Shockingly, a plant-based diet may produce more carbon dioxide that originally thought, leading scientists to question whether a vegetarian diet is any better for the environment than a diet containing meat.
In The American Journal of Clinical Nutrition, scientists concluded after analyzing the eating habits of 2000 French adults that carbon emissions from growing fruits and vegetables generated a higher level of greenhouse gas than previously thought because in order to get the same amount of protein in a meat-based diet, a vegetarian needs to consume up to 9 pounds of fruit and vegetables daily to equal a smaller serving of meat.
All aspects of a food’s lifecycle were taken into account, including the cooking method.
Approximately 1,600 grams of carbon dioxide were emitted for every 100 grams of meat produced, more than 15 times the amount of greenhouse gas emitted during the production of fruits, vegetables and starches. It is also 2.5 times higher that gas emitted from fish, eggs, pork, and poultry.
However, when the researchers looked the grams of carbon dioxide emitted per 100 kilocalories the gap narrowed. 857 grams of greenhouse gas, the highest level, was still emitted to produce 100 kcal of meat, but it was only three times the emissions level from a similar amount of energy from fruit and vegetables.
The fruits and vegetables themselves are not high in greenhouse gasses, but it the production of the volume necessary that raises the level. In fact, the vegetarian diets studied produced 5000 grams of CO2 emissions per day per person.