Mining is an extremely important primary industry that supports our modern societies during development. Mining is the first step before building, expanding, and growing civilizations. It’s also the backbone of the modern global economy, since inventing new products is one of the main drivers of growth in our societies.
Very few materials are as strong and durable as metals. Biomass and plastics are worthy contenders – but they can’t match metals when it comes to ‘special properties’. Remarkable heat and/or electricity conductor characteristics, combined with low-density, make metals the favored material for plenty of modern products.
As our economies continue to seek growth and manufacture products at an ever-increasing rate, metal demand will undoubtedly increase. Additionally, the high-tech-dependent climate change targets set by countries around the world will require a considerable amount of metal. Green-tech like solar panels, wind turbines, or electric vehicles are made from many different metals, some of which are quite rare.
This upcoming ‘green revolution’ alone is projected to double clean tech’s current mineral demand by 2040 under our present policies – or up to 6 times our current demand by 2040 if the world aims for net-zero emissions in 2050.
Unfortunately, metal recycling won’t really help reduce primary supply that much, especially for high-tech devices [with our current technologies and waste management systems]. We’ll see why in detail in later sections, but the bottom line for now is that even with increased efforts and innovation in recycling processes worldwide – mining activity will still boom.
Procuring the metals required to transition to renewable technology will be difficult enough, but it doesn’t stop there. These technologies have the added challenge of ‘expiring’ every 20-40 years – so we can’t just complete the transition and stop mining [since recycling isn’t a perfect solution]. Note that the increasing digitalization of our societies is also increasing metal demand [e.g. sensors, IoT devices, servers, etc…].
A Few Clarifications
It’s important to be able to differentiate metals, minerals, ores, and rocks. Minerals are what’s being mined from rocks. They’re found in different concentrations [‘grades’] – where higher concentrations mean the mineral is abundantly present within the rock. Minerals are considered ‘ores’ when mining them becomes profitable. After extracting mineral ores, metals can be retrieved using different methods, but most are energy-intensive and polluting. Metals can then be mixed together to make alloys.
It’s also important to understand the difference between reserves and resources. A mineral reserve is the amount of mineral that we know exists and that we can mine for the current market price. In other words, reserves are the known profitable mining sites. A mineral resource, on the other hand, is the amount of mineral we know exists and could theoretically be mined in the future [i.e. there has to be a somewhat accessible mineral deposit]. Mineral resources are much larger than mineral reserves.
Typically, reserves are more profitable than resources [at any given point in time] because the minerals are found in higher grades. Hence, depleting reserves usually leads to the mining of lower grade mining sites.
Note that the same resource vs. reserve difference exists for metals, but requires the added step of estimating how much metal is contained in the mineral ore being mined.
Continuous Mining Cycles
Faced with an ever-increasing demand, the mining rate continues to grow. Since recycling doesn’t affect mining activity too much, we’re going through reserves at a furious pace. These reserves are depleting, meaning that some metals are becoming rarer – and are therefore becoming more valuable. As the price for these metals rises, mining companies can afford to mine other sites that have now just become profitable, because they can sell the metal at higher prices. With this system, it would seem that we won’t be running out of metals in the near future, since we can just tap into the extremely large resources every time reserves are depleted.
Unfortunately, that takes a toll. Mines pollute all along their life-cycle, contributing to both climate change and biodiversity loss. Between metal leaching, acid rock drainage, tailing dam failures, decreases in the local water table elevation, dust and noise pollution, and vibration caused by mining blasts – it’s clear that mines can pollute their environment in a number of ways. As for unregulated mines, and mines that end up exceeding their ‘close & clean-up’ budgets, it can get much worse.
While mineral extraction requires energy [often provided by fossil fuels], that usually isn’t the most energy-intensive step in the metal production process. That accolade goes to the refining plants, where metals are extracted from their mineral ores. These plants employ energy-intensive and/or chemical-heavy processes to separate the metals – so that’s not great. Additionally, there may be multiple steps required before being able to produce the final metal, which only increases energy consumption [as is the case for steel or aluminum].
High energy requirements mean high pollution levels, especially when fossil fuels dominate the industry’s energy mix. For example, the iron & steel industry accounted for roughly 5.8% of global CO2 emissions in 2018 [2.1 of 36.42 billion tonnes], with coal meeting 74% of the industry’s energy demand. Alas, many metals are even more polluting than iron & steel per unit weight produced– but fortunately their demands aren’t as high as iron & steel’s.
Back to It
Let’s get back to the ever-increasing metal production. The continuous opening/depletion cycle of mining sites works if metal prices increase – and if that doesn’t reduce demand too much [i.e. increasing a product’s cost so far that customers would no longer buy it]. As metals become more valuable, their minerals become profitable in lower-grade deposits and/or at less accessible sites. Unfortunately, extracting metals in those conditions increases energy-intensity, production costs, GHG emissions, and waste volumes – which all have significant impacts. And even if slight advances are made to mitigate metal production impacts, our rising material demand will still lead to increased pollution within the sector – for decades.
Alternatively, companies can try substituting the depleting resources with more common metals – but that’s not always an option. Modern day products are made from an insane number of different metals, all used for their specific properties. Some of these metals just aren’t substitutable, while others can be replaced – but the product then loses efficiency. That makes sense since we’ve been using the most cost-effective metals for the job, so switching to anything else now is usually worse.
It’s important to note that lowering efficiency can mean increasing mining rates. For example, we’d need far more low-efficiency solar panels than higher-efficiency ones to generate a given amount of electricity.
It’s also important to note that there is another option, which is hoping that we’ll innovate our way out of problems by finding more efficient materials at lower costs. Unfortunately, we’re too short on time to just cross our fingers and hope that innovation will save us. And besides, this type of solution isn’t sustainable forever either.
Switching from one finite resource to the next may have short-term benefits [e.g. switching to more abundant metals, reducing costs], but in the end the new reserves will deplete as well. And at that point, we’ll need to innovate an even better solution to avoid losing cost-effectiveness through substitutions or by mining lower grade deposits [which isn’t sustainable since infinite efficiency advances aren’t possible – on top of dealing with finite resources].
Renewables and High-Tech
Transitioning from fossil fuels to metal-intensive renewables will certainly shake things up. If countries follow through with their renewable energy targets, and the majority of the global energy mix shifts to renewables – then mining will soon become king [especially in an increasingly digital world due to high-tech devices]. And while reducing carbon emissions remains a priority, we need to consider the green revolution’s collateral damage.
Rare Earth Metals
Rare earth metals aren’t all that rare, but like many metals that are key to the green revolution – they’re rarely found in high concentrations [i.e. low-grade mineral ore and/or low metallic content within the ore]. And unfortunately, extracting lower-grade minerals and producing metals that have lower-metallic concentrations can have higher mining and refining impacts.
These rare earth metals are used in almost every high-tech product and renewable energy technology for their unique properties [often in very small amounts – yet play vital roles in our devices]. Unfortunately, just a few of them are substitutable, and alternatives are far less efficient. These rare metals are clearly indispensable for the green revolution – and consequently their demand is set to skyrocket as renewable technologies start their long journey to phase out fossil fuels.
The following graph shows how clean tech’s metal demand will increase in the next couple of decades.
Although transitioning to renewable-dominated energy mixes will definitely help reduce carbon emissions now – increased mining activity will increase the mining sector’s environmental impacts. Similarly, switching to renewable energy within the mining and refining sector would effectively reduce carbon emissions [e.g. with renewable-powered mining equipment]. However, that will require more mining – which will mean more renewable energy is required, and so on.
That’s a problem when dealing with finite resources like metals. Our increasingly consuming and metal-intensive societies will eventually face metal scarcity [either when the metals become too expensive for consumers or when extraction struggles to meet demand] in the absence of unrealistic circular economies. While it can take a few decades or even over a century to get to that point, it doesn’t make our current mining demand any more sustainable. And by increasing energy consumption year after year, the amount of time left before reaching metal scarcity continues to decrease. Time we could spend to voluntarily lower our dependence on energy – before we’re forced to anyway.
Without mentioning that increasing energy consumption will make our goals of phasing out fossil fuels much harder and lengthier.
Transitioning to renewable technologies remains the priority, but metals are finite resources. Governments that transition to renewables will therefore need to consider the sustainability of continued mining activity and take appropriate measures. Reducing energy and material consumption is one way to speed up the transition to renewables and ensure metal demand remains reasonable.
For reference, the chart below should help visualize which countries will play a large role in the world’s upcoming energy transition. Politics will be a determining factor in our global race for decarbonization and will ultimately decide if metal supply will be a problem in the near future or if our common interests will prevail.