<
https://www.propublica.org/article/water-aquifers-groundwater-rising-ocean-levels>
"As the planet gets hotter and its reservoirs shrink and its glaciers melt,
people have increasingly drilled into a largely ungoverned, invisible cache of
fresh water: the vast, hidden pools found deep underground.
Now, a new study that examines the world’s total supply of fresh water —
accounting for its rivers and rain, ice and aquifers together — warns that
Earth’s most essential resource is quickly disappearing, signaling what the
paper’s authors describe as “a critical, emerging threat to humanity.” The
landmasses of the planet are drying. In most places there is less precipitation
even as moisture evaporates from the soil faster. More than anything, Earth is
being slowly dehydrated by the unmitigated mining of groundwater, which
underlies vast proportions of every continent. Nearly 6 billion people, or
three quarters of humanity, live in the 101 countries that the study identified
as confronting a net decline in water supply — portending enormous challenges
for food production and a heightening risk of conflict and instability.
The paper “provides a glimpse of what the future is going to be,” said
Hrishikesh Chandanpurkar, an earth systems scientist working with Arizona State
University and the lead author of the study. “We are already dipping from a
trust fund. We don’t actually know how much the account has.”
The research, published on Friday in the journal
Science Advances, confirms
not just that droughts and precipitation are growing more extreme but reports
that drying regions are fast expanding. It also found that while parts of the
planet are getting wetter, those areas are shrinking. The study, which excludes
the ice sheets of Antarctica and Greenland, concludes not only that Earth is
suffering a pandemic of “continental drying” in lower latitudes, but that it is
the uninhibited pumping of groundwater by farmers, cities and corporations
around the world that now accounts for 68% of the total loss of fresh water in
those areas, which generally don’t have glaciers.
Groundwater is ubiquitous across the globe, but its quality and depth vary, as
does its potential to be replenished by rainfall. Major groundwater basins —
the deep and often high-quality aquifers — underlie roughly one-third of the
planet, including roughly half of Africa, Europe and South America. But many of
those aquifers took millions of years to form and might take thousands of years
to refill. Instead, a significant portion of the water taken from underground
flows off the land through rivers and on to the oceans.
The researchers were surprised to find that the loss of water on the continents
has grown so dramatically that it has become one of the largest causes of
global sea level rise. Moisture lost to evaporation and drought, plus runoff
from pumped groundwater, now outpaces the melting of glaciers and the ice
sheets of either Antarctica or Greenland as the largest contributor of water to
the oceans."
Via Susan ****
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
