Draft script:
From Wired on 24 January 2024 comes this headline: The World’s Essential Aquifers Are in Deep Trouble. Here’s the subhead: New research finds that the groundwater systems that hydrate your life are in rapid, sometimes accelerating decline around the globe. Here’s how to stop the retreat.”
Here’s the lede: “The water that pours out of your tap, or that’s unnecessarily packaged in a single-use bottle, or that helped grow the produce in your fridge—all of it may well have come from aquifers somewhere.” The first paragraph continues with an explanation of an aquifer: “These are layers of underground material that hold water, and can be made up of porous rock or sediments like sand and gravel. When it rains, some water collects in lakes and rivers and eventually flows out to sea, but some soaks deep into the ground, accumulating in these subterranean stores.”
The following paragraph explains why we must be concerned about aquifers and especially the water they hold. “We dig shallow wells or drill deeper boreholes to tap into aquifers to hydrate our civilization, but that extraction has gotten way out of hand. An alarming new paper published today in the journal Nature looked at available data on 1,700 aquifer systems worldwide and found that groundwater is dropping in 71 percent of them. More than two-thirds of these aquifers are declining by 0.1 meters a year, while 12 percent are notching a rate of 0.5 meters. (Think of this decline as like looking down into a well, then coming back the next year and seeing that the water level is 0.1 meters lower.) Nearly a third of the aquifers are experiencing accelerated depletion, meaning the decline is speeding up, in particular where the climate is dry and there’s a lot of agriculture that needs watering.”
Co-lead author of the new paper in Nature is water scientist Scott Jasechko of the University of California (Santa Barbara). He is quoted in the paper in Wired: “Real-world observations—300 million of them in hundreds of thousands of wells around the globe—show two main findings. One is that rapid groundwater declines are unfortunately widespread globally, especially in dry places where croplands are extensive. And then second, even worse, groundwater declines have, if anything, accelerated over the last four decades in a disproportionately large share of the global landmass.”
The paper in Wired continues: “Aquifers are supposed to be reliable banks of water, safely locked underground where the liquid can’t easily evaporate away. They’re a rainy-day fund—or, more accurately, a dry-day fund—available to tap into in times of need, like during a drought. But from Chile to Afghanistan to India to China, and back to the United States, humans are emptying these water stores at an unsustainable pace. In areas where an already dry climate is getting drier because of climate change, people have less aboveground water to rely on, and so they’re forced to over-extract aquifers.”
The paper in Wired points out that crops will need more water as the planet continues to warm. In many places on Earth, reduced precipitation has resulted from climate change. In these locations, climate change exacerbates the extraction of water by humans to grow food. As water scientist Scott Jasechko said in the article, “A very large share of the aquifer systems that are experiencing accelerated groundwater level declines are also in places where precipitation has declined over the last 40 years.” He fails to point out that growing food at scale is usually intended to line the pockets of billionaires rather than feeding more than eight billion people.
The article in Wired points out that additional threats result from groundwater depletion. Notably, groundwater feeds into the rivers that supply humans and other animals with a multitude of services. In addition, the reduction of groundwater allows seawater to flow into the aquifer, therefore contaminating water supplies for people and crops.
Finally, and even more dramatically, the extraction of groundwater is causing land to sink. I observed this phenomenon, known as subsidence, while I was living in Tucson, Arizona. Subsidence was—and is—causing buildings to collapse. Stopping the use of existing wells, along with not allowing any new wells is the obvious solution. Try telling that to more than a million people who depend upon the water for their own survival.
Let’s take a look at that peer-reviewed, open-access paper in Nature, published 24 January 2024. Written by eight scholars and titled Rapid groundwater decline and some cases of recovery from aquifers globally, the abstract reads as follows, with abundant references to peer-reviewed literature: “Groundwater resources are vital to ecosystems and livelihoods. Excessive groundwater withdrawals can cause groundwater levels to decline, resulting in seawater intrusion, land subsidence, streamflow depletion and wells running dry. However, the global pace and prevalence of local groundwater declines are poorly constrained, because in situ groundwater levels have not been synthesized at the global scale. Here we analyse in situ groundwater-level trends for 170,000 monitoring wells and 1,693 aquifer systems in countries that encompass approximately 75% of global groundwater withdrawals. We show that rapid groundwater-level declines (>0.5 m year−1) are widespread in the twenty-first century, especially in dry regions with extensive croplands. Critically, we also show that groundwater-level declines have accelerated over the past four decades in 30% of the world’s regional aquifers. This widespread acceleration in groundwater-level deepening highlights an urgent need for more effective measures to address groundwater depletion. Our analysis also reveals specific cases in which depletion trends have reversed following policy changes, managed aquifer recharge and surface-water diversions, demonstrating the potential for depleted aquifer systems to recover.”
The relevant section in the peer-reviewed paper in Nature is titled Slowing and reversing groundwater-level declines. After providing a few positive examples, this section concludes with a paragraph that reads: “Although these examples illustrate that groundwater declines can be slowed or reversed, several caveats must be kept in mind. In general, rates of groundwater-level shallowing are much slower than rates of groundwater-level decline. Of the aquifer systems in Figure 3 with rising twenty-first century groundwater levels (blue and purple points), only 6% are rising faster than −0.2 m year−1. By contrast, of the aquifer systems with deepening twenty-first century groundwater levels, 25% are falling faster than 0.2 m year−1. Furthermore, across these aquifer systems, the average rate of twenty-first century deepening … exceeds the average rate of shallowing … by a factor of four. Thus, rapidly rising groundwater levels are rare, but they demonstrate that aquifer recovery is possible, especially following policy changes, managed aquifer recharge and inter-basin surface water-transfers.”
In other words, readers looking for hope would be advised to look elsewhere. I have witnessed few examples of policy changes, managed aquifer recharge, or inter-basin surface water-transfers. Even fewer examples are found using all of these approaches at the same time.
Thank you Red_Dog. People think I’m crazy (not for the right reasons) when I mention this example of overshoot. Or any example of overshoot. Always good to have additional sources. Peace.
"Influxes of meltwater into the North Atlantic eventually lead to warmer and drier conditions over Europe."
https://eos.org/articles/melting-ice-in-the-polar-north-drives-weather-in-europe?fbclid=IwAR1XyNSonb2fyC9IRBloDcperVO0hmCJo8oblTou3VTCpBJ_PehCMokj86U