[This is a guest post by Alex Cull]
In his play “Ten Billion”, Stephen Emmott makes several references to the amount of water required for food production, stating that:
1) 3000 litres of water are needed to make one beefburger.
2) 30 trillion litres are used annually in the UK burger industry.
3) 27,000 litres are needed to make one bar of chocolate.
4) 100 litres are needed to make one cup of coffee.
BEEF
Firstly, it might be a good idea to explain the three different classes of water that are often mentioned when someone tries to calculate a country’s or an industry’s “water footprint”. These are “green water” (rainfall), “blue water” (water abstracted from rivers or pumped from aquifers) and “grey water” (any extra water required to assimilate pollutants.) Many publications refer back to studies by water engineers Mesfin M. Mekonnen and Arjen Y. Hoekstra in the Netherlands, which are also used on the waterfootprint.org website maintained by the University of Twente [1].
Clearly, using “green water” is the most desirable path to raising beef, from an environmental point of view, and “blue water” the least. And this is what waterfootprint.org says about beef:
“The production of one kilogram of beef requires 15 thousand litres of water (93% green, 4% blue, 3% grey water footprint). There is a huge variation around this global average. The precise footprint of a piece of beef depends on factors such as the type of production system and the composition and origin of the feed of the cow.”
This must be where the figure of 3000 litres per burger comes from, although the weight works out at about 200g per burger, which seems suspiciously generous; a “quarter-pounder”, after all, would be only about 113g. Thus we can immediately see that beef production uses water that is 93% “green”. That is the global average, however. It is the UK that Emmott specifically mentions, stating in “Ten Billion” that here in Britain we get through 10 billion burgers in a single year (and thus 30 trillion litres of water, if the 3000 litres per burger figure is accurate.) And it does appear that the figures might be exaggerated. The UK has a population of around 63 million. It would mean that each of us, on average, would need to eat almost 160 beefburgers a year, roughly one burger every two and a quarter days. Is that correct? It seems a colossal number of burgers per person, per year. In addition, the rate of 1kg of beef per 15 thousand litres of water is a global average (and thus very approximate – there is a “huge variation”, remember), and the 200g weight per beefburger seems mysteriously ample. Taking all these factors into account, Emmott’s numbers could be way too high.
However, as will be revealed, even if they were to be entirely accurate, these calculations would also be almost completely irrelevant, to a UK audience at least. Britain’s beefburgers come from a variety of sources, but it might be worthwhile to glance at one of the biggest vendors of burgers, which is restaurant chain McDonald’s. Where do McDonald’s in the UK get their beef from? According to their website: “McDonald’s UK only uses 100% British and Irish beef to make our burger patties”. [2]
Let’s look at England, then, as an indicator. According to a document called “Testing the Water” produced in 2009 by EBLEX (English Beef & Lamb Executive) the proportions of green/blue/grey water, with regard to English beef production, are: green 84%, blue 0.4% and grey 15.2%. The EBLEX publication also has some interesting things to say about the impact of green and grey water.
“Green water… is the rainfall used by crops (including grass) at the place where it falls. This water is essentially unavailable for other uses. In the absence of grassland or crops, it would be consumed to almost exactly the same extent by other vegetation. Indeed, deeper-rooted tree and scrub cover would lead to even higher levels of water use than crops or grassland. And the alternative of leaving the land bare is neither feasible without considerable input to restrict natural regeneration, nor desirable in terms of soil erosion and run-off. Since it cannot be used elsewhere and levels of usage are not increased by its role in crop production, green water consumption carries little or no hydrological impact. Grey water is a notional provision, representing the volume required to dilute pollutants to levels that maintain defined water quality standards. It also carries relatively little hydrological impact since it does not physically consume the resource and deny it for other uses. After all, water notionally required to reduce the biological oxygen demand of accidental slurry or silage effluent leaks, or counter higher than acceptable nitrate or phosphate concentrations from soil leaching, is, at the same time, also available to meet human consumption or environmental maintenance needs. Grey water as a concept is, arguably, of most value to water companies as a measure of the ‘cost’ of countering any negative water quality impacts from farming.”
Green water use is not a problem, then, economically or environmentally, and grey water use is not a problem either. Which leaves blue water (abstracted from rivers or pumped from aquifers) – and only 0.4% of English beef production uses blue water. The situation is similar in Ireland (and probably Wales and Scotland too) although the rates for imported beef might, of course, be different. So the fact, therefore, that 30 trillion (or fewer) litres of water might be used annually in the UK burger industry represents something of a complete and utter non-problem, especially when the beef in question is raised domestically. All but a tiny part of the water that nourishes the cattle that provide the beef to make the burgers falls from the sky as rain and if it was not used would drain away into the ground and be lost. At least where water use is concerned, eating a McDonald’s beefburger in the UK ought to be a guilt-free experience.
REFERENCES
[1] http://www.waterfootprint.org/?page=files/home
[3] http://www.eblex.org.uk/documents/content/news/p_cp_testingthewater061210.pdf
Geoffchambers's Blog 
I wonder how much oxygen Emmott ‘takes’ from the environment?
…All but a tiny part of the water that nourishes the cattle that provide the beef to make the burgers falls from the sky as rain and if it was not used would drain away into the ground and be lost….
Water is not f****ing lost!
I can’t think how many times I’ve had to shout that.
Water goes in a cycle. ALL water eventually comes back again. There is essentially NO DIFFERENCE between the water that soaks into the ground and fills an aquifer, or gets passed up the roots of some grass and into a cow, or goes into a river and is pumped into a chemical plant. ALL of it cycles round. And we will never run out of it……
Dodgy Geezer
Agreed. I think Alex was putting himself in the shoes of the imaginary 3000 litres-per-burger Emmott type who worries about the water that gets past the cow and that therefore misses the burger – the leakage, in other words, in a system or model where the whole climate cycle is conceived as a method of making burgers.
It’s not a useless activity – conceiving the whole of a relevant part of the world as a model designed to achieve a certain limited end. It’s how battery farmers give us ultra cheap eggs; how Ryanair flies us all over Europe for peanuts; how you put a country on a war footing.
The first measure of the efficiency of your model is economic of course – how the punter views the prospect of a cheap flight to Alicante versus a cheap cake from Tescos. Then the second, third and fourth measures kick in – the assessment of the non-monetary factors – the ethical, aesthetic and environmental ones: – are you willing to see hens treated like Ryanair passengers so that you can have a cheap cake? How many river valleys are you willing to dam in order that everyone can have their own jacuzzi? and so on – politics, in other words.
The mistake of environmentalists is to try and circumvent the politics by saying: “you can’t do that because there’s not enough water” (or air or oil, or something). Then if that doesn’t work, they fall back on the Emmott argument: “you can’t do that because we’ll all die if you do”.
The marvel of the set-up is that the extreme long stop weirdo postition is often occupied by the most prestigious scientific bods – the Lovelocks, Hansens, Ehrlichs and Emmotts – leaving the green busybodies free to go about their business stopping us doing the little things, like building airport runways or maintaining a manufacturing base.
Dodgy Geezer, I take your point entirely about water not being “lost” – there’s probably a more apt word or phrase I could have used. You’re right, of course, none of the “green water” going into crops/livestock etc., (as per the Mekonnen/Hoekstra classification) would otherwise be actually lost to nature or humanity. It’s “renewable”! Worrying about it going to waste would be as useless as people fretting about wasting sunlight or gravity.
But fret they do! And if you thought all the agonising over beef – 93% of the water to produce it being of the renewable “green” variety, globally – was silly, wait till you read my next instalment, about chocolate! I’ll choose my words with care.
Geoff, I think your point is good, too – there are always externalities, but these are not being rationally discussed, especially with climate change being used as a trump card to justify environmentally ruinous policies like biofuels. Take away CAGW as a justification, and I think it would become clear (or even clearer, rather) that fracking, for example, is less harmful than cutting down forests for combustible biomass.
The production of one kilogram of beef requires 15 thousand litres of water (93% green, 4% blue, 3% grey water footprint). There is a huge variation around this global average.
I’ll say there is “huge variation”. So much so that the average is meaningless.
They say “The unfavourable feed conversion efficiency for beef cattle is largely responsible for the relatively large water footprint of beef.” but much of the world’s beef is grass fed.
Maybe some of your European and US cows are grain fed. But the Australian, NZ, Argentinian ones aren’t (just like the British ones).
The solution if you wan to reduce the blue water use in beef is to expand the free market so that grass fed cows are the norm (the Argentinian ones are cheaper too for being grass fed, and better quality to boot). This, of course, runs directly contradictory to the Green ethos of local food.
@ Mark P, re Europe. it’s interesting to see that in the Netherlands, for example, which (according to a 2011 report by Gerbens-Leenes, Mekonnen and Hoekstra) has negligible grazing land, and where beef production is either in the “mixed” or “industrial” categories, “green water” use still comes out at between 87% and 88%.
And the Netherlands is supposed to be less “water-stressed” than the UK (it’s roughly in the centre of the water-scarcity index of EU countries). So it’s a complex picture, really. Not sure how Dutch beef compares to e.g., Argentinian, though, taste-wise.
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