Vital Veg in Scotland delivers to each CSA customer

One of the knocks on Community-Supported Agriculture is that the model burns up more fuel than traditional food systems. And this means CSAs reputedly produce more CO2, which means CSAs are suspected of contributing more to global warming than regular shopping trips to Kroger.

Ouch. Is that really true? What does the research show?

The SANET-MG discussion group recently hosted a spirited discussion about research done in Iowa on two local food distribution systems by Rich Pirog, associate director of Iowa State University’s Leopold Center for Sustainable Agriculture, and Rebecca Rasmussen, a graduate student at ISU’s College of Business. (Click here to download the PDF.) The basic conclusion:

” . . . the delivery option using a Toyota Prius resulted in 2.77 times lower fuel usage and CO2 emissions than the consumer pickup option using U.S. average fuel economy for passenger vehicles. However, if all the CSA customers who used vehicles for pickup drove a Toyota Prius, farmer distribution would still be more efficient, but only 1.35 times more than that of customer pick-up.”

In addition to making me wish I could afford to buy a Prius today, the study made me wonder if there will ever be enough research to provide definitive answers on all the questions about whether CSAs are a net plus or net minus in terms of greenhouse gas emissions.

One question is how well this study in Iowa fits the reality in other locations around the country. Do customers in Iowa drive longer distances to pick up their produce from a CSA than the typical customer outside Hartford, CN, or Palo Alto, CA? I happen to live less than a mile from the Michigan State University Student Organic Farm. Does that mean I can justify buying a share more than someone who lives 15 miles away?

Rebecca Titus of Titus Farms in Michigan deposits her customers’ CSA boxes at numerous locations around the Lansing area. Is that going to be the dominant model and does it make the best sensel?

And while I understand that no single study can ever answer address all the variables we care about, I wish that this study had looked at the actual vehicles used, both by the growers and the customers. I think of the customers in their SUVs in the Midwest compared to the New Jersey suburban Mom in her Saab. Are the customers who frequent CSAs more likely to drive fuel efficient vehicles than their supermarket-shopping counterparts? Do they therefore deserve extra “points” for being more likely to engage in other green practices outside food shopping?

How many farmers in Iowa actually do drive Toyota Prius trucks? (I would love to know.) I have talked about this issue with some of my favorite local growers, and most said that they would be delighted to have the money to buy a hybrid. So is there a hidden benefit if CSAs provide farmers a greater share of the profits on food sales so that they can afford a Prius — or afford one sooner?

The study is also silent on how much energy would have been used if these customers had purchased similar produce from their local grocery stores. How much diesel fuel does it take to get a quart of strawberries from Chile to the Wal-Mart in Dubuque? And how does that stack up in terms of how much CO2 spews into the environment as a result?

Contrarian that I am, I also wonder whether people waste more of their supermarket food than food they buy from local growers directly. I know that I value the food I grow myself or that I buy from local growers I know personally more than the “corporate food” from my local supermarket. (I would also like to see research comparing the methane emissions produced when I eat the food versus when I throw it away or compost it.)

An interesting post on the SANET-MG list concerned a CSA in Scotland called Vital Veg. The custom there is for the CSA to deliver directly to the homes of each customer. (I am old enough to remember horses delivering milk and the “egg man” who stopped each week.)

Not only will it be interesting to see which approaches work best in different cultures, but one of the bigger and more important challenges will be to educate people about how they can cut overall fuel usage by more carefully planning their trips. One quick tip is just to stop making left-hand turns. Even back in 2006, when gas cost far less than today, UPS calculated that they save $600 million a year by having their drivers make nothing but right-hand turns. They have a computer program that allows them to create routes that avoid the dangers (left-hand turns result in more accidents), while saving fuel and money in the process.