TODAY鈥橲 focus on the credit crisis and rising prices for food and oil has temporarily put another global scarcity in the shade: water. The UN predicts that by 2025, two-thirds of us will experience water shortages, with severe lack of water blighting the lives and livelihoods of 1.8 billion. According to the UN World Water Assessment Programme, by 2050, 7 billion people in 60 countries may have to cope with water scarcity. At this year鈥檚 World Economic Forum, UN secretary-general Ban Ki-moon recommended that water scarcity should be at the top of the international agenda. 鈥淎s the global economy grows, so will its thirst,鈥� he said, warning of a future marred by conflicts over water.
There is no doubt that we need to rethink how we use water, especially with the human population growing rapidly, and global warming likely to produce unpredictable patterns of rainfall and drought. Nevertheless, my own research suggests that the situation may not be as dire as many are suggesting. Nations can thrive on surprisingly meagre quantities of fresh water 鈥� provided they adopt water-efficient technologies and encourage economic activity that doesn鈥檛 guzzle water. I believe the looming water crisis is primarily a problem of distribution and management rather than supply. And we can solve it with existing technologies, increased investment and political will.
The definitions of water scarcity most widely accepted and used today by the UN and others were proposed in 1986 by Malin Falkenmark, then at the Swedish Natural Sciences Research Council. She defined a country as 鈥渨ater-stressed鈥� when it cannot extract more than 4654 litres of water per person per day (equivalent to 1700 cubic metres per person per year) from its rivers and aquifers. One with less than 2738 litres available per person Falkenmark classified as 鈥渨ater-scarce鈥�. Anything below 1369 litres constitutes 鈥渁bsolute water scarcity鈥�, and threatens economic development as well as human health and well-being.
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Most of the Middle East is already classified as being water-scarce according to these definitions, but perhaps more surprisingly so are Malta and Singapore, while Denmark, Poland and the Czech Republic are classed as water-stressed. In total, approximately 290 million people live in countries that are classed as water-scarce, and another 440 million live in countries that are water-stressed. However, I believe these benchmarks need to be re-examined, and when that is done, a very different picture emerges.
The main problem with Falkenmark鈥檚 figures is that they refer to the amount of water required for a country to be self-sufficient in food production in a semi-arid region. Agriculture is among the most water-intensive human activities, particularly where crops need irrigation. According to the report Water Footprints of Nations, published in 2004 by the UNESCO-IHE Institute for Water Education, producing a kilogram of wheat takes more than 1300 litres of water, for example. For rice, the figure is almost 3000 litres.
However, such self-sufficiency is no longer essential because the global food supply is much more integrated than it was even 20 years ago. Research by Tony Allan at King鈥檚 College London, for example, reveals that countries across the Middle East have increasingly compensated for water scarcity by importing grains grown elsewhere. Allan coined the term 鈥溾�� to describe this trade, since the imports substitute for water that would otherwise be required locally to grow crops. Recent figures from the UN Food and Agriculture Organization (FAO) show the trend of rapidly increasing global trade of 鈥渧irtual water鈥�. Between 1970 and 2001, food trade increased 60 per cent in calorie terms.
Trading virtual water
Some of the world鈥檚 least developed countries now participate in the global food trade, breaking the link between local water resources and food security. Figures from the FAO show that in 2002, imports made up a fifth of the grain supply across sub-Saharan Africa, the region with the lowest average national incomes in the world, with food aid making up less than a fifth of the total food imports in least developed countries. Since the 1960s the world鈥檚 least developed countries have changed from being net exporters to being significant net importers of agricultural commodities, and hence have become major importers of virtual water, even though most are not particularly short of water.
Of course, trade in virtual water does not reduce overall demand for water but rather shifts it from one place to another. However, with such a growing trade in virtual water, it no longer makes sense to use self-sufficiency in food production to define water scarcity. As with so many other commodities that are traded globally, self-sufficiency in food production is not a requirement for individual countries so long as water resources remain adequate at the global level, in the same way that so many countries are heavily dependent on the global oil trade, without which their economies would grind to a halt.
Globally, there is adequate fresh water available, and that looks set to continue in the long term. Figures from the FAO indicate that we currently extract less than 10 per cent of the 43,750 cubic kilometres of fresh water returned each year to the Earth鈥檚 rivers, lakes and aquifers. The water is not distributed evenly, of course. Within a given country water consumption can vary from less than 1 per cent of available resources to more than 100 per cent, meaning that in some cases resources are being overexploited and degraded. Nevertheless, countries such as France, Germany, Italy and Spain have all shown that it is possible to extract 20 per cent or more of renewable water resources a year while maintaining acceptable environmental quality. Globally we are still some way from hitting any real environmental ceiling on consumption, and the growing trade in virtual water means that scarcity in one region can be compensated for by increased production in places with more plentiful supplies.
I am also dubious that water scarcity, as defined by Falkenmark, determines a country鈥檚 economic development. My own comparison of basic indicators of human, social and economic development with national water availability reveals no such relationship. Knowing the size of a country鈥檚 fresh water resources does not allow you to predict how developed it is. In many desert states in the Middle East, for example, you will never lack safe drinking water, whereas in many water-rich countries in Africa you will.
So how much water does a country really need? The lowest estimate on the table is just 20 litres per person per day, put forward by Guy Howard at the UK Department for International Development and Jamie Bartram at the World 午夜福利1000集合 Organization in Geneva. This figure, however, considers only the water required for drinking, cooking and very basic hygiene. My own assessment, to be published next month, considers domestic, agricultural and commercial water use, and aims to show how much fresh water a country needs to provide its people with a decent standard of living 鈥� and it puts a very different perspective on the global water crisis ().
Any calculation of this kind is bound to involve value judgements, such as what level of development is adequate and what sort of development is acceptable. Although far from perfect as a measure of whether a country provides its people with a decent standard of living, the Human Development Index established by the UN Development Programme is arguably the best global indicator now available. It combines various measurements of health, education and wealth to provide a broad overview of development, ascribing countries such as Qatar, Mexico and Tonga a high level of development alongside countries more commonly considered developed.
With this as my starting point, I examined domestic water usage in countries with high levels of human development to get an idea of how little water people can get by on in their homes and still have a decent standard of living. FAO figures indicate that of highly developed countries, the Netherlands, the UK and Uruguay are the most water-efficient. People there use fewer than 100 litres a day, compared with more than 700 litres in New Zealand and Canada, which have the highest consumption among highly developed countries. However, figures from national sources are not always consistent with those of the FAO. In the UK, for example, the government regulator OFWAT finds that the average person uses 151 litres a day. The Association of Dutch Water Companies gives a figure of almost 125 litres a day for people in the Netherlands. These are the figures I used.
A breakdown of how the Dutch use water in their homes shows that the average person uses 52 litres for showering, 36 litres for flushing toilets, 20 litres for washing clothes, 8.7 litres for preparing food and washing dishes, 1.6 litres for drinking and 6.4 litres for other uses. If conservation were prioritised, consumption could be reduced even further. Replacing all toilets with the most efficient dual-flush models, for example, could halve consumption in this area, while flushing with recycled shower water would save the full 36 litres. So with more water-efficient appliances, the Dutch could have a very high quality of life using as little as 85 litres of water per person per day in their homes.
Next, I considered non-domestic water usage. In countries with high human development, the amount used in the industrial and service sectors (excluding agriculture) ranges from just over 3 litres of water per person per day in Malta to more than 2800 litres in Canada and Bulgaria, according to the FAO. Again, locally produced figures are somewhat different. Maltese sources indicate an average of 51 litres per person per day 鈥� which includes just 7 litres for agriculture 鈥� and puts household water use at 81 litres per person per day. So Malta shows that a country can have a high level of human and economic development with as little as 125 litres of water per person per day, if it used only recycled waste water for its agriculture.
I also looked at water consumption within different economic sectors to find out how a country with limited water resources of its own might still maintain a healthy economy. While few countries publish such informaton it is available from the UK鈥檚 National Statistics agency. This shows that the UK鈥檚 service sector consumes just 30 litres per head of population per day 鈥� less than 4 per cent of the country鈥檚 total water usage 鈥� yet contributes nearly 80 per cent of national wealth. Add in other water-efficient sectors such as construction and electrical equipment manufacturing, and you find that 90 per cent of the UK鈥檚 economic activity uses just 34 litres per person per day.
Low water mark
Admittedly there are also water-hungry sectors such as chemicals manufacturing, textiles and paper, but a country with scarce water supplies could steer its economy away from these areas and rely on trade. The concept of virtual water increasingly encompasses these products as well as food. By importing virtual water, a nation could offer a high quality of life with as little as 135 litres of water per person per day 鈥� allowing 85 litres for household needs and assuming a well-maintained water supply system with distribution losses of around 10 per cent.
鈥淎 nation could offer a high quality of life with as little as 135 litres of water per person per day鈥�
If 135 litres is the bare minimum that will allow a country to prosper, where does that leave us? At present, only Kuwait and the United Arab Emirates fall short of this low-water mark in terms of their naturally available renewable water resources, but both make up their shortfall through desalination, and human development in both of these countries is already classed as high.
Even countries without oil wealth have shown that water scarcity need not impede development. For example, FAO figures show that Malta has just 346 litres of extractable water per person per day, while the Bahamas has just 183 litres of water per person per day. Both have already achieved high human development.
Plentiful water is clearly beneficial for national development, and it is imperative that total water resources remain sufficient for global food production. However, the fundamental problem many nations face is not water scarcity but distribution both within countries and between them.
Nevertheless, there are positive signs that we can overcome these problems. According to the WHO and UNICEF, between 1990 and 2002 the percentage of the global population with access to safe drinking water rose from 77 to 83 per cent. Meanwhile, the trade in virtual water continues to grow, shifting agricultural production from areas of water scarcity to those with relative plenty. Governments are also starting to rethink their water management policies 鈥� although admittedly these are still often fragmented and contradictory. What鈥檚 more, with desalination now as cheap as 50 cents per 1000 litres, all but the world least developed countries can afford to supplement their natural supplies of fresh water as long as they have a coastline. Millions are suffering because of a lack of water, but ensuring the supply of 135 litres per person per day is not beyond our reach.
