Tobias Duft

 Humans have cultivated animals for food production for centuries and meat has been a staple in our diet and culture ever since. But with the industrialization the meat industry has also intensified their production and meat consumption has risen significantly. Facing the problematic of climate change, meat has been moved into a bad light regarding its high environmental costs and a more plant-based diet has risen in popularity. This post focuses on the impact of meat production and which factors influence greenhouse gas emissions the most. Additionally, this article wants to look at the transportation emissions of local meat and whether it has a beneficial influence compared to imported goods.

 Food production and distribution is responsible for 26% of human caused greenhouse gas emissions. These emissions can further be attributed to different sectors. If we look at animal products, fisheries and livestock cause 31% of all food related emissions. Adding the emissions caused by animal agriculture emerging from land use and crop production, the total amount of its share of all food related emissions rise to 53%. Additional factors include transportation, packaging and further processing, but usually only add a small amount to the total emissions(Hannah Ritchie, 2019). In total, meat production causes roughly 14% of globally made greenhouse gas emissions. To face these agricultural emissions to achieve our goal of net-zero emissions, various solutions already exist, such as improving resource efficiency, circular use of nutrients like nitrogen, carbon offsetting, alternative protein sources and implementing new policies (Fao, 2019).

 Comparing meat (especially beef) to other food sources regarding greenhouse gas emissions

When comparing food emissions, it’s important to choose a fitting scale. As for meat, comparing the emissions per 100 grams of produced protein makes the most sense, since this is the main reason, why people consume it.

Figure 65.1 – Comparing the greenhouse gas emissions per 100 grams of protein (Hannah Ritchie & Max Roser, 2021)

The production of 100 grams of protein from beef leads to 49.89 kg of greenhouse gas emissions (See figure 66.1). Other meat and dairy products also lead to high emissions when compared to their plant-based alternatives. For example, peas and soybeans cause roughly 25 times less greenhouse gas emissions than beef.

There are a lot of different factors influencing the comparingly high emissions from meat production compared to plant production, including manure management, land loss (deforestation) and crop consumption. Manure for an example leads to an increase in methane and N2O emissions caused by anaerobic fermentation and other microbial digestion such as denitrification (Chadwick et al., 2011). The significant difference regarding beef emissions and other animal emissions arises from enteric fermentation. Enteric fermentation is the process of microbial degradation of plant material such as cellulose, sugars and starches inside the cattle’s digestion track. As a byproduct of this process, methane is released by the cow, leading to an increase in greenhouse gas emissions. Additionally, methane is 24 times more potent than CO2, leading to a bigger warming potential. The difference in emissions caused by the two types of beef (beef herd and dairy herd) has two main reasons. Dairy cows produce other products like milk during their lifetime, resulting in lower meat emissions. The second reason is the type of feed these animals get. As mentioned previously, the enteric fermentation releases methane when decomposing plant material. The amount of released methane is related to the quality of feed these animals get, meaning that higher quality feed such as grass hay leads to lower emissions. Dairy cows usually consume this type of better feed, since they also produced side products in the process, resulting in lower emissions from fermentation (Chang et al., 2019).

 Transportation

An important aspect of society is the origin and transportation of the food they consume. Ideally, food should be produced and sold locally, leading to the conclusion that it is favorable for the environment. Transportation is something that is observable by people and additionally an easy concept to understand: the further something must travel, the more greenhouse gases it emits. Although the concept is correct, transportation emissions vary a lot and have less influence on total emissions than most people assume. Regarding emissions in the food production, transportation only accounts to 6% of total food emissions (Hannah Ritchie & Max Roser, 2021).

Figure 65.2 – Comparing the emissions by transportation method (Hannah Ritchie, 2020a)

Considering the numbers of figure 66.2, we can see that air transportation leads to the highest emissions. Road transport causes four times more emissions than rail transport, while shipping has the smallest effect, causing 20 times less emissions than road transport. Since transportation has a small influence on total emissions, it is important to mention that despite this, air transport can have a significant effect on emissions.

If we look at beef, transportation accounts for less than 1% of its overall emissions. A similar principal accounts for most animal products. Since their production emissions are already high, the small amount of additional emissions caused by transportation adds only a small amount. If we take this information and combine it with the numbers from figure 66.2 it is observable, that transportation of meat has little to no effect on its overall emissions, especially since long travel routes done by boat have a much smaller than local/road transport. When we look at total emissions, locally produced meat therefore has little to no beneficial effect compared to imported meat (Hannah Ritchie, 2020b).

Conclusion

Reducing food emissions is one of the biggest challenges the human population is currently facing, since food security plays a huge role in this discussion. Meat and especially beef are the drivers for these emissions, causing about 14% of total human emissions. If we improve land use changes caused by livestock and manure management, emissions can already be reduced. An easy solution is the reduction of meat consumption and replacing this protein source with plant-based options such as legumes and upcoming meat alternatives. The production of these plant-based products leads to lower emissions and additionally less influence on other environmental aspects such as deforestation.

Regarding locally produced food, it can have a positive effect, but this is only observable in plant-based products, since their production has a smaller carbon footprint and transportation therefore has a bigger influence on overall emissions. Locally produced meat, due to its high production emissions, shows almost no advantage to imported meat, when only considering transportation. In general, it is way more important to be conscious about what type of food is consumed, rather than thinking locally produced goods are sustainable. A piece of locally produced meat almost always has higher emissions than imported plant-based food of the same nutritional value, due to the huge difference in production emissions and the small effect of transportation.

References

Chadwick, D., Sommer, S., Thorman, R., Fangueiro, D., Cardenas, L., Amon, B., & Misselbrook, T. (2011). Manure management: Implications for greenhouse gas emissions. Animal Feed Science and Technology, 166–167, 514–531. https://doi.org/10.1016/J.ANIFEEDSCI.2011.04.036

Chang, J., Peng, S., Ciais, P., Saunois, M., Dangal, S. R. S., Herrero, M., Havlík, P., Tian, H., & Bousquet, P. (2019). 6 International Institute for Applied Systems Analysis, A-2361 Laxenburg, Austria. 7 Present address: International Institute for Applied Systems Analysis. https://doi.org/10.1038/s41467-019-11066-3

Fao. (2019). Five practical actions towards low-carbon livestock.

Hannah Ritchie. (2019). Food production is responsible for one-quarter of the world’s greenhouse gas emissions. https://ourworldindata.org/food-ghg-emissions

Hannah Ritchie. (2020a). Very little of global food is transported by air; this greatly reduces the climate benefits of eating local – Our World in Data. https://ourworldindata.org/food-transport-by-mode

Hannah Ritchie. (2020b). You want to reduce the carbon footprint of your food? Focus on what you eat, not whether your food is local – Our World in Data. https://ourworldindata.org/food-choice-vs-eating-local

Hannah Ritchie, & Max Roser. (2021). Environmental Impacts of Food Production – Our World in Data. https://ourworldindata.org/environmental-impacts-of-food