June 17, 2024

There’s a certain kind of person— usually, in my experience, a certain kind of middle-aged male— who will delight in telling you that “there’s no such thing as a free lunch,” and then nod sagely while they wait for your mind to be blown. This occurs to me because the point of this post, in a way, is that everything costs something, and while I know that’s not a surprise to anyone, sometimes the practical reality of it still catches me off guard. Reading “How to Steal a River” by Rollo Romig, I was startled, despite myself, at the high, and growing, costs of sand.

Romig writes about how the rapid urbanization of India, and the boom in construction that goes with it, have led to increased demand for sand, which is a key ingredient in glass, asphalt and, especially, concrete. (If you’re like me, you tend to use the words “concrete” and “cement” interchangeably, but really cement is a component of concrete, a binder that glues together some kind of “aggregate,” which can be a bunch of different things but is most often sand). This demand is so insatiable that illegal sand mining is now a big business— so big that people are literally killing each other over it. The (practically) unregulated mining also has all kinds of environmental effects, as the beds and banks of rivers or lakes are altered and water is redirected or, as in Romig’s piece, essentially disappears.

(Interestingly, too, not just any sand will work. Specifically, the grains of desert sand are too round; the most desirable stuff is sand made by water erosion. One result of this is that desert countries like the UAE and Qatar, which are largely desert, have to import sand from Australia.)

This article sent me down a bit of an internet rabbit hole this weekend, through which I learned that this problem is by no means unique to India. There is, in fact, something of a global crisis, with the water level of Chinese lakes dropping precipitously, African beaches eaten away, and around twenty Indonesian islands vanishing completely, their land illegally scooped up and, probably, sent to Singapore. Vince Beiser, writing for WIRED, calls it a “deadly global war for sand”; the Indian villagers Romig spoke to talk about a “sand mafia.”

Again, none of this should be particularly surprising, at least in the broad strokes. If a whole bunch of new roads and buildings and bridges are getting built, then the stuff they are built out of has to come from somewhere, and eventually that stuff is going to start to run out. It’s just that I’m used to thinking about certain materials in this way more than others— for instance, that using too much wood will lead to excessive logging. Concrete, though, seems to me to come from nowhere. One advantage of concrete construction is that it can be poured into all kinds of shapes, and because of that malleability it doesn’t seem connected to anything in nature at all. But, of course, everything is.

Other construction materials also have problems; one NGO has started a “blood bricks” campaign to draw attention to the labour conditions of workers in brick kilns in India (and we can add Bangladesh to the list as well). Wood takes trees; plastic is made from oil. And at the kind of scale seen now in places like India and China and Nigeria, the downsides of any choice of materials are magnified.

One route out of this trap, at least in theory, is new materials. Meg Miller writes about the growing biomaterials industry, in which plants or microorganisms are used as, or used to create, building materials. Companies have managed, for example, to create bricks by replicating the process by which coral forms, or develop an alternative to particle board made by mushroom roots as they digest agricultural waste. These seem to offer a real alternative to traditional materials, though none of them are ready for the market yet. But I still wonder about the problem of scale: if any of these processes were to be used to in the quantities that would be needed for the kind of construction going on in China right now, would problems still emerge? Is sustainability really an inherent characteristic of the materials, or does every material merely have its own sustainable scale? If the latter is the case, then new materials whose sustainable scale is substantially higher would still be a significant improvement, but not a complete solution. There’s no such thing as a free lunch.

One potential downside that occurs to me is the classic problem with cash crops (broadly defined): they tend to push out other, less profitable, production. So, hypothetically, we could imagine a rush to produce more mushrooms in order to get enough mycelium for building demands, resulting in less space and fewer resources being given to basic food crops. That might be a bad example; I don’t know how much fungiculture really competes with food production in practice. But I think the basic logic makes sense, even if I’m wrong about the details: deciding to grow one thing rather than another imposes opportunity costs, and deciding to make a whole lot of any one thing will increase those costs.

At the same time, high demand for any product creates pressure for efficiency and volume, which tends to encourage standardization. For building materials, even more than food crops, we’d want every “crop” to be as close to identical as possible, at least in its structural qualities; if half of what is produced isn’t strong enough to actually build anything with, nobody is going to shift over to using these materials. But, as in food crops, standardization might also present dangers, in the from of vulnerability to disease and so on. In the U.S., more and more local libraries who are building libraries of local seeds to help maintain crop diversity in the face of climate change. (My favorite detail from this article: in many places, the seeds are stored in the old wooden card catalogs.) This is seen as a need now because of the standardization of seeds, led by a few massive agribusiness corporations. If everybody is growing the same variety of corn, say, and that variety doesn’t do well in a hotter climate, then we have a problem. So, is any one variety of biomaterial vulnerable to particular weaknesses? What if, say, a bacterial infection or blight of some kind infected the mushrooms that produce mycelium? Again, I don’t know how well the analogy here actually works, biologically speaking— how vulnerable, for instance, mushrooms are to such problems. But if there is a high demand for such products, and everybody therefore ends up making the same thing in the same way, it seems reasonable to ask what problems will be created by the pressure to standardize.

All of which underlines the point that there’s no magic bullet. Producing food and clothing and shelter for 8 billion people is going to present these kinds of problems, and they only get worse as the population grows. I’m generally pretty skeptical of Malthusian-type, “population bomb” theories, and I don’t really mean to suggest that this is a linear problem of growth; it does seem like the switch to biomaterials would be better, even if it is subject to some of the same problems in the long run. I just mean that “sustainability” is partly a matter of context; lots of the things we do now that are ecologically problematic would be fine at smaller scales, and lots of things that work now will cause problems at larger ones.


Tangentially related:

This week I also finished reading Dinosaurs: How They Lived and Evolved, by Darren Naish and Paul Barrett. It’s a great book; it’s definitely for the non-scientist “general reader,” but doesn’t assume that means we want to avoid all the big words or important details. (Dinosaurs are known almost entirely from bones, so if you want to learn about them, you need to talk about anatomy). I call this tangentially related because one of the reasons that so many new dinosaurs have been discovered in China recently is the amount of construction they are doing: new areas are dug up, an in the process fossils are uncovered. That’s not the only, or even the main reason— there’s also geology and politics involved— but it is part of the story.

I also read about tests on a new kind of steel, based on the structure of bone. It has a “multiphase laminate structure,” which keeps stress cracks from spreading from one layer to others, making it more durable. (The actual research that this article is describing is in “Bone-like crack resistance in hierarchical metastable nanolaminate steels,” by Koyama et al., in Science, March 10, 2017, v 355 issue 6329, pp. 1055-1057).

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