Nonrenewable Resources

Nonrenewable resources are all those materials and energy sources consumed by our industrial society at a rate that exceeds the rate at which natural processes can renew those resources. This contrasts with renewable resources such as food and timber, which, presumably can be replaced continuously at the same rate as they are used up. Almost exclusively, these nonrenewable resources come from the Earth and from processes that operate within the Earth. Therefore, nonrenewable resources are essentially the same as Earth resources. Included among nonrenewable resources are such things as metallic and nonmetallic minerals, fossil fuels, and clean, fresh water.

Humans have a voracious appetite for every possible resource, but relative demands for any particular resource fluctuate with desire and need. Social, economic, and political factors that are not entirely predictable need to be balanced against our incomplete understanding of Earth processes. Shifts in technology or fads can turn a renewable resource into a non-renewable resource and vice versa overnight. For example, the use of chromium in the manufacture of automobiles changed drastically as auto makers shifted away from chrome-plated bumpers and trim to painted rubber bumpers and cleaner design.

In any discussion of resources, one fact must be kept clearly in mind: the ultimate resource is energy quality. Of all the things we humans use to maintain our standard of living, all but energy quality are available in essentially infinite amounts. At least some measurable, if minute, quantity of every possible resource exists everywhere. What matters for the ultimate, useful exploitation of natural resources is the distribution concentration and form that those resources take. Finding, concentrating, and refining natural resources requires the expenditure of energy currency—expenditure inevitably accompanied by the conversion of high-quality energy to less useful and lower-quality energy (the second law of thermodynamics—entropy). For example, the gasoline or diesel fuel burned by a tractor or truck is high-quality energy that represents the accumulation of the sun's energy in organic matter and its slow transformation and concentration in the form of fossil fuel. But, once an engine consumes that fuel, it is dissipated as heat that is practically useless as a source of energy to do work. Given a choice, we will always select as a source for any resource those [Page 624]deposits that are easiest to find, collect, and refine into useful products. It is the fundamental uncertainty about exactly where nonrenewable resources leave off and renewable resources begin that leads to the conflict between those who view resources within a Malthusian perspective of limits to growth and those who hold there is no practical limit to resources exploitation.