When we buy home energy, car fuel or plane tickets, it’s fairly easy to work out the carbon footprint incurred. For other items, it’s not so simple. It’s immensely complicated to work out the precise carbon cost of even a simple product such as a bag of sugar; inevitably it’s trickier still to work out the emissions involved in producing an item with a long and complex supply chain – a new kitchen, say, or a television. In some cases, you might find a carbon footprint label, but in other cases you’ll need to either use intelligent guesswork or do some online research to get a rough sense of the “embedded carbon” or “embedded energy” in each item.
Though they currently appear on only a small number of products, labels specifying the carbon footprint of a product are likely to become increasingly common in coming years. The standard carbon labelling scheme in the UK was developed by the Carbon Trust, a quango set up by the government to help businesses cut emissions. The label shows the total carbon footprint of a product in grams or kilograms of carbon equivalent (ie all the greenhouse gases emitted during the production of the item, expressed as CO2 for the sake of simplicity).
In some cases extra information is provided on the label to help consumers get a sense of how the product compares to the alternatives. For example, the carbon labels that appear on the various types of Tesco orange juice state that freshly squeezed juice creates more emissions than juice made from concentrate. This isn’t surprising, given that making fresh juice involves transporting the whole fruit to the processing plant, rather than just the juice, but the carbon label usefully quantifies the difference – 360 grams per serving, compared to 240 grams – and in doing so helps the consumer make an informed choice.
Some experts have expressed niggles about the methodology behind the Carbon Trust’s labeling scheme but in most cases these are caveats rather than anything fundamental. One example is that the rules, which have been formalized by the British Standards Institute under the name PAS 2000, don’t apply a multiplier to CO2 emissions from planes on the grounds that the science isn’t yet sufficiently clear. This means that airfreighted goods look greener than they probably should. Overall, though, the rules are fairly robust and the labels are a useful way to raise carbon literacy among consumers.
Looking up carbon footprints
For the vast majority of items that don’t feature a carbon label, it can be difficult to get even an approximate sense of their carbon footprints. Individual reports, articles and blog posts have focused on the emissions caused by the manufacture of various specific items, so sometimes it’s possible to track down useful information via Google. Surprisingly, however, no single site pulls together footprint estimates for a wide range of objects. This can make it challenging not only to weigh up the carbon impact of different purchases but also to assess the environmental benefits of upgrading from old appliances to modern energy-efficient ones (a calculation that’s impossible to make without knowing the embedded carbon in the new machines).
A reliable carbon footprint website will doubtless eventually emerge, but in the meantime the most useful starting place for researching the climate impact of objects is WattzOn. The site’s Embedded Energy Database (EED) provides ballpark figures for the energy consumed in the manufacture of everything from dishwashers to footwear. Since energy use is the main source of greenhouse-gas emissions for most manufactured goods, these “embedded energy” figures give a useful indication of the relative carbon footprints for the various items listed.
Another useful source for information about the carbon footprint of everyday objects will be Mike Berner’s-Lee forthcoming book, How Bad are Bananas? The Carbon Footprint of Everything. Due to be published in 2010, the book details the climate impact of more than a hundred items.