Demand for water to outstrip supply by 2050: Study

Global demand for water will outstrip supply if the current population growth trends and present of levels of water consumption continue, a study has predicted.

The researchers used what is called a delayed-feedback mathematical model to analyse historic data to help project future trends.

Per-capita water use has been declining since 1980, largely due to improved efficiency measures and heightened public awareness of the importance of conserving Earth's limited supply of freshwater. This has helped offset the impacts of recent population growth, the study published in the journal WIREs Water noted.

"But if population growth trends continue, per-capita water use will have to decline even more sharply for there to be enough water to meet demand," said researcher Anthony Parolari from Duke University.

The world's population is projected to surge to 9.6 billion by 2050, up from an estimated seven billion today, the study pointed out.

"For every new person who is born, how much more water can we supply? The model suggests we may reach a tipping point where efficiency measures are no longer sufficient and water scarcity either impacts population growth or pushes us to find new water supplies," Parolari noted.

The researchers said that periods of increased demand for water -- often coinciding with population growth or other major demographic and social changes -- were followed by periods of rapid innovation of new water technologies that helped end or ease any shortages.

Based on this recurring pattern, the model predicts a similar period of innovation could occur in coming decades.

Water recycling, and finding new and better ways to remove salt from seawater, are among the more likely technological advances that could help alleviate or avoid future water shortages, he said.