What is your dinner doing to the climate?
By Bijal Trivedi LOCAL or imported? Conventional or organic? Can you make choices that will keep your diet healthy and reduce your carbon footprint? Is it possible to eat green? Does it even matter? It may surprise you to learn that our diets account for up to twice as many greenhouse emissions as driving. One recent study suggested that the average US household’s annual carbon food-print is 8.1 tonnes of “equivalent CO2 emissions” or CO2eq (a measure that incorporates any other greenhouse gases produced alongside the CO2). That’s almost twice the 4.4 tonnes of CO2eq emitted by driving a 25-mile-per-US gallon (9 litres per 100 kilometres) vehicle 19,000 km – a typical year’s mileage in the US. As greenhouse gas emissions attract ever greater scrutiny and criticism, the fields of sustainable consumption and life-cycle carbon accounting have prompted academics to tally the greenhouse gas emissions of hundreds of products and manufacturing processes so that we can make more environmentally friendly food choices. In the UK some supermarkets have already begun pilot programmes to label foods with their carbon footprint. One potato crisp producer is now labelling some lines with their CO2eq footprint – the makers calculated that each 34.5-gram packet that leaves the factory accounts for 75 grams of CO2eq. The Carbon Trust, a campaign group based in London, is working on a standardised system that companies can follow to work out the CO2eq footprint of any product. So how do you calculate your stomach’s CO2eq footprint? It’s far from simple. For a start,