Posted on 15 October 2003
The world is facing a water crisis. It is estimated that over 2 billion people are affected by water shortages in over 40 countries, and the extensive withdrawal of water for agriculture from river, lakes and aquifers results in limited supplies for other human needs, such as for drinking, washing, and sanitation. According to the UN World Water Development Report, the average supply of water per person will drop by a third in the next two decades.
Agriculture is by far the biggest user of water. Because of this, the water that everyone ‘eats’ everyday contained in food products is much larger than the volume of water a person drinks. Of all freshwater withdrawn for human use, industrial and household uses account for 20 and 10 percent respectively, while agriculture consumes on average around 70 percent and much more in some locations. Furthermore, it is expected that by 2030 the global average agricultural water withdrawal for irrigation itself will be some 14 percent higher.
Agriculture provides many opportunities for water-savings as much of it is currently wasted in transit to the field, through inappropriate irrigation methods, and by growing crops that are not suited to the local environment. Such waste is driven by misplaced subsidies and artificially low water prices (unconnected with the amount used), low public and political awareness, and poor water management, while not being checked by incomplete environmental legislation.
As a result, unsustainable agriculture harms the environment by sucking rivers, lakes and underground water sources dry, increasing soil salinity and thereby destroying its quality, and by washing pollutants and pesticides into rivers destroying downstream ecosystems as far as corals and breeding grounds for fish in coastal areas. Disruption to marine ecosystems is at least as important as that in rivers, with both suffering from changed flood and sediment regimes and blocked migration routes created by dams. Ultimately unsustainable agriculture destroys the livelihoods of the farmers practicing it, and of fishermen and communities dependent on natural ecosystems.