One-third of the world's population is facing shortage of water, a situation that was not predicted to arrive until 2025, says a report.
One in three people endure one form or another of water scarcity, according to the findings released by the Comprehensive Assessment of Water Management in Agriculture at World Water Week in Stockholm on Monday night.
"Worrisome predictions in 2000 had forecast that one third of the world population would be affected by water scarcity by 2025. Our findings from the just-concluded research show the situation to be even worse," said Frank Rijsberman, director general of the Colombo-based International Water Management Institute (IWMI).
"Already in 2005, more than a third of the world population is affected by water scarcity. We will have to change business as usual in order to deal with the growing water crisis we see in some countries like India, China and the Colorado River basin of the US and Mexico."
The comprehensive assessment was carried out by 700 experts from around the world over the past five years.
David Molden, who led the assessment, said: "To feed the growing population and reduce malnourishment, the world has three choices: expand irrigation by diverting more water to agriculture and building more dams, at a major cost to the environment; expand the area under rain-fed agriculture at the expense of natural areas through massive deforestation and other habitat destruction; or do more with the water we already use."
He said it was possible to reduce water scarcity, feed people and address poverty, but the key trade-off was with the environment. People and their governments would face some tough decisions on how to allocate and manage water.
"Not all situations are going to be a win-win for the parties involved, and in most cases there are winners and losers. If you don't consciously debate and make tough choices, more people, especially the poor, and the environment will continue to pay the price," Molden warned.