Global water tables matter; in fact the level of our water tables can be a matter of life and death. Among other things, the future of food depends on water and they're not making any more of it. The water that dinosaurs drank and the water that floated Cleopatra's boat could be the same water flowing out of our faucets.
The fact is that more and more of it is becoming unavailable for our lawns, pools, car washing and growing food which includes livestock and diary in addition to farmed fruit and vegetables.
An unintended consequence of draining an aquifer faster than the water can be replaced is subsidence.
The problem is that when the underground water is pumped out, the land on top of it doesn't stay put. It subsides, or sinks, in step with the falling water table.
An illustration of this is the photo on the left showing a well casing with a span of 52 years shown. This is in the prime produce growing region of the San Joaquin Valley southwest of Mendota, California.
In 1925 the land was at the top of the well casing. By 1955 it had dropped approximately 24 feet and in 1977 the ground level was under the feet of the man posing for the photo.
Today the land has probably subsided another 20 feet or so.
Subsidence is what gives us sinkholes in Florida that swallow up homes and cars.
Putting water in perspective, consider that while we live on a planet almost covered by water, over 97% is salty and 2% is ice and snow. So less than 1% of the earth's water is available for drinking, cooking, cooling power plants, irrigating crops and raising livestock.
Speaking of raising food animals, when you take that next bite of beef, pork or chicken, think about the 1,857 gallons of water it takes to produce one pound of beef, or the 756 gallons needed to give us a pound of pork, or the 469 gallons used to produce a pound of chicken.
These are factory farm figures, courtesy of National Geographic (April 2010), and includes the water the animal drinks, to grow their feed and clean up their waste.
Looking at the big picture, a diet that regularly includes meat uses 60% more water than a vegetarian diet. Sticking with the factory farm model and considering beef cattle, it is roughly 3 years from birth to slaughter.
During that time, 808,400 gallons of water will be used to grow the 18,700 pounds of feed it will consume and another 6,300 gallons for drinking and another 1,900 gallons for cleaning stables, feed lots and the like.
All that water to produce 440 pounds of boneless beef. The figures are global averages and will vary according to the practices in the facility and processing procedures used. At any rate, all that water has to come from somewhere and that "somewhere" is our local water tables.
What do we mean by water tables? Picture an underground lake that occupies all the spaces, pores, cracks and any other voids in the underlying rock. The top of that underground water is the water table and the water in the "lake" is groundwater. One more term to know is "aquifer" which is the underground layer of permeable material such as gravel or sand which holds the water. As water is pumped out of an aquifer faster than it can be naturally replaced, the water table will fall and water will have to be extracted from greater depths and deeper wells dug.
OK, so it takes a lot of water to produce food protein, what's the big deal? The big deal is that as the world heats up, so does the atmosphere. Hot air holds more moisture than cool air and a warming earth tends to evaporate more water and increase wind currents; all of which dry out the land.
In the U.S. we use about 100 gallons of water per day in the home while millions of people in the poorest regions are limited to less than five gallons a day. A little less than half the world's population doesn’t have running water in their homes and many have to walk several miles each day to get what they can carry.
A warming earth is causing glaciers everywhere to retreat. At the highest altitudes of the Himalayas the ice and snow is shrinking which could spell disaster for two billion people who depend on the water flowing from those glaciers and snow fields.
If they are even aware of what is going on and they thought about how their future of food depended on those glaciers, we might see the start of a massive human migration.
Falling water tables, aquifers being drained faster than they can be replenished, dry lake beds where once were large bodies of water, shortened or absent rainy seasons and extended drought are becoming the norm in much of the world including the U.S. What does all this tell us about the future of food?
The embedded You Tube video below, uploaded by visionvictory on 9/2/2011 under the Standard You Tube License is included here to put a face and pictures on how water will affect the future of food.
Now we jump from water tables to the monoculture to consider how modern mega-farming methods can imperil the food supply.