Tuesday, January 11, 2005

The Livestock Connection

This little piece is taken from vegansociety.com. The numbers indicate research notes and sources, which I did not include.


The UN Water Assessment Programme states: "At the beginning of the twenty-first century, the Earth, with its diverse and abundant life forms, including over six billion humans, is facing a serious water crisis." [1]

We all know that ours is a Blue Planet, mostly made up of water, so it can be difficult to believe that this most precious of natural resources could ever become so scarce as to endanger future food production and general planetary health. However, only 2.53% of the earth's water is fresh and most of this is inaccessible - some two-thirds being captured in glaciers and permanent snow. [2] The remaining fresh water is almost entirely made up of groundwater.

According to Sandra Postel, Director of the Global Water Policy Project, the world overdraws 200 km3 of its global groundwater 'bank account' every year. [3] This over-exploitation has serious consequences for future food production and global health. In fact, the WorldWatch Institute rates aquifer depletion, alongside HIV and shrinking cropland area per person, as one of the three most potentially devastating problems facing our species. [4]

Water pollution serves to compound the problem, with global wastewater estimated to be in the region of 1,500 km3. The UN suggests that 1 litre of wastewater pollutes, on average, 8 litres of freshwater, which would result in a freshwater pollution burden of around 12,000 km3 worldwide. [5]

Estimates suggest that climate change could cause a 20% increase in global water scarcity. [6]

In their 'Global Water Supply and Sanitation Assessment 2000' UNICEF and the World Health Organisation (WHO) estimate that at present 1.1 billion people have no access to safe water supplies. 2.4 billion people have no access to any form of improved sanitation.
"As a consequence, 2.2 million people in developing countries, most of them children, die every year from diseases associated with lack of safe drinking water, inadequate sanitation and poor hygiene" - Gro Harlem Brundtland, Director-General, WHO and Carol Bellamy, Executive Director, UNICEF. [7]

The situation is predicted to worsen as population expands and consumption per capita increases as more and more people adopt resource-intensive Western-style lifestyles.
The UN's 2003 Water Development Report predicts that "by the middle of this century, at worst 7 billion people in sixty countries will be water-scarce, at best 2 billion people in forty-eight countries." [8] In fact, the problem is so serious that many environmental and political commentators predict that the resource wars of the future will be fought over water rather than oil.

To ensure our basic needs, we all need 20 to 50 litres of water free from harmful contaminants each day. [9]


Worldwide, agriculture uses up 70% of fresh water resources. [10] This is largely because a lot of cropland has to be irrigated to make it agriculturally viable and to increase and improve crop yields.

As has been shown, much of this land is entirely wasted by being used to grow feed crops for livestock rather than food for people. The water used on this land - as well as that consumed directly by livestock - represents yet another wasted resource.

There has been much disagreement over precisely how much water is squandered in this way. Professor David Pimentel of Cornell University's Ecology Department has calculated that it takes 500 litres of water to produce 1kg of potatoes, 900 litres per kg of wheat, 3,500 litres per kg of digestible chicken flesh and a massive 100,000 litres for 1kg of beef. [11]

A more conservative estimate comes from Beckett and Oltjen of the University of California's Department of Animal Science. [12] In a study partly financed by the California Beef Council, they concluded that wheat production requires 120 litres per kg and beef 3,700 litres per kg. It is interesting to look a little more closely at these figures as they show that, even by the most conservative of estimates, beef production still represents a scandalous misuse of one of our most precious natural resources.

1 kg of meat yields about 2800 kcal and 174 g of protein. [13] 1 kg of wheat yields 3300 kcal and 110 g of protein (100g after adjustment for digestibility). According to Beckett and Oltjen, the kilogram of beef requires 3,700 litres of water and the kilogram of wheat requires 120 litres of water. If we put all of these figures together, we find that whilst wheat provides us with an average 27.5 kcal for each litre of water used, beef provides only 0.76 kcal per litre. This means that - based on the data presented to show that other figures were "overstated" - beef still requires 36 times as much water per calorie as wheat. When the same calculations are done for digestible protein, wheat comes out as 18 times more water efficient than beef. These figures are summarised in table 2.


By these figures, one kilogram of beef uses as much water as:
40 baths
300 toilet flushes
100 times the clean water needed by an individual according to UNESCO

Since a large percentage of the crops we feed to our farmed animals are grown on 'ghost acres' in developing countries, this wasted water is coming not just from our own reserves but from the very countries where drinking water is most scarce.


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