I don’t personally see much promise in the idea of putting labels on products that tell consumers how much carbon was emitted to produce them. Firstly, people don’t have much context for understanding what that means. Secondly, people don’t particularly seem to care. Thirdly, voluntary consumer action isn’t a sufficiently fundamental change to deal with the problem.

All that said, such labels could have benefits in unexpected places:

The process of calculating the carbon footprint for Walkers crisps revealed an unexpected opportunity to save energy. It turned out that because Walkers was buying its potatoes by gross weight, farmers were keeping their potatoes in humidified sheds to increase the water content. Walkers then had to fry the sliced potatoes for longer to drive out the extra moisture. By switching to buying potatoes by dry weight, Walkers could reduce frying time by 10% and farmers could avoid the cost of humidification. Both measures saved money and energy and reduced the carbon footprint of the final product.

The value of carbon footprinting and labelling lies in identifying these sorts of savings, rather than informing consumers or making companies look green. According to a report issued in 2009 by the Tyndall Centre for Climate Change Research at the University of Manchester, in England, “the main benefits of carbon labelling are likely to be incurred not via communication of emissions values to consumers, but upstream via manufacturers looking for additional ways to reduce emissions.” It is not so much the label itself that matters, in other words, but the process that must be gone through to create it.

While we are waiting for economy-wide measures like carbon pricing to be implemented, more limited initiatives like this are probably especially valuable.