Do you take a packed lunch to work or buy a sandwich from the shop? The carbon footprint of your sandwich could be having a major impact on greenhouse gas emissions, according to new research.
Researchers at The University of Manchester have carried out the first ever study looking at the carbon footprint of sandwiches, both home-made and pre-packaged. They considered the whole lifecycle of sandwiches, including the production of ingredients, sandwiches and their packaging, as well as food waste discarded at home and elsewhere in the supply chain.
The most carbon-intensive sarnie
All together the team looked at 40 different sandwich types, recipes and combinations. They found the highest carbon footprints for the sandwiches with pork meat (bacon, ham or sausages) and those containing cheese or prawns.
Of the recipes considered, the most carbon-intensive variety is a ready-made ‘all-day breakfast’ sandwich which includes egg, bacon and sausage. The researchers estimate that this type of sandwich generates 1,441 grams of carbon dioxide equivalent (CO2 eq.). This is equivalent to CO2 emissions from driving a car for 12 miles.
The sandwich with the lowest carbon emission equivalent is a simple home-made favourite, ham and cheese. The study also found that making your own sandwiches at home could reduce carbon emissions by half compared with ready-made equivalents.
Sandwiches vs cars
According to the British Sandwich Association (BSA), more than 11.5 billion sandwiches are consumed each year in the UK alone. Around half of those are made at home and the other half are bought over the counter in shops, supermarkets and service stations around the country. That means the UK spends nearly £8 billion a year on the breaded snack, at an average cost of £2 per snack.
‘Given that sandwiches are a staple of the British diet as well as their significant market share in the food sector, it is important to understand the contribution from this sector to the emissions of greenhouse gases. For example, consuming 11.5 billion sandwiches annually in the UK generates, on average, 9.5 million tonnes of CO2 eq., equivalent to the annual use of 8.6 million cars.’
PROFESSOR ADISA AZAPAGIC
School of Chemical Engineering and Analytical Sciences