Rising oil prices have focused the world's attention on the depletion of oil reserves. But the depletion of underground water resources from overpumping is a far more serious issue. Excessive pumping for irrigation to satisfy food needs today almost guarantees a decline in food production tomorrow.
In the Middle East, where populations are growing fast, the world is seeing the first collision between population growth and water supply at the regional level. For the first time in history, grain production is dropping in a geographic region with nothing in sight to arrest the decline. Each day now brings 10,000 more people to feed and less irrigation water with which to feed them.
Another agricultural trend of growing concern is the increased nutrient content of coastal waters resulting from fertilizer runoff in agricultural regions. Augmented by urban sewage discharge in some situations, this results in huge algal blooms, which, as they die and decay, deplete the oxygen content in the water, leading to the death of the fish.