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”. Rethinking the material footprint may be essential to accurately evaluating sustainability and climate impact.

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

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.

It’s Not That Resource Use Doesn’t Matter — It’s That the Material Footprint Fails to Capture Why

There are at least three reasons why we should be measuring and monitoring our resource use and rethinking the material footprint:

1. 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.
2. To measure the environmental impact of extracting 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 on OWID). 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.

Read the full article about rethinking the material footprint by Hannah Ritchie at Our World in Data. Read the full article