extraction do not consume fewer resources to support the way of life of their inhabitants – quite the contrary. The comparison of the United States and Japan presents a counter-example of lifestyle moderation through proximity to mines. If one follows the assertion described above, Japan, which has not been a major mining country since the late 19th century, should consume more material per capita than the United States, Canada or Australia, which are, on the contrary, major mining producers. However, the exact opposite is true. In 2015, Japan had a material footprint of 23 tons per capita compared to 30, 34 and 42 tons, respectively, for the three mining countries (UNEP 2016). It could be contested that these three mining countries are much less dense than Japan, which implies more consumption for the construction and maintenance of infrastructure. This is true, but does not the latter country better reflect the case of European countries? The facts are stubborn, because a study published by the PNAS (Wiedmann et al. 2015) shows, through a statistical analysis of 137 countries and controlling for land density, that the volume of mining per capita is positively correlated with the material footprint per capita and domestic consumption per capita. In other words, countries that extract more minerals and resources on their territory also consume more materials to sustain the lifestyles of their citizens (the study also shows this for the subset of metals);
– This naturally brings us to the fourth point. We must stop perceiving the energy transition as a supply problem that can only be solved by greater use of renewable energies (even if we do not disqualify the latter). With the exception of specific and local issues (such as chlorofluorocarbons for the hole in the ozone layer), supply-side policies alone have never succeeded in solving our global environmental problems (Dinda 2004), most of the time substituting one problem for another. It is also necessary to look at demand to cut off the pressure transfers downstream. Also, in the case of the upcoming energy transition, we must allow ourselves energy efficiency solutions and, above all, achieve greater sobriety.
One can also question the role of substitution as a natural market response to the tensions that affect mineral resource markets. Could it change the mineral resources landscape in the decades to come in a sustainable way? Intra-material substitution has always existed and will probably continue to be a predominant response to local or specific problems. Permanent magnets using rare earth metals have been replaced by copper wound rotors in a number of electric vehicle engines, following geopolitical conflicts over these materials produced almost exclusively in China. However, as Florian Fizaine shows (Chapter 5), this response by substitution depends not only on the technical possibilities, of course, but also on the scale of the implementation (inter-elements, inter-components, inter-system, etc.) to which are added multiple qualitative constraints of a cultural, legal, economic, physical, etc., nature. Even if this response through substitution existed and could be mobilized at a sufficient scale, the question of the implementation of “forced” substitution raises even more legitimate doubts.
It is one thing to note that substitution takes place under the effect of “natural” forces, it is quite another to trigger this mechanism through taxes and other tools at the disposal of the States. On the one hand, the objective to be achieved is sometimes totally missed or contributes to the emergence of another problem due to poor anticipation of the behavior of agents and the complex interplay of the economy. For example, Söderholm (2011) returns to the case of Sweden, a country that has taxed the extraction of gravel produced locally and intended for export (10% price increase). Initially, the measure was aimed at protecting the landscape and maintaining the availability of clean water, for which gravel reservoirs play a major role. This very indirect measure of reduction of primary extraction via the tax is theoretically quite risky as it can fail on different pitfalls or go through other channels: a weak reaction of demand to the price of the material, an increase in imports of the material (here untaxed), an increase in recycling, a substitution toward alternative untaxed materials such as crushed rock from demolition materials. In this particular example, the feedback shows that the tax has changed the behavior of the agents by pushing them more toward the substitution of crushed rock rather than toward other forms of leverage. There has been no reduction in the use of raw materials and no real increase in recycling. Moreover, crushed rock is more energy-intensive than primary gravel extraction and the production of concrete from crushed rock requires more cement, leading Söderholm to consider the policy questionable from an environmental point of view. If the aim was to reduce extraction, the economist would have advocated using regulation as operating licenses rather than economic tools such as taxes. On the other hand, mobilizing the leverage of substitution may also face social resistance. Creating an “artificial” unavailability of a resource can thus create discontent and lead to the withdrawal of the tools at its origin under social pressure (the carbon tax comes to mind). All these reasons lead us to believe that we will not profoundly modify the mineral resource landscape of our own free will via the mechanism of substitution.
In a more macroeconomic perspective, Thierry Lefèvre (Chapter 6) develops in his contribution the questions related to the possibility of decoupling GDP and natural resources. This question of decoupling is complex and today mobilizes a large number of researchers, particularly within the United Nations Environment Programme’s (UNEP) International Resource Panel (IRP). The question of decoupling obviously refers to the tool of material efficiency, which aims to create more with less. By increasing the material productivity of our activities, we could gain in both ways: by continuing to increase GDP, while reducing our consumption of resources and the impacts left in its wake. This postulate of dematerializing the economy is an old one, notably through the concept of ephemeralization evoked by Philippe Bihouix (2019) in his latest book. We also come across it under the terms of decoupling, delinking or via the material Kuznets curve. But here again, the practical application shows poor results. Most of the time, decoupling is well below the scale effect of population and GDP per capita growth. On this point, the researcher’s contribution somewhat dashes our expectations by showing that the material footprint of most industrialized countries has grown over time.
Similarly, other studies conducted worldwide (Krausmann et al. 2017) also temper our expectations regardless of the raw materials studied. Thus, there seems to be no exception: economic growth always outweighs material productivity. Would it be enough to increase the speed of dematerialization in order to compensate for the increase in activity? Here again, the facts contradict this idea, particularly through the example of the increase in silicon productivity in the IT sector between 1970 and 2010, which, although without precedent (a factor of 10 million), has been associated with an increase in silicon consumption of a factor of 60 over the same period! Another study on sector productivity comes to the same conclusion (Dahmus 2014): sectors that have come closer (or have reached) absolute decoupling are not characterized by a high level of material productivity but rather by a low increase in their activity (scale effect). We should therefore once again either review our objectives or look at other leverage.
Another form of leverage is deemed as highly promising, that of recycling. Alain Geldron’s very comprehensive contribution (Chapter 7) on the subject of metal recycling appears enlightening from several points of view. First of all, far from the sometimes blissful optimism shown by the environmental press on urban mining and the circular economy, there is a wide gap between the discourse and the empirical facts: recycling rates are still far from circularity for base metals, and are even almost zero for minor metals. Indeed, there are several fundamental differences between the extractive metal economy and the metal recycling economy, which explain why we cannot switch from one to the other without major adjustments.
First of all, the returns to scale derived from the size of the stakeholders and the volume of deposits are quite different between the two activities, clearly contributing to the domination of the first over the second. Moreover, the share of the informal sector is still very significant in the recycling economy, whereas it remains very marginal in the extractive economy, at least when we look at the volumes supplied. Second, the qualities of the materials from primary and secondary deposits differ considerably (Fizaine 2020), again with a marked
