According to latest research, ever increasing rates of usage mean that resources of copper, zinc and other metals may not continue to meet the needs of the global population — even if they are recycled.
The researchers believe that scarce metals such as platinum face depletion risks this century because of the lack of suitable substitutes in devices such as catalytic converters and hydrogen fuel cells. They also found that for many metals, the average rate of use per person continues to rise and therefore even more plentiful metals face similar depletion risks.
Reported in the January issue of the Proceedings of the National Academy of Sciences, the study says that if all nations were to use the same services enjoyed in developed nations, even the full extraction of metals and extensive recycling programmes may not meet
the environmental and social consequences of metals depletion become clearer from studies of metal stocks — those in the earth, in use serving people and lost in landfills — instead of tracking the flow of metal through the economy in a given time and region.
Using copper stocks in North America as a starting point, the researchers tracked the evolution of copper mining, use and loss during the 20th century. They then applied their findings and additional data to an estimate of global demand for copper and other metals if all
nations were developed and used modern technologies.
“There is a direct relation between requisite stock, standard of living and technology in use at a given time,” said Gordon. “We therefore offer a different
approach to studying use of finite resources, one that is more directly related to environmental concerns than are the discussions found in the economics literature.”
According to the study, all of the copper ore, plus all of the copper currently in use, would be required to bring the world to the level of the developed nations for power transmission, construction and other services and pro-ducts that depend on copper.
For the entire globe, the researchers estimate that 26% of extractable copper in the Earth’s crust is now lost in non-recyclable wastes. For zinc that amount is 19%. But prices do not reflect those losses because supplies are still large enough to meet demand, and new methods have helped mines produce ever more material. As a result, the study suggests that these metals are not at risk of depletion in the near future.
“This is looking at recycling on a broader scale,” said Cynthia Ekstein, the National Science Foundation officer who overseas the Yale award. “This is looking at the metal lifecycle from cradle to grave.”