With many aspects in life, it’s easy to see which choice is the better one for the environment. We can see the exhaust from cars, so we know that biking and public transit are more environmentally friendly options. We know that waste has to be hauled away and that it builds up in landfills, so we know that recycling and composting are better options. However, with the food we decide to eat, it’s not so straightforward.
You might have heard that eating a plant-based diet is better for the environment. In fact, it’s the most significant thing you can do to lessen your impact on the environment. Here’s why:
One reason we eat food is to get energy. All energy in food originates from the sun. If we look at a simple ecological pyramid on a given area of land, we have a huge group of producers of energy on the bottom — plants that harness energy from the sun. Above them is a smaller group of “primary consumers” — herbivores who eat the plants. At the top of the pyramid is a very small group of “secondary consumers” — carnivores who eat the primary consumers.
Each level of the pyramid is smaller than the one below it because only about 10% of the energy obtained is passed up to the next level. About 90% of the energy is used up just for the organism to stay alive, metabolize, reproduce, and do whatever it does all day. What does this mean for us? Well, if we live like herbivores, we can fit a lot more of us in the same area than if we live like the small group of carnivores at the top of the pyramid. That same piece of land can sustain a considerable number of herbivores but only a few carnivores.
Studies have shown that it takes 2.2 kcal of energy input to produce 1 kcal of plant protein, whereas it takes 4 kcal of energy to produce 1 kcal of chicken protein. With other animal proteins it gets worse: 14 kcal for cow milk, 39 kcal for egg, and 40 kcal to get 1 kcal of beef protein.
Water use and water contamination
Eating high on the food chain consumes excess water and creates water pollution. To produce 1 kg of animal protein it takes about 100 times more water than it takes to produce 1 kg of plant protein.
Animal farming has created “dead zones” in water bodies from the excrement which is either dumped directly into waterways or is washed into waterways as it rains over manure-laden fields. Excrement from fish farms has also created dead zones along coastal areas where they are situated.
Land use and threats to ecosystems
According to the World Wildlife Fund, farmed animals threaten more than one-third of terrestrial ecosystems. The United Nations Food and Agriculture Organization (FAO) stated that the number 1 factor in the destruction of tropical rainforests in Latin America is the production of beef which is mostly for export — so basically we are “eating up” our precious rainforests and ecosystems.
The FAO also stated that most of the world’s major fisheries are fished at or above sustainable yields. Overfishing by the industrial fishing fleets has already caused wild Atlantic cod and salmon populations to collapse. Fish farms are not an environmentally friendly alternative since they destroy precious coastal habitat through the release of fecal wastes, antibiotics, and diseases that spread to the remaining wild individuals. They also require excess amounts of wild-caught fish which are made into feed for the farmed fish.
Eating high on the food chain causes air pollution as well –- in particular, greenhouse gases. The United Nations report entitled Livestock’s Long Shadow estimated that the livestock sector contributes 18% of greenhouse gas emissions — which means it is the main contributor to global warming, greater than the transport sector (i.e., all transportation combined). According to a later analysis by the Worldwatch Institute, livestock has an even more significant contribution: 51% of greenhouse gas emissions. Either way, animal farming plays a major role in global warming.
Consider this: Eating 1 kg of beef creates the same amount of greenhouse gases emitted by driving an average car 250 km.
If you’re thinking that it’s strange that so much greenhouse gas emissions could be coming from animal farming, note that the methane and nitrous oxide created by farm animals and their wastes are much stronger greenhouse gases than carbon dioxide. Methane is about 23 times as strong as carbon dioxide while nitrous oxide is almost 300 times stronger.
Don’t let all these impacts overwhelm you. You already have the tools to drastically reduce your impact on this delicate planet. They are your fork and spoon.
Marco Pagliarulo has a B.Sc. and M.Sc. in Toxicology and a Graduate Certificate in Ecosystem Restoration and has worked and volunteered in various environmental disciplines. He follows a vegan diet for reasons of compassion, environment, and health.