Now it’s peak water

09/12/2013

We’ve had peak oil, now there’s peak water.

Peak oil has generated headlines in recent years, but the real threat to our future is peak water. There are substitutes for oil, but not for water.
  
We drink on average four liters of water per day, in one form or another, but the food we eat each day requires 2,000 liters of water to produce. Getting enough water to drink is relatively easy, but finding enough to produce the ever-growing quantities of grain the world consumes is another matter.

Grain consumed directly supplies nearly half of our calories. That consumed indirectly as meat, milk, and eggs supplies a large part of the remainder. Today roughly 40 percent of the world grain harvest comes from irrigated land.

During the last half of the twentieth century, the world’s irrigated area expanded from close to 250 million acres in 1950 to roughly 700 million in 2000. But since then the growth in irrigation has come to a near standstill, expanding only 10 percent between 2000 and 2010.

Today some 18 countries, containing half the world’s people, are overpumping their aquifers. Among these are the big three grain producers—China, India, and the United States—and several other populous countries, including Iran, Pakistan and Mexico.

During the last couple of decades, some of these countries have overpumped to the point where aquifers are being depleted and wells are going dry. Several have passed not only peak water, but also the peak in grain production that often follows. Among the countries whose use of water has peaked and begun to decline are Saudi Arabia, Syria, Iraq, and Yemen. In each of these countries peak grain has followed peak water. . .

Over pumping of aquifers is a problem but there are solutions including more efficient irrigation and water storage.

Some aquifers have been over-pumped in New Zealand but that is being addressed and peak water isn’t likely to be a problem here where we are blessed with so much water.

Our problem isn’t how much, or how little, water we have, it’s where we have it.

Water isn’t always where we need it, when we need it.

One solution to that is water harvesting – storing water when there’s more than enough to use when there’s too little.

That provides not only environmental benefits but social ones too through recreational opportunities and it’s a very good way to beat peak water.


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