FAO.org

Home > Fight hunger > Detail

Water – the most basic resource but also the most essential

How much water do we use for… ?


07 May 2014

Basic facts

The world contains an estimated 1 400 million cubic km of water. Only 0.003% of this vast amount, about 45 000 cubic km, are what is called “fresh water resources” - water that theoretically can be used for drinking, hygiene, agriculture and industry. But not all of this water is accessible. For example, seasonal flooding makes water extremely difficult to capture before it flows into remote rivers.

In fact, only about 9 000-14 000 cubic km are economically available for human use - a mere teaspoon in a full bathtub when compared to the total amount of water on earth. With a fast increasing population , will this be enough water to sustain human life? Of course, quantity isn’t the only issue. The quality of the water supply is also important.

Did you know?

water

Agriculture is by far the biggest user of water, accounting for almost 70 percent of all withdrawals, and up to 95 percent in some developing countries.

As a rule of thumb the water needed for crops amounts to 1500 cubic meters per tonne of cereal harvested. Put another way, it takes 1.5 tonnes of water to grown 1kg of cereal.

The daily drinking-water requirements per person are 2-4 litres. However, it takes about 3000 litres of water to produce a person’s daily food.

Water is important for food security, which is defined as the regular access of people to enough high-quality food to lead active, healthy lives. This is especially true in developing countries.

Did you know?

water_1Drought ranks as the single most common cause of severe food shortages in developing countries.

For developing countries alone $103 billion per year are required to finance water, sanitation and wastewater treatment through 2015.

In 2011, 768 million people did not use an improved source of drinking-water and 2.5 billion people did not use improved sanitation.

The right to food is not negotiable. Feeding our growing population and reducing hunger will only be possible if agricultural yields can be increased significantly - and sustainably.

With so much of the Earth’s water being used for agriculture, it is clear that an improvement in the management of agricultural water becomes key to the achievement of global food security.

water_3- FAO estimates that the world’s growing population will require about 60 percent more food by 2050 compared to 2006. In the last 30 years, food production has increased by more than 100 percent.

- Over the next 35 years, 70 percent of gains in cereal production are expected to come from irrigated land.

- FAO estimates that irrigated food production is projected to increase by 8 percent by 2050, but the amount of water used by agriculture will increase by only 10 percent, thanks to improve d irrigation practices.

Share this page