Reading - Part 4

Food miles

Recently, campaigners have encouraged us to buy local food. This reduces "food miles", that is, the distance food travels to get from the producer to the retailer. They reason that the higher the food miles, the more carbon emissions. Buying local food, therefore, has a lower carbon footprint and is more environmentally friendly. However, the real story is not as simple as that.

If our aim is to reduce carbon emissions, we must look at the whole farming process, not just transportation. According to a 2008 study, only 11% of carbon emissions in the food production process result from transportation, and only 4% originated from the final delivery of the product from the producer to the retailer. Other processes, including fertilization, storage, heating and irrigation, contribute much more.

In fact, imported food often has a lower carbon footprint than locally grown food. Take apples, for example. In autumn, when apples are harvested, the best option for a British resident is to buy British apples. However, the apples we buy in winter or spring have been kept refrigerated for months, and this uses up a lot of energy. In spring, therefore, it is more energy-efficient to import them from New Zealand, where they are in season. Heating also uses a lot of energy, which is why growing tomatoes in heated greenhouses in the UK is less environmentally friendly than importing them from Spain, where the crop grows well in the local climate.

We must also consider the type of transport. Transporting food by air creates about 50 times more emissions than shipping it. However, only a small proportion of goods are flown to the consumer country, and these are usually high value, perishable items which we cannot produce locally, such as seafood and out-of-season berries. Even then, these foods may not have a higher carbon footprint than locally grown food. For example, beans flown in from Kenya are grown in sunny fields using manual labor and natural fertilizers, unlike in Britain, where we use oil-based fertilizers and diesel machinery. Therefore, the total carbon footprint is still lower.

It's also worth remembering that a products journey does not end at the supermarket. The distance consumers travel to buy their food, and the kind of transport they use will also add to its carbon footprint. So, driving a long way to shop for food will negate any environmental benefits of buying locally grown produce. Furthermore, choosing local over imported food can also badly affect people in developing countries. Many of them work in agriculture because they have no other choice. If they are unable to sell produce overseas, they will have less income to buy food, clothes, medicine and to educate their children.

Recently, some supermarkets have been trying to raise awareness of food miles by labelling foods with stickers that show it has been imported by air. But ultimately, the message this gives is too simple. Lots of different factors contribute to a food's carbon footprint besides the distance it has travelled.