There’s a chance (as yet unquantified) that you’re eating a sandwich as you read this. If so, you might pause to consider its carbon footprint – which, it turns out, is likely to be content-dependent. That’s one of the findings of a 2018 study from Dr Namy Espinoza-Orias and Professor Adisa Azapagic of the Sustainable Industrial Systems dept., School of Chemical Engineering and Analytical Sciences, The University of Manchester, UK.
“This study estimated the carbon footprint associated with the production and consumption of sandwiches, prepared commercially and at home. In total, 40 most popular recipes were considered. The carbon footprint of a ready-made sandwich ranges from 739 g CO2 eq. for egg & cress to 1441 g CO2 eq. for the breakfast option. The carbon footprint of the most popular home-made sandwich (ham & cheese) varies from 399-843 g CO2 eq. per serving. The average impact from the home-made option (609 g CO2 eq.) is 2.2 times lower than the impact from the commercial equivalent with the same ingredients (ham, cheese and mayonnaise).”
Details of their paper : Understanding the impact on climate change of convenience food: Carbon footprint of sandwiches can be found online in the journal Sustainable Production and Consumption, Volume 15, July 2018, Pages 1-15.
And which may be digested in full here