How to assess the carbon externality of metals

These figures allow a value to be calculated for the carbon externality of metals in response to a target set by the Roadmap for the Circular Economy initiated by the French government in 2018. Two main conclusions emerge. First, the additional cost of the carbon tax (using as a reference 57 euros per ton, the average value retained by the Stern-Stiglitz report), all other things being equal, would be less than 11%, and often less than 5% for the extraction and refinement of most metals, except for steel (25%), aluminum (60%) and magnesium (more than 100%). Second, assuming that the addition of a carbon price in the form of a tax, or the payment of an ETS-type charge does not change the selling price, consumption, and alternatives to the use of a given metal, etc., the share of the additional cost would generally be modest, given the volumes produced. The exceptions are aluminum, and steel-- and again, magnesium, which is a smaller issue.

Because of the large volumes produced, aluminum and steel are responsible for a substantial proportion of carbon emissions from the mining and refining sector, and logically would bear the brunt of carbon pricing. However, attention must be paid to all metals to fulfill the objectives of the Paris Agreement and the National Low Carbon Strategy (NLCS). The internalization of the carbon externality could thus lead to a major transformation in their use, favoring moderation and the circular economy.