According to a study published in August’s Nature, the annual demand from the planet’s 783 large aquifers is 3.5 times the amount of water that is being replenished. This demand could have profound long-term consequences: groundwater sustains over 2 billion people, and provides just under 40 percent of the water used for worldwide crop irrigation.
Tom Gleeson, a hydrologist from McGill University, compared the area needed to sustain aquifers with the size of the aquifers themselves.
“In many of the places where the footprint is larger than the aquifer, we are unsustainably mining groundwater,” says Gleeson
Gleeson is amongst a growing body of scientists urging countries to switch to more water-efficient methods of farming. India, Pakistan, Saudi Arabia, Iran, Mexico, and the United States are the countries that are overtaxing their groundwater supplies the most.