The recent reboot of the "Mad Max" movie franchise portrays an apocalyptic future in which civilization has collapsed and leather-clad crazies, who've apparently never heard of alternative energy, are battling over the supply of gasoline. But judging from a pair of just-released scientific studies, the resource that we actually may be fighting over in the future is groundwater.
The new research, led by University of California, Irvine scientists, reveals that humans are rapidly draining water from about a third of the world's biggest underground basins, or aquifers, more rapidly than they can naturally be replenished.
What If California Runs Out of Water?
Worse yet, we don't have a clear idea how much water is left in those natural reservoirs, which in the U.S. alone supply drinking water to about half of the population and are a key source of water for the agricultural irrigation systems that help put food on our tables. That means we may well be in danger of running out, and not even realize it.
"Available physical and chemical measurements are simply insufficient," UCI professor and principal investigator Jay Famiglietti, who is also the senior water scientist at NASA's Jet Propulsion Laboratory, said in a press release. "Given how quickly we are consuming the world's groundwater reserves, we need a coordinated global effort to determine how much is left."
We're already seeing the effects in California, which remains desperately parched due to a brutal extended drought.
Californians have been draining water so rapidly from underground aquifers that tens of thousands of square miles of land reportedly are sinking - so drastically that the shifting surface is starting to destroy bridges and crack highways across the state, according to a recent report by the Center for Investigative Reporting.
The two studies, which are being published in the journal Water Resources Research, represent the first effort to use satellite data to look at groundwater loss all over the planet. The researchers utilized data collect by NASA's twin Gravity Recovery and Climate Experiment satellites. The latter measure dips and bumps in the Earth's gravity which are affected by the weight of groundwater.
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The scientists examined the planet's 37 biggest aquifers over a 10-year period ending in 2013. Of those, eight were overstressed, with no natural replenishment to offset human use. Another five aquifers were extremely or highly stressed, meaning that even though they still had some water flowing into them, it wasn't enough to maintain their water levels.
The most critically endangered water supply in the world was the Arabian Aquifer System, which supplies water to 60 million people in the Middle East. Next on the list was the Indus Basin aquifer of northwestern India and Pakistan, while the Murzuk-Djado Basin in northern Africa was third.
Other institutions that participated in the study included NASA, the National Center for Atmospheric Research, National Taiwan University and the University of California, Santa Barbara.