The cow stands accused of drinking the planet dry. The headline number is 15,000 litres of water for a single kilo of beef. A monster, apparently. Let us settle her bill, line by line, and see what the planet is actually owed.
Line one, the big one: rainfall. That 15,000-litre figure is what hydrologists call a water footprint, and for beef more than 90 percent of it is green water, meaning rain that fell on the grass the animal ate. Rain that was going to land on that hillside whether a cow stood on it, a sheep stood on it, or nothing did. We are billing the animal for the weather. Strike it out.
Line two: the blue water, the stuff that actually comes from taps, rivers, and aquifers, the water humans genuinely compete over. For beef this runs to roughly 50 litres per kilo as a global average, and in rain-soaked Britain, where cattle drink the sky and graze unirrigated grass, the figure for a kilo of beef carcass is around 67 litres. A bucket, give or take. The honest consumptive figure for beef lands somewhere between about 300 and 1,300 litres a kilo, not fifteen thousand.
Line three: what she did with the bucket. She drank it, ran it through, and returned almost all of it to the field as urine, dung, and breath, where it rejoins the same cycle it was always in. Water is not consumed the way petrol is; it is borrowed and handed straight back, very slightly warmer.
For perspective, a single glass of dairy milk carries a water footprint of about 126 litres, and a glass of the almond milk sold as its virtuous replacement about 74. Both, like the beef, are overwhelmingly green water. Rain. The same rain.
So the final, honest invoice for the planet-draining beast reads: a bucket of borrowed water, returned to sender, plus a very large charge for rain that fell on a Welsh hill of its own accord.
The 15,000-litre number is, in the main, a bill for the sky. Send it to the sky.