Conductors are very important in technology. At the current rate of extraction how long until the world's reserves of copper are depleted?

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    $\begingroup$ I think you need to define "last". Last for what purposes, and in what quantities? Do you want to measure the time till their commercial use stops? Or till their total quantity on earth falls below 1kilogram? or when there is less than 1ypm trace amount left? Given your question, I believe you're looking for the first interpretation, but it's good to define your terms completely. $\endgroup$ Commented May 9, 2018 at 9:52
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    $\begingroup$ I would add that, unless for some reason we start shooting insane quantities of stuff in space, it's not like copper is going anywhere - it's all still here, in devices and objects subject to rapid obsolescence, and unlike - say - oil, it can be recovered. Although recent high-tech devices make separation more complex, reading around I see that currently recycled copper amounts to around 35% of the world annual copper usage. $\endgroup$ Commented May 9, 2018 at 10:26
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    $\begingroup$ 35% Wow that's huge $\endgroup$ Commented May 9, 2018 at 10:29
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    $\begingroup$ @theenigma017: yep, and if reserves started to finish I'd expect we could do significantly better than that. $\endgroup$ Commented May 9, 2018 at 10:44

1 Answer 1


How long will these reserves last?

Short answer: longer than you think and will outlast me, you, our children and our grandchildren. Possibly last forever.

Long answer: This is a fairly complex issue. There was a book published about this topic several years ago claiming that we are running out of metals. Turns out that the book had a major flaw in its reasoning, so the same publisher followed up with a second book refuting the first one. Both books are open access and freely available so I recommend having a look.

The problem lies in the definition of the word reserve.

What are reserves?

A reserve is an ore deposit (that is, a concentration of a certain metal) that we know exactly how much is in there to a good degree, and we have detailed plans on how to extract it. This means, we have plans to build a mine, we know the cost of running the mine, etc. In some countries (for example, Canada and Australia) you are not allowed to call something a reserve unless you have the plans. This is a legal definition.

What are resources?

On the other hand, if you know how much metal is in the deposit, but you haven't made the plans to extract it yet, it is a resource. You are not legally allowed to call it a reserve.

The work required to develop a resource into a reserve costs money. You have to employ mine engineers, you need to get environmental approval, you have to do a lot of lengthy and costly things. Therefore, you don't "declare" a reserve until you have to. If you are a mining company and you have reserves of 40 years, why bother converting more of your resources into reserves? And this is exactly the problem: alarmists and the media consider the reserves, without the resources. Of course we have limited reserves! Because it's pointless to turn the resources to the reserves if we still have reserves!

Quoting Antonio Arribas, an exploration geologist, from an enlightening article published in the SEG Newsletter:

One was published in issue 2605 of the international science magazine New Scientist in May 2007 (Fig. 5). In it, the author claims that, based on data by researchers from Yale University and the University of Augsburg, “if predicted new technologies appear and the population grows, some key resources will be exhausted” within what is graphically shown as an alarmingly short time frame (Cohen, 2007). Among the mineral resources covered, platinum, indium, and copper are particularly illustrative of the errors of interpretation contained in the article and the overall fallacy that this report represents.

According to the article, humankind should be running out of platinum within four years (15 years from 2007). However, despite production of 2,000 t of platinum between 2007 and 2017 and a metal price drop of 26%, the global reserves of platinum group metals have decreased only by 2.8%3 (data from USGS, https://minerals.usgs.gov/ minerals/pubs/mcs/). Likewise, according to this report we should have run out of indium sometime between 2012 and 2017. Never mind that, as a key component of indium tin oxide (ITO), this metal has been present as a transparent thin film conductor in the touch screen displays of every smartphone and tablet manufactured since then—including the 1.2+ billion iPhones sold by Apple alone since the product’s release in June 2007, barely a month after publication of the New Scientist article.

The second article and infographic selected were titled “Global resources stock check” and appeared in a June 18, 2012, article from BBC Future (www. bbc.com/future/story/ 20120618-global-resources-stock-check). In this report, the world supplies of indium, antimony, and copper, just to choose three, were projected to last through 2024, 2020, and 2044, respectively. I would argue that nothing but common sense is needed to believe that by the time of the Paris Olympiad in 2024, ITO-based transparent thin film conductors (or a new, and likely superior, substitute) will continue to be present in digital displays and thin-film photovoltaic cells, among many other applications. As for antimony, how do we reconcile the prediction that we should have only two years left of the metal now when, after production of 1.1 Mt between 2011 and 2017, global reserves remain unchanged within the 1.5- to 2.1-Mt range that has existed every year since 1997, when the U.S. Geological Survey started to record reserve estimates? In other words, for the time being and for the foreseeable future, the reserves of this metal are controlled by economics, technology, geopolitics, etc., and not by absolute limitations of availability in nature.

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    $\begingroup$ I may agree with you that we have endless resources, but can they also be converted into reserves with 100% efficiency? For example, resources that are located in more troublesome parts of the Earth (volcanic/flooded/stormy) would require more cost investment than profit output. So, from a commercial point of view, they won't really be useful, and hence remain untouched. $\endgroup$ Commented May 9, 2018 at 10:14
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    $\begingroup$ @GaurangTandon Everything depends on cost, which is driven by demand. New technologies emerge that allow economical extraction of metals that were previously in low abundance or inaccessible. You should also remember that recycling is getting more and more efficient with time. I recommend reading the second book I linked to in my answer, or at least parts of it. $\endgroup$
    – Gimelist
    Commented May 9, 2018 at 10:27
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    $\begingroup$ One obvious and interesting example is that it's nearly economic to mine old landfill sites. Prices of some materials wouldn't have to go up much for that to be viable. In fact they probably don't have to go up at all, as the costs will fall because the process is still in a protoype stage. $\endgroup$
    – Chris H
    Commented May 9, 2018 at 10:58
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    $\begingroup$ @GaurangTandon Which is exactly why the idea of "peak some resource" has always been a manipulation and doom-mongering. As prices increase and/or technologies improve, sources that weren't profitable in the past become profitable. There's probably more gold dissolved in the oceans than has been mined in human history, but it's not economical to extract it right now. But "being economical" is not a constant - it's a (complicated) product of supply and demand, technology, investment... If oil prices keep increasing, at some point bio-oil will become profitable, no intervention needed. $\endgroup$
    – Luaan
    Commented May 9, 2018 at 11:55
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    $\begingroup$ @ChrisH Today's junk is tomorrow's valuable resource :) This has happened so many times over in human history, it's crazy how it hasn't become ingrained in people's minds yet. They usually don't even have a clue of what kind of waste processing we're already doing. Heck, pretty much the whole petroleum industry (including plastics, medicine, fertilizers...) started as a way to do something useful with the byproducts of petroleum production (which was just burned for light and heat!). In some places, most of the profit from herding cows is from the sale of manure, rather than milk/meat. $\endgroup$
    – Luaan
    Commented May 9, 2018 at 12:00

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