By Thin Lei Win

ROME (Thomson Reuters Foundation) – A “creeping, silent crisis” is menacing the world’s food supply as water shortages could jeopardise up to 40% of all irrigated crops by 2040, a U.S. think tank said on Monday.

Erratic rainfall caused by climate change also threatens the water supply for a third of crops that rely on monsoon, said the World Resources Institute (WRI).

“Humankind is not very good at acting before crisis happens. We’re really good at crisis management but that’s very reactive,” said Rutger Hofste, an associate at WRI.

“This is a creeping, silent crisis and we would like to ring the alarm bells before it’s too late,” he told the Thomson Reuters Foundation by phone.

Scientists say water supplies are threatened by many factors, including climate change and mismanagement, but farming is one of the largest factors, using 70% of freshwater.

On Monday, the think tank launched an online tool called Aqueduct Food, which maps water risks for more than 40 crops, including banana, coffee, soybean and cotton.

Among irrigated crops, it found nearly 67% of wheat, 64% of maize and 19% of rice could be in areas with extremely high water stress by 2040.

The three crops together account for more than 40% of the world’s calorie supply, according to the United Nations’ Food and Agriculture Organization (FAO).

Urgent action is needed, be it to improve irrigation and soil, better crop choices and less food loss and waste, it said.

(Reporting By Thin Lei Win @thinink, Editing by Lyndsay Griffiths )