Demand for metals over the past century are leading to a dramatic shift from a geologic resource base to a metal-stock-in- society approach, according to a new report by the UN.
The report, "Metal Stocks in Society" notes that "if the total world population were to enjoy the same levels of use as the industrialized countries, the amount of global in-use metal stocks required would be 3−9 times those existing at present."
Metals such as copper have a lifetime of 25-40 years in buildings, after which they can become targets for 'urban mining', or 'mining above ground.'
It turns out that copper is one of only four or so metals for which there is information to analyze the stocks available in the post-geologic environment.
The UN report is the first of 6 planned to examine long term metals supplies globally.