Les Houches, March 2018. José Halloy of the Université Paris Diderot discusses mineral depletion in his presentation. Note how he utilizes Hubbert curves to estimate the trajectory of mineral extraction. He predicted that the dearth of very rare elements will negatively affect the electronics industry, perhaps killing it completely.
José Halloy's presentation at the Les Houches school of physics was focused on the availability of rare minerals for electronics. This is a problem that's rarely discussed outside the specialized world of the "catastrophists", that is of those who think that mineral supply may be strongly restricted by depletion in a non-remote future. In this field, Halloy seemed to side with the "hard" catastrophists, that is expressing the option that depletion will make certain things, perhaps even the whole electronics industry, impossible.
The problem, indeed, is there: modern electronics is based on the unrestricted use of very rare minerals - the term "very rare" indicates those elements which are present only in traces in the earth's crust and which, normally, do not form exploitable deposits of their own. If you pick up your smartphone, you probably know that it contains several of these very rare elements gallium (for the transistors), indium (for the screen), tantalum (for the condensers), gold (for the electric contacts) and more.
Most of these elements are "hitch-hikers" in the sense that they are produced as impurities extracted from the production of other elements: for instance, gallium is a byproduct of aluminum production. Whether we can continue to supply these elements to the electronic industry in the future depends on a host of factors, including whether we can continue to extract aluminum from its ores. In this sense, recycling is not a good thing since recycled aluminum, of course, does not contain gallium, because it has already been extracted during the refining phase. Note also that recycling tiny amount of very rare elements from electronic devices is extremely difficult and very costly. So, in the future, the supply of these elements is going to become problematic, to say the least.
Does it mean the end of electronics? José Halloy seemed to be very pessimistic in this sense, but I think the question was not posed in the correct way. If you ask whether current electronic devices can survive the future dearth or rare mineral, the answer is obvious: they can't. But the correct question is a different one: what kind of electronic devices can we build without these elements?
Here, I think we face a scarcely explored area. So far, the industry has been produced all kind of devices focusing solely on performance on the basis of the assumption that there aren't - and there won't ever be - mineral supply problems. Can we make a smartphone without gallium, indium and all the rest? That is, limiting the elements used to the basic ones, silicon, aluminum, and other common materials? It is a difficult question to answer because, really, it has never been addressed, so far.
Yet, I think there are excellent possibilities to develop a new generation of electronic devices which are both using very little (and perhaps zero) rare elements and which are designed for complete (or nearly complete) recycling. The basic element of all electronic circuits, transistors, can be made using silicon and, in general, there are alternatives to rare metals for most devices, even though in most cases not with the same performance. For instance, light emitting diodes (LEDs) are currently based on gallium nitride (GaN) and there seem to be no comparable substitutes. Without LED, we would have to go back to the old cathode ray tubes (CRTs) which we consider primitive today. But, after all, CRTs performed well enough for us up to not many years ago. So, it would be an inconvenience, but not the end of the world.
So, it is clear that we'll have to settle on reduced performance if we want an electronics without rare elements, perhaps on a strongly reduced performance. But maybe we don't need the kind of performance we have been used to in order to keep going. Think about your smartphone: it is an incredibly complex and powerful device used mostly for trivial tasks such as looking at clips of cute kittens and sending likes and thumbs-up to other machines. Does "civilization" really need these devices? It is all to be seen.
For a fascinating discussion of an industrialized world running without rare metals, see the excellent book by Pierre Bihouix "L'age Des Low Tech" (in French - alas!)
