In the midst of a climate crisis, small decisions like what to have for lunch can seem insignificant. In reality, though, the opposite is true. If ever there was a time to think about what we eat and how it is produced, it’s now. Globally, around one-third of all human-caused greenhouse gas emissions come from food systems and animal agriculture has a disproportionate climate impact. This is particularly the case with beef and dairy production.
Are cows contributing to global warming?
Farming cows on an industrial scale produces massive quantities of heat-trapping greenhouse gases, making the beef and dairy industries key contributors to global warming. The problem is not so much that cows are inherently bad for the planet but that they are farmed in such high numbers.
How do cows affect climate change?
Cows directly affect climate change by belching and exhaling methane, a powerful greenhouse gas. In just one year, an individual cow can emit 154 to 264 pounds of methane gas.
Beef and dairy production influence Earth’s climate in other ways too. The world’s 1.5 billion farmed cows occupy a lot of land, much of which has been converted from forests, which are natural carbon sinks. Clearing trees and other vegetation to make space for grazing cattle or growing feed grains releases carbon dioxide into the atmosphere and reduces the amount of emissions that can be absorbed in the future.
How do livestock produce methane?
Cattle, buffalo, sheep, and goats produce methane when they digest food. Ruminant animals (mammals with four stomach compartments) have a unique digestive system that allows them to live off vegetation that many other animals cannot easily digest. Their largest stomach compartment, the rumen, hosts a complex biological community of anaerobic bacteria, fungi, and other microbes that work together to break down food into substances that can be used by the body. During this process, which is known as “enteric fermentation,” a group of bacteria-like microorganisms called methanogenic archaea make methane from hydrogen and carbon dioxide.
Methane is also produced when animal manure from factory farms is left to decompose in storage pits or lagoons. Together, enteric fermentation and animal manure management account for an estimated 32 percent of human-induced global methane emissions.1
Why is cow methane bad?
Once released into the atmosphere, methane is highly potent and prevents heat from the sun from escaping back out into space. At natural levels, methane and other greenhouse gasses play an important role in keeping Earth warm enough to sustain life. The problem is that human activity—including meat and dairy production—is causing a buildup of these gasses in the atmosphere and the planet is becoming dangerously hot.
Methane levels are rising rapidly. At present, the methane level in the atmosphere is almost three times that of pre-industrial times.
The global average temperature of Earth is fast approaching 1.5 degrees Celsius above pre-industrial levels. As a result, ice sheets are melting, sea levels are rising, and extreme weather events are becoming more frequent and intense. Methane is responsible for around 30 percent of this warming.
Climate change is having an enormous impact on people and animals around the world, for example by making safe drinking water and healthy food more difficult to access. With every fraction of a degree of further warming, the effects of climate change will only get worse.
In addition to being a powerful greenhouse gas itself, methane harms people and the planet by reacting in sunlight with other chemicals in the air to form tropospheric ozone, a greenhouse gas and dangerous air pollutant. Exposure to tropospheric ozone (also known as ground-level ozone) can damage people’s airways, cause breathing difficulties, and worsen respiratory conditions such as asthma. It can also adversely affect the growth and health of plants, leading to crop losses and a decline in biodiversity.
How bad is methane compared to carbon dioxide?
The climate impact of a greenhouse gas is determined by three key factors: how much of the gas is in the atmosphere, how long it remains there, and how effectively it traps heat. Methane is found in lower concentrations than carbon dioxide and remains in the atmosphere for a shorter length of time but is far better at absorbing heat.
Over 20 years, the global warming potential (GWP) of methane is around 80.2 This means that one ton of methane traps 80 times as much heat over this period of time as one ton of carbon dioxide. Over 100 years, the GWP of methane is 27.
The fact that methane is a powerful but short-lived gas could be used to our advantage. Action taken now to slash methane emissions will help to slow down climate change in the short term while we are waiting for cuts in carbon dioxide emissions to take effect.
In fact, researchers estimate that reducing methane emissions by 45 percent this decade would prevent almost 0.3 degrees celsius of warming by 2045.3 Globally, it would also reduce air pollution enough to save the lives of 255,000 people per year and increase annual crop yields by 26 million metric tonnes.
How much do cows affect climate change?
Estimates vary, but according to the Food and Agriculture Organization of the United Nations (FAO), farmed animal production is responsible for 14.5 percent of all human-caused global greenhouse gas emissions. Of that 14.5 percent, an estimated 65 percent of emissions come from farming cows.
What are other sources of methane emissions?
The vast majority of methane emissions from farmed animal production are due to enteric fermentation and manure management. A relatively small amount of methane comes from growing rice for animal feed, but according to one estimate this accounts for only 0.5 percent of animal agriculture’s total greenhouse gas emissions.
Why are some people saying beef production is only a small contributor to emissions?
Meat and dairy companies, as well as individuals with a vested interest in animal agriculture, frequently downplay the climate impact of meat and dairy production in order to protect their bottom line.
In addition, some people argue that focusing on emissions from animal agriculture deflects attention away from fossil fuel emissions. However, evidence shows that in order to avoid the worst impacts of climate change, we have to tackle both issues.
Many proponents of beef production also say that by grazing land that is unsuitable for growing crops, cows convert or “upcycle” grass and other plants that humans cannot eat into high-quality protein. Yet this argument is built on the idea that uncultivated land has little worth, when in fact such areas can be thriving wildlife habitats, and intensive grazing of rangeland is a major driver of biodiversity loss.
Some farmers are perhaps skeptical of the climate impact of meat production because they feel unfairly blamed, and that’s understandable. Consumers cannot reasonably expect farmers to mass produce cheap meat and then hold them solely responsible for the resulting environmental damage. To build a fairer, higher-welfare, and more sustainable food system, campaigners and farmers need to work together.
Does regenerative agriculture produce fewer emissions?
“Regenerative agriculture” generally describes ways of farming that prioritize ecosystem health, though the term and can be misused by meat and dairy companies to greenwash unsustainable beef production.
The climate impact of regenerative agriculture is a subject of much debate. Some research suggests that in some cases grazing animals can help the soil to store more carbon. However, this does not mean (as beef proponents often claim) that grass-fed beef is a climate solution.
On an ultra-small scale, regenerative agriculture has the potential to mitigate many of the problems caused by intensive animal agriculture and could be part of a future without factory farms. For example, on farms where low densities of animals are raised alongside crops, the animals can roam outdoors, feed on plants or insects that might harm crop growth, and fertilize the soil with their manure. Such systems can benefit animal health and welfare while simultaneously reducing the need for harmful agricultural chemicals and manure management systems. If we shifted away from intensive rearing of cattle in favor of regenerative systems, our levels of beef and dairy consumption would have to substantially reduce.
Why is eating cows bad for the environment?
The environmental impact of eating cows (or their milk) doesn’t end with greenhouse gas emissions. Beef and dairy production are major causes of many of the biggest environmental issues affecting our planet today. Raising cows at an industrial scale for food uses vast stretches of land, consumes huge quantities of water, contributes to land degradation, and pollutes waterways, among other problems.
You might have heard it said that to reduce your climate impact, you should eat pork, chicken, or fish instead of beef, but this advice is misguided. While beef consumption at its current levels is unsustainable, the same is true for pork, chicken, and fish consumption. Eating more of these foods would increase the number of individual animals who are killed for food and, as a result, exacerbate the animal welfare, human health, and social impacts of factory farming.
The farming of livestock is a top contributor of greenhouse gas emissions globally. What can you do to help? Eat conscientiously—consuming as few animals as possible, ideally none.