Metal mining provides the elements required for the provision of energy, communication, transport and more. The increasing uptake of green technology, such as electric vehicles and renewable energy, will also further increase metal demand. However, the production lifespan of an average mine is far shorter than the timescales of mineral deposit formation, suggesting that metal mining is unsustainable on human timescales. In addition, some research suggests that known primary metal supplies will be exhausted within about 50 years. Here we present an analysis of global metal reserves that suggests that primary metal supplies will not run out on this timescale. Instead, we find that global reserves for most metals have not significantly decreased relative to production over time. This is the result of the replenishment of exhausted reserves by the further delineation of known orebodies as mineral exploration progresses. We suggest that environmental, social, and governance factors are likely to be the main source of risk in metal and mineral supply over the coming decades, more so than direct reserve depletion. This could potentially lead to increases in resource conflict and decreases in the conversion of resources to reserves and production.

Copper is vital to modern life and has an often-irreplaceable role in everyday infrastructure and technology. However, while the planet’s Cu endowment is finite, global Cu production continued to increase over the past century—a growth that has been matched by significant growth in estimated Cu mineral reserves and mineral resources. Here, we present a study of 2015 global Cu resources and reserves, updated from a previous paper (Mudd et al., 2013a) that outlined global Cu resources for 2010. The 2015 global Cu resource database consists of 2,301 deposits, of which 1,284 have code-based resources and 1,017 have noncode-based resources, with a further 403 of these projects having code-based reserves and a further four having noncode-based reserves. All mineral deposit types within the database have recorded an increase in Cu resources between 2010 and 2015 (except one), although grades are often similar or slightly lower (by ~5%) or are significantly lower, depending on the mineral deposit type considered. Porphyry deposits still dominate global Cu resources and reserves, containing ~75% of the contained Cu in our database. Equally unsurprisingly, Chile dominates global Cu resources and reserves, followed by the United States and Peru. The resources within the database contain some 3,034.7 million tonnes (Mt) of Cu, up from the 1,861.3 Mt reported in our 2010 study, plus we report 640.9 Mt of Cu contained in reserves (included in resources). This is a significant increase, even if all noncode-based resources were removed (i.e., 2,489.4 Mt Cu in code-based projects). There are three main reasons for this increase. First, this study is more comprehensive, with an increase in deposit numbers (730 vs. 2,301). Second, there have been new discoveries made (or rather resources outlined) between 2010 and 2015. Third, a significant proportion of resources within the 2010 study have grown in size (by a mean value of 13%), often coincident with significant amounts of production. This highlights the approaches taken by mining companies that do not delineate entire mineral deposits, especially if the systems are not completely understood, but instead drill out parts of mineralized systems, putting these into production and then often using the revenue to expand resources and reserves. This needs to be factored in when researchers are considering global metal resources, as using snapshots of resource data without considering they will most likely grow over time can often lead to erroneous conclusions. Finally, our study presents key long-term trends in Cu production as well as relationships between production, reserves, and resources. Overall, this study demonstrates that Cu resources continue to grow over time coincident with production, again suggesting that although discovery is important, the other factors that control the conversion of resources to reserves to production (e.g., mineralogic, environmental, political, logistical, and economical) are even more influential in terms of the future supply of Cu.

The critical minerals and elements are natural substances that are essential to modern life but have insecure supply. This lack of a secure supply clashes with the increasing importance of these elements, especially given their use in technologies needed to reduce global CO2 emissions and mitigate against anthropogenic climate change. In this contribution we review the by-product nature of the critical minerals and elements and the inherant uncertainties in reported critical mineral and element annual production as well as the relationships between these commodities and main-product metals and associated concentrates. We explore the geological and geographical barriers to critical mineral and element supplies, as well as how the lack of available data and the uncertainties in the data that are available hinder our ability to estimate global resources with confidence.