SOURCE: Bloomberg
DATE: October 2, 2019
SNIP: Another slow-motion, man-made environmental disaster has been discovered, and it’s underneath your feet.
About 70% of the water pumped out of underground aquifers worldwide is used for agriculture while much of the remainder quenches the thirst of cities. As industrial development spreads at a speedy clip, the rate at which those critical reservoirs are emptied is far outpacing the rate at which they are naturally replenished.
A new study released Wednesday says that diminishing groundwater is causing the level of streams and rivers to fall as well. Like the shrinking aquifers, surface water is critical to farms, towns and cities for everything from food to trade to energy production.
With water systems all over the planet already strained by global warming and overuse, this new discovery poses an additional threat.
“Our overuse of groundwater resources is one of those quiet, under-appreciated challenges,” says Jason Morrison, president of the Pacific Institute, who wasn’t involved in the study. “The impacts are more profound than we understood. We’re kind of in this Wile E. Coyote moment where we’re over the cliff and we’re running still.”
The authors of the study, from universities in the Netherlands, Germany, Canada and the U.S., say their results “reveal the current and future environmental legacy of groundwater use.” The research is novel for its focus on the effects of pumping water out of the ground on the rest of the watershed. They define the threshold as diminished stream-flow for at least three separate months, two years in a row—or the point at which the flow can’t keep animals and plants in an ecosystem alive.
That threshold has already been eclipsed in as much as 21 percent of watersheds where pumping is common (about half of watersheds overall). Areas already in trouble, like those in the U.S. and India, belong to hotter climates that rely on groundwater for irrigation because rivers don’t supply sufficient volume. In America, the affected watersheds are also home to much of the nation’s agriculture production, a prime culprit in the drop in groundwater.
But Upmanu Lall, director of the Columbia Water Center in New York, says that while raising the issue’s profile is important, current water policies don’t provide much hope that this new threat will be quickly addressed.
“Even where groundwater depletion poses an existential or economic threat,” he says, “governments aren’t managing to do much.”