Carbon footprints

There’s a modern myth that food miles are bad. But measuring the carbon footprints of food items produces surprising results. We discover, for example, that bringing New Zealand lamb to our table — according to information collated by Oxford’s Environmental Change Institute — can generate fewer emissions than if the Sunday joint originated in Wales, due to higher emissions from UK feed and rearing methods. And it’s not cool to buy roses from Dutch hothouses. We should fly them in from Kenya, where they grow in the sun.

Now Defra, the Carbon Trust and the (independent) British Standards Institute have jointly published a ‘fast-track product carbon footprint standard’ called PAS 2050 to help legitimise product footprint development and encourage its use. They have set out the terms under which companies can have their products’ footprints measured and approved. The aim is to assure shoppers worried about global warming that the footprint means what it says on the tin — allowing them to choose products with smaller footprints.

But the footprint concept is too simplistic to be really useful. It seeks to record emissions released during the production, distribution and consumption of the product, and the disposal of packaging and food waste. But how can a retailer know whether shoppers use products in any prescribed way? How many retailers work only with suppliers whose production methods and energy use are clearly defined? How can those suppliers track the renewable element of the energy they use? They can’t, so the standard has to rely on averages to calculate electricity emissions for any given product.

Like a real footprint, a carbon footprint can be quickly washed away. Supermarkets sell many fast-moving items, which are themselves dependent on fast-moving commodities markets overseas — where middlemen obscure the origin of produce from a variety of sources.