It is well known that meat is less carbon efficient than plants as a source of food. Producing 100g of protein from beef emits at least 25kg of carbon dioxide, on average. Chicken produces far less, at 4–5kg of carbon dioxide per 100g, but we eat vastly more chicken than beef. Per 100g, tofu produces 1.6kg carbon dioxide, beans 0.65kg and peas 0.36kg. Some nuts are carbon negative even after transport, because tree nuts are replacing crops and taking carbon from the air.26
