.....and other such thoughts.
Buying “local” food and supporting local farmers and their local produce is one bullet point mantra often touted to be far more sustainable than buying food at a supermarket that belongs to a big company. The main claim for this is that local produce has very low transport costs (from the farm near by to the market), so the carbon footprint for this produce is extremely low. This then would mean that it is far less energy consuming and in the long term far more sustainable.
For a while I thought this was a compelling argument, and sometimes pondered over how guilty I should feel for not heading out to the local farmer’s market to buy “local” produce. But then, ever the skeptic, I decided to actually see if this was true.
First of all, at least in most of the US, local food now means food grown not necessarily 10 miles from the city, but within the state. Obviously, there are many cities near which there is no significant farming/agricultural land growing wheat, corn, fruit and vegetables. While Dallas does have farms a hundred miles or so from it, “local” predominantly means within the state of Texas. But since Texas is almost three times the size of France with most of the population in the four large urban centers (Dallas-Fortworth, Houston, San Antonio and Austin) it is very likely that a significant portion of the “local” food is being trucked across hundreds of miles from various rural, agricultural parts of the state to the cities. So that immediately weakens the distance and high energy consumption argument.
But could it still be possible for me to be more energy efficient (and our food more sustainable) if I shopped at a farmers market and not at a supermarket chain? Here is what some simple but rigorous calculations suggest:
Dallas has a lovely farmers market as well as other stores that sell local produce extensively. All of them are located around 8-10 miles from home. So a return trip is about 20 miles by car, through significant traffic. In addition, these stores only sell produce, so if I need a toothbrush or soap or any other daily use produce, I need to head out to a pharmacy or a general store to buy it. So if I get my food from a farmers market my gas consumption will be about gallon of gas a week (or over 50 gallons of gas a year). It also is a significant investment of my time.
In contrast, we live about 500 yards from a supermarket owned by Safeway/Tom Thumb, which is at the end of the street our house is in. It is the typical big American supermarket which sells everything from food and produce to kitchen towels and brooms. In our case, shopping is done on the way back from work without any detour, and on occasion I walk down to the store to pick up stuff. The total extra annual gas consumption for our shopping is zero gallons. In addition, it also saves a lot of time during the week since there is no need to make additional shopping trips for items of daily use that is not food or produce.
All of this only considers individual energy consumption (which can be quite significant), and does not go into the significant energy efficiencies brought about by economies of scale achieved by larger supermarket chains.
There is tremendous value in local food and local crops, and there should be a significant space for it. But even a simple hard look suggests that it is not necessarily a more “sustainable” and energy efficient method of food production. The more I research these issues (and those around “slow food”), the more it seems like they are largely seductive rants against corporations and globalization. Where there remains much value in these ideas, and they should be encouraged, they will not meet any rigorous analysis of sustainability and energy efficiency unless one uses similar eyewash metrics that large, inefficient corporations use.
(For a fascinating and rigorous information on a host of these issues, Just Food is an excellent read).