The direct impact animal agriculture has on farmed animals is clear. In the industry, billions of land and trillions of aquatic animals are forced into unnatural quarters, made to live in their own excrements and often killed before reaching the age of one; in the dairy and egg industries, mothers are repeatedly artificially inseminated and separated from their young, causing extreme distress for all (Farm Transparency Project, 2022; RSPCA, 2022). Not so obvious are the secondary effects this industry has on the environment, which affects all its inhabitants—human and nonhuman.

By 2050, the world’s population is expected to reach 10 billion, requiring an increase in global food production by 70%, with greenhouse gases projected to increase by 80% (Dent, 2020; University of British Columbia, 2016). It is important to acknowledge the environmental harm the production of animal products causes—including high levels of greenhouse gas emissions, mass deforestation, extreme water use, and water pollution—in order to make sustainable choices that that are less damaging to our environment.

Greenhouse gas emissions

Cows and sheep are ruminant animals with four stomachs containing bacteria that allows them to digest tough, fibrous food, such as grass. This complex digestion process causes them to belch methane—a greenhouse gas that is 30 times more powerful than carbon dioxide (CO2) over the period of 100 years (Dunne, 2020; Petrovic, 2015). As a result, animal agriculture is responsible for 18% of all greenhouse gases worldwide; to put this into context, animal agriculture contributes more greenhouse gas emissions than all forms of transportation combined, which is responsible for 13% of global emissions (Brown, 2022; Ritchie & Roser, 2021; University of British Columbia, 2016; Stehfest, et al., 2009).

(Source Ritchie & Roser, 2021)

In Europe, food alone is responsible for 30% of total greenhouse gas emissions, with meat production making up most of that percentage (Petrovic, 2015). Buying locally produced animal products remains an unsustainable alternative. Head researcher from Our World in Data, Dr. Hannah Ritchie, along with its founder, Dr. Max Roser, find that the transportation of animal products once packaged, no matter how far, amounts to “only a small fraction” of emissions (Ritchie & Roser, 2021). They found that “…most of our food emissions come from processes on the farm, or from land use change” (Ritchie & Roser, 2021, n.p.).

Cows contribute more than double the greenhouse gas emissions than the next highest contributor, lambs, due to how long it takes the former to reproduce and grow until ready for slaughter. [1] In addition to belching and releasing methane through their stool during their 1.5 years of life, cows raised for beef need a great amount of food and water during that time, putting pressures on the Earth’s limited resources (Dunne, 2020). As populations exponentially rise, so too are demands for meat. In addition to directly contributing towards greenhouse gas emissions through the previously mentioned factors, clearing out forest space for an ever-increasing number of livestock has resulted in the fading possibility of using carbon sequestration to fight climate change—the natural ability of ecosystems to store carbon (Brown, 2022; USGS, 2022; Dunne, 2020).

[1] According to Farm Transparency Project (2022), cows bred for meat are killed when they are about 18 months old while lambs are killed when they are around 4-12 months.


Meat production is the single greatest cause of deforestation globally, with about half of the world’s habitable land used for this purpose (Brown, 2022; Ritchie & Roser, 2021). In 2017, the Food & Agriculture Organization of the United Nations (FAO) announced that livestock production uses 70% of all agricultural land; in the last two years, that number grew to 77% (Ritchie & Roser 2021; FAO, 2020; FAO, 2017). Agricultural land is made up of pasture for grazing and land to grow crops for animal feed (Ritchie & Roser, 2021). Despite taking up such a large (and ever-rising) percentage of land, livestock “only produces 18% of the world’s calories and 37% of total protein” (Ritchie & Roser, 2021, n.p.). In other words, if crops such as soya were grown for the purpose of directly feeding people, as opposed to being used to mass-feed cattle, the world would be more abundant in food.

Cutting down trees and demolishing forests, including parts of the Amazon Rainforest, is not only harmful for the biodiversity that resides there, but for combatting climate change, as these forests are essential for carbon capture and sequestration (Brown, 2022; Dunne, 2020; Stehfest, et al., 2009). In South America, forests are purposely set on fire by farmers, resulting in exactly the opposite of what these beneficial forests are meant to do. Greenpeace UK contributor Natalie Brown notes, “[i]n Brazil, farmers are deliberately setting forest fires—like the Amazon rainforest fires you may have seen in the news—to clear space for cattle ranching and to grow industrial animal feed, like soya, for farms back in the UK” (Brown, 2022, n.p.). She continues: “[h]ealthy trees are essential for absorbing carbon from the atmosphere. If we cut them down, they can no longer help us in the fight against climate change” (Brown, 2022, n.p.). Deforestation is causing wild habitats to be destroyed and distorting the natural ability of forests to produce their own rainfall, making it increasingly difficult for forests such as the Amazon Rainforest to sustain themselves (Brown, 2022; Ritchie & Roser, 2021). Giving up animal products is a direct way one can help these ailing ecosystems. In their research “Climate benefits of changing diet”, Elke Stehfest et al. discovered the following:

“By using an integrated assessment model, we found a global food transition to less meat, or even a complete switch to plant-based protein food to have a dramatic effect on land use. Up to 2,700 Mha [million hectares] of pasture and 100 Mha of cropland could be abandoned, resulting in a large carbon uptake from regrowing vegetation.” (Stehfest et al., 2009, pg. 83).

In addition to requiring mass-deforestation, meat production is also straining global water supply.

Water use

About 90 percent of the world’s water footprint comes from agriculture, with the industry currently using 70 percent of all available freshwater—three times more than what was used 50 years ago (Holdinghausen, 2021; University of British Columbia, 2016). Growing crops for livestock feed requires significantly more water than growing fruits, vegetables and beans for direct human consumption (FoodPrint, 2022; University of British Columbia, 2016). As a result, producing a single pound of beef takes about 1,800 gallons (8,183 litres) of water—the equivalent of filling 39 bathtubs to the top (A Greener World, 2022; FoodPrint, 2022; Madel, 2022; Delynko, 2019). While requiring less water, pork (720 gallons/pound), goat meat (660 gallons/pound), and chicken (520 gallons/pound) remain unsustainable alternatives (A Greener World, 2022). On the other hand, a serving of black beans requires only 49 gallons of water (Madel, 2022).

While the massive amount of water needed to produce a single pound of animal meat such as beef sounds hard to believe, one must take into account that cows raised for beef are eating thousands of pounds of grass, corn, soya and grains during their lifetime—all of which needs water to grow. “In general, more water is needed to produce meat than plant-based foods such as grains or beans. The average water footprint per calorie for beef is 20 times that of grain” (Holdinghausen, 2021). As a result, a person’s diet makes up the largest part of their water footprint (FoodPrint, 2022). The world’s freshwater resources will become increasingly scarce as scientists predict that water demand for food production will triple by 2050 if habits are not changed on a large scale (A Greener World, 2022).

On top of using most of the world’s freshwater supply, animal agriculture is polluting the freshwater that we have left available.

Water pollution

When water is not being used for meat, dairy and egg production, it is being infected with toxins and waste from the industry. The mass number of crops to feed livestock are treated with extreme amounts of fertilizers and pesticides (including herbicides, insecticides, fungicides and bactericides), the excess of which runs off into surrounding waterways (Brown, 2022; Clean Water Action, 2022; FAO, 2017). Crispin Dowler, a senior reporter at Unearthed—an investigative environmental journalism project funded by Greenpeace UK—reported that Brazil, a country home to 20% of the world’s biodiversity, has become the world’s “…most important market for highly hazardous pesticides,” being the “…biggest consumer of pesticides classed as seriously hazardous to health or the environment” due to the country’s vast soya beans and corn production (which, as mentioned earlier, mainly goes to feed livestock all over the world) (Dowler, 2020, n.p.). “Almost two-thirds of this Brazilian highly hazardous pesticide (HHP) spending went on the country’s sprawling soya plantations, grown to service a global demand for animal feed for chickens, pigs, cows and fish” (Dowler, 2020, n.p.). These pesticides are detrimental for both human and nonhuman health—increasing risks of cancer, reproductive failure and overall toxicity in humans and wiping out species populations, some of which have not yet been discovered (Brown, 2022). Bee populations are one of the species at risk, which puts the entire world’s food security in jeopardy, considering that “one of every three bites of food we eat comes from a crop pollinated by bees” (Center for Food Safety, 2022). Natalie Brown put the urgency of the issue this way:

“We depend on a healthy environment for our own survival. The huge abundance and variety of the natural world (sometimes called biodiversity) is essential for food, clean water and medicines. The rapid loss of biodiversity, largely driven by industrial farming, could be as big a threat to our existence as climate change.” (Brown, 2022, n.p.).

Livestock waste has proved to be an additional cause of water contamination. Manure, in addition to releasing methane emissions into the atmosphere, pollutes water quality by containing nitrates, phosphates and ammonia (Clean Water Action, 2022; FAO, 2017). The organization Clean Water Action states:

“If it’s not being sprayed onto fields, manure is typically stored in open lagoons that are susceptible to overflow during flooding or leakage due to faults. This releases harmful substances like antibiotics, bacteria, pesticides, and heavy metals into the surrounding environment.” (Clean Water Action, 2022, n.p.).

What can I do to help?

In the UK, the average amount of meat consumed by each person—220 grams per day—is nearly double the world average of 117 grams (Viva!, 2022). Europe ranks second in the world for red meat consumption, “…exceeding the level needed for a healthy and sustainable diet by more than four times” (Dunne, 2020, n.p.). A global switch to veganism “…could save almost 8 billion tonnes of CO2 emissions a year by 2050, when compared to a ‘business-as-usual’ scenario” (Dunne, 2020, n.p.).

The production of animal products is innately tied with environmental degradation in various forms:  increasing greenhouse gas emissions, requiring deforestation, using unsustainable amounts of the Earth’s limited freshwater supply and contaminating the freshwater that is leftover. By leaving animals and their by-products off our plates, we are taking a huge step in helping the state of the environment; forests will be allowed to regenerate—allowing for carbon sequestration to take place and biodiversity to return, global greenhouse gas emissions will reduce significantly—helping to fight the current climate crisis, water use will become a fraction of what it currently is (and projected to be) and the water leftover will contain drastically less contaminants. Switching to a plant-based diet is truly a win-win-win—for the animals, the environment, and people.

Written by: Vivian Sandler
Vegan Content Manager, IAPWA