Peak Metal
by Devilstower
Sat Jul 05, 2008 at 07:00:07 PM PDT
For those not frequent readers of Asimov's Science Fiction Magazine, not every item that appears there is actually fiction -- though sometimes we may wish it were. This month's column by Robert Silverberg focuses on the depletion of resources that don't get as much press as oil.
The element gallium is in very short supply and the world may well run out of it in just a few years. Indium is threatened too, says Armin Reller, a materials chemist at Germany’s University of Augsburg. He estimates that our planet’s stock of indium will last no more than another decade. All the hafnium will be gone by 2017 also, and another twenty years will see the extinction of zinc.
If some of these elements seem rather exotic, odds are you're looking at them right this moment. Both gallium and indium are used in the making of flat-screen displays (along with other electronics). If there's one name on that list that should stand out, it's zinc. Zinc is not particularly rare, but we're consuming it at a rate that's far faster than we're finding new sources. That's also true of our old friend copper, which is why construction sites the world over are often plagued with thieves who ransack locations for copper plumbing and wiring.
But the sobering truth is that we still have millions of years to go before our own extinction date, or so we hope, and at our present rate of consumption we are likely to deplete most of the natural resources this planet has handed us. We have set up breeding and conservation programs to guard the few remaining whooping cranes, Indian rhinoceroses, and Siberian tigers. But we can’t exactly set up a reservation somewhere where the supply of gallium and hafnium can quietly replenish itself. And once the scientists have started talking about our chances of running out of copper, we know that the future is rapidly moving in on us and big changes lie ahead.
Of course, we're not really consuming these metals, not in the way we do oil or coal. They're not actually gone, merely spread out in forms that are extremely difficult to recover. Even with our best efforts at recycling electronics, it's likely that we're years, not decades, away from making do without some of these rare earth elements. In the last twenty years alone, we've consumed about one third of available resources. Want to make a guess as to how long this can continue?
A 2007 study published in the journal New Scientist, looked at of the elements used in producing electronics and came to the same conclusion. Indium is gone within a decade. Zinc and tantalum in about twice that. The increasing scarcity of some metals is reflected in their prices.
He estimates that we have, at best, 10 years before we run out of indium. Its impending scarcity could already be reflected in its price: in January 2003 the metal sold for around $60 per kilogram; by August 2006 the price had shot up to over $1000 per kilogram.
This report also highlights a similarity between oil and rare earth elements used in electronics -- the vast majority are imported, often from politically unstable countries.
In fact, these elements can contribute directly to that instability. For some of the elements, like gallium, there's simply no good source of high quality ore. Oddly enough, that's one aspect of this story that might be a good thing. Those elements that are both extremely rare and isolated to a few high quality sources are a spark for corruption, murder, and environmental destruction. We may be currently engaged in a war for oil, but corporate proxies are also taking brutal actions in a war for tantalum, better known these days by the name of it's principle ore, coltan.
There are steps we can take, including rethinking ordnances that require copper pipes and making it easier to recycle electronics (which is similar to broadband in that it's simple in many municipalities, while rural areas often lack access). Those are good steps, and the sooner we act, the easier it will be to avoid fighting wars over copper, zinc, and their rarer cousins.
There are also those who suggest mining of landfills, and undoubtedly this is going to be tempting in the next few decades. After all, rare elements may be found at a higher concentration in some landfills than can be located in any source of ore. They're also a domestic source. However, metals trapped in consumer goods are often soundly locked in stable, complex compounds. Mining them, and freeing these elements for reuse could mean all the same disruptions to the water table, toxic chemicals used in extraction, and smelting familiar in traditional metals mining. Anyone cheering for broad application of landfill mining as a solution to our shortage of rare metals needs first to look at the pits remaining from copper mines in the west -- then think about how many of these you want next to your home town.
