Animal Agriculture | Is it All Bad?

Animal agriculture is a leading driver of ecological destruction. But what if it’s not all bad? Read on to find out if livestock farming could ever do more good than harm.

If you’re concerned about animal agriculture, you’re in good company. We’ve got to a point where mammal livestock outnumbers wild mammals 15-1, and 77% of all agricultural land is used for livestock and their feed.^{1, 2} Accurate data about factory farming is hard to come by because there is no agreed definition of “factory farming” and no globally agreed means to report and record data about livestock’s living conditions. But around 75% of livestock animals on land are likely to be factory-farmed, meaning that at any given time, about 23 billion farm animals live in cramped and stressful conditions.³ 

This is an issue for a number of reasons. As well as the obvious welfare concerns, factory farming is a leading cause of antibiotic overuse in agriculture, driving the development of antibiotic-resistant superbugs dangerous to humans.⁴ Furthermore, feeding grain to animals instead of humans is a less efficient way to get calories into our bellies, making industrial animal agriculture more resource-intensive than grain and vegetable crops.⁵ Additionally, livestock animals contribute around 12% of all anthropogenic greenhouse gas emissions, mostly coming from cattle.⁶ Based on these factors, many environmental organisations and food security experts now agree that we must eat less meat and dairy in high-income countries.^7,8,9

Knowing all this, I’ve done my time boycotting the meat industry. But after 12 years of going cold (veggie) turkey, I have started eating local and so-called “regenerative” meat a couple of times a month. While there isn’t a set definition of regenerative agriculture, most farmers agree that it means producing food alongside measurable ecological benefits - like healthier soil, which holds more carbon and water, and boosting on-farm biodiversity.

Read more about how regenerative farming works here

I still have the odd bout of guilt about eating animals, but I am comforted by the hares, deer, and wild boar I see grazing alongside cattle on my neighbours' farms. Buzzards and royal kites hunt for snakes amongst the wildflowers. I’ve lost count of the rare plants growing in those meadows, and even after the heaviest rainfall, the soil keeps sucking up water like a sponge. So, in the hottest summer months, the grass stays healthy without irrigation. This all seems to fit the regenerative bill. And yet, I find myself unsteady when I see the scientific data. Poore and Nemecek's research, which did a meta-analysis of around 40,000 farms worldwide, discovered that even the lowest-impact meat products tend to exceed those of plant-based products.¹⁰ 

Of course, the meat my neighbours produce is not the norm, and the impact of the same food’s production can vary as much as 50 times depending on the local context and methods used.¹⁰ But after ‘Big Meat’ planned to present animal products as “good for the planet” at the latest COP summit despite the proven harms of industrial animal agriculture, I wonder how this relates to my neighbours.¹¹ Walking through their living fields, I have to raise my voice over singing crickets. 

Is it true that livestock can do good for the Earth, too? Or am I falling for the meat industry’s clever marketing campaigns? The food system is too complex for anyone to understand fully, but let's see if we can get any closer to the truth.

A systems approach to food

On average, meat products have a more significant impact than plant-based products when we consider multiple factors such as land use, freshwater withdrawals weighted by local water scarcity, greenhouse gas emissions and a product’s contribution to acidification and nutrient pollution of water bodies.¹⁰

But the methods used to produce both meat and plant-based products can differ vastly. Let's take chicken as an example.

Destructive Poultry Systems

Chicken raised in a factory farm within a delicate water basin will likely poison the river due to nutrient runoff from faeces. For example, the rapid rise of poultry units in the UK’s River Wye basin has led to the water being described as a “wildlife deathtrap.”¹⁴ What’s more, if those chickens eat imported grain, their diet could contribute to deforestation and destruction in some of the world’s most biodiverse habitats. In 2020, an investigation into UK supermarkets and fast food outlets found that Tesco, Lidl, Asda, McDonald’s and Nando’s all sourced chicken fed on soy linked to forest fires and deforestation in the Brazilian Cerrado Biome.¹⁵

Harmful algal blooms are the results of a process called eutrophication, which occurs when the environment becomes enriched with nutrients. Algae blooms can disrupt water ecosystems causing a variety of problems such as a lack of oxygen needed for fish and shellfish to survive, which leads to a loss of biodiversity.

Regenerative Poultry Systems

This is a different picture from the Poultree company in Extremadura, Spain, who raise chickens outside, beneath trees, moving them often with the help of portable hen houses and temporary fencing. According to the owner, José, the chickens forage for grass and insects while improving the health of the soil and the trees above. Because the land has the time to rest, a suitable number of animals' faeces enrich the fertile ground instead of burning the vegetation or getting washed away to pollute water. Grazing also offers nutritional and psychological benefits to the chickens compared to being raised indoors on grain. And if animals eat food sustainably produced on-site, we can be more confident that environmental harm isn’t exported to vulnerable places.¹⁶

But it’s hard for the average consumer to separate marketing images of happy chickens from the genuine ecological impact behind the meat or the egg. If you want to align your wallet with your values, the supermarket isn’t an easy place to do it. You’ve got a better chance by buying food directly from the producer at a farm shop or farmers market. However, that typically comes with a higher price tag, and not everyone has the hard funds or emotional commitment to make that financial leap.

And even if you do put your cash behind “regenerative” meat - is it doing any genuine good for the planet? Let’s have a look at what the evidence has to say.

Livestock and climate

Firstly, what you eat is more important than how local. This is because only a small percentage of carbon emissions come from transporting food. (Except air-freighted foods, which should be avoided when possible).¹⁷ With that in mind, eating only from the local butcher doesn’t automatically mean your diet is less impactful than a vegan who doesn’t care where their food comes from or how it was produced.

When it comes to what you eat, the differences in emissions between foods are enormous. A kilogram of beef produces 60kg of carbon dioxide equivalent, 60 times more than the same amount of peas.¹⁷ Of course, they aren’t nutritionally equivalent, but vegetables are generally less climate-warming. Meat, dairy, fish, eggs, and cheese produce more greenhouse gases than plant foods like grains, fruits, and veggies. (Except for chocolate and coffee, which are also high on the impact scale.)¹⁸

Carbon Store vs Carbon Sink

Most livestock emissions come from land use change - for example, clearing the rainforest for new pastures and animal feed.¹⁷ But this gets complicated because livestock can also sequester carbon in the soil. According to the FAO, 33% of the world’s soil is degraded from things like ploughing, overgrazing and the overuse of synthetic inputs.¹⁹ As soil degrades, it goes from a carbon sink (storing carbon) to a carbon source (releasing carbon). (Despite the poor state of our world’s soils, they still hold more carbon than our atmosphere and all vegetation combined.)²⁰

Regenerative farmers claim that livestock can improve the amount of carbon held in the soil by carefully managing grazing so the land can rest, recover, and integrate fertility-boosting faeces. (This is sometimes called holistic grazing or regenerative grazing). There is some impressive anecdotal evidence. Like Gabe Brown, a successful regenerative rancher, who saw his soil carbon increase from 1.9 in 1991 to 6.1% in 2021, which he puts down to a combination of regenerative practices, including livestock integration.²¹

Alan Savory’s institute has trained over 20,000 people in holistic planned grazing, which he says can restore grasslands, reverse desertification, and sequester carbon.²² He highlights research such as a study in Spain where regenerative grazing techniques improved topsoil carbon storage by 3.6% compared to traditional rotational grazing.²³ These percentages may seem small, but Project Drawdown says that increasing soil carbon from 1-2% to 5-8% means 25 to 60 tons of additional carbon could be stored per acre of farmland.²⁴ (In modern-day USA, the average heavy meat eater’s diet contributes about 3.3 tons of carbon dioxide equivalent to the atmosphere per year).²⁵

The problem is that evidence for the success of regenerative grazing to store carbon is still largely anecdotal, and peer-reviewed studies tend to have small sample sizes. That doesn’t mean that the lived experience of farmers worldwide is meaningless. But in the hierarchy of evidence, the scientific data supports livestock production as a carbon source far more often than a carbon sink.

Evidence that regenerative grazing can improve the amount of carbon held in the soil exists, but remains largely anecdotal.

What about methane?

Methane is a powerful greenhouse gas which is sometimes (but not always) accounted for as part of “carbon dioxide equivalent” in studies about livestock greenhouse gas emissions. Its main sources in agriculture are the enteric fermentation of ruminant livestock and the anaerobic digestion of animal manure and other organic wastes.²⁶ In simple terms, the way that ruminant animals like cows digest and ferment food releases methane, and so does animal manure if it breaks down without enough oxygen - in the industrial model, animal manure is often stored in “lagoons” where it ferments anaerobically, instead of properly decomposing on healthy land.

Reducing methane emissions from livestock could drastically reduce the amount of methane emissions within agriculture. This could be achieved by reducing the global cattle herd - eating less meat - but it’s an unlikely path forward given the global livestock herd is estimated to grow and emit 9% more GHGs by 2031 compared to 2022 - due to a growing human population and shifts in diets that increasingly favour meat.²⁷

As well as eating less meat in richer countries, proposed solutions for methane emissions from the livestock industry include genetics (breeding animals that produce less), management (rotating pastures and incorporating trees into farms), and nutrition (feeding animals foods or supplements that reduce methane emissions). One nutritional solution could be adapting the diet of cattle to reduce the amount of methane they produce. For example, feeding them seaweed has been shown to reduce methane emissions dramatically - up to 95%, though other studies have had less dramatic results.²⁸ This isn’t a “silver bullet” solution to all the impacts of livestock production, but drastically reducing methane from cattle digestion is becoming increasingly possible. If it can be sustainably implemented at scale, it should be. It’s worth remembering that seaweed is a nutritious and abundant food that has been used as a cattle feed for livestock for millennia in coastal communities such as Greece.²⁸ Sometimes, modern “breakthroughs” have roots that go way back into the past.

See how seaweed is produced around the world

Asparagopsis taxiformis is a species of red algae. Of the seaweeds so far tested, Asparagopsis shows the most promise for use in beef cattle feed as a methane inhibitor.

Of course, there is variation in the methods livestock farmers use - and the impact of meat depends on where and how it is grown. In the report “Feeding Britain from the Ground Up”, the Sustainable Food Trust looked at how Britain might be able to transition to sustainable agriculture without becoming less food secure. Their modelling found that livestock was an essential part of fertility building on sustainable, mixed farms. On the one hand, the report found that Britain would have to reduce pork and chicken production by 75% if it used sustainable practices. This is largely because British farmers couldn’t produce the grain necessary to keep pace with factory farming. But as well as doubling fruit, veggie, and pulse production, beef and lamb production could stay the same, even using strictly sustainable grazing practices.²⁹

When managed correctly, livestock can certainly boost soil fertility while providing protein. But to what extent livestock can meaningfully sequester more carbon than they emit in carbon dioxide equivalent is still debatable.

Livestock and biodiversity 

Clearing land for agriculture, particularly livestock and livestock feed, is a major cause of the biodiversity crisis. 69% of measured biodiversity populations have declined since 1970, and the United Nations Environment Program has warned that “the planet is experiencing a dangerous decline in nature. One million species are threatened with extinction, soils are turning infertile, and water sources are drying up.”^{30, 31}

There is no doubt that agriculture as we know it, particularly industrial animal agriculture, needs to change. But in the case of ancient grasslands (as opposed to new pastures slashed and burned from the rainforest), the picture is more complex.

Perhaps surprisingly, grasslands are among the earth's most species-rich habitats - sometimes even more so than tropical rainforests. Many of the species found in grasslands are endemic, meaning they need this habitat to survive.³²

Some studies indicate that regenerative grazing techniques (moving livestock often, letting the land recover) can improve the local species diversity of soil microorganisms, earthworms, and insects.³³ Evidence also suggests regenerative grazing helps ground-nesting birds flourish. The improved forage, combined with regenerative farmers being less likely to kill wild mammals, meant that wild mammal populations on regenerative farms have shown some of the greatest improvements.³³ The evidence for increased plant diversity needs to be clarified. Some studies demonstrate increased plant diversity, whereas others show decreased diversity, especially during droughts.³³ More research is needed, and I cannot overstate that regenerative grazing and industrial meat production are different systems, so the potential benefits of regenerative grazing have nothing to do with the factory-farmed animals that big meat might like to present as “good for the planet”. 

As the biodiversity and climate crises unfold in real-time, there is a strong case for vegetarianism. But there is also a case for supporting small mixed farms that produce meat and dairy using traditional and sustainable methods while reducing overall meat consumption in rich countries. (It is less snappy, though; I'll hand it to you.) For the majority of the world’s population, who produce their own food and the majority of the world’s land, where the land isn’t conducive to growing crops - exploring the very best way to farm livestock while protecting biodiversity and sequestering carbon is a vital key in stabilising our climate and reversing biodiversity loss.