Our Co2 calculator partner uses leading life cycle assessment (LCA) data to account for the impacts at each stage of a food’s life cycle including farming, packaging, processing, transport, retail and waste. Where relevant, impacts from cooking and end-mile delivery are also included. The LCA values are largely based on a study by Poore and Nemecek (2018). Where country-specific LCA values are available, the carbon footprint of food is calculated according to the ingredient countries of origin. If the country of origin is unknown, or unavailable within the existing data, the carbon footprint is calculated in line with average British consumption. This uses International Trade Centre data to map where food in the UK is typically sourced from. All of our Co2 scores and calculations are completed to the Greenhouse Gas Protocol Standard.