Energy Footprint: What a Hamburger Really Costs

The entire lifecycle of raising animals for beef production — from growing and harvesting feed to transport, processing and refrigeration — consumes a considerable amount of energy, most of which comes from fossil fuels.

Raising a cow from calf to hamburger places a real burden on our planet's resources. Producing a single quarter-pound hamburger consumes up to 6’056 litres of water.

This water is needed to grow the feed the cow consumes, to irrigate crops and for waste disposal. Furthermore, beef production is highly energy-intensive: approximately 2 to 3 kilowatt-hours of energy are required per burger — and that energy comes from fossil fuels.

In addition, each cow requires approximately 4.5 hectares of land for grazing and feed production — that is 4.5 hectares for every cow raised, ultimately to become a hamburger. That is, to say the least, an incredible amount of land.

Moreover, beef production is a significant source of greenhouse gases, releasing approximately 44 to 55 pounds (approx. 25 kg) of CO₂ equivalent per hamburger. When one considers how many hamburgers are eaten around the world every day, the scale becomes apparent.

But the impacts do not stop there. Cattle farming frequently leads to deforestation and habitat loss, particularly in sensitive areas such as the Amazon rainforest, which harms biodiversity, disrupts ecosystems and simultaneously contributes to carbon emissions.

Cows are also not very efficient at converting feed into meat, as they require approximately 15 pounds (about 7 kg) of feed to produce just 5 pounds (2.27 kg) of beef. To make beef production more sustainable, we can apply several strategies.

Raising animals consumes a great deal of energy

A new study has recently attempted to quantify the entire process and demonstrate that it is not solely a matter of reducing greenhouse gas emissions.

Scientists from Norway, Austria, and Switzerland, working within the Industrial Ecology Programme at the Norwegian University of Science and Technology (NTNU), have taken a close look at the energy requirements of our global food system.

The study shows that our consumption of animal products has a greater impact than we might imagine.

When evaluating the figures for the years 2015 to 2019, it was found that a full 60% of global agricultural energy demand is attributable to animal products.

«This energy comes predominantly from fossil fuels,» says Edgar Hertwich, professor at the NTNU Industrial Ecology Programme and lead author of the study.

As we have seen, society increasingly views electricity as a clean energy option. However, this does not readily apply to agriculture.

The consumption of animals: An energy-hungry industry

One of the greatest challenges highlighted in the study is the inefficiency of animal husbandry.

Put simply, we grow food to feed the animals, and then we consume the animals — but the energy return on this “investment” is disappointingly low.

The study found that while livestock farming accounts for the largest share of agriculture’s energy footprint during the period under review, it supplies only 18% of the calories consumed worldwide.

Led by Kajwan Rasul, the team sought to calculate the energy return on energy investment in order to assess the efficiency of our food system.

It is a simple equation. If the figure is less than 1, it means that more energy is required to produce the food than we recover by consuming it.

Mapping the energy footprint

To conduct this study, Rasul used two models, EXIOBASE and FABIO, which allowed him to estimate energy consumption across various sectors and track the production, trade, and consumption of food.

The integration of these two models using innovative methods enabled the team to examine the energy footprint of our food system at a much deeper level than had previously been possible.

The study covered ten food categories composed of 123 different raw materials and spanned 20 regions worldwide.

They also examined the energy footprint of the food system across two five-year phases, namely 1995–1999 and 2015–2019, which allowed them to identify trends.

Rasul and the team of scientists found that the energy efficiency of global food systems improved significantly over the two decades.

The energy return on energy investment rose from 0.68 in 1995 to 0.91 in 2019. However, this still meant that in 2019, every calorie made available to society cost 10% more energy than was returned through consumption.

In regions with less industrialised food systems, such as parts of Africa and Asia, the energy return was consistently higher than one.

This is encouraging, as 68% of the world's population lives in these regions.

Rasul found that this trend is also observable in four of the five high-income regions of the world. However, he expressed concerns as to whether this trend could genuinely be attributed to efficiency gains.

Food security and the fossil fuel energy equation

The findings of this study have implications that reach further than greenhouse gas emissions alone.

If the energy required for food production were unlimited and environmentally neutral, we would not need to worry about inefficiencies in agriculture. But that is not our reality.

Food security is a matter of serious concern. If our agriculture continues to depend heavily on fossil fuels, we could be heading towards a severe crisis.

This is not merely a theoretical claim: historical events such as the energy crisis of the 1970s or the recent impacts of conflicts illustrate the potential risk clearly.

As the study's authors aptly put it, agricultural systems that are heavily dependent on fossil fuels make “the question of food security a question of energy security.”

It is time for all of us to take note of and reconsider what ends up on our plates.

The complete study was published in the journal PNAS Nexus .

You can help all animals and our planet with compassion. Choose empathy on your plate and in your glass. Go vegan.