Unanticipated Consequences of the Energy Transition

Fossil fuels are not the biggest component of humanity’s negative effect on the planet. They are the principal cause of climate change.

How can both statements be true?

It’s because climate change is not the biggest problem facing the world. It is a symptom of the much larger problem of overshooting earth’s carrying capacity. This means that humans are using natural resources and polluting at rates beyond the planet’s capacity to recover. The predicament that we face includes climate change, pollution and biodiversity loss.

CO₂ emissions are just part of this larger problem. A solution begins with an awareness that the future prosperity of human society is critically dependent on the health of the total ecosystem of which we are a part.

Material Footprint

One way to quantify what that means is a measure called the material footprint.

Material footprint is an indicator of the broader effect of human energy and material consumption on the planet. In a 2015 paper, Wiedmann et al defined material footprint as

“The global allocation of used raw material…[from] the beginning of a production chain (where raw materials are extracted from the natural environment) and its end (where a product or service is consumed).”

The United Nations Environmental Program described material flows as,

“A framework for describing the interaction of a domestic economy with the natural environment and the economy of the rest of the world in terms of flows of materials, waste and emissions.”

The components of material footprint are biomass, fossil fuels, metal ores and non-metallic minerals. Together, these include primary material extraction, physical trade (imports and exports), waste and emissions.

From this perspective, fossil fuels are not the biggest component of society’s material footprint. They account for only 17% of society’s effect on the planet (Figure 1). Non-metallic minerals account for 47%, biomass for 27% and metal ores for 10%.

Non-metallic minerals are the materials that society uses including bricks and other building materials, cement, sand, gravel, clay, crushed rock and fertilizer. Biomass consists mostly of food but also includes wood, crop residues, paper, fodder, and animal products. Metal ores include iron, uranium, aluminum, chromium and titanium as well as the principal minerals needed for renewable energy machines like solar panels, wind turbines and batteries. Fossil fuels are chiefly crude oil, condensate, natural gas, coal, peat, oil shale and tar sands.

In Figure 2, I have combined and relabeled fossil fuels, metal ores and biomass in order to investigate the relative material footprint of energy versus materials.

Considered in this way, society’s energy footprint is approximately equal to the footprint of its material needs, and about half of the energy footprint is from biomass. I recognize that this is coarse comparison because some of what is grouped as energy may be materials. Nevertheless, it provides a high-level framework for understanding how different human activities may affect the broader ecosystem

Unanticipated Consequences of an Energy Transition

As society attempts to reduce its carbon footprint, we should be equally mindful of how this may affect its material footprint on the planet. There will be unanticipated consequences that our energy transition initiative has not considered.

That plan chiefly involves substituting fossil energy with mineral/renewable energy. Ignoring the substantial problems with mineral energy (mainly intermittency and lower power density), it is unlikely that the total energy footprint will be much different during and after the transition. Nor is it probable that biomass energy will decrease.

The level of society’s material footprint has been increasing at almost 3% annually over the last decade. This is happening despite indisputable evidence of the destruction of rainforests, the collapse of animal populations, the pollution of land, river and seas, the acidification of the oceans, and loss of fisheries and coral reefs.

Society’s material footprint and global GDP correlate almost perfectly with an R² of  0.99 (Figure 3). This indicates that  continued economic growth will result in ever-greater levels of society’s material footprint. That in turn suggests that an energy transition will have little net effect on society’s material footprint on the planet.

That’s a big problem because climate change is not just about the carbon emissions that human activities produce but how effectively earth’s forests, oceans and atmosphere are able to process those emissions. If society’s material footprint on earth’s natural systems continues to increase, it is unlikely that there will be much if any reduction in net carbon emissions despite efforts to replace fossil with mineral energy.

The only way out of this trap seems to be through a reduction in material consumption. That is not part of the path that world leadership is presently following and that is worth thinking about.