The worst sandwiches in terms of carbon footprint:

1) Ready-made all day breakfast: 1,441 CO2 eq.

2) Ready-made ham and cheese: 1,350 CO2 eq.

3) Ready-made prawn and mayo: 1,255 CO2 eq.

4) Ready-made egg and bacon: 1,182 CO2 eq.

5) Ready-made ham salad: 1,119 CO2 eq.

But don’t despair. For all you organised individuals out there, sandwiches made at home are less harmful to the environment. Researchers found that a homemade ham and cheese sandwich, made from 58g of bread, 8g of ham, 20g of cheese and 13g of mayo, is less detrimental in terms of its carbon footprint. Although researchers advised avoiding ingredients with a higher carbon footprint such as tomato, cheese, lettuce and meat.

“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,” said Professor Adisa Azapagic, from the university’s School of Chemical Engineering and Analytical Sciences.

“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.”

About 11.5 billion sandwiches a year are eaten in the UK, according to the British Sandwich Association (BSA). Around half are pre-made at home and the remainder bought elsewhere.

This should be some food for thought next time you think about having a sandwich for lunch.

Images: Raphael Noqueira / Carly Jayne

Here’s why you should think twice before buying a pre-packaged sandwich