Resource use matters, but material footprints are a poor way to measure it Adding up the weight of very different materials doesn’t tell us about their scarcity, environmental, or socioeconomic impacts.
What do a tonne of potatoes, gravel, coal, and copper have in common? Not much, except that they all weigh the same, and are treated exactly the same in a metric called the “material footprint”.
The material footprint sums up the weight of all the resources used within an economy. So if a country’s material footprint is 60 million tonnes, it extracts 60 million tonnes of “stuff” per year. This includes both non-renewable resources like metals and fossil fuels, and “renewable” ones like crops and wood. The scarcity or environmental impact of different resources is not considered, so every kilogram of stuff is considered just as important as every kilogram of something else.1
Note that the “material footprint” can differ from “domestic material consumption” as it attempts to adjust for traded goods, capturing total consumption within an economy.
Some readers may not be familiar with this metric, but it has gained increasing popularity in environmental discussions and international policy. It’s included as a key metric in the United Nations’ Sustainable Development Goals, which is why we have charts on it in our SDG Tracker. This metric is tracked in per capita terms and is shown in the chart below.
It is also used in the planetary pressures index by the UN Development Programme, and you’ll find many reports on it by the OECD, European agencies, and others.2
However, for reasons I’ll explain in this article, I don’t find this metric helpful in understanding the sustainability of resource use or its environmental impacts. I fear that rather than helping us tackle some of our biggest environmental and resource challenges, it obscures our understanding and takes our focus away from the most pressing problems.
There are at least three reasons why we should be measuring and monitoring our resource use:
To see if we risk running out of a particular resource . If we’ve depleted the world’s copper, cobalt, or lithium and are at risk of running out, then we need to know about it. But to assess this, we need to know how much of that specific material we’re using, and how much is left. We’d need to know how much copper, cobalt, or lithium we use each year and the state of our global reserves. To do that, we need to look at specific mineral datasets (which exist and are published by organizations such as the US Geological Survey or British Geological Survey). We have a lot of this data on Our World in Data. This is also true for “natural” ecosystems or populations we’re depleting. If we’re concerned about the depletion of Atlantic bluefin tuna, we must look at how much of that population or species we’re catching, how many are left, and how quickly populations regenerate. Our team also shows this data on fish catch and depletion for specific species. Looking at a metric that throws the weight of tuna together with wood, coal, and gravel does not help understand the scarcity of any of them. To measure the environmental impact of e xtracting and consuming resources . Mining uses land, can disrupt landscapes, and cause pollution. Burning fossil fuels generates carbon emissions and air pollution. Beef production can drive deforestation and biodiversity loss. These impacts are extremely important to monitor (we cover most, if not all, of them here on Our World in Data). But material footprints don’t tell us much about the environmental impact. The production of a tonne of gravel does not have the same impact as a tonne of uranium or pork. To measure the socioeconomic consequences of e xtracting and consuming resources . Mining can be associated with unsafe working practices, and some supply chains rely on exploitative labor. But, again, the material footprint does nothing to help us identify and improve these conditions. Cobalt and gold mining are associated with poor working conditions in countries like the Democratic Republic of Congo, but material footprints don’t tell us that. In fact, many of these precious minerals are extracted in relatively small quantities, so they barely show on a whole-economy material footprint. Some of the most documented exploitative practices have been in textile supply chains. In terms of material footprint, clothing has a very low “material intensity”, so judging by this metric, it would be deemed a more “responsible” way to spend your money.
Resource use does matter for these reasons, but the material footprint, at best, captures them poorly and, at worst, hides some of the most negative impacts.
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