To measure Walkers' carbon footprint, the Carbon Trust, on our behalf, has calculated the carbon footprint of a standard packet of Walkers Cheese & Onion Crisps.I really like this idea of putting the carbon footprint on every day items, so you can get a feel of the embedded carbon in them.
The final carbon footprint calculation is 75g.
The flow-chart on this page shows exactly what percentage of our carbon footprint is expended at each stage:
1) 44%: Our raw materials: Potatoes, sunflowers and seasoning
2) 30%: Manufacture: Producing crisps from potatoes
3) 15%: Packaging our crisps
4) 9%: Distribution: Bringing our crisps to you
5) 2%: Disposal of the empty packs
I also like the breakdown in stages as it lets you know that the raw materials have the majority of the impact and therefore probably the best place to try and reduce emissions. I think many people would have thought that the manufacturing and distribution were the main culprits, and this lets you see that raw materials have an even greater impact than both of them combined.
The 75g number is ultimately the key value on the label, but without something to compare it to, it is not that interesting on its own. Hopefully in the future other potato chip manufacturers and food producers will also label their products so you can choose a low carbon product. Off hand, the only thing I can think of to compare it to is a gallon of gasoline which has around 9 kg of emissions, so one bag of chips is around 1/120 of that.
via Walkers via Food System Factoids