You might not realize it, but almost everywhere around you are rare metals from the earth.
In your phone, computer, or any other LCD screen, for example, you’ll find a dash of indium, a soft, malleable metal that is in short supply in the Earth’s crust. Gallium, which can emit light from a jolt of electricity, is used in semiconductors, LEDs, lasers, and the solar industry. Rhenium, one of the rarest elements in the earth’s crust, is most commonly needed in jet engines.
In other words, in our daily lives, we rely on many metals that are either uncommon, environmentally damaging, or located almost solely in places like China, Bolivia, or the war-torn Democratic Republic of Congo (i.e., not nations the U.S. is always on good terms with). What’s the risk that one day we won’t be able to depend on any of these elements?
That’s the question asked by researchers from Yale University, who have now catalogued how much we’re in danger of putting all our eggs in one basket.
Looking at each of 62 metals that we use today, including each element’s scarcity, concentration in one nation, and the difficulty of finding suitable replacements, the study creates a periodic table of risk (or as the researchers call it, “criticality”).
Metals like zinc, copper, and aluminum–the ones most commonly used in manufacturing industries since long before the computing revolution–pose little risk, and therefore have relatively low “criticality” scores.
However, unlike metals that were common in eras passed, those used in today’s newer and emerging technologies, including smartphones, batteries, advanced solar cells, and various medical applications, are not as reliably easy to get, the assessment shows. Some of these elements, like arsenic and selenium, can’t even be mined alone; they are usually the byproduct of other mining processes.
The study, published in the Proceedings of the National Academy of Sciences, found that supply limits are most important for metals used in electronics, such as gallium and selenium. For environmental implications, metals like gold and mercury proved the biggest risks. Imposed supply restrictions could affect the supply of metals like chromium and niobium, which go into forming important steel alloys, and tungsten and molybdenum, which are used for high-temperature alloys.
The larger point for the study’s authors is to underscore the need for greater electronics recycling programs as well as a change in thinking about design. The more these metals are put back into circulation, the less the demand for fresh mining becomes, notes the lead author, industrial ecologist Thomas Graedel.
“I think these results should send a message to product designers to spend more time thinking about what happens after their products are no longer being used,” he says.