For three decades, Saudi Arabia has been drilling for water from underground aquifers. Engineers and farmers have tapped hidden reserves of water to grow grains, fruit and vegetables in the desert of Wadi As-Sirhan Basin. Photograph: Landsat/Nasa.
By
Damian Carrington. The Guardian, 21st May, 2012
Humanity's
unquenchable thirst for fresh water
is driving up sea levels even faster than melting glaciers, according
to new research. The massive impact of the global population's
growing need for water on rising sea levels is revealed in a
comprehensive assessment of all the ways in which people use water.
Trillions
of tonnes of water have been pumped up from deep underground
reservoirs in every part of the world and then channelled into fields
and pipes to keep communities fed and watered. The water then flows
into the oceans,
but far more quickly than the ancient aquifers are replenished by
rains. The global tide would be rising even more quickly but for the
fact that man-made reservoirs have, until now, held back the flow by
storing huge amounts of water on land.
"The
water being taken from deep wells is geologically old – there is no
replenishment and so it is a one way transfer into the ocean,"
said sea
level
expert Prof Robert Nicholls, at the University of Southampton. "In
the long run, I would still be more concerned about the impact of
climate change, but this work shows that even if we stabilise the
climate, we might still get sea level rise due to how we use water."
He said the sea level would rise 10 metres or more if all the world's
groundwater was pumped out, though he said removing every drop was
unlikely because some aquifers contain salt water. The sea level is
predicted to rise by 30-100cm by 2100, putting many coasts at risk,
by increasing the number of storm surges that swamp cities.
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