The common perception that many of the world’s most valuable minerals, such as copper and aluminum, are becoming scarce is challenged in a new report that also highlights the environmental and social keys to unlocking future resources.
Concerns over mineral scarcity grew after the 1972 book “The Limits to Growth” predicted copper and aluminum reserves would be exhausted within about 30 years, and recent scientific and corporate reports have predicted the same, warning of profound effects on the economy and society.
“The reality is we have a lot of resource material. For some metals, we have hundreds of years of potential resources,” said John Thompson, professor of earth and atmospheric sciences and co-author of the report “Future Global Mineral Resources,” published in the latest edition of the journal Geochemical Perspectives. “And we’re fairly confident that we’ve only explored a small fraction of the Earth’s surface, so when we run out of known resources we will be able to find more, assuming we’re willing to keep exploring and improving our understanding of the Earth,” he added.
Thompson says one of the reasons mineral data is misconstrued is because of the complex approach to defining reserves – concentrations of minerals that are demonstrated to be economically viable for mining. But reserves are a small portion of a mineral’s overall global presence, and they’re often more dynamic than people think. Reserves can grow, even as a mineral is being mined, because concentrations of that mineral once considered unprofitable to mine become economically attractive. For instance, copper reserves were estimated to be less than .5 billion metric tons in 1988, but despite heavy mining, reserves are actually higher today. That’s because estimates of the Earth’s identified and undiscovered copper resources have more than tripled since that time, and a portion of these resources is converted to economic reserves each year.
“We often add reserves by doing more work to demonstrate economic viability. That can be drilling holes to increase our understanding, it could be changing the technology or it could be simply that the price of a commodity has gone up. All of those factors can turn something from being an uneconomic resource into an economic reserve,” said Thompson.
While technology and other factors are helping to grow reserves, the report cautions that the challenge to accessing them is the ability to get the material out of the ground in an energy-efficient way that causes as little disturbance to people and the environment as possible.
“It’s very energy intensive to turn rock into metal, and the footprint is large because to get to the material that’s valuable, we move a lot of rock. That rock, waste, sits around on the landscape and can degrade, causing problems such as acid generation. Similarly, the ground rock left over after metal extraction has to be managed better than in the past,” said Thompson, pointing to mining incidents such as the 2014 Mount Polley disaster in Canada and the 2015 Bento Rodrigues disaster in Brazil. In both cases, dams broke and released waste materials into nearby rivers and lakes. In the latter disaster, 17 people died.
The report also highlights social challenges to accessing mineral reserves. Approximately 1 million people worldwide work as, or support, artisanal miners – usually local people who often don’t follow regulations or have permits, but rely on mining as their only source of income. “They don’t use the best methods, and they cause a lot of disturbance. So do we move them off the land and help them do other things? Or do we help them actually mine, but in a way that’s cleaner and more effective,” asked Thompson.
Gaining community approval for mining operations can also slow the addition of new reserves, taking as long as 20-25 years to move from discovery to excavation. That can cause short-term shortages and price volatility when there are quick jumps in demand. For instance, the demand for copper might not be met if a sudden spike in electric car production were to occur.
“Social pressure and sustainable development are going to be the keys to unlocking new resources for the future as much as, and perhaps in some cases more than, the availability of the resources in the ground,” said Thompson.
Other contributors to the report include researchers from the University of Geneva, University of Grenoble Alpes, University of Michigan, and consultants from Australia and Canada.
Syl Kacapyr is public relations and content manager for the College of Engineering.