Exponential Growth Forever… And Beyond

Source: Visual Capitalist

According to a study published in Nature in 2020 the weight of all human made stuff has surpassed the weight of all things living on this planet for the first time in human history. If you are well read, probably this is no news to you. What is most interesting here, however, is that half of this material was mined, transported and turned into civilization fairly recently: it simply wasn’t there two decades ago. Now close your eyes and imagine half of your house, half of the roads between buildings, half of your washing machine, car and computer disappear. Welcome to the year 2000.

All this was due to exponential growth (a perfect fit for the past century), where we were doubling the amount of human made stuff every 20 years. In case you were wondering: this rate of growth is actually rather modest on an annual basis: equaling a mere 3.5% per annum. Despite these modest gains, the collective mass of materials covered with our fingerprints has gone from 3% of the world’s biomass in 1900 to surpassing 100% of it in a mere 120 years. This is the power of exponential growth. Yet, at least seemingly, we still occupy the same cities with roughly the same infrastructure. Where did all this stuff go then? 

Well, most of it (81%) has been turned into concrete and gravel. Roads. Bridges. Buildings. Most of it in China. Yes, in the meantime some of the old stuff was demolished, scrapped and buried underground as waste, but the net accumulation of human-made material did not stop for a minute. And this is just what we actually use: the untold amounts of mining waste and the fossil fuels required to move them is simply not accounted for. If you consider the weight of rocks extracted from a mining site and the mass of the actual ores mined, the picture changes considerably. Take a gold wedding band for example:

Since gold nuggets lying around freely or easily washed out of water bodies have long since been fully collected, 4–12 tonnes (average approx. 12 tonnes) of rock must be mined today to extract four grammes of gold, i.e. the average amount of gold in a wedding ring, from which 1–4 tonnes (average approx. 2.5 tonnes) of gold-bearing ore can be selected, which can then be further crushed and mixed with toxic chemicals such as cyanides or mercury, as well as huge amounts of water, to enable the extraction of a total of 4 grammes of gold (Cooper et al. 2018)

Now, add 309 Gigatons (or billion metric tons) of cumulative world coal production (plus the overburden/waste rock), the dredging of rivers and canals, the earth removed from a house’s foundation etc. and you get about 7,000 Gt of materials moved and transformed by humanity, or rather: fossil fuels. At this point I want you to just try and visualize the 2,500 billion metric tons of carbon dioxide emitted during the process frozen into neat white cubes of dry ice. Now if you had built a tower of these, similar to the one on the info-graphic above, it would be twice as high (and heavy) as the one depicting human made materials. Compare that to the weight of Earth’s biomass (1120 Gt), and try to hold on to the view that all this extra carbon has nothing to do with tipping the balance of the planet… Folks, this amount of CO₂ is not a slight nudge, but a jumping flip kick in the face.

Considering all this huge amount of material and the untold amounts of fuel burned during the process, the question poses itself: can this go on for another round? Since we are talking about an accelerating trend, we are actually on course (at least in theory) to triple all the human made stuff by 2040. Just to put this into context, this would mean, that we would need to mine and transport more minerals than we did during the course of the entire human history. This is the rate of growth we are talking about.

A cut-out from the chart above. Source: Visual Capitalist

It is not hard to see then that even a small change in energy demand (due to ever lower resource quality) would make a colossal difference here. When you need to move ever more, ever lower grade ore (containing less and less useful materials) and grind them into ever finer dust to be able to leach out ever smaller grains of metal, you start to appreciate the “““challenge””” ahead (in triple scare quotes). Combine all this with a rapidly deteriorating surplus energy from oil and you start to see that this growth is “rather unlikely” to materialize.

The issue is, that we need this exponential growth in order to prevent a rapid collapse in infrastructure. As the length of roads and bridges grow, so does the continued investment in their maintenance get bigger and bigger. Most of what we have today has been built in the last couple of decades, since the 1960s. Now this is becoming end-of-life and begs to be replaced. What used to be an added bonus to the economy six decades ago has become a huge liability. Most of it is beyond repair. The only way to prop this system up is to add newer and newer roads to it every year. A stop in material growth would equal certain decay and collapse. Literally.

Now factor in that all this material was (and is still) moved by oil, which is not only peaking, but falling in net energy terms and you have the most “interesting” decades of human history ahead.

This doubling in material demand and waste flow, with its transportation and processing needs, would quickly double, then triple the related energy demand. While mining is responsible for 3.5% of our global energy use, moving this vast amount of stuff around the globe already takes a whopping 30% of the global energy supply (most of it in the form of gasoline and diesel). Remember: everything needs to be transported at least once during its lifetime. Rocks need to be mined then hauled by a truck. Concentrated ores need to be taken to a smelter. Finished metal products need to be carried to a manufacturing site. Finished goods need to be lugged to a store or warehouse. Raw materials need to get into a cement kiln, then mixed concrete needs to be delivered on building sites, along with crushed rocks, bricks, metal beams and many more. After the building’s eventual demolition debris must be carried away and buried “somewhere”.

Now imagine what would happen if we would need to double, then triple the amount of material mined and moved around the planet, but this time involving ever lower grade minerals (i.e. by moving even more barren rock), and using ever lower grade energy (fossil fuels requiring ever more energy to get every year)… If I may venture a guess here: global energy supply will not be able to cope with this extra demand (heck, we will be happy if it won’t contract rapidly as cheap to produce oil fields deplete). Could we then sacrifice an ever larger portion of our energy supply to increase material flows? Will anyone have the energy left to transform these minerals into products then, and finally power their use? Hardly.

The only thing this falling net energy supply, combined with a desperately rising demand, could result in is: shortages. Price spikes, then bankruptcies. In wave after wave. Absent of a new energy source, completely independent of oil, what we are facing is not another round of doubling in material use, but a slowly then rapidly failing mining and transportation industry, and a sharp drop in manufacturing output due to all kinds of shortages. And not only that. In our infinite wisdom we have based our entire financial system on uninterrupted growth. The repayment of interest (now at an ever rising rate) depends wholly upon a steady economic expansion — without which the service of debt becomes impossible, unless one takes out another loan to pay the previous one. Without materials and energy underpinning real growth, however, all these financial liabilities will turn into non-performing assets at first, then a bust soon after…

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How about recycling then? Well, virtually that means reusing metals, 3% of the total weight of the matter we have accumulated over the past century. The rest is practically impossible to recycle at scale. Used concrete, bricks and asphalt can only be mixed with new material up to a very limited amount. At best, these substances can be repurposed as road gravel to be paved over with new stuff for a smooth cover, but mostly end up in landfills. Plastics have also a bad recycling rate due to the fact that they are often mixed with other materials (and with each other). Even if selected properly, their quality degrade with every recycling round as long polymers break down into ever smaller fragments. If there were no new sources of plastics, concrete, asphalt and bricks, we would run out of these substances very-very quickly. Can you imagine a civilization without these? Well, I can, but it would look a whole lot like ancient Greece.

Photo by Who’s Denilo ? on Unsplash

Now back to metals. As I keep telling on this blog, most of the products we use are not designed to be recycled. At all. Metal components are often welded to other components, coated and combined with other metals, or find themselves buried deep inside in an injection molded plastic part. Except for large frames, machine parts, shafts, wheels, housings etc. made from a specific alloy, a good portion of metal in current use will never be recycled. It is too complicated to separate components and identify their exact material composition. It shouldn’t come as a surprise then, that recycling companies focus on highly valuable metals (like platinum, silver, gold) and large components listed above, while discarding the rest as mixed waste. This is not to mention that collection and separation also poses a huge challenge, in addition to transportation costs. According to a UN report on the subject:

Recycling rates of metals are far lower than potential for reuse. Less than one-third of 60 studied have a recycling rate above 50 per cent, though many are crucial to clean technologies such as batteries for hybrid cars or magnets in wind turbines.

Even if we would be able to achieve a 90% rate of recycling (which is basically the practical limit for industrial applications), we would still lose 10% of our valuable metals in every round. For the sake of simplicity let’s calculate with a generous 10 year lifetime for an average product. If we stopped mining, we would suffer the loss of 65% of our valuable materials in a century, and reduce our vast treasure of 39 Gt of metals to less than a metric ton under two hundred years. The power of the exponential function cuts both ways. 

The bad news is: we surely can’t get there in such a smooth fashion. All this would presume that we would not run out of fuel for the trucks, recycling plants, smelters and the rest in the meantime, or that electrification of long distance transport, high heat industrial applications or a circular economy in general is possible. I have my doubts (see the case with copper for reference). If we were to rely on recycling alone, it would work only for a short while, then after falling under a certain threshold, our complex network of technologies would simply collapse due to one or more of our critical metals becoming ‘extinct’. Without many of these special metals, for example, there are no computers, AI, or a thing called the Internet… And without those, how do we expect to manage our super-complex societies?

The periodic table of global average end-of-life (post-consumer) functional recycling for sixty metals. Most of the elements marked with dark orange are vital for semiconductor manufacturing, but are only used in trace amounts and get buried deep inside chips and circuit boards — making them practically impossible to recover. Source

After understanding all this, it is not hard to see where we are headed. (Not for the stars for sure.) Demand for polluting transportation fuels will just keep growing and growing, until it no longer can, due to the fact that it will take more and more energy to produce these fuels (which is already higher than what they can provide). At this point, well before electric vehicles could make a dent in oil consumption, growth in material use will stop and go into reverse. Keep in mind that these much hyped vehicles could only reduce fuel use after a huge upfront investment in mining and transportation (powered by fossil fuels), and thus contribute greatly to an increased demand in diesel and coal. The same is true for “renewables” (not only for the production of these technologies, but for the much needed compensation for their intermittency as well). So, is it any wonder then that fossil fuels still account for 82% of our primary global energy consumption, just like half a century ago? Or that CO2 emissions are just keep rising and rising — hitting a record high of 34.4 billion metric tons last year — “despite” an unprecedented increase in wind and solar output…? 

Inconvenient as it may sound, there are no “renewables” or nuclear without fossil fuels: an increase in “renewable” capacity means an increase in CO2 emissions. Consequently, as fossil fuels start to taper off, so will the production, replacement and maintenance of all alternative energy sources do. All this at the worst possible time. As the “energy transition” rolls on in a desperate attempt to make up for the loss of surplus energy from fossil fuels, and as old infrastructure and buildings begins to crumble (not to mention the proposed carbon capture and storage technologies, or an increased demand for freshwater and the need to mitigate the terrible effects of a climate breakdown caused by our burning desire to accumulate wealth), the “problems” requiring more energy — and not less — to “solve” will simply overwhelm us. It looks like, that we have built the mother of all Ponzi schemes, now weighing more than the entire living biosphere of the planet, and the chumps want to cash in all at once.

Photo by Jeremy Bishop on Unsplash

Until next time,

B