Well, unlike oil at least steel and most other metals can be easily recycled. Remember that the definition of what is ‘economic’ changes with minerals. Lower parts-per-million ores can be mined, if there is enough energy to do so.
Still, this will come as a shock to many economists that seem to think there are no global limits.
Geoscience Australia calculates that the country’s “economic demonstrated resources” of iron — an estimate of what is likely to be available for mining in the long term — currently amount to 24 gigatonnes, or 24 billion tonnes.
According to the Australian Bureau of Agricultural and Resource Economics, that resource is being used up at a rate of 324 million tonnes a year, with rates expected to increase over coming years.
“If you extrapolate that out, then it’s pretty easy to see that within 30 to 50 years, the high quality ore in the Pilbara will be essentially mined out,” says Mudd.
That’s a figure that Law broadly agrees with. “My calculation is 56 years if you take the current production rate and what we know about in that economic demonstrated resource basket.”