Meat the Consequences: The Impact Livestock have on our Environment

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Written by: Emma Warmerdam

Fig.1 Cattle in the Brazilian Amazon. Photo Credit: Rodrigo Baleia10

Food is essential for our health and wellbeing but how do our diets impact the health of our planet?

Human food production has undergone drastic changes. From early hunter-gatherer lifestyles to the first domesticated plants and animals and the agricultural revolution that followed.1 Since then scientific and technological advances have allowed humans to produce vast amounts of food and export it around the globe. These advances have come at a cost. The associated land-use changes, water usage, greenhouse gas (GHG) emissions and pollution are taking a toll on the environment.2

 Livestock plays a major role in foods impact on the planet. Livestock encompasses domesticated animals used for their meat, dairy or eggs.3 They provide valuable nutrition to people across the globe but require a lot of natural resources to raise.4 This sector impacts the environment in several different ways. One is the deforestation associated with expanding pastures and growing feed for them, this leads to biodiversity loss.8 It is estimated that when excluding humans, 94% of mammal biomass is livestock.5 This impresses the immense scale of the industry.

Another consequence is the GHG emissions associated with this method of food production. 14.5% of total human GHG emissions are produced by the livestock sector. Carbon dioxide, methane and nitrous oxide are the GHGs of most concern when it comes to livestock. As seen in the diagram below (Fig.2) the animals themselves contribute 39% of the sector’s emissions by their ruminant digestive processes.6 Carbon dioxide from land-use changes (e.g., turning forested land into pasture) also contributes. Feed production is the most critical, making up 45% of the sector’s emissions.6

Fig.2 The sources of livestock emissions. Those in red indicate direct emissions from livestock6.

By 2050 the human population is expected to reach 9.7 billion.7 As incomes rise in developing countries and urbanization persists the demand for animal protein will continue to increase.6 It is therefore imperative that we find ways of keeping up with animal product demand while also taking care of our natural resources.

How do we mitigate the environmental issues associated with livestock production? On the individual level, we can choose to cut down on our meat consumption and opt for plant-based proteins. These require less land and water and have lower GHG emissions associated with them.2 At the industry level action must be taken to produce animal protein more efficiently. This can be done by switching to intensive farming systems. This can reduce water and land needed but there are downsides. Animal welfare is often compromised, disease can spread faster and there may be more concentrated pollution.3 Another option is to use crop leftovers and grass to feed livestock instead of feed produced from arable land.8 Once it becomes feasible lab grown meat may be the future of animal protein production, this will resolve many of the environmental impacts discussed here.9

Food production is dependent on the environment. The livestock sector contributes to climate change. In a changing climate, water may become scarcer; temperature rise may cause heat stress in animals and diseases may become more virulent.4 These changes will in turn have implications for the agricultural industry.

References

  1. Thrall, P. H., Bever, J. D., & Burdon, J. J. (2010). Evolutionary change in agriculture: the past, present and future. Evolutionary Applications, 3(5–6), 405–408.
  2. Swain, M., Blomqvist, L., McNamara, J., & Ripple, W. J. (2018). Reducing the environmental impact of global diets. Science of The Total Environment, 610–611, 1207–1209.
  3. de Vries, M., & de Boer, I. J. M. (2010). Comparing environmental impacts for livestock products: A review of life cycle assessments. Livestock Science, 128(1), 1–11.
  4. Herrero, M., Wirsenius, S., Henderson, B., Rigolot, C., Thornton, P., Havlík, P., De Boer, I., & Gerber, P. J. (2015). Livestock and the Environment: What Have We Learned in the Past Decade? Annual Review of Environment and Resources, 40(1), 177–202.
  5. Hannah Ritchie and Max Roser (2020) – “Environmental impacts of food production”. Published online at OurWorldInData.org. Retrieved from: ‘https://ourworldindata.org/environmental-impacts-of-food’ [Online Resource]
  6. Grossi, G., Goglio, P., Vitali, A., & Williams, A. G. (2019). Livestock and climate change: impact of livestock on climate and mitigation strategies. Animal Frontiers, 9(1), 69–76.
  7. Nations, Department of Economic and Social Affairs, Population Division (2019). World Population Prospects 2019: Ten Key Findings.
  8. Van Zanten, H. H. E., Herrero, M., Van Hal, O., Röös, E., Muller, A., Garnett, T., Gerber, P. J., Schader, C., & De Boer, I. J. M. (2018). Defining a land boundary for sustainable livestock consumption. Global Change Biology, 24(9), 4185–4194.
  9. Bryant, C., & Barnett, J. (2018). Consumer acceptance of cultured meat: A systematic review. Meat science, 143, 8-17.
  10. https://www.theguardian.com/global-development-professionals-network/gallery/2017/jan/30/state-amazon-rainforest-deforestation-brazil-in-pictures