The study — which was based on previous research, industry information, and expert interviews — represents the first peer-reviewed assessment of the criticality of all of the planet’s metals and metalloids.
“The metals we’ve been using for a long time probably won’t present much of a challenge. We’ve been using them for a long time because they’re pretty abundant and they are generally widespread geographically,” Graedel said. “But some metals that have become deployed for technology only in the last 10 or 20 years are available almost entirely as byproducts. You can’t mine specifically for them; they often exist in small quantities and are used for specialty purposes. And they don’t have any decent substitutes.”
These findings illustrate the urgency for new product designs that make it easier to reclaim materials for re-use, Graedel said.
The paper, published in the Proceedings of the National Academy of Sciences, encapsulates the Yale group’s five-year assessment of the criticality of the planet’s metal resources in the face of rising global demand and the increasing complexity of modern products.
According to the researchers, criticality depends not only on geological abundance. Other important factors include the potential for finding effective alternatives in production processes, the degree to which ore deposits are geopolitically concentrated, the state of mining technology, regulatory oversight, geopolitical initiatives, regional instabilities, and economic policies.
In order to assess the state of all metals, researchers developed a methodology that characterizes criticality in three areas: supply risk, environmental implications, and vulnerability to human-imposed supply restrictions.