Freshwater on the Earth is becoming increasingly scarce.
Vast underground reservoirs (aquifers) that provide much of the world population with water are being emptied up to 50x faster than they’re being filled.
(About 1/4 of irrigated farming in the USA depends on the Ogallala aquifer. Once that’s drained it could take around 6,000 years to refill!)
Agriculture uses 70% of all freshwater, and the primary consumer of this water is the beef industry.
On top of this, it can be up to 10x less water-efficient to grow food for cows in non-tropical areas (like most of the USA and Europe) than it is in tropical areas.
In an extreme example, in Nebraska, around 100,000 litres of water can be taken from an aquifer to produce just 1kg of beef.
This chart shows you the relative water burden of different protein sources.
According to the Institution of Mechanical Engineers, a single gram of steak sets the world back about 16 litres of water.
That’s equivalent to turning your kitchen tap on for 5 hours every time you eat a steak.
That's a lot of water.
In most cases, it’s about 85% more water efficient to get your protein from beans and pulses rather than from beef.
Why is beef so water intense?
Like humans, cows drink and sweat…
But that's not the main reason they have such a large burden on water.
Cows are extremely inefficient with their food. In fact, they lose around 80% of the protein they’re fed in their poo.
This means that cows need to eat a huge amount of plants in order to grow. These plants all need to be watered.
The primary use of farmland worldwide is either for animals, or to grow food for animals, and the biggest consumer of this food is cows.
Ideally, all of these plants would be watered by the rain, but because that's only possible in a few places, a staggering amount of the world's freshwater is diverted into irrigation systems to grow crops for cows.