What is virtual water?
Virtual water is the volume of water used to produce consumer products. The total volume of water refers to all of the water used in the production of a product. For example, the total volume of water used in a food product would include the water used in the agricultural process, but also the water used in packaging and shipping. Virtual water is essentially all of the “hidden” water behind a product. Every product we consume contains virtual water.
How much water do we really consume?
Virtual water is indirect water use, as opposed to direct water use, which includes drinking water, bathing, and cooking. The average non-vegetarian in the U.S. or the EU consumes about 5,000 liters of water daily while the average vegetarian consumes bout 2,700 liters of water a day.
To put this in perspective, the average non-vegetarian consumes 15 water-filled bathtubs and the average vegetarian consumes eight water-filled bathtubs.
Every product has a unique water footprint. Meat is the greatest virtual water-consuming product. For example:
- A hamburger uses approximately 2,400 liters of virtual water. Water is consumed during the entire process, from growing feed crops for the cows, to slaughtering and processing the meat.
- A cup of coffee uses approximately 140 liters of virtual water to produce. Water is consumed throughout the production process, from growing to producing, to packaging and shipping.
When we export a product, we are exporting our water supply. Nations export and import billions of liters of water each year. Trade of agriculture-based products makes up approximately 80 percent of international virtual water. When Argentina exports beef, it is exporting water. When Canada exports grain, it is exporting water. The list goes on. The U.S. exports around one-third of the water it withdraws, leading to extreme environmental consequences such as the drying out of the Rio Grande, which cannot even reach the ocean for the majority of the year.
Why should we care?
The majority of the public is unaware of just how much water we consume in our daily lives. It is easy to over-consume, especially when we don’t know just how much we are actually consuming. Without understanding our consumption, it is unlikely that we will succeed in reducing our virtual water footprint. Communities and countries around the world face water issues of scarcity, sustainability, sanitation and accessibility.
Food is the main source of virtual water consumption. In fact, the average American consumes about 33,000 glasses of virtual water every day. These numbers are only expected to increase with increasing populations. Understanding virtual water is a key consideration for sustainable water management.