Industrial animal agriculture is one of the leading contributors to climate change, responsible for about 15.4 percent of global greenhouse gas emissions. That’s nearly as much as the entire global transportation sector — that means that the meat and dairy industry emits almost as much heat-trapping gas as all the planes, trains, and cars in the world combined. No matter how you cut it, raising, feeding, and then killing billions of animals is an inefficient and resource-intensive way to feed our growing global population. After all, it takes about 10 pounds of grain to produce just 1 pound of meat, according to the United Nations Convention to Combat Desertification.
We often worry about the climate footprint of the planet’s 7.8 billion people, but overlook the environmental consequences of sustaining 70 billion farm animals each year. However, just like human beings, animals require tons of food to do basic things like gain weight, develop muscle mass, and stay alive. Ultimately, factory farming exacerbates deforestation and water scarcity, and is responsible for methane and nitrous oxide pollution that is detrimental to the planet.
Land Use and Deforestation
Forests, which are crucial for sustaining life on Earth, are being destroyed at unprecedented rates. These ecosystems store huge quantities of carbon in their biomass, making them critical carbon sinks. However, they are frequently cleared in order to grow feed or to pave grazing land for livestock, posing a grave threat to our climate.
In the US, roughly 260 million acres of forested land have been cleared to make room for crops, and more than 67 percent of these crops — predominantly soy, corn and grains — become food for livestock, rather than food that is consumed directly by people. Despite taking up so much land, meat and dairy products provide only 36 percent of the calorie content of the US food supply.
This deforestation crisis is global. In Brazil’s Amazon Rainforest, for example, animal agriculture is linked to 75 percent of historic deforestation, as ranchers burn forests in order to convert them to pasture for beef and leather. Similarly, between 2000 and 2014, the Congo Basin — the world’s second largest rainforest — lost an area of forest the size of Bangladesh due to slash-and-burn deforestation.
While growing food is always going to require significant amounts of land and water, animal agriculture is particularly inefficient. Farm animals consume a third of the planet’s grain production and a third of the planet’s ice-free land. If people primarily consumed plants, agriculture would be responsible for significantly less deforestation.
In addition to polluting the air and degrading natural lands, industrial animal agriculture uses an enormous amount of freshwater. In the US, it is responsible for 55 percent of water consumption, whereas domestic water use — the water used in households — makes up only 5 percent. Globally, factory farming uses 16 percent of the planet’s freshwater.
Here’s another way to think about it: it takes about 2,500 gallons of water to produce one pound of beef, while most fruit, vegetables, and plant-based proteins require between 15 to a couple hundred gallons of water per pound to produce. Similarly, producing cow milk requires twice as much water as producing almond milk — and almond milk is the most water-intensive plant-based milk alternative. When you scale those differences, it makes an enormous impact. By eating plant-based, it’s estimated that one person can save approximately 219,000 gallons of water per year.
Environmentally-conscious individuals may try to reduce their water usage by doing things like taking shorter showers, but dietary choices have a much larger impact. If you switch from a hamburger to a veggie burger one time, you’ll save as much water as not showering for two entire months. As the world’s water supply continues to shrink, conserving our freshwater is critical.
The myth of climate-friendly chicken
In recent decades, millions of Americans have opted to eliminate red meat from their diet — since 1950, beef consumption has declined by 23 percent. This dip is, in part, due to growing concerns about the environmental impacts of the industry. At the same time, Americans have increasingly turned to white meat, and chicken consumption has more than tripled.
However, the notion that the chicken industry is a climate-friendly one is, to put it simply, false. Chickens are the top feed crop consumer — responsible for consuming about third of the world’s cropland. In turn, greenhouse gas emissions per serving of poultry are 11 times higher than those for one serving of beans.
Greenhouse Gas Emissions
From start to finish, factory farming is a huge source of heat-trapping, greenhouse gases emissions. The industry — which includes the production of feed crops, the manufacturing of fertilizer, and the shipment of products — is responsible for more than 75 percent of total agricultural emissions.
Factory farming produces carbon dioxide in a number of ways. For one, animals consume high-energy crops that require large amounts of chemical fertilizer. Globally, the production of this fertilizer emits 41 millions tons of carbon dioxide per year. CAFOs also burn about 90 million tons of carbon in fuel, which are emitted as a result of cooling, heating, ventilation, operating machinery, among other processes. Clearing land for feed crops and grazing further leads to deforestation and desertification that emits hundreds of millions of additional carbon tons.
Then, there’s the methane problem. Methane, a byproduct of cows’ digestive processes and manure, is a greenhouse gas that is about 84 times more potent than carbon in the short-term. Animal agriculture is responsible for nearly half of the world’s methane emissions, which is deleterious for our climate. In the US, factory farming is also responsible for 65 percent of human-related nitrous oxide, which stays in the atmosphere for 150 years and has 296 times the global warming potential of carbon dioxide. Nitrous oxide is present in the atmosphere in far greater quantities than ever before, at about 16 percent higher levels than in 1750.
To make matters worse, as the human population proliferates, so does the consumption of animal and animal products. Between 1961 and 2020, anthropogenic emissions from the livestock sector increased by 51 percent. Furthermore, by 2050, consumption of meat and dairy products is expected to rapidly proliferate, by 76 and 64 percent, respectively. This increased demand is unsustainable, particularly given that scientists have unequivocally agreed that global emissions must be significantly reduced if the worst effects of climate change are to be averted.
The good news is in recent years, more and more Americans have transitioned away from animal products and toward a plant-based diet. Approximately 9.7 million Americans are now vegan, compared to 290,000 just 15 years ago, and many more are considering the transition. Food scientists and chefs are producing alternatives to meat and dairy that taste and feel just like the real thing, and prominent medical experts are disseminating critical information regarding the health benefits of a plant-based diet. The success of giants like Beyond and Impossible Burger — as well as the booming sales of alternative milks and cheeses — illustrates a major societal shift. People increasingly understand the environmental consequences of the industrial animal agriculture system. Now, it’s time for sweeping systemic change.
Noa Dalzell is a graduate student at Northeastern University and FFAC Fellow.