Sunday, January 25, 2009

Why grow (and eat) seasonal produce?

Throughout human history people have eaten what grows in their geographic area in its season. Today, although there are occasionally some fruits and vegetables that you can’t find on a given day of the week, Americans can find most types of produce in markets regardless of season.
Even though having that kind of choice in our diets seems like it’s an absolute good, is it really? At what cost to our planet and ourselves do we continue to invest time, energy and resources into making sure produce from all over the world is available in supermarkets year-round? As concerns about energy costs and sources and pollution from transport and traditional farming methods grow, Americans need to take a hard look at whether we can sustain this type of one-size-fits-all approach to agriculture in the decades to come.
So what kinds of costs to our society and our collective health are we talking about? According to an April 26 article in the New York Times titled Environmental Cost of Shipping Groceries Around the World, fuel for international freight carried by sea and air is not taxed. This has led to some pretty strange food production strategies where locally produced food is either sent far abroad for processing or left to spoil because importing food from thousands of miles away is less expensive due. One example is the citrus market is Spain. Spain imports lemons from Argentina but lets local lemons fall of the trees and rot.
So what about buying domestic produce at the grocery store rather than fruits and vegetables grown in a foreign country? This should make sense, but it’s not that simple. You can approximate the amount of energy required and pollution generated by shipping produce using a concept known as food miles.
On the National Resource Defense Council’s website (NRDC's This Green Life Page) the organization provides some examples of the number of miles various food products travel to get to a typical market in New York City. Washington apples must travel more than 2,900 miles in refrigerated trucks to get to that store. The peaches in the store are from Chile, and travel 5,000 miles by ship. Both methods are energy intensive and polluting, but which method produces more pollution? The method of transport, whether by air, ship or truck, changes the amount of pollution dramatically. Marine transport produces the least amount of pollution of the three transit types though it’s still bad for the environment and marine life.

The following chart from the National Sustainable Agriculture Information Service, an organization managed by the National Center for Appropriate Technology (NCAT) and funded under a grant from the United States Department of Agriculture's Rural Business-Cooperative Service, offers a useful quick comparison:

There’s also a basic social cost. As a kid in Orange County, California I can remember the annual strawberry harvest. Along Valley View St., now taken over by office parks and warehouses, were fields of strawberries. When spring turned to summer, each field would have its own small stand selling fresh strawberries. The local markets all of a sudden had baskets and baskets of the red berries, and even local chain restaurants like Marie Callenders’ had strawberry pie from mid-summer through early fall. My grandfather also used to grow strawberries right in his backyard, and throughout the summer my sister and I would grab a few to snack on.
In California, even though strawberries harvested across the state are actually produced locally, they are still shipped by truck to large cooling rooms where they are stored until they are shipped to stores. Here’s an interesting look at the USDA’s recommendations for storing and transporting strawberries to keep them fresh. USDA Strawberry Recommendations
So what can we do to make our global approach to agriculture more sustainable? First, we can use available land in urban areas, rather than clearing more wilderness, to offset some of the costs of traditional agriculture. Using community gardens, CSAs and our own backyards is a good place to start. And when it comes to making our own yards productive, that’s where Yard Farmer comes in. More on this subject in an upcoming post.

No comments:

Post a Comment