Environmental Effects of Animal Agriculture

“Everyone wants to change the world but no one wants to change themselves”

So you care about the environment and the future of our planet, which is hopefully why you’re reading this, and that’s great! It is the single most important thing us humans have and we should do our utmost to look after it, both for ourselves and for future generations. There are a lot of things people can do to reduce their impact on our amazing planet and ideally even leave it a little better off than when we found it.  However one aspect of our lives that is often overlooked is the food we eat. People focus on showering less, turning unnecessary lights off, and using a refillable water bottle, which are all great changes to make but we blissfully ignore the issue that would make the biggest difference of all. The impacts of animal agriculture can be seen across all aspects of the environment, be it our rainforests, our oceans or our atmosphere. The information below is only the tip of the iceberg when it comes to learning about the harm caused by animal agriculture and all of it can be avoided by easy steps like choosing to replace your mince with lentils or your milk with soy milk.

Where to start, except for climate change of course. Arguably the most pressing issue of our generation. Among 31,000 young people questioned, 48% said it was the most important global issue today and 78% said they would change their lifestyles to protect the environment. Frankly I’m surprised this number is not 100%, as climate change will affect almost every single person on Earth for the worse. Whether these effects are experienced through extreme weather patterns such as storms and droughts, resource shortages or simply missing the chance to witness many of nature’s glories, like breath-taking coral reefs or beautiful wildlife. However if you’re in that 78% I have some good news for you, we have a quick, easy, cheap and effective way to alter your lifestyle to protect our planet! More will be talked about this amazing discovery at the end, but in the mean time, here are the important facts about animal agriculture and its impacts on the environment.

Greenhouse gases: 

Greenhouse gases (GHG’s) are the main driver of our man-made climate change yet the public often overlooks the impact of animal agriculture on gases such as carbon dioxide (, methane and nitrous oxide. The Food and Agriculture Organisation (FAO) of the UN valued greenhouse gas emissions of the animal agriculture industry at 14.5%, which is even larger than the global transport sector at 14% (1) .Now it may be hard to envisage how big this number actually is, but context helps a lot here. Switching from a high meat diet (what most people in the UK eat) to a vegan diet would save 1,560 kg’s of CO2   equivalent per person each year. This would be the same as a family driving a small family car 6,100km(2). A return flight from New York to London is valued at 960 kg of  equivalent each year, so the transition is equivalent to flying roughly 18,000 km less each year.

While driving an electric car or living off solar power may be unattainable for most people, the easiest way to reduce your carbon footprint in a meaningful way would be to simply avoid animal products. This applies especially to cows, as their meat and dairy products account for 65% of the total emissions from the animal agriculture industry.

Deforestation:  Amazon and worldwide

Another key contributor to climate change and habitat loss is deforestation. This is extremely evident in rainforests all over the world, such as the Amazon, in Indonesia and in the Philippines. It is particularly damaging in the Amazon, which is home to over 5 million different species and produces over 20% of the world’s oxygen Since 1970, 91% of the deforested land in the Amazon is used for cattle ranching (3). Globally, animal agriculture accounts for 80% of deforestation (4), and just over 1 acre of rainforest is cleared each second (5). Now if those numbers don’t indicate that something is seriously wrong, I’m not sure what will. When the rainforest is cut down, huge amounts of CO2 that were previously locked in the trees of old growth rainforest are now released into the atmosphere as a GHG.  Furthermore deforestation reduces the ability of land in the future to absorb CO2 in the atmosphere, which is an increasing problem with our growing GHG emissions. Deforestation is not only a driver of climate change but it also contributes to species loss on a massive scale. Estimates from the UN environmental programme are that 150 species of plant and animals (including insects, reptiles, mammals etc.) go extinct each day (6). Now of course all of this isn’t happening in the rainforests, but cutting down the most bio-diverse region on our planet is certainly doing no favours.

The majority of the cleared land is not even used for the 56 billion land animals that are raised and slaughtered each year, but merely for their feed. The feed-to-food caloric flux (how many calories they produce over how much they eat) for cows is a dismal 3%, and still only 9% for pigs and 13% for chicken (7). This clearly leads to a massive misallocation of resources, so bad that livestock feed accounts for one third of all the arable land on earth (8). Imagine the increase in global food supply, if this land was instead used to grow grain, fruits, vegetables all intended for human consumption. Imagine the potential to reduce global hunger, currently estimated to affect 800 million people. Instead, money is spent on subsidies to keep these farmers turning a profit, despite the impact on our environment.

Water usage:

So why is using water bad? Several years ago, when confronted with the fact that animal agriculture uses an insane amount of water I would just say “But it’s a cycle, it’s not gone forever”. This seemed very obvious and clever at the time but unfortunately I never took the time to really research this issue or think about it in any great depth.  While indeed there is a water cycle, it is not as quick or efficient as I initially thought. Our extraction rate of freshwater is greater than the natural regeneration rate, so we must deplete our groundwater supplies. Furthermore, extraction and filtration of groundwater is energy intensive and only further promotes the use of harmful fossil fuels. There also lies an uncertainty of how long this groundwater will last, and then we truly are at the brink of disaster. Already water scarcity is an increasingly problematic issue and the growing consumption of animal products is only making this worse, especially as our own population increases.

Only 1% of the water on earth is freshwater that is accessible to us (not trapped in ice). Of this, 92% is used for agriculture with a sub-set of 29% only used for animal agriculture (9). This is primarily due to the fact that beef needs 10 times more water for a single calorie or gram of protein compared to pulses, such as beans and lentils. Cereals (grain), pulses and vegetables are more water-efficient compared to chicken, eggs and milk both in terms of calories and grams of protein (10).


Fish for some reason seem to be the hardest meat to give up. This may be due to the fact they seemingly have a smaller impact on the environment, but this is hardly the case. It is estimated that anywhere between 0.97-2.9 TRILLION wild fish are caught each year (11). At the conservative estimate, that is approximately 1,000,000,000 fish.  This number is so huge that fish catch is generally measured in metric tons, not individuals. This had led us to the stage where 52% of fish stocks are fully exploited with a further 25% being either over-exploited or even depleted (12). These numbers are incredibly high due to the inefficiency of trawler nets and food chains. Trawler nets are generally several miles long and catch anything, without any discrimination to the marine animal inside. Due to this, generally 40% of what is brought up is referred to as bycatch, which is unwanted sea life that is discarded at sea or returned to port and left to die (13). This is especially true for fish, which have the highest bycatch ratio of 4.5:1. This means for every kg of shrimp you eat, 4.5kg of fish are brought up with a net, only to be discarded back into the ocean after they’ve died. Not only does this harm native fish species, but also it is estimated that 650,000 whales, dolphins and seals are killed each year as a result of bycatch. Even worse than this is the roughly 12 million sharks captured in a similar way with these massive and destructive nets.

Now this is where you might say, “Thank god I only eat farmed fish” and give yourself a nice pat on the back. However this too is inextricably linked to the farmed fish above and other environmental issues.  Most commonly eaten fish, such as tuna, salmon, swordfish and cod, are carnivorous and must eat smaller fish. Due to this, roughly 0.45-1 trillion of caught wild fish are fed to the fish in aquacultures. In addition, farmed fish can escape and spread diseases to natural populations of surrounding fish. Not to be forgotten about, thousands of sea lions and seals are attracted to fish farms, only to be shot by farmers or die when ensnared in a net. The waste, fertilizers and antibiotics produced by aquaculture is also responsible for the loss of 20% of the world’s mangroves, which are vital for natural ecosystems and storing carbon dioxide in their roots (14). Now it may seem like farmed fish isn’t quite the “green” alternative you originally thought, and you would certainly be right.

Massive dead-zones in the oceans, where there is no plant or animal life, exist due to effluent run-off from dairy and meat farms. When toxins and fertilisers from these farms are dumped in waterways and end up in the oceans, it causes massive algal blooms. This process is called eutrophication, where the increase in nutrients from fertilisers and waste, increased algae production which in turn uses up all the oxygen in a water source, leaving surrounding animal species to die. The most well known example is in the Gulf of Mexico, where the dead zone extends over 21,000 square kilometres. This is an obvious effect when you consider that 2,500 dairy cows produce as much waste as a city of 411,000 people, and this doesn’t even begin to touch on the meat industry (15).


As my friends may tell you, I was never the biggest supporter of veganism. This manifested by getting into multiple Facebook arguments and telling vegans how wrong they were, just because I couldn’t handle my beliefs being challenged. It took a couple of years but eventually what I read was finally starting to sink in. If we can be happy and healthy without damaging our planet and causing animals to suffer unnecessarily, why shouldn’t we be? Is a brief sensation of taste truly worth the harm that we are inflicting?

Going vegan was the best choice I’ve made and undoubtedly, I live a happier, healthier and even cheaper life than before. People may say that it’s difficult or it’s expensive but this could not be further from the truth. Just compare a kg of chicken breast at the absolute cheapest of £5 to a kg of dry kidney beans (which yields 3kg of cooked beans) at £2.50. You can hopefully see that cutting meat out of your diet and replace it with beans and pulses is an extremely economic move. You can find these beans, lentils, soy milk, grains and every other staple I eat in any supermarket you go to, so it really is convenient. You can even find a vegan-ised version of any of your favourite meals, be it a pizza, burgers, spaghetti carbonara or chocolate cake.

So that might be quite a lot to take in. Frankly I would be impressed if anyone read this the whole way through; it just seems like a never-ending list of damage that is being caused by the animal agriculture industry. However there is a way to stop all this and significantly reduce your carbon footprint, your death footprint and the mark you leave on this world. As cheesy (no pun intended) this may sound, you have to be the difference you want to see in the world. This quote springs to mind “Everyone wants to change the world but no one wants to change themselves”. You can’t quite yet afford an electric car but you CAN pick up a tin of beans instead of mince, and making small steps towards a plant based diet. By doing this, others around you are more likely to be conscious of what they eat as well and together, that is a very meaningful impact on the welfare of our planet. Eating a plant-based diet is not only good for the environment, as I hope you’ve seen from above, but also good for your health and good for the animals. The real question is, what’s stopping you?


By James Ozden



(1)- http://www.fao.org/news/story/en/item/197623/icode/

(2)- https://link.springer.com/article/10.1007/s10584-014-1169-1

(3)-http://documents.worldbank.org/curated/en/758171468768828889/pdf/277150PAPER0wbwp0no1022.pdf -page 9

(4)- https://www.cbd.int/doc/speech/2007/sp-2007-05-22-es-en.pdf

(5)- https://msu.edu/~urquhart/professional/NASA-Deforestation.pdf


(7)- http://iopscience.iop.org/article/10.1088/1748-9326/11/10/105002

(8)- ftp://ftp.fao.org/docrep/fao/010/a0701e/A0701E07.pdf

(9)- http://www.sciencedirect.com/science/article/pii/S2212371713000024

(10)- http://temp.waterfootprint.org/Reports/Mekonnen-Hoekstra-2012-WaterFootprintFarmAnimalProducts.pdf

(11)- http://fishcount.org.uk/fish-count-estimates

(12)- http://www.fao.org/newsroom/common/ecg/1000505/en/stocks.pdf

(13)- http://oceana.org/sites/default/files/reports/Bycatch_Report_FINAL.pdf

(14)- http://www.reuters.com/article/us-mangroves/mangroves-under-threat-from-shrimp-farms-u-n-idUSBRE8AD1EG20121114

(15)- https://nepis.epa.gov/Exe/ZyNET.exe/901V0100.txt?ZyActionD=ZyDocument&Client=EPA&Index=2000%20Thru%202005&Docs=&Query=%28411000%29%20OR%20FNAME%3D%22901V0100.txt%22%20AND%20FNAME%3D%22901V0100.txt%22&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&UseQField=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5CZYFILES%5CINDEX%20DATA%5C00THRU05%5CTXT%5C00000011%5C901V0100.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=hpfr&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=2&SeekPage=f, page 7



(1)- http://shrinkthatfootprint.com/food-carbon-footprint-diet

(2)- http://uk.businessinsider.com/r-forests-shrink-70-percent-now-less-than-1-km-from-edge-2015-3?r=US&IR=T

(3)- http://www.wri.org/blog/2013/12/world%E2%80%99s-36-most-water-stressed-countries

(4)- https://conserveturtles.org/11537-2/

(5)- https://robertscribbler.com/2015/05/05/ocean-dead-zones-swirl-off-africa-threatening-coastlines-with-mass-fish-kills/

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