Environmental impact To understand the environmental impact, let's take an omnivorous diet. To produce one kilogram of beef, that would amount to around 27 kg CO₂e produced, we understand the environmental, for a vegetarian diet, to produce cheese for example, the carbon footprint amounts to around 13.5 kg of CO₂e. For a vegan diet, the carbon footprint for producing lentils is around 0.9 kg of CO₂e. (source Poore and Nemecek study 2018).