How Much Does Material Consumption Matter for the Environment?

Can we reduce environmental impact even as countries grow wealthier? Is consumption inherently tied to impact? These are core environmental questions facing us today, hinging on the notion of “dematerialization,” or the reduction of the amount of raw materials needed to make useful products. If we can dematerialize the economy, the argument goes, we might also be able to mitigate our impact on the environment.

A recent MIT-led study on global dematerialization, however, sheds some disheartening light on this idea. Examining consumption trends for dozens of chemicals and commodities over time, the authors find no evidence, for most products, of absolute dematerialization. That is, even though technological change has increased the efficiency of many materials examined, this efficiency has not resulted in any absolute decrease in their consumption. As the study’s lead author Christopher Magee said in a press release, “There is a techno-optimist’s position that says technological change will fix the environment. This says, probably not.”

“Fixing the environment,” however, is a different issue than reducing consumption for a set of materials. Decoupling environmental impact from economic growth does remain crucial to saving more nature, and we’re still far from reaching the point of “peak stuff.” Looking at consumption trends is thus an important part of the equation, but we also need to determine how consumption relates to specific environmental impacts like land use, water use, greenhouse gas emissions, and pollution. Although consumption is often linked with environmental impact, the relationship is not one-to-one: different materials entail very different production processes with differing impacts on the environment.

Let’s take a closer look at what the study tells us. The authors’ central question revolves around whether technological progress truly allows us to make more using less, or whether increased efficiency simply leads to increased consumption. This “rebound” effect is also called the Jevons Paradox, which dates back to the 19th century English economist William Jevons, who observed that as new technologies reduced the price of coal, coal consumption increased.

For their part, the study’s authors examined technological change and consumption trends for a group of chemicals, materials (like aluminum and polyester), and hardware products (like silicon transistors), and similarly found that while technological improvements have reduced the price and increased the efficiency of many of these products, those improvements have “rebounded” in the form of increased consumption. Silicon transistors, which are used in all our modern electronics, provide a prime example of this effect: as improved technology has radically decreased the amount of raw silicon needed to produce a transistor over time, we have also found all sorts of novel ways to use transistors as we invent new technologies and hardware. This increase in demand has outpaced the production efficiency such that today we’re consuming more silicon than ever.

So what this study tells us is that we’re consuming more aluminum, polyester, and silicon, even as technology allows us to use these materials more efficiently. But what if greater consumption of some materials substitutes for other activities that have greater environmental impact? Indeed, the authors raise this as an important area for further study, highlighting unanswered questions about the role of silicon semiconductors, for instance, in substitution. As our increased use of this technology enables us to communicate virtually, they ask, does it also reduce the amount of of emissions-intensive car rides and flights? Do more silicon-based solar panels allow us to use fewer fossil fuels for electricity production? Increased use of some materials, after all, can lead to a decreased use of others, making it more complicated to account for the full environmental trade-offs associated with material use.

Furthermore, not all commodities involve equal environmental impact. The materials reviewed in the study all come from somewhere, whether they are mined, refined, or produced through other industrial processes. What impact do these processes have on the environment, though? When we look at global environmental threats, the biggest driver of land-use change and biodiversity loss is agricultural expansion, not mining or fossil fuel extraction. As Breakthrough’s Linus Blomqvist pointed out in an article last year, the volume of resource consumption does not necessarily provide a direct prediction of environmental impact. To assess the study’s relevance for the global environment, it would be important to know how the commodities included rank as global sources of greenhouse gases, water consumption, and pollution, and whether their production processes have become more environmentally friendly over time.

It would also be interesting for future analyses to examine these consumption trends at the regional level. While global consumption of many of these products continues to increase, there may be significant regional variation that would offer some important insight. It is possible, for instance, that consumption of some materials in wealthy countries has actually peaked and started to decline as a result of stable population sizes and the demand saturation that can come with affluence. This pattern could also spread to other regions in the future, as developing countries grow wealthier and population growth slows or even reverses.

Ultimately, dematerialization provides an important metric for understanding our environmental footprint, but it doesn’t tell the whole story. Greater efficiency can certainly lead to increased consumption when we make really useful things, like silicon transistors, cheaper and more widely available. But it is also technological progress that allows us to substitute toward less environmentally damaging sources of material and energy, and to produce the same goods using less land, water, and fossil fuels. We may not see evidence of absolute dematerialization yet, but that doesn’t mean we should lose sight of the major ways in which technology helps us to reduce our environmental impact.