We’re all told to lower our carbon footprint. But as far food goes, it’s not always that simple.
Companies are increasingly attempting to label products–from cribs to Coke bottles to cabbages–with a number that encompasses all the carbon that went into producing that product. So a box of powdered laundry detergent might have a carbon footprint of 750 grams, while a bottle of concentrated liquid might have a footprint of 650 grams. It’s more popular in the EU so far, though last year California Rep. Ira Ruskin introduced a bill that would have created a labeling standard in the state. (The bill didn’t make it out of committee.)
But even if every bag of chips and tray of veggies came with a sticker telling consumers about its environmental impact, it’s not that easy.
Susanne Freidberg, a geography professor at Dartmouth, has been studying the issues, and presented some of her findings at the American Association of Geographers’ conference earlier this year.
She says that when British supermarket chain Tesco started adding “food miles” labels to produce, a common way of distinguishing between “good” locally grown food and “bad” imports, it was a “fiasco.” Most of Tesco’s produce comes from Africa, but it turns out that growing green beans in Kenya actually produces less carbon than growing them in a hothouse in Europe. “Even Tesco eventually admitted that the label was ‘of no environmental use whatsoever.'”
And even if a label includes more than just food miles, where do you stop? “Let’s say my client is a retailer comparing apples from Washington State to apples from New Zealand. What are you going to measure? It’s standard to count on-farm machinery and fertilizer,” Freidberg said, “but do you also count the emissions that make that machinery? The transport of the workers going to the farm and back? If you don’t count those workers driving to work, you’re biased against countries where people walk to work, like Kenya.” There are very few studies about life cycle assessments (LCA) on food in peer-reviewed literature, she added.
And doing an LCA–on anything, not just food–is hard. It requires “a lot of data,” wrote Scott Kaufman on GreenBiz.com. “Some of the data is relatively easy to come by — the amount of energy used in a manufacturing plant that your company owns and operates, for example. Other types can be extremely difficult to obtain — a common example is a material used in your product (such as plastic packaging) that is bought from an overseas supplier.” After Tesco ditched its food miles label, it announced it was going to put more accurate carbon footprint labels on 70,000 of its products–three years later, it’s managed to label just 120, including milk, orange juice, potatoes, and toilet paper.
Carbon footprinting isn’t all bad. Walkers, a potato-chip brand in the UK, was one of the first to sign on to have its footprint measured, in 2007, so it asked The Carbon Trust, a UK nonprofit created by the government to lower carbon emissions, studied the life of a Walkers potato chip–from growth to transport to manufacture. The Trust discovered that Walkers’ suppliers were storing the taters in humid rooms to keep their skins soft, and that a huge amount of heat was needed to dry them out before frying. Walkers now pays farmers a bonus if their potatoes are drier, which has helped reduce a bag of chips’ carbon footprint by 7 percent. But clearly more work is needed to develop a standard that is fair to all producers and yet easy for consumers to understand.
There’s currently no standard in the U.S. for carbon footprint labeling, but the International Standards Organization (ISO) is working on a set of standards that’s currently going through committee and should be published by 2011.
File photo by Rebecca Hale