Animal versus Plant-based Agriculture

In 2019, the IPCC (Intergovernmental Panel on Climate Change), the United Nations body for assessing the science related to climate change, published their Special Report on Climate Change and Land (SRCCL), the most comprehensive research and analysis to date covering “greenhouse gas fluxes related to land; interactions between climate change and desertification, land degradation and food security; land-related impacts and risks; response options that help adapt to climate change; response options that reduce land-related emissions or enhance the take-up of carbon by land systems; and links to sustainable development more broadly.”

This extensive, detailed report is noteworthy for countless reasons, the most important one being that it treats the never-ending and rapidly accelerating cycle of how our use of land affects the climate and how changes in the climate affect how we use land. The interchange between the land and the climate is incredibly complex, but simply stated, our land-use choices have been generating a rise in global temperatures (as well as engendering a plethora of environmental devastations that are not only inherently destructive, but also add fuel to the fire of global warming). As average global temperatures rise, the land and all the species that live on it suffer: in India, for example, heat waves and droughts are growing in frequency and intensity, causing significant drops in crop production which cause food price shocks which in turn lead to increasing hunger. When we add to this dismal picture chronic water shortages (for both humans and animals) that drought and heat waves exacerbate, the result is frightening…and dreadfully lethal. And this is just one small window peering into the wider picture of climate change.

With global warming presenting such an existential threat to life on Earth, it should come to no surprise that after making their conclusions about this perilous state of global affairs, the authors of the SRCCL made clear recommendations to mitigate and in some cases reverse our collective trend toward annihilation. They argue that the current climate crisis cannot be solved only by cutting emissions from transport, factories, and power plants and replacing fossil fuels with renewable energy sources (which for decades have monopolized our attention about global warming), urging changes in the way food is produced and how land is used. “The consumption of healthy and sustainable diets, such as those based on coarse grains, pulses and vegetables, and nuts and seeds … presents major opportunities for reducing greenhouse gas emissions,” the report reads.

In 2019, researchers at the University of Oxford went one step further. Their study on sustainability, published in the journal Science, the most comprehensive analysis to date of the damage our current practices of farming is doing to the planet states that avoiding meat and dairy products is the single biggest way to reduce our environmental impact on the planet. “A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use,” said Joseph Poore, who led the research. “It is far bigger than cutting down on your flights or buying an electric car,” he said, as these only cut greenhouse gas emissions. “Agriculture is a sector that spans all the multitude of environmental problems,” he said. “Really it is animal products that are responsible for so much of this. Avoiding consumption of animal products delivers far better environmental benefits than trying to purchase sustainable meat and dairy.”

Let’s pause then and look with a bit more detail at the two main axes of the damage that animal agriculture is doing to our Earth and our ability to survive on the planet: environmental degradation and climate change.

For clarity’s sake, let’s first look at the difference between “climate change” and “global warming.” Although people tend to use these terms interchangeably, global warming is just one aspect of climate change. “Global warming” refers to the gradual and long-term heating of Earth’s surface, oceans and atmosphere due primarily to the increasing concentrations of greenhouse gases in the atmosphere. “Climate change” refers to the changes in the climate over a long period of time resulting from the increasing average global temperature (i.e. global warming) including, for example, precipitation patterns, droughts, heat waves, and other extreme weather. Thus while the two phenomena are causally related, they are not the same thing.  Human-made greenhouse gas emissions are causing global warming, which in turn is causing climate change.

It goes without saying, then, that to mitigate climate change we must focus of mitigating global warming. And to mitigate global warming, we must reduce GHG (greenhouse gas) emissions, which is something totally in our control since we are the ones creating and emitting nearly all of them.

Here are some numbers: Animal agriculture generates between a shocking 51% of GHG emissions (findings by Robert Goodland and Jeff Anhang, in the report Livestock and Climate Change, published by the Worldwatch Institute in 2009) and a whopping 87% of GHG emissions (findings by Sailesh Rao, Ph.D. from Climate Healers, in Animal Agriculture Is The Leading Cause of Climate Change – A White Paper, 2019). It is no surprise that these estimates are much higher than the 14.5% stubbornly advanced by the FAO (the Food and Agriculture Organization of the United Nations), but even if we were to go by their underreported estimate, animal agriculture emits more GHGs than the combined exhaust from all transportation at 13%.

Although there are now several ways to calculate GHGs, our conclusions of those calculations are often incomplete and skewed because we tend to focus only on carbon dioxide, painted as the bad boy of greenhouse gases, when in fact special attention must be drawn to methane (CH4), a GHG that it is typically ignored because it accounts for a much smaller percentage of total emissions than CO2. Though comprising only 9-10% of GHG emissions, methane is both enormously potent (84 times stronger as a heat-trapping gas than CO2, on a 20-year time frame) but also has a much shorter half life (7-8 years compared to the 100 years of CO2).

Simply stated, this means two things. The first is that although we must reduce our CO2 emissions and redefine what types of energy we use and how we use them, the problem with focusing climate change mitigation strategies on carbon dioxide is that it has such a long lifespan in the atmosphere, taking many decades and even centuries to leave. This means that any reduction today may lower future heating, but it will not result in the rapid cooling that is urgently needed. Secondly, and more importantly, reducing methane emissions would have an immediate and positive impact on temperature rise. Knowing this, the question now becomes how we reduce methane emissions. The answer is easy once we learn that across the globe animal agricultural is responsible for 37% of human-related methane emissions – more CH4 emissions than any other human activity, even from burning fossil fuels. Ceasing (by rapidly phasing out) animal agriculture is the fastest and simplest way to halt global warming in its tracks. 

When we add to this equation the other nefarious effects of animal agriculture, we come up with the growing environmental breakdown that we have been experiencing for the past few decades. The list of animal agriculture’s other environmental evils is so very long (air and water pollution, freshwater depletion, land degradation, reduced soil fertility, soil erosion, desertification, biodiversity and habitat loss, species extinction, deforestation, acidification of the oceans and ocean dead-zones…) that addressing it requires pages of research, data and analysis, and so we are including links below to scholarly papers and research reports for those who would like to read the details. The aim here is thus to ask this question: How does plant agriculture compare to animal agriculture in environmental terms? After all, we must eat something! 

Globally, agriculture takes up half of the habitable land on Earth. The vast majority (roughly 80%) of that land is used for animal agriculture – for grazing and animal feed production. Yet meat and dairy provide just 18% of calories and 37% of protein globally. On the other hand, about 20% of agricultural land is used for growing crops destined directly to feed humans; those plant-based foods provide 82% of calories and 63% of protein globally. It is clear that when we eat plants directly, we are direct consumers of the nutrients. When humans eat animals who have eaten plants, humans are secondary consumers of plants. Aside from being an inefficient system of nutrient acquisition, animal agriculture’s other inherent inefficiencies can be explained by the fact that animals consume far more food than they produce; in other words, animals are inefficient food converters. About 36% of our global crop production is given to the animals we eat. And let’s not forget that all these animals must drink: about 25% of all our freshwater goes to these same animals. (Fun fact n°1: chickens are the largest consumer of crop-based feed eating nearly 42% of the world’s feed. Fun fact n°2: 60 billion chickens are reared for meat globally each year. Fun fact n°3: India raises about three billion chickens annually. Fun fact n°4: Chickens are the most efficient livestock animals, yet it still takes nine calories of food fed to a chicken to get one calorie back out in the form of flesh. That’s like throwing away eight rotis for every one that we eat!)      

Take a deep breath and look at the numbers: animal agriculture occupies 45% of the land surface of Earth, and globally uses one quarter of our freshwater and more than one-third of our crop production…and provides us with less than 20% of our calories! Obviously, on a planet bound by finite resources and land, raising animals for food is at best questionable and at worst senseless. Conversely, countless systematic reviews, life-cycle analyses and meta-analyses have concluded that increased consumption of plant-based foods is associated with the lowest environmental impact. These same studies also agree that even the least sustainable plant food is still significantly more sustainable than the best “environmentally performing” animal food. 

As we can see, the highly disproportionate scale and massive scope of animal agriculture is undeniably the primary cause of ecological ruin. By constantly breeding and feeding tens of billions of farmed animals we are monopolizing much of our planet and its natural resources and radically changing the biomass of Earth. “Humans have altered life on Earth by changing the use of land to such an extent that although the world’s 7.6 billion people represent just 0.01% of all living things on the planet, since the dawn of civilisation, humanity has caused the loss of 83% of all wild mammals and half of plants, while livestock kept by humans abounds,” stated a study done by researchers at Harvard University in 2013

To add insult to injury, our unbridled use of land for animal agriculture has been disastrous for biodiversity, most notably (though not necessarily most importantly) to wild mammals and birds. A research article published in 2018 found that today, humans account for 36% of the biomass of all mammals on Earth, domesticated “food animals” (like cows and pigs) make up a staggering 60%, while wild mammals make up only 4%! A similar tragic reality holds true for birds. 70% are farmed “poultry” (primarily chicken) and only 30% remain wild. Clearly, our penchant for eating animals and animal-based foods has turned our planet into what is essentially a giant indoor-outdoor meat/dairy/egg factory – to the detriment of wild mammals and birds.

Animal agriculture sadly goes way beyond merely exterminating wildlife and inefficiently using our precious natural resources and finite arable land, as if these disasters weren’t already bad enough. Animal agriculture is the major driving force behind the double whammy of deforestation and desertification, the vicious cycle of destruction brought about by clearing and using land for grazing animals and crops.  Animal agriculture turns forests and prairies into barren deserts. The process begins one of two ways. The first is with clear-cutting forests to create pastures for cattle and other ruminants. As the pastures become overgrazed, with little or no plant growth to hold it in place, topsoil is carried by rain into streams and lakes, and its productive capacity is lost forever. The second is with clear-cutting forests to create arable land to plants new crops…usually because overgrazing has left recently-deforested land (in other words, those aforementioned pastures for cattle) infertile. More often than not, these crops are monocultures (often but not exclusively to feed animals) produced with heavy industrial machinery, intense irrigation and an overabundance of chemicals (and a common predilection for GMOs), all of which takes a devastating toll on soil fertility, degrades soil structure and leads finally to topsoil erosion…and, as in the first process with overgrazing, its productive capacity is lost forever. At this point the downward spiral of desertification is in full swing, and even if there are other ways to halt desertification (for example by planting food forests), well-meaning (for the most part) but ill-advised advisors  point out that the land is suitable only for grazing ruminant animals, or, worse than that, that grazing animals can actually be the remedy for degraded land. In fact, there is a popular movement, often called “Regenerative Animal Agriculture” or “Holistic Management,” led by Allan Savory, a Zimbabwean livestock farmer, which promotes increasing livestock grazing to reduce and reverse desertification! Though his claims have been repeatedly discredited by scientists, ecologists and journalists (for example, this article written by Dr. Richard Oppenlander in 2013 or  this article published in The Guardian in 2014 by George Monbiot  or excerpts of a host of reviews published on the Internet), they have been embraced by a slew of institutions, companies and individuals…all who, incidentally, have a vested interest in ensuring the continuation of animal agriculture, even at the cost of destroying soil fertility, complex ecosystems and biodiversity, forests…

Speaking of forests, safeguarding the world’s remaining forests is often touted as a high-priority environmental goal, both for the general health of the planet, and because forests and the trees inside of them provide wildlife habitats, keep topsoil in place, replenish groundwater aquifers, absorb carbon dioxide, and stabilize the climate. When we speak of the decimation of forests, we tend to think only of certain hot-spots, like in Brazil (by the way, the World Bank estimates that 91% of the cleared land in the Amazon is used either for cattle ranching or for growing crops like soya and corn to feed to animals globally) or Indonesia (where 80% of the cleared land is used for palm oil plantations). But let us remember that though the razing of the Amazon is horrific, the same thing is happening all over the world, with no or little media coverage. And even if admittedly not all deforestation in India is due to animal agriculture (much is due to “development” projects, like urbanization and industrialization, mining, dam reservoirs, etc), the rehabilitation of our great expanses of degraded or desertified land can be achieved only by ceasing to raise animals for food. 

One of the pushbacks that is often mentioned when promoting the end of animal agriculture in India is that many animals, particularly ruminants, consume substantial amounts of byproducts from food, biofuel and fibre production that are not edible by humans and thus are seen as “waste managers.” However, those animals are not waste managers as much as they are waste transformers, converting unwanted plant byproducts into manure and urine…and so much of it that we are polluting our soils and our waterways to a point of no return. (Fun fact n°1: India is the highest milk producer in the world and has about 302 million cattle – cows and buffaloes – nearly 30% of the entire global population of 990 million. Fun fact n°2: Cows and buffaloes constitute 59% of the total livestock population in India. Fun fact n°3: The lowest estimates available show that one cow produces about 10 kg of dung per day, and one buffalo produces 15 kg per day (the lowest estimates). Fun fact n°4: Each and every day in India, cattle produce more than 3.5 million tons of dung. Quiz: Even if we allow for 50% of this manure being used as dung cakes for fuel and other preparations, what are the effects of the remaining 638 million tons that are annually strewn onto fields or dumped into waterways? 1st hint: the multi-facetted answer is not limited to only environmental harm, for manure also contaminates the aquifers that supply the drinking water in most rural communities. 2nd hint: At least one-third of global diarrheal diseases are because of zoonotic causes. A reminder: we haven’t even spoken about the tons of urine, or the waste of all the other livestock or of poultry.) Instead of feeding these inedible byproducts to animals, they could be used as “green manure” which would be not only more efficient but much more environmentally friendly. To know more about this subject, look at Organic and Veganic Farming.

Another major criticism that is heard far and wide when recommending that we stop raising animals is that animals make use of untillable pasture and grazing lands that are not suitable to produce crops for human consumption. But we have established that nearly all of that land is untillable and unsuitable for growing crops because we continue to graze animals on them! The majority of land that is currently degraded was once forest or rich grassland, and we would be wise to accept that the planet would be better off if some land was just left alone. In fact, if the entire world went vegan, global farmland use could be reduced by 75 percent, freeing up land mass the size of Australia, China, the EU and the US combined. On this freed up land, we could plant trees and grow food forests and above all we could let vast tracts of land rejuvenate without the intervention of the human hand – a process called “rewilding.”

The last critique aimed at those who advocate for an end to animal agriculture is livelihood. This critique is the most sensitive one to address, because of the very real human element of jobs and joblessness, of formal and informal income, and of poverty and economic security. We will address this issue to greater length in our section on Justice: Human Rights, but without dismissing the gravity of the issue, using livelihood as a reason to continue the ravages that animal agriculture wreaks on Earth is just another way of saying that collectively we have no alternative but to dig our own graves, that short-term targets crush long-term survival, that we can dismiss future generations’ right to a stable climate and healthy eco-systems with robust biodiversity just because we are too busy (and too lazy) keeping this deadly system afloat to think of alternatives. To borrow a phrase that was used in What is Sustainability?, nothing else really matters if we don’t have a planet to call home.

Let’s not forget that despite the immense inherent inefficiencies and the gross environmental degradation that animal agriculture generates, this sector continues to thrive because those who own and control it are not paying the true cost of their activities. All over the world, the entire gamut of animal commodity production is heavily subsidized; these subsidies are government incentives paid to agribusinesses, agricultural organizations and farms to supplement their income, manage the supply of agricultural commodities, and influence the cost and supply of such commodities.  They span from the price of fertilizers for feed crops, to the minimal cost of layer-hens, to a guaranteed, fixed selling price of animal products, to government sponsored construction of animal shelters and factory farms. In India, the dairy sector alone has an array of subsidies, called “development schemes,” among which are 1) National Programme for Dairy Development (NPDD); 2) National Dairy Plan (Phase-I); 3) Dairy Entrepreneurship Development Scheme (DEDS); 4) Support to Dairy Cooperatives; 5) Dairy Processing and Infrastructure Development Fund (DIDF).

Most animal agriculture farmers in India, from the rural, single-cow owner to the layer-hen factory farm owner are totally dependent on government subsidies to stay financially afloat because the resources needed at every step of animal food production are wastefully high. The government may be writing the cheque, but we taxpayers are forced to pick up the tab. A second pernicious result of subsidies is that they generate artificially low selling prices for the end product, and thus incentivize their consumption to such an extent that these environmentally-harmful, inefficient and intrinsically expensive products frequently end up costing less to the consumer than environmentally-friendly, sustainable and intrinsically economical alternatives.

Lastly, the animal agriculture sector continues to grow and prosper because those who own and control it are not paying the true environmental costs of their activities. Known as “negative externalities,” these are the diverse and multiple harmful effects produced in the course of their various activities. We have previously identified just a few of those effects, like GHG emissions (especially methane), freshwater depletion, water pollution, eutrophication, deforestation, biodiversity and habitat loss, land degradation, reduced soil fertility, soil erosion, desertification…

If the true cost to the environment was factored into the final cost of the product (or “internalized”), the final consumer price would be prohibitive. Particularly vicious and antithetical to societal well-being, these negative environmental externalities put an intense burden not just on our local communities or our country, but on the entire planet Earth.


The downloadable link to the complete SRCCL (Special Report on Climate Change and Land):

Livestock’s Long Shadow: the report by the FAO in 2006.

Global land use for food production: from Our World in Data, data source FAO

Biomass use, production, feed efficiencies, and greenhouse gas emissions from global livestock systems

Desertification and agriculture, article by European Parliamentary Research Service, 2020

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