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When I decided to become vegetarian, I was unaware of these numbers. But, through and because of my research, I decided to go vegan.

Veganism is a philosophy and way of living which seeks to exclude – as far as is possible and practicable – all forms of exploitation of and cruelty to, animals for food, clothing or any other purpose; and by extension promotes the development and use of animal-free alternatives for the benefit of humans, animals and the environment.

(The sources are indicated at the end of the article by a #).

Several reasons incited me to live a vegan lifestyle:

  • The environmental cost (Greenhouse gas emissions)
  • Deforestation
  • The use of water resources
  • Soil pollution
  • Animal suffering
  • World hunger
  • The Health Risks
  • The destruction of ecosystems & biodiversity loss
  • The worldwide land use
  • The number of living being killed


  • Greenhouse gas emissions

It is not sufficiently known but livestock is responsible for 14.5% of global greenhouse gas emissions, which is more than the whole transportation sector (boats + planes + trains + trucks + cars + 2 wheels) (#1). But what is even lesser known is the fact that not all gases are equal to CO2 and, they have different warming potential. Two other gases (apart from vapor) are catalysts (elements increasing the speed of a chemical reaction) of global warming.

These two gases are methane CH4 and nitrous oxide N2O, which respectively have a heating power approximately 28 times higher and 265 times higher than CO2 without climate change feedback* (with it, it is respectively 34 and 298 times) on a 100-year calculation (#2). These gases are often minimized in many studies when calculating their climate impact. A fortiori, livestock would more likely be responsible for about 51% of total greenhouse gas emissions (#3). This figure is interesting as it is shown that the UN does not take into account all the factors resulting from animal exploitation and agriculture relating to animals (animal respiration, cooling emissions of fluorocarbons, higher and longer cooking temperatures, waste livestock product’s emissions, production and distribution of their by-products, production and distribution of packaging …) (#3).

Let us first see what is the greenhouse effect.

The greenhouse effect is an essential natural phenomenon for the onset and existence of life on earth. It is constituted by all gases whose molecule is composed of 3 atoms or more. These molecules are able to absorb the infrared radiation emitted by the earth’s surface. The added greenhouse gases by humans (45% more CO2, 150% more CH4, and 20% more N2O) are destabilising and increasing the normal absorption capacity of our atmosphere (#4).

Livestock contributes for 65% of nitrous oxide emissions through the degradation of nitrogen contained in fertilizers and manure (feces). Livestock contributes to 37% of all methane emissions, the majority emanating from the enteric fermentation of ruminants (farts) (#5).

The consequences of this increase in greenhouse gas emissions are global warming. 157,8 million ‘climate refugees’ (people forced out of their homes due to environmental changes in their living areas) had to leave their homes between 2008 and 2014 (#6). This number does not include the 26,7 million refugees forced to leave their homes after earthquakes and volcanic activity (#6).

This also results in ocean acidification, which slows the growth of coral and plankton. In addition, about 20% of the original coral reefs were destroyed. The best example of that problem is the Great barrier reef in Australian, of which 93% has whitened (#7). Corals create reefs that help protect and shelter fish. The coral ecosystem is among, with the tropical forest, the most diverse and complex on the planet. Coral reefs provide a barrier that effectively absorbs offshore elements, including wave energy while helping to reduce coastal erosion. They reduce the damage occurring from storms, hurricanes, cyclones, and tsunamis (in part). The corrals help protect ecosystems between reefs and coasts, such as lagoons or human settlements on sealines.

Due to global warming, some reefs have begun to die. The death of these reefs has resulted in the disappearance of fish, leading to a vicious circle.

*Climate change feedback is the internal mechanism whereby a change in one quantity leads to a change in the second quantity and that change in the second changes the first one. I.e: increase in temperature leads the ice caps to melt which releases trapped methane and CO2 which in turn increases the temperature and so on.



  • Deforestation

The Amazon rainforest is the main tropical forest affected by agricultural exploitation and livestock farming. Livestock farming accounts for 70% (#9) to 75% (#10) and soy crops for animals and biofuels for 16% (#11). This amounts to at least 88% of agricultural related Amazonian deforestation (#12). South America accounts for 61% of the global net loss of forests between 1990 and 2010 (#13), livestock likely accounts, therefore, for more than half of global deforestation.

The consequences of deforestation are multiple: 80% of the world’s biodiversity is located in forests. However, 16,928 known species (3% of total species biodiversity, meaning the threat is clearly underestimated) are threatened with extinction (#14). Deforestation contributed 17.4% of greenhouse gases between 1970 and 2004 (#15) and accounts for 10,5% for 2010 (agriculture + Forestry and changes in land use estimated at 24,87%) (#16).


  • The use of water resources

Before talking about water, It is important to define one term, virtual water: which is the total volume of water necessary, including agricultural or industrial processes in order to produce something, notably a good (#17). This term is used because most of the water consumed is generally not found in the finished product.

Livestock requires colossal water resources. In the United States, irrigation accounts for 38% of all freshwater consumption, and agriculture uses approximately 80 to 90% of the water consumed in the country (#18). In France, it accounts for 43%, although, it depends a lot on the region you are in (#19). The most accurate figure is from the Seine-Normandy water agency, which indicates that in 2003, 68% of the water was devoted to agriculture (#20). This high consumption can be explained by the quadrupling of irrigated areas in France between 1970 and 1997 (#21).

Animal products are very water demanding for several reasons.
First, the animals need to drink. This physiological need implies significant water resources that will be partly lost through urine or evaporation.
Secondly, it is necessary to water the plants and feed that will be used to feed these animals, which can represent nearly 10 times the amount of food needed to feed a human instead of the animal.
Lastly, it also takes a lot of water to clean animal carcasses, to make sure there are no feces left, even though fecal bacterias are found on most commercial pieces of meat.

When comparing diets of 3400 calories (which is about the average in OECD nations), an omnivore has an average footprint of 3600 liters per day (5000 liters if half of the calories are derived from animal products) while a vegetarian has a footprint of 2300 liters and a vegan of 1700 liters per day ( #22).

To put all of this in perspective is needed to produce a kilo of:

vegetables: 320 liters
potatoes: 700 liters
fruit: 1,000 liters
milk: 1,000 liters
cereals: 1,300 liters
soybeans: 1,800 liters
Eggs: 3300 liters
chicken: 3,900 liters
cheese: 5,000 liters
beef: 15,500 liters.

Go and check it out the volumes yourself on by using the water usage estimation tool, which covers 40 products.

This use of water causes a number of environmental problems, such as groundwater depletion, soil erosion and salinization (#24).


  • Soil pollution

Soil pollution is another issue related to animal exploitation. This issue is twofold, there is, on the one hand, the pollution of the soil by the nitrates, and on the other the pollution of freshwater by these same nitrates through infiltration and runoff.

A 2,500 cows American dairy farm produces as much excrement as a town of 411,000 (#25).

There are multiple consequences to soil pollution. The most noticeable, due to the presence of nitrates, is the formation of green algae that emit a toxic gas, H2S known as hydrogen sulfide (it killed several wild boars, a horse and a jogger in his fifties, even though the investigation was deemed inconclusive, elements show that the most likely cause of death is the toxic gas) (#26). These algae also reduce oxygen in streams, leading to their death many marine species. This phenomenon is also known as dead zones (oxygen deficient zones caused nitrates) (#27).


  • Animal suffering

SInce 1976, the animal is considered by Article L214-1 in Chapter IV on the protection of animals of the French Rural and Fishery Code as a ‘sensitive being which must be placed by his owner in conditions compatible with the biological imperatives of its species‘ (#28).

In 2015, article 515-14 of the French Civil Code added that “animals are living beings capable of feeling sensibility”. They are still considered as goods and follow the legal regime of goods (#29).

It has been scientifically proven that animals, just like humans, are able to feel pain. The pain in animals is to what is more commonly known as nociception (sensory process at the origin of the nervous message that causes one to feel pain). This is the unconscious part of the pain, as consciousness in animals has never been scientifically proven. It is, therefore, necessary to perfectly justify any harm to animals as a strictly necessary evil (#30).

Lastly, in a German parliamentary report, is indicated the mis-stunning rate of certain animals. The mis-stunning rate (by breaking through the skull, by means of a rod that penetrates the animal’s brain) is of up to 9% for cows and bulls. This means that 1 animal out of 10 is partially or fully conscious when getting his or her throat slashed open and will be conscious for the entire time they bleed out. For the mis-stunning rate (by gasing [mixture of CO2  and air], which burns the animal from the inside for the 15 seconds it takes or by electrocution)is of up to 12,5%. This means that 1 animal out of 9 is partially or fully conscious when getting his or her jugular pierced, before being immersed in boiling water or passing through the burners (using fire to destroy bacteria), depending on the technic used in the abattoir (#31).


  • World hunger: offer a solution to the persistent problem of world hunger

Animal agriculture has one of the lowest energy ratios when compared to other types of foods. Indeed, is required to produce 1 animal calorie of:

Chicken: 4 (plant) calories
Turkey: 10 calories
Dairy product: 14 calories
Pork: 14 calories
Egg: 39 calories
Beef: 40 calories
Sheep: 57 calories
(# 32)

All of these calories could be ingested by humans directly. And it’s not as if it was impossible. In fact, we have an excess of 19 million tonnes of plant protein consumable by humans (out of the 77 million tonnes produced) that are instead fed to animals rather than to people who need it (#33). When we calculate the excess ratios regarding how many humans do not have sufficient access to food, this gives us 65 grams of protein per day per person, not counting the 58 million vegetable proteins converted to animal protein.

Our consumer choices make it so herds in the UK and France are fed and fattened, at the expense of the 34 million South Americans who suffer from malnutrition and hunger (#34).

This choice has among other consequences a destabilizing effect on certain areas of the globe and is the cause of some wars.
  • Health risks

Eating meat is not just an environmental risk.This represents a public health risk. The World Health Organization has classified red meat as probably carcinogenic to humans (Group 2A) and meat processed as a carcinogen (Group 1) (#36).

In addition, the consumption of red meat increases the risk of cardiovascular diseases and diabetes, two pathologies that alone account for 31% of deaths worldwide (#37).

The decrease and consequently the cessation of the consumption of animal products have several benefits. Here is a chart of the American Doctor and nutritionist Michael Gregor who demonstrates the effectiveness of a plant-based diet on the human body:

A study (aka the adventist study) conducted on 60,903 people over 4 years found a 78% lower incidence of diabetes and 75% lower hypertension for people on a plant-based diet compared to the people on an omnivorous diet.
People on a vegetarian diet had a 61% lower incidence of diabetes and 55% less hypertension compared to the people on an omnivorous diet (#38).

The body mass index (BMI) of people on a plant-based diet was the only one below 25 (23.13), whereas it was 28.26 for the people on an omnivorous diet. People with a vegetarian diet were slightly overweight (25,48) (#38).

In addition, 80% of antibiotics consumed in the United States are by animals (#39). France has a similar reliance on antibiotics, however, no trustworthy source was found.

Finally, 80 to 90% of farm animals consume GMO soy in France (#40). Worldwide, “70 to 90% of the harvested biomass from genetically modified plants is consumed by food-producing animals” (#41).

(The topic of health will have a entire article dedicated, that will later be linked here).

  • The destruction of ecosystems & biodiversity loss

Livestock is one of the leading causes of climate change and is the leading cause of land degradation, air and water pollution, and the loss of ecosystems (and the biodiversity living in these areas) that are disrupted or destroyed.

Livestock is responsible for 64% of ammonia emissions, which contribute significantly to acid rain and therefore to the acidification of ecosystems, both marine and land ecosystems (#42). This makes the soil more vulnerable to erosion and less fertile.

Fishing is also a major source of ecosystem loss. Currently, 53% of the world’s fishing zones are fully exploited, 28% are overexploited, 3% are depleted and 1% is recovering from depletion (#43), for a total of 85% of 100% exploitation or more!

  • Land use

Today, 30% of the planet’s land surface is dedicated to livestock farming. This represents 70% of the total agricultural land (#44).

Here is a comparison of the land area necessary per type of foods.



  • The number of living being killed

Each year, at least 62,768,239,047 land animals and birds are killed (#46, figures from 2010). Every 2 years, it is thus as many humans that have walked on earth since the birth of the humanity, 50 000 years ago, that we slaughter (#47)!



It is also 150 times more than the number of people killed in all the wars across humanity (430 million deaths approximately (#48).

And that does not take into account the 1,000,000,000,000 to 2,700,000,000,000 (One to two trillion) marine animals killed each year (#49).


This stat shows the kilos of fish pulled out of our ocean… to know the number of individual fish, multiply by 16!


Here is a link to a webpage that calculates the number of animal lives, sqm of forest, kg of CO2 and water you have saved by being vegan:

Vegan Calculator

This calculation takes into account the estimate of all animal deaths related to our consumption of meat and animal products (milk, eggs, leather, wool). It, therefore, takes into account all deaths of crustaceans, crabs and marine species in general.

With all of the figures above, an omnivore eats an average of one animal every 2 days, which, in a lifetime, represents at least 7,000 animals.


I hope this article will give you an idea of why the consumption of meat and animal products is a risk and a global issue for us all.


Oh, and if anyone ever tells you that the soya lobby is behind all of this, keep in mind that the world’s biggest soybean producer and consumer is the meat industry 😉



[Referenced as follows: Organisation/Author, ‘Title or name of the book/document‘, (edition), page (p.), year]

Some of the numbers were calculated based on the information present in the sources. To get a peek at the calculations, just send me a message.

#1: FAO, Food and Agriculture Organization, ‘Tackling Climate Change through Livestock, A global assessment of emissions and mitigation opportunities‘, p.xii, 2014.

#2: IPCC – Intergovernmental Panel on Climate Change, ‘Climate Change – The Physical Science Basis‘, 5th Assessment Report, p.714, 2013.

#3: Worldwatch Institute, ‘Livestock and Climate Change: What if the key actors in climate change are… cows, pigs, and chickens?‘, p.11, November/December 2009.

#4: IPCC – Intergovernmental Panel on Climate Change, ‘Climate Change – The Physical Science Basis‘, 5th Assessment Report, p.11, 2013.

#5: FAO – Food and Agriculture Organization, ‘Livestock’s long shadow – environmental issues and options, p.xxi, 2006.

#6: IDMC – Internal Displacement Monitoring Centre, ‘Global Estimates 2015 – People displaced by disasters‘, p.20, July 2015.

UNCHR – United Nations High Commissioner for Refugees, ‘UNHCR, the Environment and Climate Change ‘, p.5, October 2015.

#7: National Geographic, ‘93 Percent of the Great Barrier Reef Is Suffering‘, 20 April 2016.

The Guardian, ‘Great Barrier Reef: 93% of reefs hit by coral bleaching, 19 April 2016.

#8: Foodwatch, ‘Organic: A Climate Saviour? The Foodwatch report on the greenhouse effect of conventional and organic farming in Germany, p.X, May 2009.

#9: FAO – Food and Agriculture Organization, ‘Livestock’s long shadow – environmental issues and options‘, p.xxi, 2006.

#10: The World Bank, ‘Causes of Deforestation of the Brazilian Amazon‘,  Working Paper NO. 22, p.XVIII, December 2003.

#11: Le Monde, ‘Agrocarburants et bétail européens “détournent” les terres du Sud’28 November 2008.

No precise figure – “Cover a large part of the remainder”, FAO – Food and Agriculture Organization, ‘Livestock’s long shadow – environmental issues and options‘, p.xxi, 2006.

#12: The World Bank, ‘Causes of deforestation of the Brazilian Amazon‘, Working Paper NO. 22, p.9, December 2003.

#13: Calculation based off of FAO – Food and Agriculture Organization, ‘Global Forest Resources Assessment 2010 – Main Report‘, Table 3 – Trends in extent of forest 1990 – 2010, pp.229-233, 2010.

#14: IUCN – International Union for Conservation of Nature, ‘The IUCN Red List of Threatened Species – Species Extinction – The Facts‘, 2007.

#15: IPCC – Intergovernmental Panel on Climate Change, ‘Climate Change 2007 – Mitigation of Climate Change‘, 4th Assessment Report, p.105, 2007.

#16: IPCC – Intergovernmental Panel on Climate Change, ‘Climate Change 2014 – Mitigation of Climate Change‘, 5th Assessment Report, figure 1.3 panel B, p.123, 2014.

#17: (Concept invented by Tony Allan) Pr Arjen Y. Hoekstra – Twente Water Centre, University of Twente, the Netherlands, ‘The Water Footprint of food‘, p.49, 2008.

#18: USDA ERS – United States Department of Agriculture, Economic Research Service, ‘How Important is Irrigation to U.S  Agriculture‘, 2013.

#19: CNRS – National Center for Scientific Research, ‘La consommation française domestique, industrielle et agricole‘, 1995.

#20: Seine-Normandy water agency, ‘Consommation en eau ‘, 2003 (source erased, downloaded and available on demand).

#21: CNRS – National Center for Scientific Research, ‘La consommation française domestique, industrielle et agricole‘, 1995.

#22: Arjen Y. Hoekstra, ‘The hidden water resource use behind meat and dairy‘, p.6, April 2012.

#23: Arjen Y. Hoekstra – volumes based on a 2,5 L/kcal for animal calories and 0,5 L/kcal for plant-based calories – Twente Water Center, University of Twente, ‘The hidden water resource use behind meat and dairy‘, p.55, April 2012.

Water Foot Print,

#24: European Commission, Agriculture and urban development, ‘Eau et Agriculture‘, 2010.

#25: EPA – United States Environmental Protection Agency (Office of Research and Development), ‘Risk Assessment Evaluation for Concentrated Animal Feeding Operations, p.7, May 2004.

#26: Le Monde, ‘Algues vertes: la justice va-t-elle entrer en scène?‘, 25 April 2014.

Le Monde, ‘Doutes sur la mort d’un joggeur sur une côte infestée d’algues vertes ‘, 21 September 2016.

France TV Info ‘Algues vertes, l’enquête sur le décès d’un joggeur classée sans suite‘, 4 April 2017.

#27: FAO – Food and Agriculture Organization, ‘Livestock’s long shadow – environmental issues and options‘, p.209, 2006.

#28: Article L 214-1 of the French Rural and Fishery Code, 1976.

#29: Article 515-14 of the French Civil Code, February 16th, 2015.

#30: Daniel Le Bars (physiopathology of the nervous system, Inserm Paris), ‘Douleur de l’animal, douleur de l’homme‘, Edition ‘scientifiques et médicales Elsevier SAS’, pp.83-90, 2002.

#31: German parliament [Deutscher Bundestag], Drucksache, 17/10021, ‘Antword der Bundersregierung‘, p 5-6, 15 May 2012.

#32: D. Pimentel and M. Pimental in the Journal of America Clinical Nutrition, ‘Tables 2 and 4 from Sustainability of Meat-Based and Plant-Based Diets and the Environment‘ 78(suppl) pp.660S-663S, 2009.

#33: FAO – Food and Agriculture Organization, ‘Livestock’s long shadow – environmental issues and options‘, p.271, 2006.

#34: FAO – Food and Agriculture Organization, ‘The State of Food Insecurity in the World‘, figure 2, p.10, 2015.

#36: IARC – International Agency for Research on Cancer, ‘Agents Classified by the IARC Monographs, Volumes 1–121, p.16, January 28th, 2018.

WHO – World Health Organization, ‘Q&A on the carcinogenicity of the consumption of red meat and processed meat‘, October 2015.

#37: WHO – World Health Organization, ‘Annex Table 2 Deaths by cause, sex and mortality stratum in WHO regions, Estimates for 2002 ‘, p.122, 2004.

#38: NCBI – National Center for Biotechnology Information, ‘Type of Vegetarian Diet, Body Weight, and Prevalence of Type 2 Diabetes‘, May 2009.

#39: FDA – Food and Drug Administration, ‘Annual Summary 2009 on Antimicrobial Sold or Distributed for Use in Food-Producing Animals‘, 2009.

#40: Le Nouvel Obs, ‘OGM : comment les éviter dans notre assiette?‘, 20 September 2012.

France TV Info, ‘90 % du bétail français serait élevé aux OGM, sans information du consommateur‘, 20 February 2016.

#41: Alison L Van Eenennaam (NCBI) – ‘GMOs in animal agriculture, time to consider both costs and benefits in regulatory evaluations‘, p.1, 20 September 2013.

Gerhard Flachowsky (SpringerLink), ‘Animal feeding studies for nutritional and safety assessments of feeds from genetically modified plants: a review, p.1, 24 July 2012.

#42: FAO – Food and Agriculture Organization, ‘Livestock’s long shadow – environmental issues and options‘, p.xxi, 2006.

#43: FAO – Food and Agriculture Organization, ‘World Review of Fisheries and Aquaculture‘, p.8, 2010.

#44: FAO – Food and Agriculture Organization, ‘Livestock’s long shadow – environmental issues and options‘, p.xxi, 2006.

#45: WWF Suisse, ‘ Surfaces de sol nécessaires pour la production d’un kilo de ‘.

#46: FAO – Food and Agriculture Organization, FAOSTAT – World – Livestock production – No. animals slaughtered, 2010 (choose the categories and the data you wish to see).

#47: Carl Haub (PRB – Population Reference Bureau), ‘How Many People Have Ever Lived on Earth‘, October 2011.

#48:, Max Roser, ‘Global death in conflicts since the year 1400‘, 2016.

Frédéric Côté-Boudreau, ‘Chaque année, on tue plus d’animaux qu’il y a eu de morts durant toutes les guerres de l’humanité‘, p.2, 12 March 2014.

#49: FAO – Food and Agriculture Organization, ‘World Review of Fisheries and Aquaculture‘, p.3, 2010., ‘Estimating the Number of Fish Caught in Global Fishing Each Year‘ p.1, July 2010.