So a couple days ago there was a hysterical story on slashdot saying we were running out of rare earth elements. Apparently this whole thing was started by Armin Reller, a materials chemist at the University of Augsburg, whose predictions of mineral extinction dates inspired an article by Robert Silverberg in Asimov’s science fiction magazine and reported in a new scientist story that was in turn picked up by one of the Wall Street Journal blogs. Already we should be pretty skeptical. We have a panicked warning driven by multiple commentaries on a single scientists remarks and, going by the failure of any of these stories to cite a journal article for Reller’s remarks, they may not even beer peer reviewed¹.

There is certainly a kernel of truth in these stories as in most of the misleading articles New Scientist publishes. However, these articles make it sound as if we are going to run out of various rare earth metals the way you might run out of toilet paper at home, i.e., we used it all up and have to make do without it. Indeed the article in the Asimov magazine explicitly analogizes this ‘crisis’ to a science fiction scenario of a world without usable iron. True, the prices of many rare earth metals and even Zinc are rising rapidly and for many of them we are currently using them faster than they are being mined. But does that mean we will ‘run out’ or even have to give up our flat screen TVs with Indium based transparent transistors or fancy new Intel CPUs with Hafnium based high-k dielectric? Certainly not. Moreover, we most certainly won’t ‘run out’ of these metals the way these stories suggest.

The idea that the Indium on Earth is just going to be used up in 2017, Terbium in 2012 and Zinc in 2037 is just absurd from both a geological and economic point of view. As an economic matter the market won’t simply let us keep increasing our consumption until we suddenly run out. Rather, when demand increases relative to supply the price rises and decreases consumption. If companies really believed zinc was going to simply run out in 2037 do you think they would be selling it cheaply enough to make it cost effective to make pennies with it or use it in many other trivial ways? There isn’t any great crisis ahead, merely a rise in price for these metals that will cause other metals to be substituted where possible and wasteful uses to be eliminated (eliminate the damn penny!) while essential uses (LCD displays, CPUs) continue. If you don’t believe me put your money where your mouth is. If you think we will simply run out of Terbium in 4 years buy up some Terbium or Terbium futures and you’ll make a fortune.

It’s an even more absurd proposal from a geological perspective. Neither Indium or Gallium occurs naturally in high concentrations in any mineral. Rather small quantities of both these minerals are isolated from Zinc deposits (Sphalerite) and in the case of Gallium Bauxite and coal as well. Already then something seems fishy about the suggestion we would run out of Indium in 9 years but wouldn’t run out of Zinc for another 20 years after that. Surely companies aren’t going pull all of the worlds Zinc deposits out of the ground so they can isolate the 50ppm of of Gallium and then pay to store the Zinc for another 20 years. Moreover, some simple math shows how absurd the suggestion is that we will simply run out of Zinc.

Zinc makes up .0004% of the Earth’s crust and the continental crust in turn accounts for .374% of the earth total mass. Wikipedia tells us the Earth has a mass of 5.97 * 10²⁴ kilograms and doing the math gives us 8.910¹³ metric tons of Zinc in the continental crust. Given a current consumption rate of about 7.110⁶ metric tons a year we could continue at this rate for 10 million years before we depleted the Zinc in the crust.

Of course we can’t efficiently extract anywhere near all the Zinc in the crust and it’s the notion of efficient extraction that’s central to this issue. Unlike the toilet paper you keep in your bathroom mineral deposits aren’t all equally easy to extract until you suddenly run. If we were willing to pay more for minerals like Zinc companies would start mining locations that were formerly unprofitable. Conversely if the amount of Zinc we have sitting around in storage shrinks the price of Zinc will rise and consumption will decrease. Likely the numbers quoted in the New Scientist article describe the point at which current rates of usage will deplete the proven reserves of these various minerals in the ground. In other words they tell us how long these metals would last if mining companies didn’t bother to go look for more, didn’t start extracting ore from regions currently unprofitable when prices increased and people kept using them at the same rate despite increased scarcity. We might as well assume the Martians are stealing our metal with ray guns to predict future catastrophic shortages. Now I’m just guessing at what these numbers are supposed to actually mean (the articles couldn’t be bothered to tell us that) but there is no doubt that none of these articles gives cause to be anxious.