To further clarify the water usage required for beef production, it's important to note that water use in agriculture is classified into three categories:
- Green water: Rainfall absorbed by soil and vegetation, crucial for pasture growth.
- Blue water: Irrigation water sourced from lakes, rivers, and aquifers.
- Grey water: The amount of water needed to dilute pollutants to safe levels.
Most of the water used in livestock farming is green water, which comes from natural rainfall, rather than being sourced from irrigation or groundwater (Gleick et al., 2021). This is especially common in grass-fed and pasture-raised systems, where animals graze on land that is naturally watered. However, when considering blue water, the category most critical for assessing water sustainability, it accounts for only a small portion of the total water used in livestock production.
In contrast, industrial-scale crop irrigation for plant-based foods primarily relies on blue water sources, which can worsen water shortages in vulnerable regions. This highlights the importance of reevaluating water use impacts across all food production sectors, rather than disproportionately placing the burden on livestock farming.
Beyond the Beef Debate
Water use in food production goes beyond livestock, with significant but often overlooked contributions from ultra-processed foods, plant-based meat alternatives, and crop production.
Agricultural irrigation is a major factor in global water use, accounting for about 70% of the world's freshwater withdrawals, according to the Food and Agriculture Organization (FAO). Rice cultivation is particularly water-intensive, consuming a large portion of irrigation resources, especially in regions where it is a staple crop.
Other crops like avocados, walnuts, and sugarcane also require significant water resources. The Water Footprint Network estimates that avocados need 1,400 to 2,000 litres per kilogram, walnuts around 4,900 litres, and sugarcane between 1,500 and 2,500 litres. These demands highlight the pressure on freshwater resources, a challenge that is often intensified when producing raw materials for ultra-processed foods (UPFs).
According to a study by Ridoutt et al. (2019), highly processed foods generally have a greater blue water footprint per calorie compared to minimally processed animal foods. This is particularly evident with irrigation-intensive crops like soy and wheat. Additionally, ultra-processed foods contribute significantly to environmental pollution, requiring grey water to dilute pollutants from processing plants and energy-intensive dehydration techniques to extend the shelf life of end products. These environmental impacts are often compounded by the production of plant-based meat alternatives, which involve extensive processing and ingredient fractionation.
The reliance of livestock on green water contrasts sharply with the substantial blue water demands of crop production and the grey water requirements of ultra-processed foods. Livestock farming, particularly with regenerative practices, is less dependent on freshwater withdrawals compared to the intensive irrigation needed for many crops and ultra-processed foods.
Why Livestock Farming Can Be Water-Smart
When managed sustainably, livestock farming can be part of the solution to water conservation. Grazing livestock enhances soil health by improving water retention and reducing erosion. The hoof activity of cattle plays a crucial role in aerating the soil, which increases its water-holding capacity and promotes the growth of beneficial plants.
Additionally, manure from livestock enriches soil fertility, reducing the need for synthetic fertilizers that have a hidden water footprint. Urine from cattle also contributes to nutrient cycling and soil moisture, further enhancing the land's productivity.
Regenerative farming systems that integrate livestock and crops can effectively reduce reliance on irrigation by utilizing natural rainfall more efficiently. Livestock can graze on lands unsuitable for crop production due to poor soil conditions or climate limitations, making these areas productive through animal agriculture.
Moreover, properly managed grazing systems can sequester carbon in the soil, contributing to climate change mitigation efforts. These practices highlight the potential of livestock farming to support environmental goals when managed responsibly.
Understanding Water Use Across Food Systems
On World Water Day, it is important to move beyond simplistic narratives and acknowledge that all food production requires water, but not all foods contribute equally to sustainability challenges. While livestock farming has a water footprint, most of this is natural rainfall, and when properly managed, animal agriculture can support environmental goals.
The true issue lies with UPFs and crop production, which are often overlooked in sustainability debates as they carry a significant water burden due to industrial processing and crop irrigation. A sustainable future for food production should focus on responsible livestock farming alongside reducing dependence on highly processed, resource-intensive foods.
As discussions on water conservation continue, policymakers must consider the full water impact of food production and promote balanced, science-based solutions.
References
- Gerbens-Leenes, P. W., Mekonnen, M. M., & Hoekstra, A. Y. (2013). The water footprint of different diets. Sustainability, 5(1), 32-42.
- Gleick, P. H., Cooley, H., & Morikawa, M. (2021). Water footprints and sustainable diets. Annual Review of Environment and Resources, 46, 365-386.
- Mekonnen, M. M., & Hoekstra, A. Y. (2012). A global assessment of the water footprint of farm animal products. Ecosystems, 15, 401-415.
- Ridoutt, B. G., Hendrie, G. A., & Noakes, M. (2019). Dietary strategies to reduce environmental impact: A review of the literature. Sustainability, 11(8), 2257.
- Van Zanten, H. H. E., Herrero, M., Hal, O. V., Röös, E., Muller, A., & Garnett, T. (2018). Defining a land boundary for sustainable livestock consumption. Nature Sustainability, 1(10), 631-640.
- White, R. R., & Hall, M. B. (2021). Nutritional and greenhouse gas impacts of removing animals from US agriculture. Proceedings of the National Academy of Sciences, 118(14), e2010674118.