supply. To my knowledge we have never completely exhausted the supply of any metal, industrial mineral, agricultural mineral, energy mineral, or energy fluid. That is, with one exception.
But before we go there, a caveat must be added:
Niall’s question was about natural resources, and in that regard, I must restrict this discussion to non-living natural resources, i.e., mineral resources. My reasoning is simple:
Life has existed on the Earth for a minimum 3.5 billion of its 4.5 billion year old history. Very early life forms are documented in the fossil record by stromatolites, a product of blue-green algae. I say “minimum” because there are very few outcrops that are older than this age. Present knowledge of Earth history indicates that our planet’s surface was mostly covered by water by about 4.2 billion years ago. Employing the fundamental geological principle that “the present is key to the past”, where we find water we find life. Therefore, it seems likely that life has existed on the Earth for much longer than 3.5 billion years; we just do not have the rocks to prove it.
Stromatolites are rare today but still form in hypersaline lakes and marine lagoons. With infinitesimal exceptions (e.g., the aforementioned blue-green algae, horseshoe crabs at 425 million years, lobe-finned fish at about 400 million years, and some 100 million year old primitive animals such as sharks and the ubiquitous cockroach), the Earth’s species have gone or will go extinct. Therefore, depletion and the ultimate demise of life forms is a natural phenomenon, and in only a very few recent instances have they been caused by activities of man.
With that qualifier, and as with all of Mickey the Mercenary Geologist’s many Rules of Thumb, there is at least one exception to the idea that mineral resources are inexhaustible. In this case the exception is indeed the first that came to mind: Guano.
Guano is the Spanish version of a Quechua Indian word meaning “dung.” The term originally referred to huge accumulated deposits of sea-going bird, and to a much lesser extent, bat, and seal droppings along the desert coastal islands of Peru. Guano was used for centuries by the coastal and Andean civilizations of Peru as fertilizer for crops. It was so valued as a fertilizer that the source islands were considered sacred by the Incas, mining was tightly controlled, and trespassers were condemned to death.