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Rationally, should you be vegan?

Food is responsible for a quarter of CO2 emissions. While it's already a good first step that you own a glass bottle and retweeted Greta Thunberg's last post, we can no longer ignore the main issue regarding climate change: the way we eat.

This is not a manifesto for veganism, far from that. Most of us already know that animals are being raised in terrible conditions, but becoming vegan for this reason regards one's own values and principles. On the other hand, with increasing global warming, now the case of veganism concerns all of us. In this article, we will examine what would change if we all became vegan: not only regarding climate change but also regarding its impact on our nutrition and on our economy, and especially what are the motives that would make us all go vegan, and of course their limits.

Image taken from The Guardian


Since preindustrial times, the Earth has already heated up by 1C° and is set to heat up even more. The issue today is by how much we will let it heat up to, for now it is set to reach 1.5°C by 2030, but if no action is taken it will easily reach 2°C. The impact of this ? Check this chart taken from the World Resources Institute:

So how could veganism help limit this ?

The main reason for global warming is the burning of fossil fuels, as it leads to the release of greenhouse gases. The thing is, producing one calorie of animal protein requires, on average, to burn 11 times as much fossil fuel needed to produce one calorie of grain protein. But the worst isn't the releasing of carbon dioxide but of methane, increasingly produced by animals as their number keeps growing because of intensifying artificial inbreeding. As methane is 25 times as effective as carbone dioxide at trapping heat in our atmosphere, and that recent studies show that raising animals organically does not help as they produce methane in even greater quantities, the case for global warming gets worse. Lastly, according to the UN, 65% of nitrous oxide, a gaz 300 times more powerful than carbon dioxide at trapping heat, is emitted by the dairy, egg and meat industries.

The result of all of this ? While consuming a diet high in meat costs us 7.2kg of CO2 per day, a vegeterian one costs 3.8kg and a vegan one 2.9.

Along with the release of greenhouse gases, other challenges are raised by animal agriculture regarding climate change. As the population keeps growing, raising animals requires an increasing amount of space, which in turn leads to deforestation. Today, milk and cheese production take up an area as big as China. On the other hand, forests absorb greenhouse gases. Indeed, a single mature tree can absorb around 22kg of carbon dioxide per year, in addition to preventing floods, providing enough shade in order for us to have more fertile soils, and being essential to a significant proportion of our biodiversity.

The math thus seems simple: a vegan diet = less CO2 emissions and more forests to absorb CO2.

But globally switching to a vegan diet would have, obviously, a huge impact and raises other questions: can we feed 10 billion people with a vegan diet ? Would it be as nutritious ?


It is no secret that our population is dramatically increasing, and once the poorest countries in Africa will develop better living standards, the number of people living on the continent will quadruple (by 2090).

How could a vegan diet remedy to an increase in global food demand ?

Only about 55% of the world's crop calories are directly eaten by people. The main reason for this is that the majority of this crop is being fed to the animals we are eating. Therefore, being vegan would allow us to directly have access to this lost food, crucial with the limited resources we have on earth. For further explanation, here is how a food chain usually works like:

Sun > plants > animals > humans

The closer the food we eat is to the sun in this chain, the less energy and land is needed to produce it. Cutting down on animals would lead to a food chain like this one: Sun > plants > humans.

Therefore, if the entire population became vegan, the amount of food available for humans to eat would increase by at least 23 per cent, as a meat-eater’s diet requires 17 times more land, 14 times more water and 10 times more energy than a vegetarian’s, according to research published by The American Journal of Clinical Nutrition. More particularly, 700 million tons of food are consumed per year by livestocks, when researchers estimate that only 40 million tons would be required to eliminate world hunger.

So more food for all of us, but can a vegan diet actually supply us with the necessary nutrients ? What about protein ? Can we feed babies and young children with exclusively vegan food ?


So the big cultural challenge is that most people believe a vegan diet means cutting all sources of protein. While a vegan diet does lack some nutrients, which can easily be fixed by taking supplements, saying that protein in a vegan diet does not exist is a big misconception. Furthermore, the same people which make this criticism usually forget the fact that the animals we eat contain many toxic ingredients which were fed to them, which is a possible explanation for the rise in number of cancers in the past decades. Banning the possibility for a vegan diet simply because it lacks some nutrients when the food we consume every day is far from being of the best quality could, in fact, thus be seen as quite hypocritical.

The difference regarding protein between a vegan diet and a meat based diet concerns their amino acids content. Our body needs 9 particular amino acids which it doesn't produce. A source of protein containing all 9 amino acids is called complete while one that is not is called incomplete. We cannot deny the fact that most animal protein is complete while most vegan protein is incomplete, but as dietitians agree to say that we do not need the 9 amino acids on a daily basis, simply having a diverse source of vegan protein each providing different types of amino acids is vastly enough. And if you still want to have as many amino acids in your meal on a vegan diet than on a meat-based one, complete vegan protein does exist: quinoa, rice, chia seeds, peanut butter, beans... the list is long.

Therefore, a vegan diet can provide us with all the amino acids, and therefore protein, needed for our body, wether it is by consuming a diverse source of incomplete vegan food or by directly consuming complete vegan food like quinoa.

A vegan diet could provide a greater supply of certain important nutrients, such as carbohydrates, copper, magnesium and cysteine. There would actually be more than the population needs. Furthermore, the intensification of animal farming has led to less nutritious food. For instance, today six chickens raised intensively have the same amount of omega-3 than one chicken raised in the 1970's. So saying that animals are more nutritious than vegan food does not take into account the fact that animals raised in poor conditions are not as nutritious as we think they are.

On the other hand, we cannot deny that some nutriments will be lacking, some including calcium, vitamins A and D, B12, arachidonic, eicosapentaenoic and docosahexaenoic fatty acids. In addition, people exercising a lot will need a greater supply of food with a high percentage of protein, and while a vegan diet does supply the diversity of amino acids needed, a meat-based diet does offer greater quantity of protein. However, most athletes already take supplements such as whey protein powder, so a switch to vegan supplements like vegan protein powder could largely compensate a greater need for protein in their diet.

But what about children ? There are many stories about the effects of a vegan diet on their well being, but what scientific proof do we actually have ?

According to the NHS, "Babies and young children on a vegetarian or vegan diet can get the energy and most of the nutrients they need to grow and develop from a well-planned varied and balanced diet." In fact, on the NHS's website, for each nutrient that could be lacking in a vegan diet that is not very diversified, a list of vegan food is given that largely compensates the need for the specific nutrient, so there isn't any need for supplements. The reason why some babies fed on a vegan diet have had retarded growth is that their parents did not verify that the child's diet was diverse enough and supplied all the necessary nutrients. The only thing is that the parents should thus be careful that each of these nutrients needed for a child is in their meals, but other than having to pay extra attention to their diet, a child can perfectly be raised under a vegan diet.

To conclude this part, most of the population could largely be satisfied with a vegan diet as long as careful attention is being given to the supply of nutrients that there is in vegan food. Other than that, supplements can be taken, especially for athletes, but it cannot be said at all that a vegan diet would be unhealthy.


Any decision that we take, on a global scale, affects the economy, and therefore our lives. Therefore, would the sudden shift to a vegan diet, worldwide, overall benefit or damage us ?

As seen previously, a global switch to a vegan diet would lead to a decrease in food related emissions of approximately 70%. According to researchers at Oxford University, this represents £440 billion in savings.

Insofar as lower coronary heart disease, type 2 diabetes, strokes and some cancers tend to be caused by meat-based diets, switching to a vegan diet would also lead to 8.1 million fewer deaths per year, resulting in "$700–1,000 billion per year on healthcare, unpaid care and lost working day". Just in the US, where food-related problems are abundant and where healthcare is the most expensive, the savings could reach $250 billion.

Here's a chart taken from the PNAS (Proceedings of the National Academy of Sciences) on the economic value for both the environment and healthcare of switching to either a healthier, vegeterian, or vegan diet.

"Health and environmental benefits of dietary change based on global guidelines on healthy eating (HGD), vegetarian (VGT) and vegan (VGN) diets. The value of environmental benefits is derived from estimates of the social cost of carbon (SCC); and the value of healthcare benefits is based on estimates of the costs of illness (CoI).".

Clearly, the chart puts forward how switching to a vegan diet would highly benefit the economy by creating savings for both the environment and healthcare. This money obtained could then be reinvested in these same sectors in order to generally advance our country's well being.

However, there is one factor that we cannot forget: the transition.

We cannot deny the fact that the meat industry plays a very significant role in our economy and that around a billion of people worldwide dedicate their lives to working in the meat industry or on livestocks and is worth approximately $1.6 trillion by 2050. For instance, the US's meat industry brings $894 billion to the country's economy and 800 thousand people are employed in this industry.

However, it is undeniable that when new industries appear, older ones disappear. Scientific progress comes with the disappearance of sectors which we thought were essential. For instance, when other energies were found at the end of the 20th century, workers in the coal industry naturally began to face severe unemployment in western countries. Therefore, the most important task would be to provide career alternatives to the people who will face unemployment because of the transition, perhaps in the growing of crops.

Another difficult task would be for poorer populations which depend on livestocks for their survival, especially nomadic groups such as the Mongols or Berbers. However, we have to keep in mind that these people are not the ones consuming meat created in industries with high CO2 emissions. Indeed, the conditions of living of the animals they eat are far from being the same as the ones we consume in western countries, and this is the same case for the poorer populations from rural regions of the global south. Therefore, we could imagine that a vegan diet would become the norm only in countries where the only access to non vegan food is through high polluting factories.

Lastly, there is a remaining difficulty for which we have not found, yet, a solution. The growing of crops, such as wheat, often creates by-products which cannot be used for human food consumption and is thus usually sold for animals. If these are not sold anymore, as farmers would loose money the global cost of crops could dramatically grow, leading to hyperinflation. Furthermore, if these by-products were to be converted to biomass, i.e. energy, it would require the emission of CO2 and methane, thus making it counter productive for our environment. However, we have to take into account the fact that there have not been enough research in this domain to say that there is no solution for this problem. If the entire planet were to switch to a vegan diet, international summits between scientists dedicated to this question could be a first step to finding a solution. It is not because we have not found one yet to this specific problem that the case for veganism becomes impossible.


Clearly, the most difficult part to globally switching to a vegan diet would be the cultural shock: many families cannot imagine celebrating Thanksgiving without a turkey or Eid without meat. Other than that, the switch to a vegan diet would be necessary in countries where animal food is of the most polluting, and would lead to not only a major slowing down of global warming but also overall better health conditions for the population as well as a greater protection of the environment. The transition, if carefully coordinated through the communication between international organizations and local ones, could safely be assured. Lastly, it could be a possibility to leave out of the equation smaller rural populations consuming non vegan food but not contributing to the damage of the environment.

Therefore, in countries where individualism has prevailed, turning vegan is a challenge as it requires people to understand that it is not anymore solely about the animals' lives but about ours, and about our living conditions on this Earth. Education on this subject, thus, becomes a critical tool if globally switching to veganism was ever to happen.


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shoutout to Lola Truant for being right about all of this for more than 7 years


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