vir·tu·al wa·ter (noun): Also known as embedded water, the water that is used in the production of a good or service.
The Guardian recently published an article on the amount of embedded water that is essentially lost in all of the food that goes to waste in the UK.
British geographer John Anthony Allan, PhD, is credited for creating the concept of virtual water. In his book Virtual Water: Tackling the Threat to Our Planet's Most Precious Resource, Allan explained the concept of virtual waterwith the example of the amount of water "hidden" in an average breakfast:
Take a normal -- if slightly indulgent -- breakfast in the US or UK. There is a cup of tea of coffee, a slice or two of toast, perhaps bacon and eggs, maybe a glass of milk, and possibly a little fruit as a nod to health and a leaner waistline. Now, what is that in water terms? Let's start with coffee. Well, you might say, I like my coffee strong. There's barely any water in there at all. Maybe...But what if I told you that in your tiny espresso there is 140 litres of water. Yes -- 140 litres. You might think I was slightly deranged. But that is the virtual water hidden in the coffee. That is the amount of water used in growing, producing, packaging and shipping the beans that make the coffee. Here is a simple example of what we mean by something's cost in virtual water. It is, I am sure you will agree, rather a lot more water than you first thought. But it is just the tip of your breakfast's virtual-water iceberg.