First episode of our special issue dedicated to responsible eating! What is the environmental impact of our diet? Global warming, soil pollution, water contamination… Agriculture and food production have enormous impacts on our planet. But how can we reduce the carbon footprint of our diet? Which diet is the “eco-friendliest”? Which one will most protect the environment and the planet? Deciphering in depth, beyond wisdom.
In the face of all the environmental problems affecting the planet, we are increasingly aware of the role we must play in protecting nature. Among the daily actions we do for the environment, one counts more than the others: the way we eat. Our diet is one of the areas with the strongest environmental impacts. In order to produce food on an industrial scale, land is required, on which fertilizers, pesticides, herbicides, and fungicides are often used. It takes machines to harvest crops, vehicles to transport food, and conserve it. In total, it is estimated, for example, that the food sector (the entire chain) could account for up to a quarter of human greenhouse gas emissions.
Virtually every food we consume has contributed to both the use of chemicals, occupying soils, and emitting greenhouse gases. When we consume food, we have a responsibility to the planet and the environment. But how can we eat better if we want to avoid destroying the environment? We will describe for you the different diets in order to better understand their environmental impacts.
Is the vegetarian diet better for the planet?
In terms of environmental impacts, it is often said that the vegetarian diet is less harmful. Producing meat has a huge environmental impact, especially for sheep and cattle. Firstly, because producing 1 kg of meat has a higher environmental cost than producing, for example, 1 kg of potatoes. To produce 1 kg of beef, you must feed the livestock, so grow its food (cereals, hay, or other) and use water. You need to use space and in particular soil. It is then necessary to transform the animal into consumable meat (slaughter, cutting, processing, packaging…). All this contributes to the emission of greenhouse gases and certain pollution. For the potato, it is enough to plant it, to water it, and to give it certain nutrients (fertilizers for example).
In addition to this, livestock produce greenhouse gases themselves. Thus, it is estimated that an American cow raised for its meat emits between 70 and 120 kg of methane every year, the effect of which on global warming is 23 times stronger than CO2.
The carbon footprint of a vegetarian diet is therefore generally considered to be lower than that of a carnivorous diet. A study by Shrink That Footprint studied five diets: the “Meat lover”, the average American diet, the beef-free diet, the vegetarian diet, and the vegan diet. The results? Vegetarian and vegan diets are those with the lowest carbon footprint, with 1.7 and 1.5 tons of CO2 equivalent emitted per year per person, respectively. At the same time, “meat lovers” emit 3.3 tons of CO2 equivalent per year per person, twice as much as the vegan diet. On the other hand, by simply removing beef and lamb from their diet (while keeping other meat and animal products), the carbon footprint lowers to around that of a vegetarian diet, with 1.9 tons of CO2 equivalent emitted per year per person.
Why are things not as simple when it comes to the environmental impact of food?
The reason is, in terms of food, because data does not always show the concrete and global reality. Thus, most of the studies on the environmental impact of food are based on data from the United States, which in turn guides their results. For example, in the United States, 125kg of meat is consumed per year per person according to the FAO. That’s 20% more than in France. Americans also consume 53 kg of beef per year per person, compared to “only” 23 kg in the European Union. The comparison of diets will therefore be different if adapted to the geographical context.
Similarly, the calculation of the environmental footprint of meat production refers to US farming practices, where livestock are raised primarily from cereals and soybeans. And yet, soybean and cereal farming would significantly increase methane emissions from cattle: livestock raised on natural herbs, rich in Omega-3, would emit up to 20% less methane than conventional livestock. And growing grass does not emit CO2. In France, 60% of cattle feed is made up of grass. The carbon impact of 1 kg of beef in France is therefore much lower than that of 1 kg of beef in the United States.
Moreover, it is impossible for these studies to take into account all the criteria involved in the carbon impact of food. For example, for soils, it is now known that pasture-raising is better than cereal or vegetable crops in climatic terms, since it contributes to the development of grasslands, which absorb CO2. Concretely, 1 hectare of pasture dedicated to livestock greatly reduces atmospheric CO2, while 1 hectare of crops increases it slightly. However, this data is never included in environmental impact assessments.
Finally, if we consider factors other than CO2 (such as soil, water, and biodiversity pollution), things are still complicated. For instance, fruit, vegetable, or cereal crops can be very harmful to the environment because of the use of pesticides, herbicides, and other fungicides that destroy biodiversity, and pollute soil and water. On the other hand, the production of certain vegetables (cucumbers, lettuce, celery…) requires large quantities of energy and water, which makes the calculation even more complex. And all this does not take into account deforestation induced by certain crops like soybeans, or monoculture.
So, which diet will most protect the planet?
If one tries to sum up all the studies that are done on the subject of the environmental impact of different diets, it is much harder to say which “diet” is the best for the planet. Depending on the origin of the products consumed, the culture or breeding technique used, the quantity consumed, very different results can be obtained. Thus, a vegetarian diet rich in soy and vegetables can be more harmful to the planet, with equal calories, than a diet containing a little meat, if it is raised under good conditions (pastures, organic food). Conversely, an omnivorous diet containing a lot of industrially-grown beef will have far deeper environmental consequences than a vegetarian, organic, and locavore diet.
It is therefore impossible to decide, but there are some key points to be learned in order to better understand the environmental impact of our diet and to choose a diet that better protects our environment.
- Beef and lamb are among the most harmful foods on the planet, especially when they are grown industrially (cereal food, no pasture). For an eco-friendly diet, they are to be avoided and reduced, like meat in general. In fact, reducing your consumption of beef has more impact on the environment than no longer using your car.
- Pasture-grazing meat makes it possible to reconstitute soils and their ability to store carbon: these are the sources of meat to be favored. Chicken and fish also have a significantly lower environmental impact than sheep or cattle on the planet. If you eat animal products, these are the ones you must choose first.
- Vegetables and cereals have a lower overall carbon impact than meat or dairy products. Nevertheless, some vegetables have a relatively strong impact. For example, to produce 1 kg of potatoes, 2.9 kg of CO2 is emitted, and to produce 1 kg of asparagus, 3.4 kg of CO2 are emitted. If vegetables are not organic, their impact can also be very strong on biodiversity and soil quality because of chemical inputs.
- It all depends on how much you consume. Thus, to consume 600 calories of potatos (the most energetic vegetable), it would be necessary to eat more than 780 g, and this would emit about 2.3 kg of CO2. To consume 600 calories of pork spine, it is necessary to eat only 200 g for “only” 600 g of CO2 emitted in the atmosphere.
- Beware of the fruits and vegetables you consume: soybeans and vegetables rich in water such as tomatoes, cucumbers, or zucchinis need a lot of energy and water to be produced in industrial quantities and are sometimes associated with deforestation. Similarly, blueberries or bananas are fruits with a high environmental impact. It is therefore preferable to consume them only occasionally, when in season.
- Legumes (lentils for example), on the other hand, are very “sober” in environmental terms, because they require little water, little energy, and emit little CO2. They must be part of any eco-friendly diet.
- Seafood products have widely varying environmental impacts: overfishing or intensive fish farms pose many problems in terms of biodiversity in particular. Care should be taken to consume them only in season and to avoid endangered species. On the other hand, when fish stocks are well managed and products are reasonably consumed, seafood is a relatively environmentally friendly alternative to proteins such as beef in environmental terms. For more information on the consumption of seafood, do not hesitate to consult articles by our marine world expert, Niels de Girval.
- The way in which your food is produced is as important as the type of food you eat: use local food to avoid the effects of transport, production limiting chemical inputs, meat/eggs/dairy products from animals raised under good conditions (pasture-raised, without antibiotics…).
The ideas received are sometimes very complex in terms of the environmental impact of our diet. Studies are contradictory, and it is difficult to disentangle the truth from what is false. In the end, it is often common sense that an industrial product is almost always more harmful to the environment than locally produced food, through healthy and non-intensive agricultural practices. And this is good, since it corresponds to the expectations of consumers, who, in our latest study, plebiscitated a more extensive and reasoned agriculture.
So, are you ready to start an eco-friendly diet?