Governments must start devising ways of allocating water more efficiently if they are to avoid food shortages and political instability, the World Agricultural Forum (WAF) will warn on Monday. The call, to be made at the group's annual meeting in St Louis, Missouri, comes amid increasing concern about a link between water shortages, agricultural productivity and threats to global food security.
We have to manage water much better and that's going to require a new system of allocation, said Jim Bolger, the former New Zealand prime minister who chairs the WAF.
The non-profit group was founded in 1997 to raise awareness of agricultural issues among government leaders.
The WAF is concerned about the effect that depletion of water tables, desertification and overuse of water for non-agricultural purposes in developing countries is having on the world's ability to feed rapidly growing populations.
Agriculture accounts for about 70 per cent of fresh water consumed worldwide. Yet it faces competition from municipal and industrial users, who are usually able to pay more to secure the commodity. In northern China, 64 per cent of farmland is threatened by falling water levels due to over-use of ground water, according to the UN's Food and Agriculture Organisation (FAO).
It estimates that one fifth of irrigated land in the developing world has been damaged by waterlogging or salinity.
Agriculture is by far the largest consumer of water and [we] will be expected to make quite radical changes in the use of that water because there is simply not enough to go around, Mr Bolger told the Financial Times.
He cited United Nations estimates showing that by 2025, about two-thirds of the world would be living in areas of the world with water deficits.
It's a resource that has traditionally been seen as free but we need to start thinking of the value of water as a building block in the food chain. That's going to require quite a large shift in many leaders' and users' thinking, Mr Bolger said.
The WAF's call for action comes three months after the government of the Netherlands and the FAO appealed for a new economic approach to valuing water.
They asked governments to devise incentives that could be introduced to use water more efficiently, calling on agricultural, industrial and environmental interests to develop a strategic water plan to place a value on national water resources.