By KIM BELLARD
We live on a water world (despite its name being “Earth”). We, like all life on earth, are water creatures, basically just sacks of water. We drink it, in its various forms (plain, sparking, carbonated, sweetened, flavored, even transformed by a mammal into milk). We use it to grow our crops, to flush our toilets, to water our lawns, to frack our oil, to name a few uses. Yet 97% of Earth’s water is salt water, which we can’t drink without expensive desalination efforts, and most of the 3% that is freshwater is locked up – in icebergs, glaciers, the ground and the atmosphere, etc. Our civilization survives on that sliver of freshwater that remains available to us.
Unfortunately, we’re rapidly diminishing even that sliver. And that has even worse implications than you probably realize.
A new study, published in Science Advances, utilizes satellite images (NASA GRACE/GRACE-FO) to map what’s been happening to the freshwater in the “terrestrial water storage” or TWS we blithely use. Their critical finding: “the continents have undergone unprecedented TWS loss since 2002.”
Indeed: “Areas experiencing drying increased by twice the size of California annually, creating “mega-drying” regions across the Northern Hemisphere…75% of the population lives in 101 countries that have been losing freshwater water.” The dry parts of the world are getting drier faster than the wet parts are getting wetter.
“It is striking how much nonrenewable water we are losing,” said Hrishikesh A. Chandanpurkar, lead author of the study and a research scientist for Arizona State University. “Glaciers and deep groundwater are sort of ancient trust funds. Instead of using them only in times of need, such as a prolonged drought, we are taking them for granted. Also, we are not trying to replenish the groundwater systems during wet years and thus edging towards an imminent freshwater bankruptcy.”
As much as we worry about shrinking glaciers, the study found that 68% of the loss of TWS came from groundwater, and – this is the part you probably didn’t realize – this loss contributes more to rising sea levels than the melting of glaciers and ice caps.
This is not a blip. This is not a fluke. This is a long-term, accelerating trend. The paper concludes: “Combined, they [the findings] send perhaps the direst message on the impact of climate change to date. The continents are drying, freshwater availability is shrinking, and sea level rise is accelerating.”
Yikes.
“These findings send perhaps the most alarming message yet about the impact of climate change on our water resources,” said Jay Famiglietti, the study’s principal investigator and a professor with the ASU School of Sustainability.
We’ve known for a long time that we were depleting our aquifers, and either ignored the problem or waved off the problem to future generations. The researchers have grim news: “In many places where groundwater is being depleted, it will not be replenished on human timescales.” Once they’re gone, we won’t see them replenished in our lifetimes, our children’s lifetimes, or our grandchildren’s lifetimes.
Professor Famiglietti is frank: “The consequences of continued groundwater overuse could undermine food and water security for billions of people around the world. This is an ‘all-hands-on-deck’ moment — we need immediate action on global water security.”
If all this still seems abstract to you, I’ll point out that much of Iran is facing severe water shortages, and may be forced to relocate its capital. Kabul is in similar straits. Mexico City almost ran out of water a year ago and remains in crisis. Water scarcity is a problem for as much as a third of the EU, such as in Spain and Greece. And the ongoing drought in America’s Southwest isn’t going any anytime soon.
Continue reading…
