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Climate•6 min read
Explainer
One of the most overlooked factors of accelerated climate change is animal agriculture. Could changes to the human diet help us slow down the climate crisis?
Words by Sentient Media
Animal agriculture has long left its mark upon the earth. Forests have fallen and grasslands trampled in favor of crops and pastureland. Now, however, this sector’s impacts are being felt in the atmosphere – carrying troubling implications for every living thing on the planet.
The agriculture sector is one of the biggest drivers of anthropogenic – meaning human-caused – climate change. Animal agriculture, which sees the raising and processing of ruminants, poultry, and marine life, accounts for some of the biggest sources of greenhouse gasses. Global temperatures rise as forest cover decreases, and oceans warm as they absorb ever-more carbon dioxide.
Yet there are solutions to these problems – among which is the adoption of plant-based diets. It is not too late for the world to take action against the perils of a changing climate, but time for action is now.
Practicing agriculture does not necessarily come naturally to us as a species. For much of human prehistory, people lived in societies oriented around hunting and gathering. The earliest signs of agriculture can be dated at around 12,000 years ago, yet since the dawn of the Industrial Revolution, agriculture has taken on an entirely new face, adopting intensive practices such as concentrated animal feeding operations (CAFOs) which foster truly heartbreaking conditions for farmworkers, animals, and surrounding communities alike.
Called humanity’s greatest mistake by some due to the resulting hard labor, diminished nutrition, and social inequality brought by agriculture, this system of food production now presents the world with a new quandary: environmental destruction on scales that can no longer be ignored.
CAFOs produce enormous amounts of waste, which collect in vast open-air lagoons that can be breached by extreme weather events or gradually seep into groundwater. Water pollution from CAFOs can cause algal blooms which can devastate entire marine ecosystems. Air pollution is generated from CAFOs as manure is vaporized, sending toxic wafts through the air to surrounding communities.
Vast fields of monocrops also cause a host of environmental effects, including air pollution. Pesticides and herbicides are sprayed in liberal amounts, which can cause a host of debilitating illnesses, including cancers, for farmworkers and surrounding communities. Soil depletion is also a serious looming issue. Monocropping, along with the overuse of agrochemicals including synthetic fertilizers like nitrogen and phosphorus, are denying fields a fallow period or crop rotation has the effect of leeching soils of their nutrients. These practices render soils far less productive over time. It takes hundreds, if not thousands, of years for soils to become abundantly fertile again.
Out of all the human activities that cause climate change, agriculture is one of the biggest contributors. Estimates as of 2020 put the sector’s global contributions at 37 percent. Below are a few key factors accounting for climate change emissions resulting from human-cased agriculture.
A full 50 percent of the world’s livable land – meaning land that is ice-free and fertile – is being used for agriculture. No other human activity takes up more space. In contrast, all urban areas account for around one percent of livable land use. A whopping 77 percent of agricultural land is dedicated to raising animals, including grazing and the land used to grow their feed, including vast monocrops of species like corn and soy. Surprisingly, this huge expenditure of resources and land use provides only 18 percent of the world’s calories.
Land used for any type of agriculture – be it livestock or crops meant for people or animals – is brought under cultivation by clearing forests and grasslands, which are carbon sinks due to their abilities to absorb carbon. Currently, forests consume roughly a quarter of all anthropogenic CO2, yet the more forests are slashed and burned to make way for pastureland or monocrops, the less carbon will be absorbed, resulting in accelerated climate change.
Farmed animals – referred to as livestock – generate over 14 percent of all anthropogenic emissions, with estimated totals hovering around seven gigatonnes of carbon dioxide emitted every year. The bulk of these emissions are due to raising cattle for meat and dairy, contributing 60 percent of total livestock emissions. These emissions are thanks to the vast amounts of resources cows consume, the land they require for pasture (in the case of beef cattle), and other manure they produce. Cow manure contains nitrous oxide and methane, the latter being one of the most potent greenhouse gasses due to its outsized ability to absorb heat.
Marine life, including fish, shellfish, shrimp, and other animals are taken from the seas in astronomical numbers. Nets, some of which are large enough to contain 12 jumbo jet airplanes, are dragged through the water or across the bottom of the seafloor, capturing everything in their path. Direct fishing activity, plus the energy expended to transport, process, and refrigerate carcasses amounted to an estimated total of 179 million tonnes of greenhouse gasses in 2011 – and this number likely will continue to grow as demand for seafood increases.
In greenhouses designed to grow plants, the transparent glass structure allows sunlight into the greenhouse while preventing heat from escaping. The earth’s atmosphere functions in a similar way, with gas molecules acting like the glass. Certain gases are more effective at absorbing heat than others; these include methane, nitrous oxide, and perhaps the most infamous, carbon dioxide. These three gasses are among the main culprits of climatic warming and change caused by human activities.
One of the biggest drivers of global warming has been the release of carbon into the atmosphere due to the burning of fossil fuels such as natural gas, oil, and coal, which power many aspects of modern life. Even electric cars, which run on batteries and do not themselves generate carbon emissions, draw electricity from grids still run on fossil fuels (although the goal of using 100% renewable energy for electric grids is more achievable than ever). When carbon released from fossil fuel burning is released into the atmosphere, it binds with oxygen and forms carbon dioxide and begins trapping heat in the atmosphere. Because carbon emissions make up the vast majority (81 percent, as of 2018) of total greenhouse gases, they pose one of the gravest threats to climate stability.
Although carbon is the greatest emitted by volume, other greenhouse gases can be much more potent. For example, one ton of nitrous oxide – emitted by agricultural processes including the use of nitrogen fertilizers in crop production – is equivalent to nearly 300 tons of carbon dioxide.
Methane is approximately 30 times more potent in its ability to absorb and trap heat in the atmosphere than carbon dioxide.
By far, the most effective way to reduce the animal agriculture sector’s greenhouse gas footprint is to significantly reduce, and eventually eliminate animal agriculture. While this might sound “extreme”, it is the state of industrial animal agriculture – characterized by inhumane CAFOs, waste lagoons teeming with pathogens and antibiotics, and requiring enormous land and feed inputs – which is even more extreme.
This is not to say that eliminating animal agriculture is something easily accomplished. Demand will have to decrease, thanks to people turning to plant-based diets. The ease of adopting these diets is not the same for everyone, however. Many lower-income neighborhoods in the United States are classified as food deserts, where a lack of grocery stores forces people to endure extremely limited options, such as gas stations or fast-food restaurants.
People in nations like the United States who do not live in food deserts bear much of the responsibility for reducing demand for animal products. Fortunately, plant-based options abound to replace animals in a wide range of products, from cheese to milk to burgers and sausages. Beyond Meat and Impossible Foods are two of the leading companies in the plant-based meat sector, helping the idea of plant-based meats go mainstream and helping people understand that it’s possible to achieve the BBQ-worthy tastes without the climate side-effects. Plant-based meats use up to 99 percent less land and emit up to 90 percent fewer greenhouse gas emissions.
Flying in planes or driving SUVs have long been understood as having negative impacts on the global climate. While these are certainly deserving of critique and change, the agriculture sector deserves time in the spotlight. If industrial agriculture continues to grow unchecked, global warming will increase – with potentially disastrous impacts, the beginnings of which are being felt today. Methane, produced by livestock including sheep, goats, and cows, is a greenhouse gas with a terrific ability to trap heat in the atmosphere. The agriculture industry is responsible for fully 40 percent of the total anthropogenic greenhouse gas emissions.
In order to curb global warming, and keep the global temperature increase below 1.5 degrees Celsius, the United Nations Intergovernmental Panel on Climate Change says that global emissions will need to be reduced by around 40 to 50 percent. According to the U.N., the only way to achieve these reductions is to drastically increase forested land – which means reclaiming land currently under cultivation and to stop intrusions into existing forests.
Due to its profound impacts on the climate and environment around the world, agriculture may well be humanity’s gravest mistake – because it may be our undoing. Unless greenhouse gas emissions are seriously curbed, the world is going to be a far more difficult place to endure. Reducing demand for animal agriculture and adopting a plant-based diet is among the most important actions any individual can make.