Metal stocks and sustainability

Abstract

The relative proportions of metal residing in ore in the lithosphere, in use in products providing services, and in waste deposits measure our progress from exclusive use of virgin ore toward full dependence on sustained use of recycled metal. In the U.S. at present, the copper contents of these three repositories are roughly equivalent, but metal in service continues to increase. Providing today's developed-country level of services for copper worldwide (as well as for zinc and, perhaps, platinum) would appear to require conversion of essentially all of the ore in the lithosphere to stock-in-use plus near-complete recycling of the metals from that point forward.

Fig. 1.

Flow of copper per capita into use in the U.S. is known in aggregate to 1929 and is distributed into four use categories from 1929 onward.

Fig. 2.

Total per-capita copper stock in use in the U.S. through the 20th century. The GDP of the U.S. from 1929 through 1999 is also indicated.

Fig. 3.

Subdivision of the copper stock per capita in the U.S. for major categories of use.

Fig. 4.

Cumulative discovery of copper in ore and the cumulative extraction of copper worldwide in the 18th–20th centuries.