Humankind worked something of a miracle in the second half of the 20th century. Population trebled, and water consumption increased in proportion. The limits of our resources were tested. But we coped. Happily, within the next hundred years, the global population will level off after an additional two billion people accumulate. If we can continue to achieve increases in food production associated with more improvements in water-use efficiency, then we shall be water-secure. Widespread fears of futures ravaged by fighting over this most precious resource will not be realised. Indeed, scarcity need not impede, and certainly will not determine, our future. The past half century has been reassuring despite our lack of consideration for the water
The food needs of individuals and of national economies account for about 90 per cent of the water we use. So if we can get more “crop per drop”, we can feed more people. Between 1950 and 1990, agricultural revolutions in the economies of Europe and North America increased returns to water- threefold compared with rain-fed farming. Yields of wheat rose from 3 tonnes to about 9 tonnes per hectare, having languished at 1 tonne per hectare through the 17th and 18th centuries. Such is the capacity of farming systems to increase returns to water.
In China and South Asia, the production of grain jumped by between four and five times in the 30 years between 1961 and 1991. The returns to water were not so high in Asia as they were in Europe and North America. Most of the gains were achieved by applying more freshwater and partly by extending the cropped areas. India achieved food self-sufficiency despite its population growth. Meanwhile, in sub-Saharan Africa, grain yields in rain-fed farming languished at between 0.5 and 1 tonne per hectare. There has been no African agricultural
revolution. Its food production potential is still only a promise.
The second half of the 20th century was also important in showing that local water deficits could be remedied by global commerce. Trade in food satisfied the self-indulgent whims of the rich in industrialised economies. The flexibility and low prices of traded staples also dealt with strategic, demographically driven food deficits. The process was seemingly effortless. Most important, it was economically invisible and politically silent. Solutions with these qualities are pocketed by politicians who would otherwise be forced to pay terminal political prices by having to acknowledge that their nations were short of food and water.
Globally, 15 per cent of the water used to produce crops and livestock is “traded” across international borders. The water itself is not actually traded; what changes hands is the commodity that contains the water. But the process invisibly mobilises low-value water in water-rich economies — usually to remedy the shortages in water-scarce economies, where it has a high value. Not having to mobilise the 1,000 tonnes required to raise 1 tonne of grain eliminates the economic and high political stress of reallocating overcommitted water. There are no hydraulic technologies that could move the volumes intrinsic to this massive virtual water “trade”. No engineer could contemplate moving the flow of rivers as large as the Congo, the Ganges or the Yangtze to hundreds of different water-scarce destinations. Yet farmers and traders have done so for millennia, and they are currently doing so at unprecedented levels.
The major lesson of the late 20th century was that individual economies did not gain water security using their water resources alone. It was achieved by two processes. First, a strong and diverse political economy could achieve water security by enabling access to the second solution — the international crop and livestock commodity trade.
Recognition that strategically significant solutions lie beyond the statistics of water-resource endowment and hydraulic engineering is gradually gaining currency. It is a major element of the argument that the World Bank used in its report on Middle East and North African water, published in February. This document discusses how water-management solutions need to be considered as part of the wider economic policies of the countries of the region. It concludes that meeting the water needs of the growing population of the Middle East and North Africa can no longer be based on a business-as-usual approach. “Policies in other areas — agriculture, trade, land markets, finance, energy pricing — all have an impact on how much water is used and how efficiently. Managing water requires the participation of all parts of society.”
The World Bank also argues that improved management accountability is needed to achieve better returns to water and to reverse the degradation of the environmental water in the Middle East and North Africa. Despite considerable technical, policy and institutional progress within the water sector across the region, expected improvements in water outcomes are
still limited. But the outlook is positive — there will be conflict over water, but no water wars.
Tony Allan heads the Water Research Unit at King’s College London and the School of Oriental and Asian Studies.