It may be hard for us in the United States to imagine that food could ever be scarce here.  We may worry about avian flu and mad cow disease, and about the general safety of our increasingly mass-produced food supply, as from time to time some Americans sicken or die from tainted meat or spinach.  Nonetheless, when we think about food safety we seldom think about scarcity, and rich and overfed as we are, we do not fret that we are transforming ourselves into a country that chooses not to grow its own groceries.

The assumption behind this thinking is that we will always be able to trade freely and cheaply with farmers in other countries.  So assumes California agricultural economist Steven Blank, who says that the “U.S. economy no longer needs agriculture and is rapidly outgrowing it,” and this belief underlies our pervasive national unconcern that every year fewer Americans know how to raise crops or livestock, fewer can afford to do it full time, and fewer are working on family-sized farms, which when properly tended produce more per acre and pollute less.

Yes, we still grow a lot of food, and America is a large country, with over 900 million acres in farmland.  We still export a lot of food, too, and we are not yet net food importers.  But we are also a populous country of over 300 million people, and our 2 million farms make up a very small percentage of our whole.  The Department of Agriculture’s trade numbers swing up and swing down, but the amount of food we import has doubled in the last ten years, and in 2004 there were two months when we imported more food than we exported.  In 2006, the number was about $63 billion in food and drink imports, according to an analysis done in April 2007 by the Associated Press, plus another $7.6 billion in imported food ingredients such as the wheat gluten that poisoned over 100 brands of pet food last year.  The appeal of these imports is that they are cheaper, and they offer us fresh fruits and vegetables out of season.

All of this traveling food (and even our own produce typically comes from California or Florida), like so much of the rest of our economy, depends on unencumbered trade and relatively cheap petroleum.  But what happens if trade becomes less free, and transport less cheap?  What if the petroleum we use to ship, truck, and fertilize our food becomes hard or extremely expensive to get?  It is easy to imagine that something could happen to disrupt our supply of oil.  In any case, we will reach the bottom of the Middle Eastern oilfields someday, perhaps during the lifetimes of many of us.  For these reasons, we should be looking at food as an issue of national security.  Could a nation that is becoming increasingly dependent on foreign-grown food reorient itself—and quickly, in an emergency—in order to feed itself?

There are other and perhaps better reasons to fear our transformation into a country too rich to bother with farming.  Our need for oil in order to eat costs us dearly in money, pollution, foreign dependence, foreign wars, and climate change.  There are health drawbacks to our centralization: A piece of produce that travels (as the average vegetable does) 1,500 miles from field to table loses nutrients along the way, while much of our milk and meat contains growth hormones and antibiotics.  There are social and individual costs in communities of all sizes.  Writers such as Wendell Berry, John Ikerd, Bill McKibben, Michael Pollan, and Eric Schlosser have been analyzing these costs for years, and I will leave those good arguments to them.  My question here is whether, in some kind of plausible emergency, we would still be able to eat.

To answer that question nationally is a gargantuan task, so I have limited my focus to Louisville, Kentucky, the city nearest to me.  Can this good-sized city, located in a generally well-watered and still largely rural state, find enough food produced within a reasonable distance to feed itself?

Louisville is the largest city in Kentucky.  According to 2007 Census estimates, there are 709,264 people in Louis­ville/Jefferson County, and another 496,651 in the 12 surrounding counties that depend on the city for many jobs and services.  I have looked at the nine counties in Kentucky, and the three just across the Ohio River in Indiana, from which Louisville draws workers and could most logically draw food.  At their furthest reaches these counties extend about 25 miles north, 50 miles east, 60 south, and 50 west, and within these limits I have added up all the USDA production statistics I could find for whatever basic foods are grown or raised there.

The total population needing to be fed is a little more than 1.2 million people.  But these 12 counties only raise and sell enough beef to feed about 26 percent of those people per year—even though Kentucky is a state known for raising (after horses and tobacco) beef cattle.  In chicken, we do about the same—35 percent, a minimum estimate given the way chicken numbers are reported.  For pork, we can only feed about 14 percent of the population per year.  For eggs, we come very short, with enough to meet just three percent of the yearly allotment.  We do better with milk, despite the decline in recent years in the number of dairy farms.  The 12 counties produce enough to supply 42 percent of the metro area with milk to drink, or 32 percent with cheese, or 81 percent with butter—but only 15 percent with all three.

Fruits and vegetables are harder to quantify, but I can give some idea of acreage per person.  The counties on my list have about 933 acres in orchards.  For upwards of 1.2 million people, that comes to 34 square feet apiece.  That is enough room for a few blackberry bushes, or maybe two espaliered apple trees.  (Americans consume 280 pounds of fruit per year.)  In vegetables, the counties list 1,881 acres harvested, a number that does not include backyard gardens.  That is not quite 70 square feet per person, a garden seven feet by ten.  Again, hardly enough to supply a year’s worth of vegetables (428.5 pounds per person).

Not even in wheat is the area around Louisville self-sufficient.  Assuming all wheat grown is milled as whole-wheat flour, with no loss (white flour loses 30 percent of the grain), the 12 counties raise enough wheat to supply just 30 percent of the population.  Only in corn are we growing more than enough—though of course much of this grain goes to feed livestock and now to ethanol.  The area’s 6.5 million bushels would yield a year’s supply of cornmeal for over 21.5 million people.  But if we convert some of that corn to corn oil (assuming we had the plant to do it), the number falls short.  Our corn would yield a year’s supply of cornmeal for all 1.2 million people, but the leftover bushels would produce salad or cooking oil for fewer than a quarter of them (23 percent).

I could have drawn my circle wider. Adding up the cattle sold by another seven Kentucky counties lying outside my original nine shows that this extra area could feed beef to another 350,000 people besides its own.  That is a good increase, but still totals just 48-percent fed—less than half.  It leaves us with the conclusion that for most meals most Louisvillians are eating fruit and vegetables from Florida, California, and abroad; and beef that was finished, slaughtered, and probably also raised out west.

Is this important?  If we can promise ourselves that our current ability to import food and truck it across country will continue indefinitely, then the answer is no.  But we had better be convinced, because we are betting our future on it.

In an emergency, much would change in ways that are hard to predict, though we can make some guesses based on other people’s histories.  What Great Britain did during World War II, for example, was to shift her imports toward categories she needed more urgently, or could less efficiently grow or raise herself.  Great Britain has been a net importer of wheat since before the French Revolution, and by the 1930’s she was importing two thirds of all the calories she consumed.  By 1944 she had lost half of her shipping capacity in the war, so cargo space that might have been used for fresh fruit or animal fodder in 1938 was now filled with cooking oil (or munitions).  The British diet shifted away from meats to emphasize starches, and fallow lands were plowed up and sown in cereals or potatoes.  People planted Victory Gardens and grew, according to a rough estimate, between 2.5 and 3 million tons of food.  Historian R.J. Hammond, who lived through the war, remembers there was little meat and fish, few fresh eggs, not enough cooking fats, no sugar, no cream, and too many potatoes, but that food supplies were nevertheless “ample.”  It was a bland and starchy diet, but with enough calories and nutrition to keep the British healthy.

Perhaps we could expect some kind of equivalent shift here in an oil emergency.  We have many acres of fallow farmland in this country and millions of backyard gardeners, some of them knowledgeable.  In his recent book Deep Economy, journalist Bill McKibben reports that one intensively farmed 200-acre plot outside of Burlington, Vermont, provides that city of 38,000 with seven to eight percent of the fresh produce it eats, or 500,000 pounds of salable fruit and vegetables, with the unsold going to a local food bank.  Havana recently saw a resurgence of city gardens, made painfully necessary by the end of Soviet economic aid to Cuba, which shows what people can do even in urban areas (although these vegetables are very expensive when paid for in regular pesos).  City chicken projects are now in vogue in the United States, encouraging people to raise small flocks of hens for eggs and meat.  Perhaps most importantly, the number of farmers’ markets has grown rapidly in recent years.  The latest count (from 2006) is 4,385 markets nationwide, an increase of 18 percent since 2004.

It is still possible in many parts of North America to eat a completely local diet—as Canadians Alisa Smith and J.B. MacKinnon (authors of The Hundred-Mile Diet) and Americans Bill McKib­ben and Barbara Kingsolver have shown.  In preparing an article for Gourmet in 2005, Mr. McKibben spent a year eating only those foods he could find raised near his home in Vermont, and while that experiment did not cost him any more in grocery money (if anything it was less, he says), eating that way did entail more time.  Mr. McKibben does not say how much, but J.B. MacKinnon told one interviewer that eating local basically added a part-time job to the day, because of the time it takes to find sources, make meals from scratch, or preserve summer food to eat in winter.  In Animal, Vegetable, Miracle: A Year of Food Life, Barbara Kingsolver and her family give great (and often joyful) detail about the hours they spent growing a large garden, canning food, freezing it, raising hens for eggs and butchering poultry.  Eating this way has its compensations, but it is unquestionably less convenient.

Most of the rest of us demand convenience, and in doing so take eating for granted.  Yet where we buy our bread and meat and fruit (from whom, that is), what and how much we choose to eat out of season, how much we buy locally—all of these choices may be essential someday to our ability to eat satisfactorily at all.  We cannot count on our national wealth and our Yankee trading smarts forever, nor can we afford to abandon farming simply because we are told over and over again that “we live in a service economy.”  As Wendell Berry has argued, we can only say that “we live from the service economy” if by the word live we mean “make a living.”  If we mean instead to think, breathe, and function—well, try a staple diet of overnight package delivery, or financial services, and see how many miles you get.

One of the points historians make about Britain in the 1940’s is that even given the difficulties of shipping in wartime, the British government found homegrown food supplies less predictable than imported ones.  But Britain could not have done without the home effort, either.  For America to become dependent on China, India, Mexico, and South America for food—to become a country that has no farming infrastructure and in particular no experienced farmers—seems reckless.

This month, the Metro mayor’s office will release a study of how Louisville can better feed itself from the surrounding communities.  The city is looking at what is being raised nearby and what facilities exist to distribute, can, freeze, or butcher this food—the whole infrastructure of eating.  Some pieces of this infrastructure already exist.  Here, as in many other places during the growing season, you can find farmers’ markets all over town.  There is a year-old distribution business called Grasshoppers, created to help farmers find markets for their crops, and another partnership has just announced plans for a year-round farmers’ market downtown.  The result of these efforts remains to be seen, but clearly a number of Kentuckians are working to restore a more self-sustaining, more local food economy, as Louisville asks itself the questions every community should ask.