Long-term shortage of metalliferous ores and metal scrap

The ratios of ore and scrap reserves to annual production and consumption have been dropping irreversibly.

For example, recent calculations in the USA indicated that country would exhaust its own iron ores in 100 years. Exhaustion of world iron reserves was estimated at 350 years. Metals for which reserves will be exhausted in the twenty-first century include many essential for industrial production.