The Environmental Impact of Varying Diets

With the food industry requiring around 30% of total soil available on Earth and 20% of all fossil fuels consumed, the food that humans eat drastically impacts the environment. These environmental impacts include climate change, deforestation, decline of freshwater, eutrophication, and mass extinction. With an exponentially increasing human population, the future of Earth’s well-being will rely on the food that humans consume as well as the practices of growing and producing that food. With the food industry being a major contributor to environmental issues, human diet needs to be placed under the microscope of sustainability.

To begin, meat production is incredibly energy intensive, inefficient, and damaging to the environment. On average, the ratio of fossil fuel expenditure to protein output for meat production is approximately 25:1, with beef and lamb being 40:1 and 57:1, respectively (1). These ratios demonstrate the inefficiency of meat production. For reference, the grain protein production ratio is approximately 2.2:1 (1). This is problematic because meat and seafood are the two most rapidly growing ingredients in the global diet. Therefore, the increasing human population combined with an increasing meat diet proposes massive energy demand issues for the future. Not only does meat production demand an incredible amount of energy, but it contributes to many environmental issues across the world. “Livestock production is responsible for 70% of the Amazon deforestation in Latin America, where the rainforest has been cleared to create new pastures” (1). Even more importantly, one third of the world’s land suitable for growing crops are growing crops to feed farmed animals for humans to consume (1). The inefficiency of livestock production is magnified by using massive amounts of land and resources to feed the energy inefficient animals to then feed ourselves. Secondly, cows and sheep are responsible for 37% of all anthropogenic methane emissions (1). Methane is 25 times more effective of a greenhouse gas as carbon dioxide, so cow and sheep production greatly contributes to global warming. In addition, approximately 70% of all freshwater consumption on the planet is used for animal farming and agriculture (1). These facts demonstrate the amount of energy and resources humans are spending on meat production. However, there are alternatives for diets without meats that do not require nearly as many resources.

Reports have shown that switching to an organic, local, vegetarian or vegan diet drastically decrease one’s environmental footprint. The scientific paper “Evaluating the environmental impact of various dietary patterns combined with different food production systems” uses a standard LCA to analyze three different diet plans: omnivorous diet (OMNV), vegetarian diet (VEGET), and vegan diet (VEGAN), in conjunction with two different production methods: conventional farming (INT) and organic farming (BIO) (2). The report measured damages to human health, damages to ecosystem quality, and damages to resources. Figure 1 shows the impact assessment of the LCA.



Figure 1: LCA Impact Assessment Results

Omnivorous diets had the highest impact. Vegetarian diets the second lowest impact, and vegan diets had the least impact. In every case, organic farming methods resulted in a lower impact due to the non-use of pesticides and chemical fertilizers which contribute to eutrophication. Also important to note that the single most impactful piece of food on the environment was beef. Overall, this report demonstrates that humans can drastically reduce their environmental footprint by switching over to a vegan or vegetarian diet, as well as eating organically.

I believe we all need to find ways to work towards a sustainable future regarding every aspect of our life. In the coming years, resource demands for diets will greatly affect our entire Earth. It will affect the rate of climate change, ocean temperatures, species endangerment, deforestation, and our water supply. I know that most people are quite reluctant to change their diets, but I think this is a heavy enough issue that we should all find ways to reduce our impact such as simply eating less meat, especially beef, and eating organically.



Would you change your own diet for the sake of the Earth’s well being?

Do you think it is realistic or feasible for the world to shift towards a more balanced diet incorporating less meat?




9 thoughts on “The Environmental Impact of Varying Diets

  1. Im not sure that I would completely change my diet to become vegan or vegetarian. I would definitely consider eating less beef and switch more over to chicken or other animals who dont have as big of an impact on the environment. The one thing that will cause people to not switch to organic products is the cost of the food. The organic food is always more expensive because they lose crop because they dont spray pesticides or herbicides. When people are trying to save money, the last thing they would want is their food prices going up. In theory, its a good idea to help people curb their beef production, but I dont think society will ever give up meat in favor of a vegetarian or vegan diet.


  2. I would definitely be more willing to transition to more of a chicken based diet, however I firmly believe that switching diets doesn’t significantly affect food production.


  3. I think it is absolutely possible for the typical diet in the United States to incorporate less meat. I think the number one factor affecting this is the price of meat. As resources become more limited or the resource input increases, the price of meat will rise accordingly. I myself have been eating less meat solely because I save a lot of money every month by cutting out meat from one of my meals everyday.


  4. I think eating less meat would be beneficial. However, I’m not sure I could give it up completely. However, the form of meats we choose to eat needs to be examined on the individual level. We’ve heard countless times throughout the semester how bad certain meats are and how others (cricket farming) can be more efficient.


  5. Like Trey, I’ve noticed how much I save each month because I’ve cut most meat from my diet. How did the study categorize omnivorous and vegetarian diets? If I recall correctly, I read a study that suggested a 60% (could’ve been 80%) vegetarian diet was the most sustainable.


  6. I would be able to change my diet to decrease the environmental impact, mainly because I already do not eat a lot of meat to begin with. However, for it to make a large impact, I think the way manufacturers and the farmers produce goods will have to change as well. As long as they are overproducing and marketing the food, then people will keep buying and the contributing to the harm.


  7. After watching this documentary Cowspiracy, changing our diets really doesn’t have that large of an impact on the environment because of the environmental cost of switching to an all vegetable diet still greatly impacts the environment.


  8. Did you find any data about what the effects of everyone switching to a vegan diet would be? I imagine that we would need a lot more land to do such intensive agriculture which might not make the diet as good as it seems initially.


  9. I’m really not willing to change my diet to vegetarian or vegan. The first reason for this is because I firmly believe that things aren’t going to change. Any alternative diet made by a massive amount of the population will require such a large agricultural shift that the environmental impact will be just as bad. Not to mention the problem of millions losing jobs because of a massive shift. The other reason is just that I really enjoy eating meat and feel like it is important to human health.


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