Saturday, November 13, 2010

thirst for water

Back on Nov. 2, Green Inc. blog posted an article describing the amount of sealevel rise that can be attributed to human use of groundwater.  The story summarizes some recent publications that suggest that 25% of the rise in sea level seen is due to pumping groundwater.  The idea is simple - we dig wells, pump out ground water, use that water for agriculture etc., and then it drains eventually into the ocean.  But the magnitude of this effect had not been estimated previously.  Many areas of the world grow food using ground water - and unfortunately we are discovering that this is an unsustainable process, because the groundwater is not being recharged as quickly as we are pumping it out.  Eventually the removal of all that water from the ground will run the tap dry - at least in some areas locally or regionally.  And if the water runs out, and there is no other source, and the food doesn't grow, and there is nothing to eat, .... well it ain't pretty.