Food is not simple. To make it, you have to balance myriad variables—soil, water, and nutrients, of course, but also various social, political, and economic realities. But because our consumer culture favors fixes that are fast and easy, our approaches toward food advocacy have been built around one or two dimensions of production, such as reducing energy use or eliminating pesticides, while overlooking factors that are harder to define (and ditto to market), such as worker safety.
Consider our love affair with food miles. In theory, locally grown foods have traveled shorter distances and thus represent less fuel use and lower carbon emissions—their resource footprint is smaller. And yet, for all the benefits of a local diet, eating locally doesn't always translate into more sustainability. Because the typical farmers market is supplied by dozens of different farms, each transporting its crops in a separate van or truck, a 20-pound shopping basket of locally grown produce might actually represent a larger carbon footprint than the same volume of produce purchased at a chain retailer, which gets its produce en masse, via large trucks.