Groundwater usage has more than doubled since 1960s. And the rate of replenishment hasn’t managed to keep up. A new study of groundwater usage has also come to the alarming conclusion that most of the groundwater that is being pumped up is ultimately draining into the sea where it is adding to the global rise of ocean levels.
A team led by Marc Bierkens of the Utrecht University and the International Groundwater Resources Assessment Center at Deltares in the Netherlands used a model of water flow across the landscape to gauge the extent of runoff water, and exactly how much runs off or evaporates from shares of land across the globe. The data was also merged with historical records of groundwater patterns that are available.
The culprit is agricultural irrigation. It totals up 70 to 80 percent of all groundwater usage. The areas of concern around the globe are also agricultural hotspots: northeastern China, northwestern India, Iran, northeastern Pakistan, southeastern Spain, the central United States, California’s Central Valley and Yemen.
What’s a further worry is the fact that 95 percent of the water is being wasted as runoff into the oceans where it has a quarter’s share in raising the sea levels. Compare these conclusions to the fact that a third of the world is facing acute water crisis. A finite resource like water is being wasted and its direct impact will be felt by the agricultural sector.
Marc Bierkens says about the crisis that’s still largely ignored,
“A lot of this is abstracted by small farmers with small wells. It doesn’t mean that the water is depleted immediately, but it could mean that the small farms wouldn’t be able to reach it anymore. If you run out of water you cannot grow crops anymore. You are basically extending your crop production on borrowed water.”
Groundwater depletion is a global problem whose tentacles will touch all sectors, not only the agricultural one. As Bierkens elaborated,
“The food that I eat is connected through global trade to groundwater depletion in another part of the world. It’s not only a local problem, it’s a global problem.”