Cattle and the carbon footprint

We’ve previously discussed what the carbon footprint actually means and how important it is to look at it from more than one standpoint. In order to really grasp the complete impact, there are several methods in place. LCA and CO₂ equivalence (CO_2-e) play an essential role to help us grasp the full issue, also when it comes to leather. In this article, we look at the actual impact of cattle rearing and meat consumption on global warming.

CO₂ equivalence as carbon standard

Carbon Dioxide Equivalence uses CO₂ as a basis to establish the potential impact of emissions. The base value for CO₂ is therefore a CO_2-e of 1, which represents one metric tonne of CO₂. This form of conversion is very useful, but also creates controversy as the global warming potential of different gasses changes over time. The best example is methane in comparison to CO₂, the first has a CO_2-e of 28, but its effect only lasts for 9 years. CO₂ stays active in the atmosphere for a 1000 years, so has a much longer warming period and therefore a bigger impact. The current method of calculating the CO_2-e doesn’t take this difference in longevity into account.

The carbon footprint of livestock farming

The global footprint of animal agriculture is measured using direct measurement in the air, but the contribution different sectors make are estimated. These estimates are continuously improved as better data comes in. As mentioned before, most of the livestock carbon footprint comes from methane a short-lived gas.

In 2005, the total amount of GHG emitted by the world was 49 Gt CO_2-e. Cattle accounts for 7.1 Gt CO_2-e, which breaks down like this:

The exact breakdown differs per country, feed and rearing methods.

Of the 7.1 Gt CO_2-e total emissions, 65% comes from cattle rearing (4.6 Gt CO_2-e). This represents 6% of the total global GHG. High-income countries have up to 36% fewer cattle, but still produce the same amount of meat. Beef contributes 2.9 Gt CO_2-e and milk is 1.4 Gt CO_2-e. Estimates of how much carbon footprint is associated with a kilogram of aggregated meat and milk protein is placed at 160.3 kg CO_2-e/kg protein.

Regional differences in CO₂ footprint

A clear assessment of the cattle-farming footprint has been provided by the Food and Agriculture Organisation (FAO) of the United Nations in a report on the relationship between livestock and climate change (Gerber et al., 2013). It states that livestock contributes around 14.5% of global emissions. Obviously, there is not one standard for emissions from cattle rearing and regional differences can be significant. For example, livestock plays a smaller part in the total of GHG emissions in the USA, with only 3.6%. In high-income countries almost 85% of the GHG comes from transport and energy generation. The type of animal (ruminants vs. non-ruminants), type of farming, manure management and animal age all affect the final emissions. The longer life an animal has, the greater the emissions.

A necessity for a growing world

What does this all mean? One obvious conclusion is that CO_2-e helps to show that the food industry is only one of the marginal contributors to global warming. Even more important, according to Haniotis (2019) global beef consumption has increased by 0.6%. This would seem contradictory to the previous statement, but we have to look at the growth of the global population, which is at 1%. This means beef consumption is relatively dwindling. 

Yet, meat plays a vital part in feeding our growing population and the land livestock occupies (around 70% of farming land) is unsuitable for crop farming. Many plants that livestock consume are inedible for humans and many other mammals. These plants contain cellulose and cattle can break this down and release the solar energy contained in this vast resource.

Globally, 1 billion people make a living through agriculture. This includes leather production, which uses the leftover hides in a circular way. Our world may be changing, but cattle remains a vital part of our lives.

References

• FAO. (2018). Global livestock environmental assessment model (GLEAM). Available at: FAO. [Accessed: 7 January 2019]
• Gerber, P.J., Steinfeld, H., Henderson, B., Mottet, A., Opio, C., Dijkman, J., Falcucci, A., and Tempio, G. (2013). Tackling climate change through livestock – a global assessment of emissions and mitigation opportunities. Food and Agriculture Organisation (FAO) of the United Nations (UN), Rome.
• Haniotis, T. (2019). Opinion paper: Beef, climate change and a slice of common sense. Animal, Volume 13, Issue 9. September 2019, pp. 1785-1787.