Sustainable metal management exemplified by copper in the USA

A sustainable management of non-renewable metals calls for scientific-ecological understanding of the regional material household. The copper household in the USA between 1900 and 2100 was chosen to illustrate mathematical modelling of such systems. Relatively limited and inaccurate sets of data already allow a first approximation of the metal management system. The copper fluxes of the 20th century have contributed to the formation of two new ore deposits of the same order of magnitude as the currently still available reservoir (90 million tons), i.e. copper stock in consumption products (approx. 70 million tons) and in landfills (approx. 40 million tons). The “landfill”, therefore, contains copper whose potential use is lost due to dilution. The long-term copper consumption stock is greater than the short-term stock. Scenarios show that the current economically mineable Cu-stocks will be exhausted in 30 to 50 years if a change in the existing management system does not occur. In case of a reorientation, the use of copper as a “new resource” in the consumption stocks appears to be the most promising strategy. The future waste management processes will have to increase their copper recycling rates. Received: 24 February 1999 · Accepted: 8 June 1999