While we worry about gas prices, the costs of milk, meat and fresh produce silently skyrockets. So like the end of cheap energy, is the era of cheap food also finally over?

Since the farm depression of the early 1980s - remember the first Farm Aid concert in 1985 - farmers have gone broke in droves from cheap commodity prices. The public shrugged, happy enough to get inexpensive food. Globalization saw increased world acreage planted and farmed under Western methods of efficient production. And that brought into the United States even more plentiful imported food.

Continued leaps in agricultural technology ensured more production per acre. The result was likewise predictable: the same old food surpluses and low prices. My late parents, who owned the farm I now live on in central California, used to sigh that the planet was reaching 6 billion mouths and so things someday "would have to turn around for farmers."

Now they apparently have. Food prices are climbing at rates approaching 10 percent per year. But why the sudden change?

There have been a number of relatively recent radical changes in the United States and the world that, taken together, provide the answer:

Modern high-tech farming is energy intensive. So recent huge price increases in diesel fuel and petroleum-based fertilizers and chemicals have been passed on to the consumer.

The U.S. population still increases while suburbanization continues. The sprawl of housing tracts, edge cities and shopping centers insidiously gobbles up prime farmland at the rate of hundreds of thousands of acres per year.

In turn, in the West periodic droughts and competition from growing suburbs have made water for farming scarcer, more expensive - and sometimes unavailable.

On the world scene, 2 billion Indians and Chinese are enjoying the greatest material improvement in their nations' histories - and their improved diets mean more food consumed than ever before.

The result is that global food supplies are also tightening up, both at home and abroad. America has become a net food importer. We seem to have developed a new refined taste for foreign wines, cheeses and fresh winter fruits even as we are consuming more of our corn, wheat, soybeans and dairy products at home.

Now comes the biofuels movement. For a variety of reasons, ranging from an attempt to become less dependent on foreign oil to a desire for cleaner fuels, millions of acres of farmland are being redirected to corn-based ethanol.

If hundreds of planned new ethanol refineries are built, the U.S. could very shortly be producing around 30 billion gallons of corn-based fuel per year, using one of every four acres planted to corn for fuel. This dilemma of food or fuel is also appearing elsewhere in the world as Europeans and South Americans begin redirecting food acreages to corn-, soy-, or sugar- based biofuels. Continued...