Authors: Jayson Lusk
That local foods travel fewer miles is taken as self-evident proof that they are thus better for the environment. Self-evident, that is, until one does even the least bit of critical thinking. The truth is that the number of miles a food travels has very little to do with its overall environmental impact. One extensive review in the journal
Trends in Food Science and Technology
concluded, “It is currently impossible to state categorically whether or not local food systems emit fewer [greenhouse gases] than non-local food systems.”
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Just to take one example, researchers have found that Londoners would use less energy and emit fewer emissions if they bought lamb raised half a world away, in New Zealand, rather than locally.
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How can it be four times more efficient to buy lamb that’s traveled ten thousand more miles? Comparative advantage and the low costs of sea transportation. New Zealand is naturally endowed with abundant, grassy land and a climate that is especially suitable for rearing sheep. Better New Zealand weather means more grass and less need for supplemental feed and fertilizer than are required to produce British sheep. When you add up the energy savings from the more efficient New Zealand lamb production, it more than offsets the extra energy required to get the stuff to London.
What’s true of sheep is also true of all kinds of other commodities. Tomatoes, for example, require ample amounts of warm weather to reach full potential. Outside a few months in the summer, the research shows that it is more energy efficient for northern European cities to ship tomatoes up from the south than to grow them locally in greenhouses.
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Natural
differences in weather, availability of tillable land, and other resources convey comparative advantages to specific regions that add up to significant differences in the amount of energy required to produce certain food. There are good economic reasons why corn tends to be grown in Iowa, wheat in Kansas, potatoes in Idaho, peanuts in Georgia, and grapes in California. It is because these crops can be grown there at higher qualities and in greater quantities using fewer resources than in other locations.
Moreover, successful farmers of a crop that benefits from a region’s natural resources can often expand and gain economies of scale. The larger size provided by scale economies results in more efficiency and less energy use. One environmental economist suggests the possibility that “larger producers, because they are more energy-efficient, can transport food longer distances and still have a smaller environmental impact than smaller, local producers.”
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Of all the global warming impacts that are said to come from food consumption, only 10 percent is due to transportation, whereas 80 percent is a result of activities on the farm.
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The implication for those worried about global warming is clear: to reduce the carbon impacts from food consumption, one should grow food on farms where production is most efficient and then ship it to the consumer.
While locavores obsess about the distance foods travel to get to them, seldom do they emphasize how far
they
have to travel to get to the food. Shipping food by boat or barge is incredibly efficient, and while shipping by semi is worse, it isn’t all that bad. The really inefficient part of food transportation comes from our cars’ emissions from the home to market. One
study estimated “that if a customer drives a round-trip distance of more than [4.15 miles] in order to purchase their organic vegetables, their carbon emissions are likely to be greater than the emissions from the system of … large-scale vegetable box suppliers. Consequently some of the ideas behind localism in the food sector may need to be revisited.”
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So, unless locavores are one-stop-shopping at the farmers’ market, chances are that the extra stop to buy local foods is creating more emissions than any that might have been saved getting that food to market. That’s also the reason Harvard economist Ed Glaser says that urban agriculture is environmentally harmful: by diverting living space to crops, it increases commuting distances, which causes much more environmental harm than any benefit accruing from the local fare.
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As far as the environment goes, it is important also to recognize that “buy local” is a cause, not a certifiable production practice.
Some
local producers use organic and low-tillage production methods, but many do not. At least with organic, there is a certifying body that requires adherence to certain standards to attain the organic label. There is no standardization with local. Some locavores think that’s a good thing. But one consequence is that you can never really be sure (even if you ask) that a local tomato was grown with more or fewer pesticides or in a way that caused more or less soil erosion than the tomato traveling cross-country. In fact, one of the main goals of locavorism is to increase consumption of vegetables, and as I have already revealed when discussing farm policy, growing fruits and veggies can require more pesticides and fungicides than growing grains. More chemical usage hardly implies improved environmental impacts. Maybe you
think that means you should buy organic, but what does that have to do with local?
And what happens to all the food a local farmer can’t sell? One study showed that a large percentage of the crops brought to farmers’ markets were never sold and thus simply perished. More than half the tomatoes suitable for market had to be thrown away because nobody bought them. The local farmers also had trouble growing produce of an acceptable size and appearance to consumers, and thus another 20 to 30 percent was thrown away even before market. This kind of waste is not nearly as problematic on large-scale commercial farms. As the authors put it, “[A] large proportion of each type of squash (especially the zucchini squash), cucumber, bell pepper, and okra could not be marketed due to poor quality or because it was too large for the market. In a large-scale production state such as California, much of the defected produce could be salvaged by frozen-food processors or possibly by a food cannery.”
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Because they share weather and temperature, all farms within a given region are likely to have their produce come to market around the same time. In a world with regional and international trade, that isn’t a big deal, as the surplus can be shipped out to other locations. But in the locavore’s world, the result is inevitable: spoilage and waste—not something typically prized by recycling environmentalists.
In a diatribe against food imports (although I presume he’s excepting Italian olive oil, Belgian chocolate, and French Champagne),
Mark Bittman writes, “I’m not a jingoist, but I’d prefer that more of my food came from America. It’d be even better, really, if most of it came from within a few hundred miles of where we live. We’d be more secure and better served, and our land would be better used.”
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The idea that a more local food supply is a more secure food supply rests on shaky premises. As we’ve already seen, local food production will often mean less-efficient food production, which in turn means less food. That’s fine if you’re trying to cut calories, but food security means that food is available when you want it.
It would be foolish to invest all your retirement savings in a single stock. The financial experts tell us to diversify. And if we shouldn’t keep all our financial eggs in one basket, the same goes for hen-laid varieties. One of the things that make farming unique compared to other businesses is its unusually large reliance on the weather. An unexpected drought, rain at the wrong time, an early freeze, or a hailstorm can devastate a whole farming community or even an entire region. While farmers protect themselves financially against these kinds of risks by buying crop insurance, what about the food consumer?
In a world of extensive food trade, there is little need to worry about the consumers of Northville if their farmers face a flood, because Northville consumers can readily buy their food elsewhere. But a world where the locavores have tied the hands of farmers in Northville, Southville, Eastville, and Westville to supply only their local consumers is one where a weather disaster in one location can have dire effects on the consumers who live there. After all, agriculture is a business that requires long production lags. A farmer can’t produce potatoes on a whim; it takes months of planning and foresight.
The world sought by the locavores isn’t more food secure, it’s riskier—in terms both of the availability of food and of the prices we’d have to pay.
The locavores want us to imagine that only those small farmers planting heirloom tomatoes are adding to the diversity of regional cropping systems. The reality is that the so-called mono-cropping systems that are the bane of the locavore’s existence are far less “mono” than they let on. A large farmer who plants corn this year typically rotates to soybeans the next. Even continuous corn or soybean farmers will often plant a fall cover crop of wheat, rye, or barley. And as I’ve already shared, many of the big farmers do use the low- or no-tillage production practices praised by the locavores. It is true that the crops these farms plant are not as diversified as those on the farms prized by the locavores, but there is much more temporal and geographic diversity in the global food system than locavores often admit.
Most of us could stand to eat a few more fruits and veggies. But what does that have to do with local food? The conclusion that local food is healthier is a non sequitur. It depends on what local food you eat, when you eat it, and what you do with the extra time and money you don’t spend seeking out local products. In short, eating local has nothing to do with eating healthily.
It is true that many fruits and vegetables are most nutrient-rich immediately after being picked ripe. But large growers and processors often quickly freeze just-picked produce
to preserve freshness. In fact, frozen vegetables are typically more nutrient-dense than fresh veggies that have been off the vine for several days. One of the big problems for locavores participating in community-supported agriculture or food co-ops is that they are delivered much more produce than they can eat in a timely fashion. One member of a local farm association admitted, “Ordinarily, I would never eat turnips. I managed to go 30 years without buying one. But now every winter I’m faced with a two-month supply, not to mention the kale, collards, and flat-leaf Italian parsley that sit in my refrigerator, slowly wilting, filling me with guilt every time I reach past them for the milk.”
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Not only is this wasteful, it’s not even all that healthy. The nutrient content of veggies that have been sitting around for a few days can deteriorate to the point that eating canned would be better—at least from a nutritional standpoint. That’s why one group of scientists concluded “that exclusive recommendations of fresh produce ignore the nutrient benefits of canned and frozen products.”
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Eating healthy means more than eating just a few kinds of vegetables. You won’t do your body any favors with a broccoli-only diet. Nutritionists tell us that a key component of a healthy diet is the diversity of the foods we eat. For example, a recent paper in
The Journal of Nutrition
indicated, “The recommendation to eat diverse types of foodstuffs is an internationally accepted recommendation for a healthy diet.”
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A person who restricts his diet to only those things grown locally is restricting diversity in his diet—especially in the winter. Wander around almost any supermarket in almost any town in America almost any time of year, and the diversity
and abundance of fruits and vegetables are absolutely astounding. Vidalia onions from Georgia, oranges from Florida, California lettuce, sweet corn from Iowa, mangoes, bananas, and jalapeños from south of the border—if you live in the right location, you
might
have access to such a cornucopia a few weeks or months out of the year, but Walmart offers it to us every day. Fifty to a hundred years ago, the available transportation and storage technologies required people to eat a lot more local food. Yet, despite weighing a bit less, people weren’t healthier then. One reason, among many, is that our great-grandparents lacked the diversity of the diet we enjoy when we eat food from places from beyond our backyard.
At certain times of the year and with certain veggies, fresh local food can taste better than nonfresh imported food. But that’s no argument for government promotion of local foods. Dinner at a three-star Michelin-rated restaurant tastes better than pizza from Domino’s. Yet I don’t see a campaign to limit meals to only those cooked by chefs who can rate a star. Few reasonable people would argue that governments should subsidize top chefs. Locavores must hold the rest of us in pretty poor esteem if we can’t be presumed to know what tastes best.
While I’ll grant the locavores their premise at certain times of the year, the same isn’t true all year round. Maybe local winter squash, broad beans, and beets do taste better than the ones grown farther away. But in the winter, the real choice isn’t between local or imported winter squash. With abundant trade, we can choose between local winter squash and
imported peaches, oranges, and tomatoes. You’ll have a hard time convincing me, and the vast majority of other Americans, that in February winter squash will taste better than peaches, oranges, tomatoes, and lettuce brought up from Florida or South America. No one comparing apples to oranges would win even a high school debate, and yet the locavores hope to convert us by hiding the fact that they’re comparing winter squash to summer sweet corn.