EDIT
In the first place, this old world just has more mouths to feed. Second, grain production is being disrupted by weather patterns, especially drought. That seems to be the result of global warming, which many say is caused by the burning of fossil fuels. To counteract that, the U.S. and most other nations are trying to cut use of fossil fuels - the supplies of which are getting tighter anyway - by using more biofuels, such as ethanol.
Of course, biofuels are made from corn, wheat and other grains, so the more we grow for fuel, the less we have for the table and the price of what we do put on the table goes up because of the law of supply and demand. Even the wheat farmer who gets a premium price for his crop, gets caught in the cycle because that tight supply of fossil fuel means he has to pay higher prices for diesel and fertilizer to produce that $9 wheat.
In other words, every time we tinker with one commodity to make up for another, we encounter an equal and opposite reaction somewhere in the chain.
So the next time we're tempted to chuckle at a little kid frustrated about achieving equilibrium with his balloon, maybe we should look at what we adults are doing.
EDIT/END
http://www.timesrecordnews.com/news/2007/oct/07/let-them-eat-cake/