It is a grim reality that no Arab state has enough water for its needs. The populations of every Arab state have exploded far beyond what was thought possible a few decades ago, but the volume of water contained in the rivers and clouds has remained the same. In addition, in every state the population is set to continue rising well beyond today's large numbers.

However, in the face of this crisis, free trade has allowed the Arab states to remain relatively peaceful despite their shocking lack of water. Although Arab countries cannot grow enough of their own food for their populations because there is simply not enough water to make that possible, nonetheless there is enough food to be found in other parts of the world. This means that countries that are short of water can import food and so get themselves out of their water crunch in the short term. Trade has been the saving grace that has allowed the Arab states to continue along the development path that they have chosen.

And the Arab states are not alone: they share this lack of water with most countries in the world. Just because most Arab states are generally dry and many have large deserts does not make them unusual in their need to import food. Of the more than 190 states in the world, 180 are net importers of food, according to Professor Tony Allan of the School of Oriental and African Studies at the University of London. This also means that they are importers of water, contained in the food they import.

It is startling how much ‘virtual water' can be imported in this way. Allan has made a detailed study of the water footprints of different foods. For example, every kilogram of rice consumes 3,400 litres of water from the time that it is planted as seedlings in the paddy to the time that it is harvested. So every time a kilogram of rice is brought into the UAE, the country has saved itself 3,400 litres of valuable water from its desalination plants. The equivalent figure for milk is that it takes 1,000 litres of water to produce one litre of milk: the grass has to be watered for the calves to eat as they grow and become cows, drinking water all the time, and finally they produce the milk.

The same principle applies to many other kinds of goods, since everything that is manufactured and sold will have taken a certain amount of water to produce. In mining, a vast amount of water is used to wash minerals, so any metal produced will have consumed a certain amount of water. Any item of clothing will come from some kind of fibre that has to be grown, harvested, and woven. Allan's work has defined a T-shirt as taking 2,700 litres of water to produce. He has even measured that an A4 sheet of paper will take 10 litres to produce.

The point of this exercise is to emphasise that just as most actions and objects have a carbon footprint, they also have a water content. The international community has to face the fact that the amount of available water in the world is limited, while the many uses that is has acquired over the centuries assume that it is both free and unlimited. This means that today it is vital to both nurture the supply of water, and also to make sure that it is used to the best effect.

Breaking point

Although trade has managed to cope with the problem so far, it will not be able to do so forever. Far too much strain is being placed on the world's water resources in too many regions. There is a looming global crisis over water use that is fast coming to a head. The ongoing dispute between Egypt and Sudan over how much Nile water each is entitled to take is only one example. Another is the horrifyingly high salinity in the lower Euphrates, thanks to too much water being removed by the dams higher upstream over the past few years, which has already wrecked most of Iraq's farm land.

Because water is integral to so many spheres, the solutions lie in different areas. Production of clean water is vital, and in the Gulf this will depend on developing more desalination capacity, since there are no rivers or rain, and the aquifers are running dry. This means that access to water depends totally on access to energy, and the Gulf states are making a priority of looking at nuclear desalination plants, since in the long term they know that their gas will run out.

But simply producing more and more water is not the answer. It will become vital to think of water as an increasingly valuable commodity, and learn to treat it with care. People and industries will have to get used to looking at any process with an eye to its impact on water consumption. Just as we have learnt to care about our carbon footprint, we will need to learn to care about our water footprint. This will include being much more rigorous in collecting waste water and treating it for re-use.

Without action on all these fronts, the grand plans of the Gulf states will begin to falter, since water is not something that can be ignored. It is a vital element of life, and has become a crucial part of much of our economy.