Mineral Resources, Economics and the Environment

Our global appetite for mineral resources is so great that even large mineral deposits are exhausted rapidly, making it necessary to search constantly for new ones. No example of this is more dramatic than the Prudhoe Bay oil field in Alaska, which was discovered in 1967. With an original recoverable oil reserve of 9.45 billion barrels (Bbbl), Prudhoe Bay was the largest oil field in North America and the 18th largest in the world (Carmalt and St. John, 1986). Before Prudhoe Bay was discovered, the largest field in the United States was East Texas, which ranked 56th in the world with “only” 5.6 Bbbl. The discovery of Prudhoe Bay increased US oil reserves by about 30%. Your first reaction in 1967 might have been that we could relax; this huge field would take care of our needs forever. Not so. At the 1967 US consumption rate of 6 Bbbl annually, we could have exhausted Prudhoe Bay in less than 2 years. It lasted longer only because it joined many other already-producing fields and was produced at a much slower rate. Even so, US oil production peaked in 1989 and declined steadily until shale-oil production started in 2007.

This is a distressingly short period of time to exhaust something that nature took thousands or millions of years to form. That is why we call mineral deposits non-renewable resources. They differ greatly from renewable resources such as trees and fish that can be replenished naturally in periods similar to our lifetimes. It follows that we must think of Earth as having a fixed inventory of minerals to supply our needs.

You might say that there is no point in looking for deposits if even the large ones will be exhausted so rapidly. This argument is no more logical than it would be to stop fixing meals because each one is eaten as soon as it is prepared. So, let's look into what mineral exploration entails.