Multilevel Anthropogenic Cycles of Copper and Zinc: A Comparative Statistical Analysis

Abstract

Contemporary cycles for copper and zinc are coanalyzed with the tools of exploratory data analysis. One‐year analyses (circa 1994) are performed at three discrete spatial levels‐country (52 countries that comprise essentially all anthropogenic stocks and flows of the two metals), eight world regions, and the planet as a whole‐and are completed both in absolute magnitude and in per capita terms. This work constitutes, to our knowledge, the first multiscale, multilevel analysis of anthropogenic resources throughout their life cycles. The results demonstrate that (1) A high degree of correlation exists between country‐level copper and country‐level zinc rates of fabrication and manufacturing, entry into use, net addition to in‐use stocks, discard, and landfilling; (2) Regional‐level rates for copper and zinc cycle parameters show the same correlations as exist at country level; (3) On a per capita basis, countries add to in‐use stock almost 50% more copper than zinc; (4) The predominant discard streams for copper and zinc at the global level are different for the two metals, and relative rates of different loss processes differ geographically, so that resource recovery policies must be designed from metalspecific and location‐specific perspectives; (5)When absolute magnitudes of life‐cycle flows are considered, the standard deviations of the data sets decrease from country level to regional level for both copper and zinc, which is not the case for the per capita data sets, where the statistical properties of the data sets for both metals approach being independent of spatial level, thus providing a basis for predicting unmeasured per capita metal flow behavior.