According to Crippa, M., Solazzo, E., Guizzardi, D., Monforti-Ferrario, F., Tubiello, F. N. & Leip A. (2021). Food systems are responsible for a third of global anthropogenic GHG emissions. Nature Publication (34% of global GHG emissions).
Calculated from the Eat Lancet Commissions Report, IPCC and Vermeulen current emissions from the food system are between 8.5 - 13.7 GtCO₂-eq / yr (page 463) the emissions boundary calculated to be 5Gt (hence a necessary reduction of 41%-64%). Remark: the latest IPCC Report AR6 (page TS-88) summarizes that emissions increased to 17 GtCO₂-eq / yr (23%-42% of global GHG emissions) by 2018. In the IPCC Special Report on climate change and land different mitigation potentials of diets are discussed in chapter 5 (page 488). Highlighting the “Flexitarian” diet from Springmann Nature Publication as the minimal possible diet scenario that keeps greenhouse gas emissions (and in general our planetary option space) within a save limit by 2050 with a mitigation potential of 5.2 GtCO₂-eq / yr. Or as profiled in the Eat Lancet report as half of the emissions compared to a “business as usual” diet (figure 6 page 473).
In the 2012 publication from Vermeulen et al. emissions from our food system are estimated to be 9.8-16.9 GtCO₂-eq / yr, with 12.7% being the postproduction chain. Hence the reduction of the whole food supply chain that is needed to reach our climate goal of 5Gt are respectively 50 - 64% (a reduction from 10-16Gt to 5Gt).
Accordingly we define any meal that is 50% below the our current emissions as "climate friendly". We expect Europe to reach this target within the next 12 years. Hence pioneering products and restaurant should aim to reduce 50% of their emissions in the next 2-3 years. Already today everyone can provide a climate friendly option.
We carefully calculate based on our data the average CO₂ consumption, which we use for comparison. Here you find more information on the latest results and the methodology: Average food consumption used for comparisons [EN/DE].
It relies on calculating the total CO₂, as well as the total amount of food in terms of relative macronutrients, to calculate a ratio. As it is described here: Daily Food Unit - DFU [EN/DE].
Based on the comparison we can now clearly determine for each product, recipe, restaurant or any collection of foods the respective ratio and compare it with the average. The percentage - how much it is better - is used by Eaternity across the board to label meals as climate friendly. Or not. The formula you find here: Improvement percentage calculation [EN/DE]
You can find a documentation for the different thresholds of the more granular Eaternity ratings here:
2023-04-26-Legende_Eaternity_5-Symbol.pdf
2023-04-26-Legende_Eaternity_3-Stars.pdf
Eaternity Gastro - Bewertung der Klimabilanz (Küche) 04.2022.pdf