Is Going Local Good for the Environment?

Santa Barbara County is one of the largest agricultural regions in the world. It grows approximately $1.2 billion worth of produce a year, putting it in the top one percent of U.S. counties. Paradoxically, most of this produce is consumed outside of the county rather than within it. As David Cleveland, environmental studies professor at UC Santa Barbara, discovered, 95% of the produce consumed within the community is imported ("You Eat What You Are, Part II"):

This is what really shocked us: we found that when you added up all these different ways in which locally grown produce got to people in Santa Barbara County, that less than five percent of the fruits and vegetables consumed in Santa Barbara County were actually grown in Santa Barbara County, and the other ninety-five percent were imported.

This paradox came to a head in 2005 when a mudslide blocked the shipping (i.e., road and rail) lines between Santa Barbara and Los Angeles for about a week. Because fruits and vegetables couldn’t be imported into the county, the produce sections of many grocery stores lay empty. An obvious solution was for the stores to buy produce from local farmers, but they couldn’t because they were under contract with suppliers from outside of the county. So, their produce sections remained empty and the fruits and vegetables grown by local farmers rotted in the fields.

Stories like this illustrate how there’s something wrong with the market for produce. A common theme is that agribusiness is the guilty party, but as the economist Tyler Cowen points out, while there are serious problems with the current state of agribusiness, there is no reason to throw the baby out with the bathwater. Without it, even more of the world would go hungry than already does ("You Eat What You Are, Part I"):

I think agribusiness and consumerism are seen as the great villains. I think both are essential; we can’t do without them. They feed the seven billion people in the world. We do need to improve them, but I would work on them through innovation. The biggest food problem in the world today is that agricultural productivity is slowing down and for a lot of the world food prices are going up. And for that we need more business, technology and innovation, not locavorism.

Localvorism? By this Cowen is referring to a belief held by many that the solution is to eat more food grown locally.  Why should food be shipped around the world when it can be grown and consumed locally? Not only does it taste better, but it's often more nutritious (because it can be harvested later), and it's better for the environment. This theme appears in numerous books, such as Michael Pollan’s “The Omnivore’s Dilemma” and “In Defense of Food," it is reflected in the philosophy of certain restaurants, such as Chez Panisse in Berkeley, CA, and in the increasing popularity of farmer’s markets at which local farmers sell their goods to urban consumers.

But is "going local" better for the environment? David Cleveland, the environmental professor from UC Santa Barbara mentioned earlier, found that it didn't benefit the environment as much as he'd hoped or expected ("You Eat What You Are, Part II"):

We wanted to look at what effect 100 percent localization of the Santa Barbara County system — which is a physically and biologically a very feasible thing to do — what effect would that have on greenhouse gas emissions? And we found that it wouldn’t make a lot of difference. Our savings in greenhouse gas emissions, per household, as a proportion of the total food system greenhouse gas emissions, was less than one percent (emphasis added).

Cleveland’s research built on the research of Chris Weber and H. Scott Matthews (“Food-Miles and the Relative Climate Impacts of Food Choices in the United States”), who found that most of the energy associated with food production is in the production phase rather than the transportation phase. There is something we can do to reduce the carbon footprint of food production. Eat less red meat and dairy products. Why? Because cows are some of the worst polluters on the planet:

It is generally believed that cars and trucks and airplanes contribute an ungodly share of greenhouse gases. This has recently led many right-minded people to buy a Prius or other hybrid car. But every time a Prius owner drives to the grocery store, she may be canceling out its emission-reducing benefit, at least if she shops in the meat section. 

How so? Because cows — as well as sheep and other cud-chewing animals called ruminants — are wicked polluters. Their exhalation and flatulence and belching and manure emit methane, which by one common measure is about twenty-five times more potent as a greenhouse gas than the carbon dioxide released by cars (and, by the way, humans). The world’s ruminants are responsible for about 50 percent more greenhouse gas than the entire transportation sector. 

Even the "localvore" movement, which encourages people to eat locally-grown food, doesn't help in this regard. A recent study by two Carnegie Mellon researchers, Christopher Weber and H. Scot Matthews, found that buying locally produced food actually increases greenhouse gas-emissions. Why?

More than 80 percent of the emissions associated with food are in the production phase, and big farms are far more efficient than small farms. Transportation represents only 11 percent of food emissions, with delivery from producer to retailer representing only 4 percent. The best way to help, Weber and Matthews suggest, is to subtly change your diet. “Shifting less than one day per week’s worth of calories from red meat and dairy products to chicken, fish, eggs, or a vegetable-based diet achieves more greenhouse-gas reduction than buying all locally sourced food,” they write (Super Freakonomics, p. 167).

All of what appears in this post (and more) is covered in more detail in a recent two-part Freakonomics podcast – You Eat What You Are, Part I and Part II. The first part explores what has gone wrong with the production of food in the United States and talks with food philosopher Michael Pollan, the economist Tyler Cowen, and the founder and owner of Chez Panisse restaurant Alice Waters. The second part examines whether going local is the answer, and as you have probably already guessed (if you’ve made it this far in this post), many of the answers are surprising (e.g., it's better for the environment for people living in England to buy tomatoes grown in Spain than to grow it themselves, and the per capita carbon footprint of high rise apartments is lower than it is in rural communities).

As always, the Freakonomics podcasts can be listened to on-line or downloaded from iTunes. The accompanying blogposts (from which I pulled most of the quotes) are informative as well.