Livestock depletes and pollutes global water sources – Happy #WorldWaterDay

Water is essential for the continuation of life as we know it, yet over the years it has become dangerously depleted and polluted. This post briefly highlights the impact commercial livestock farming has on the world’s water sources.


While it is said that the average person uses between 30 and 300 litres of water a day 1, it takes up to 3000 litres of water to produce the food  in their daily diet, particularly meat and dairy.

Commercial livestock farming uses over 8% of global water, of which almost 90% is used to produce animal feed 1. Sadly, the vast majority of this animal feed is produced in areas that are already facing considerable water scarcity. Approximately 38% of the world’s population live in water stressed areas and it is predicted that by 2025 this will rise to 64% 1. By 2023, roughly 33% or 1.8 billion people will be living in water-scarce areas such as South Africa, India, China and Pakistan 1. Predictions such as these will have disastrous consequences on the food system, as it was already estimated that close to 350 million tonnes of food was lost to water depletion in 2012 4.

The concept of “virtual water” refers to the total volume of water needed to produce a  commodity or provide a  service 2. Animal products have a higher virtual water content than plant products, as the living animal needs drinking water, service water, and as mentioned before, the water needed to produce animal feed 2. Based on this concept, it is estimated that 200 litres of water is used to produce just 200ml of milk; 135 litres of water is used to produce one 40g egg; and 2400 litres of water is used to produce one hamburger patty weighing 150g 2.

The use of virtual water is not always monitored in terms of where the commodity is produced but rather where it is consumed. For example, the 90% of virtual water used for producing animal-based commodities in Japan actually comes from imported animal feed  2.|Thus it is  actually countries outside of Japan that shoulder the majority of water depletion necessary to meet the Japanese demand for animal products.

Apart from depleting water sources, livestock is also heavily involved in polluting them. Animal manure used as fertiliser is very nitrogen-rich and the excess remaining after plant uptake can saturate soils and contaminate surface and groundwater sources via leaching and soil runoff 5. Nitrogen then accumulates in water bodies such as lakes, rivers and oceans, and encourages the growth of oxygen-consuming algae. This leaves less oxygen available for aquatic life, a process known as eutrophication 5. It is estimated that livestock adds 32% of the nitrogen load and 33% of the phosphorus load into fresh water sources 1.

Algae overgrowth due to Eutrophication

Algae overgrowth due to Eutrophication

A significant amount of pollution occurs by way of antibiotics, pesticides and heavy metals 5, 6. The amount of antibiotics used in the livestock industry worldwide has also not been quantified due to the heavy reliance on estimated international data 6. Antibiotic use in livestock has been banned in the EU; however, approximately 11,200 metric tons are used each year by livestock producers in the US to promote animal growth 6. This may be contributing to the growing number of antibiotic-resistant bacteria circulating within the human population, for example Aeromonas spp, which was identified in human drinking water in the US from as early as the 1980s 6. Antibiotics can even be absorbed by certain crops, as once observed in carrots, corn and lettuce 7.

The sobering conclusion of the state of the world’s water is that the impact will only felt as the situation gets worse;  making it more difficult to implement improvement strategies, especially in poverty-stricken areas 7. Scientists at the Stockholm International Water Institute (SIWI) predicted that by 2050 there will be not be enough water to maintain the intense animal farming needed to feed an expected population of 9 billion 8. To avoid this, intervention is needed to reduce animal-based calorie intake from current levels of 20% to just 5%, as well as to improve water usage within the sector 8.



  1. Steinfeld H, Gerber P, Wassenaar T et al. (2006) Livestock’s Long Shadow: Environmental issues and options. FAO/LEAD, Rome, Italy.
  2. Chapagain AK & Hoekstra AY (2004) Water Footprints of Nations – volume 1: Main Report; Value of Water Research Report Series No. 16. UNESCO-IHE;
  3. Turner K, Georgiou S, Clark R, Brouwer R, Burke J. 2004. Economic Valuation of Water Resources in Agriculture, from the Sectoral to a Functional Perspective of Natural Resource management; FAO paper reports No. 27. Food and Agriculture Organization of the United Nations
  4. FAOSTAT (2013) Statistics Division of the Food and Agriculture Organisation of the United Nations. Available:
  5. Martinez J, Dabert P, Barrington S, et al. (2009) Livestock Waste Treatment Systems for Environmental Quality, Food Safety, and Sustainability. Bioresource Technology; 100; 5527–5536
  6. Kümmerer, K (2009a) Antibiotics in the Aquatic Environment – A Review – Part I. Chemosphere; 75; 417–434
  7. Kümmerer, K (2009b) Antibiotics in the Aquatic Environment – A Review – Part II. Chemosphere; 75; 435–441
  8. Jägerskog A., Jønch Clausen T (2012) Feeding a Thirsty World – Challenges and Opportunities for a Water and Food Secure Future. Report (eds.) Nr. 31. SIWI, Stockholm.



Meat doesn’t grow on trees – so let’s cut them down

To mark the United Nations’ International Day of Forests on March 21st, this post briefly highlights the association between deforestation and arguably its  single largest cause – commercial livestock farming.



Beef consumption contributes to deforestation in the Amazon

In our modern world of dietary indulgence, where a person can order an entire platter of pork ribs, or a bucket of chicken wings, and receive it in matter of minutes, one can’t help but wonder just how did it become so easy to satisfy our cravings for all things meaty, and who or what is paying the real price for this convenience.

One doesn’t have to be an economist to understand the concept of ‘supply and demand’ – meaning that any increase in demand must be met by an increase in supply. So essentially, the livestock industry needs ensure that the supply is sufficient to satisfy consumer demands. This usually means scaling-up on existing production by acquiring more land space to house animals and grow food to feed them. Seeing that livestock already takes up around 45% of the global surface area 1, there is little space left to occupy – apart from rainforests.

The term “hamburger connection” was coined in 1981 to describe the United States’ then growing, and now firmly established love affair with beef 2. Cheap beef from cattle in Central American countries was produced and sold largely at the expense of their rainforests 2. In fact, over the past forty years, Central America alone  lost close to 40% of their rainforest  to cattle ranching alone 3. It wasn’t only US meat consumers enjoying cheap meat ranched on deforested land – in 2004-2005, approximately 1.2 million hectares of rainforest was cleared to grow the soybean crops that fed pigs and chickens in Europe 4. These figures are incorporated in the13 million hectares of global rainforest that has been cut down every year since 2000 5

The problem worsens as one travels further South, where the bulk of deforestation is taking place, and pasture land and feed crops make up the largest proportion of agricultural land 6. Brazil, believed to possess 62% of the Amazon rainforest, has already lost close to 80% of it; 70% of which was designated to cattle ranching 6.  Sadly but not surprisingly, this rate is increasing. From August 2012 to July 2013, Brazil reported a 35% increase in deforestation, as a space three times the size of New York City (2,338 sq km) was cleared 7.  The rate of deforestation in the Amazon was five times higher in 2013 than it was in 2012, which according to Reuters was “linked closely to soybean producers’ continual ‘indirect’ use of cattle ranchers’ deforested land.” 7


So what is all the fuss about deforestation anyway? Perhaps someone working in environmental health, or maybe a climatologist should be asked to comment. Up to 75% of Brazil’s greenhouse gas emissions is said to be caused by deforestation 8. From a global perspective, deforestation is responsible for a monumental 2.4 billion tonnes of carbon dioxide emissions every year 9, making it the largest contributor within the livestock sector. Deforestation also leads to considerable land degradation, which causes an estimated 75 billion tonnes of soil to be removed each year, at an average cost of US$400 billion dollars 6. Soil has a rich biodiversity of microbes that not only contributes to plant growth 10, but also determines much of the nutrient content of foods 10. During deforestation, organic matter is removed 10, leaving microbes with less of the carbon it needs to regulate nutrient delivery to plants 10, thus contributing to food and nutrition insecurity.

Deforestation, Climate Change, and Food Insecurity

Deforestation, Climate Change, and Food Insecurity

Environment scientists cite deforestation as one of the main causes of plant and animal species loss in tropical rainforests 11. This is hardly surprising when considering that just one quarter-pound hamburger imported from Latin America can destroy 165 pounds of living matter, including 20-30 plant species, 100 insect species, and dozens of bird, mammal, and reptile species. 12 It is even predicted that the number of birds threatened with extinction in the Amazon should triple within the next few decades 13. If current deforestation rates increase or even stays the same, species extinction will continue up to three decades after deforestation has ceased 13 – if it ever does.

Much of the ‘powers that be’ appear to be taking a “wait and see what happens” approach to deforestation and its impact on the environment and life as we know it. Unfortunately, much of the science is saying that by the time we begin to experience the real effects of deforestation, it may already be too late to prevent, reverse or halt any of the damage being done. In a sense, the real ‘power’ lies in the hands of the consumer, who can decide whether or not they want to learn more about how their diet contributes to deforestation, and whether or not they choose to do something about it.

Further reading:

Brighter Green

Case Study: Brazil Livestock

Deforestation: Disastrous consequences for the climate and for food security


  1. 1.      Thornton P, Mario Herrero M, Ericksen P (2011) Livestock and climate change. International Livestock Research Institute.
  1. 2.      Hecht SB. (1993) The Logic of Livestock and Deforestation in Amazonia. BioScience, Vol. 43, No. 10, pp. 687-695
  1. 3.       Food and Agriculture Organisation.  Cattle ranching and deforestation. Livestock Policy Brief 03
  1. 4.      Food and Agriculture Organisation: Livestock’s role in deforestation
  1. 5.      United Nations (2010) Deforestation in decline but rate remains alarming, UN agency says. United Nations News Centre.
  1. 6.      Steinfeld H, Gerber P, Wassenaar T et al. (2006) Livestock’s Long Shadow: Environmental issues and options. FAO/LEAD, Rome, Italy.
  1. 7.      Prada P, Barbara P (2013) Brazil data indicate increase in Amazon deforestation. Reuters.
  1. 8.      Tollefson J (2011) Brazil revisits forest code. Nature News
  1. 9.      McMichael AJ, Powles JW, Butler CW, Uauy R (2007) Food, livestock production, energy, climate change, and health. Lancet; 370: 1253–63
  1. 10.  Zhu YG (2009) Soil Science in the Understanding of the Security of Food Systems for Health. Asia Pac J Clin Nutr;18(4):516-519
  1. 11.  School of Natural Resources and Environment – University of Michigan; Modern Causes of Species Extinctions: habitat Destruction
  1. 12.  Julie Denslow and Christine Padoch, People of the Tropical Rainforest (Berkeley: University of California Press. 1988), 169.  cited by – McSpotlight – Beyond Beef:
  2. 13.  Wearn OR, Reuman DC, Ewers RM. (2012) Extinction Debt and Windows of Conservation Opportunity in the Brazilian Amazon. Science 337, 228; doi: 10.1126/science.1219013