By J.D. Capelouto
LONDON, March 29 (Thomson Reuters Foundation) - Farmers around the world are using an unsustainable amount of well water to irrigate their crops – which could lead to an uptick in food prices as that water runs low, international researchers warned Wednesday.
Farmers are increasing their use of groundwater — water naturally stored underground — to grow staple crops such as rice, wheat and cotton, the scientists said.
But much of that water use is unsustainable as water is being pumped out faster than it can be naturally replenished.
"Groundwater depletion is increasing rapidly, especially in the last 10, 20 years, due to the increasing populations and also associated food production," said Yoshihide Wada, deputy water program director at the International Institute for Applied Systems Analysis, a science organisation based in Austria.
The shortages are occurring in some big agricultural producers such as India, China and the United States, he said. But they could have an impact on a much wider area of the world because "much of the agricultural production is traded internationally", he said.
An estimated 11 percent of crops irrigated using non-renewable groundwater are traded internationally after harvest, the researchers said in a report published in the journal Nature.
Countries such as Pakistan, Iran and India, which use the most groundwater to grow food, are already suffering from water scarcity, the report said.
For many countries "it doesn't really make sense that you're exporting a lot of food that comes from groundwater depletion", Wada said in an interview with the Thomson Reuters Foundation.
Economically, unsustainable use of groundwater could lead to rising future food prices, as countries are forced to spend more money to find water to irrigate their crops, he said.
Depleted supplies of groundwater could also hurt local people, who rely on the water for day-to-day use and for other things, including fighting fires or dealing with other emergencies, the scientists said.
Droughts, which are expected to increase as a result of climate change, could also increase the shortages of groundwater and impact food supplies, lead author Carole Dalin added in a statement.
"Where and how the products are grown is crucial, and basic foods like rice and bread could have a damaging impact on global water supplies," said Dalin, a research fellow at University College London's Institute for Sustainable Resources.
Unless both food producers and food buyers adopt strategies to use water more wisely, "most of the world's population risks seeing increased food prices or disrupted food supply", she warned.
Wada said governments should more closely monitor the use of groundwater and invest in things like drip irrigation technology, which can dramatically cut water use, to better prepare for the future and conserve natural resources.
(Reporting by J.D. Capelouto; editing by Laurie Goering :; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, climate change, resilience, women's rights, trafficking and property rights. Visit http://news.trust.org/climate)