I’m late publishing this article, and just as well, because since Friday, the day I normally publish, I came across a new study that sort of muddied the waters of this topic again. It just goes to prove just how much this area of research is evolving. As always I’ll revise this article as I find new info and endeavour to make the information as easy-to-understand as possible.
I started writing this article back in 2018 when I read that reducing your meat and dairy intake is the single biggest way to reduce your impact on earth but held off completing it until I felt there was enough data, and analysis of that data to offer some reasonable guidance.
Since that first article there have been other articles calling on us to reduce meat consumption by 90% in order to avert climate crisis (2019) and advocating for less meat and dairy (2019). But is eating imported plastic-wrapped fruit & veg or dairy / meat substitutes more sustainable?
Read on to find out what we know about the environmental impact of our food choices.
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A quick note before you dive in
First and foremost, this is a generalised article about the environmental footprint of meat and dairy. It is written from the perspective of someone living in a society where most meat and dairy is purchased from butchers or supermarkets. It doesn’t take into account meat derived from wildlife culls or backyard raised chickens. Also it doesn’t take into account areas of the globe where animal husbandry might be the only food of viable food production, as might be the case for nomadic communities or societies that border deserts.
The article is based on published studies and publicly available interpretations of them. This means that there are gaps in data. There is also very little data of Irish origin so I’m having to refer to global and UK based studies in a lot of instances.
I aim to present this information as objectively as possible, highlighting any discrepancies or omissions that I might notice or read about. If you know of published academic studies or government reports that contradict information given in this article please do send them to me. I promise to update the article with new information if it’s from a credible source
This article is also not about the social value of farming nor is it about the geo-political question of where should the world’s beef or dairy be produced. This article is also not about the ethics of eating meat or the ethics of modern farming. I’m not saying that none of these are important, just that they’re intentionally excluded from this article in the interest of brevity.
This article is written for those of use who are wondering whether cutting meat and dairy will have much impact on our carbon footprint and why.
If you don’t want to read all of the supporting information you can skip down to the heading CONCLUSIONS at the bottom of the page.
The Carbon Footprint of What we Eat
The term carbon emissions used in this article is generally a short hand for greenhouse gas (GHG) emissions. GHGs are all of the gases that contribute to climate change and include carbon, methane and nitrous oxide to name a few. Sometimes you’ll see studies using the term ‘carbon dioxide equivalents – CO2eq/CO2e ‘. This is a combined figure for all the GHGs emitted by the item in question.
It is worth noting that not all GHGs behave the same. Methane is considered to be approximately 30 times more damaging in terms of climate change than carbon but it only has a lifespan of about 15-30 years, unlike carbon which can exist for hundreds of years. Livestock generate a lot of methane from burping, which contributes to the high carbon footprint of the sector. Because methane is more damaging than carbon dioxide in the short term, some argue that we should restrict all livestock as an emergency measure to give ourselves time to develop strategies to solve the climate crisis. While others argue that we should focus more on strategies to deal with the longer-lasting problem of carbon dioxide in the comfort that today’s methane emissions will be gone in 15-20 years. This article gives a measure view of this issue.
In terms of GHG emissions, the Irish agriculture sector emits nearly twice the amount of transport and more than 3 times the amount of residencies (source: EPA.ie), but it’s unclear if those figures take into account the amount of carbon captured and locked-in (sequestered) by grazed pastures in this country.
Globally, food accounts for about a quarter of human greenhouse gas emissions and of this, livestock constitutes about 56%, while only providing 37% of our protein and 18% of our calories. On average, beef and lamb production have the highest carbon footprints of all the food types, with pork having a smaller footprint and chicken smaller again. The higher footprint of beef or lamb is generally down to the amount of land they use, the time it takes to slaughter and, in the case of lamb, the amount of meat you get from each animal.
Interestingly it is possible for the lowest-emission beef (9kgCO2eq per 100g of protein) to have the same carbon footprint as chicken or eggs but only when compared to the high-impact chicken and eggs. The average carbon footprint for chicken is 4.3kgCO2eq per 100g of protein, and 3.8kgCO2eq per 100g of protein for eggs. Also, low-emission beef tends to be from dairy farms and partly due to the fact that the emissions are divided over a wider base of protein. So even though a dairy farm producing milk and meat generates the same carbon emissions as a beef farm, the very fact that its carbon footprint it being spread over more food products (milk & meat) makes the carbon footprint of those individual food products less. It’s like spreading icing on a big cake versus a small cake. If you use the same amount of icing you’ll end up with a thin layer on the big cake and a thick layer on the small cake.
If the world moved to a vegetarian diet we’d save up to 60% of carbon emissions, and if we went vegan that increases to 70% . (To be honest, I am surprised that we’d only save an additional 10% by going vegan, but we have to remember that carbon emissions don’t take into account water quality and biodiversity impact.)
But what about emissions from tillage?
It would be wrong to suggest that growing plants for human consumption is not without its issues too. Tilling the land releases carbon and the use of herbicides and pesticides are devastating to biodiversity, not to mention pollution of waterways due to inappropriately applied fertiliser. Recent studies have found that a no-till approach to farming could reduce greenhouse gas emissions from arable farming by up to 30%. And use of legumes in a crop rotation could reduce the need for fertiliser by 50% reducing carbon emissions by 43%
Actually some plant-based foods can be carbon negative, meaning the production of these foods removes more CO2eq from the atmosphere that is emitted when growing and processing them. This is particularly true for nuts because some nut trees can grown along other crops, thereby spreading the carbon footprint across more food items.
But what about grasslands offsetting emissions from grazing?
It is true that carbon emitted from grazing animals can be sequestered into the soil by the grass that the animals feed on. In 2010 the researcher Soussana found that grazed pastures in Europe absorb twice as much in terms of greenhouse gas emissions than livestock were emitting in terms of methane and nitrous oxide from fertiliser.
One global research project looked into the issue and concluded that “In some specific contexts, where the climate, soil, land use history, and grazing management are just right, additional carbon [through grazing] can be removed from the atmosphere and sequestered in soils.” But they went on to add that “realistic rates for this are far below those claimed outside of the scientific literature. And only rarely can sequestration outweigh the greenhouse gas emissions from the grazing animals.”
The authors of the study went on to say that, at a global level, the absolute largest possible sequestration potential from grazing management “offsets only 20-60% of annual average emissions from the grazing ruminant sector and makes a negligible dent on overall livestock emissions.” You can see an explanatory video of these findings here.
Another analysis by the Food Climate Research Network in 2017 confirmed this, finding that grass-fed cows released more greenhouse gas emissions through belching and manure than they are able to offset through boosting soil carbon levels.
A study into the possibility of a carbon-neutral dairy farm in Ireland is underway (Source: Agribusiness Report 2020, pg 24) and it will be great to read the results when they’re published.
What about converting methane from pig & poultry into energy?
Researchers in the Netherlands showed how methane from manure storage could be successfully oxidised in soil by methanotrophic bacteria but so far it hasn’t been explored commercially. Similarly the use of anaerobic digesters to help capture methane and convert it to energy has potential but it is not currently commonplace on farms.
Is eating locally raised meat & dairy better than imported plants?
Even though air miles have been found to have a larger climate impact than previous thought, emissions from transportation is on average only 11% of the carbon footprint of a food item, and so buying local won’t trump low-emissions when comparing food types. It’s worth noting that transport emissions increase when food is flown or trucked rather than shipped or sent by rail. So as counterintuitive as it sounds, eating food that’s been shipped from very far away could actually have lower carbon emissions than food that travels by road from the UK or Europe.
In a global study looking at imported plant-based milk versus locally sourced dairy milk, the authors concluded that even allowing for packaging and emissions from transportation, plant-based milk still have lower footprints than locally sourced dairy based milk.
Is low-carbon meat better than imported plants?
In terms of eating local meat versus imported plants this article does a very good job of outlining why eating plants is nearly always better than eating low-emission meat
But it’s worth noting that there are some exceptions. The highest-emitting tofu (3.5 kgCO2eq) puts more carbon into the atmosphere than the lowest-emitting chicken (2.4 kgCO2eq) and high-emissions nuts (2.4 kgCO2eq) can have a carbon footprint on a par with low-emission chicken.
But in general plant based foods are generally lower in emissions than meat and dairy and when it comes to beef that difference is substantial.
It’s worth noting that low-emission meat typically means higher-density and younger slaughter ages. Because of the additional land use involved in raising free-range and organic chicken, meat from these sources will have a higher carbon footprint than intensively raised chicken so organically or free range raised meat wouldn’t be classed as low-emission.
Is packaged-free meat & dairy better than packaged plants?
In a similar way to transportation, packaging only adds a small percentage onto the carbon footprint of a food item. For example a carton only adds an additional 5% onto the carbon footprint of milk, and plastic packaging only adds a further 4% to the carbon footprint of pork.
Is eating locally-raised meat better than lab-grown meat / meat substitutes?
Interesting lab-grown meat was found to have a higher carbon footprint than chicken, and myco-protein based products (aka Quorn) were found to have a similar carbon footprint to chicken, but in comparison to beef meat alternatives have a dramatically lower carbon footprint.
It’s worth noting that the comparison to chicken mentioned above is most likely to have been for intensively reared chicken as there was no reference to free-range or organic in the study. Therefore it is reasonable to conclude that the meat-free alternatives could have a lower carbon footprint than free-range and organic chicken.
Here are two very interesting comparisons between Beyond Burger and beef and between Quorn and beef. They’re written by an Irish research scientist working in the University of California, Berkley in the US. In summary, they both beat beef in relation to emissions, land use and water use.
Another useful article by the same writer is this one on the sustainability of tofu, although written from a US perspective the author has family in Ireland and so gives some advice to readers on this side of the pond too.
Food also Impact Wildlife
The carbon cost of land is already factored into the carbon emissions of a food type but there is another impact of using land and that’s the displacement of wildlife.
Of the world’s approximately five billion hectares (12 billion acres) of agricultural land, 68% is used for livestock with one-third of that used for crops dedicated to producing food to feed to livestock.
If we all went vegan, one study estimates that we could reduce the land used by agriculture by 75%. For example, if strawberries were grown on 1/100th of the cropland currently used to grow animal feed we could provide 1.9 million adults their 5 a day for an entire year. And if one third of cropland currently used to grow animal feed was assigned to fruit or veg it could provide 62 million adults their 5 a day for an entire year – almost the entire UK population.
Does Soy-based Meat Alternatives cause Deforestation of the Rainforest?
You may have heard the argument that soy-based food products are causing deforestation of the rainforest in South America. Deforestation of the rain forests is being caused by soy plantations and some of that soy is being grown for human consumption, but it is worth noting that only 7% of soy grown is used in human food and that most of that goes to Asia. This is primarily because South America tends to grow GM crops, which is not attractive to European customers and so most of the soy we eat in Ireland is sourced in Europe.
In Ireland we import two thirds of fodder for livestock, a large percentage of which is soya bean, almost certainly from the USA, Argentina and Brazil (source: Irish Examiner).
Industrial Livestock Farming causes Water Pollution
In the UK, grasslands are the main user of nitrogen, with 425 kilotonnes applied in 2015. Permanent grassland used 73% of this amount. A global switch to plant-based food systems has been estimated to reduce
eutrophication by 49%.
In Ireland the weedkiller Glysophate has been detected in the water in Co Mayo. It’s not clear if this entered the water system from farms but this report suggests that quite a few farmers have been fined for failing to comply with restrictions regarding the application of chemicals to land.
Sometimes the waste from pigs and poultry is applied to the soil as a form of fertiliser but it can contain high doses of copper and zinc, which the pigs are fed to promote growth. Also if the waste is too high in nitrogen and potassium it can overload the soil leading to water pollution and the degradation of the soil. (Source: fao.org).
Industrial Farming threatens Biodiversity
The farming of animals is listed as the main threat to biodiversity on a global level with 94% of the mammals on the planet (excluding humans) being livestock. In Ireland in 2017 there were 6,673,600 cattle, which is approximately 1.4 cows for every person on the island.
Some suggest that grazing animals are important from the point of view of biodiversity, and I’ve seen a report from Natural England citing the importance of grazing animals for wildlife conservation cited frequently as evidence of this. I think it’s quite a point worth considering and investigating, and I’d be very interested to see how these grazed landscapes compare to other types of landscape. Interestingly the same report is very negative against scrub, which if you read/listen to Isabell Tree’s fabulous book ‘Wilding‘ you’ll learn is essential for the development of tree saplings, which ultimately go on to become forests. Finally the authors of the report cite over-grazing as one of the most devastating hazards to wildlife conservation, so as is often the case, it’s not always what is done but how it’s done.
Industrial Farming threaten our Health
Industrial Livestock Farming causes Air Pollution
Another concern with intensively reared pigs and poultry, is the amount of ammonia the process creates. In research coordinated by Greenpeace it was found that the majority of ammonia pollution (94%) stems from livestock farming and in 2015 the EU agricultural sector emitted a total of 3.75m tonnes of the stuff. Ammonia can affect air quality, worsening the impact of fine particulate matter (Source: Poultry World). Just to put this in context ongoing exposure to fine particular matter has been linked to premature death in people with heart or lung disease, nonfatal heart attacks, irregular heartbeat, aggravated asthma, decreased lung function and increased respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing (Source: EPA.gov). Interesting only farms raising more than 40,000 chickens, 2,000 pigs or 750 sows are required to submit data to the register so ammonia emission are in fact higher than reported in the European Pollutant Release and Transfer Register (E-PRTR) (Source: Poultry World)
Overuse of Antibiotics in Livestock Farming
Farmed animals are a major use of antibiotics, and there is evidence that overuse of antibiotics in animal rearing farms is contributing to the development of antibiotic resistant super bugs, contributing to antibiotic resistance in humans, which is a growing issue globally and regarded by the World Health Organisation as one of the biggest threats to public health.
That said Ireland has amongst the lowest use of antibiotics use in Europe. and if an animal is raised organically they can only be given pharmaceuticals, including antibiotics, as a last resort and the farmer must wait a specified amount of time before the animal can be sent for slaughter as an organic animal. Also if the treatment is used for a second time the product (meat or milk) cannot be sold as organic (Source: organicmeat.ie)
The Impacts of Eating Meating on the body
Sometimes concerns over health prevent people from reducing their meat and dairy intake. This is despite numerous reports showing how a vegetarian and vegan diet can protect us from many diseases.
“It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes.”
Also according to the NHS, you can get most of the nutrients you need from eating a varied and balanced vegan diet and research in 2019 confirmed that a vegetarian or vegan diet can provide enough protein and amino acids for older people too.
Indeed a shift away from meat and dairy wouldn’t just positively impact our health, it would also impact our wallets. According to a study in 2016 a global shift to plant-based diets is capable of reducing health care costs by $31 trillion. The study also showed that, should everyone go vegetarian by 2050, we would see a global mortality reduction of 6-10%, thanks to a lessening of coronary heart disease, diabetes, stroke and some cancers. Eliminating red meat accounts for half of that decline, while the remaining benefits are thanks to scaling back the number of calories people consume and increasing the amount of fruit and vegetables they eat. A worldwide vegan diet would further amplify these benefits: global vegetarianism would stave off about 7 million deaths per year, while total veganism would knock that estimate up to 8 million. Fewer people suffering from food-related chronic illnesses would also mean a reduction in medical bills, saving about 2-3% of global gross domestic product.
Of course there is devil in the detail. It is quite possible to become an unhealthy vegetarian or vegan by filling your diet with high-salt and high-sugar processed foods. In the same way that it’s possible to have a healthy meat and dairy based diet by eating small quantities of fresh, local, organic produce.
Industrial Farming is Linked to a Rise in Pandemics
Researchers have established that ‘since 1940, agricultural drivers were associated with more than 25% of all – and more than 50% of zoonotic (animal based) – infectious diseases that emerged in humans, proportions that will likely increase as agriculture expands and intensifies.‘
Which is healthier, veganism, vegetarianism re low meat / dairy consumption?
In their Planet Healthy Diet the EAT- Lancet commission, a mix of 27 experts from farming to climate change to nutrition stated that we needed to reduce red meat down to one burger a week or one steak a month in order to feed 10 billion people by 2050 without destroying the planet. They do include a couple of portions of fish and chicken a week, 1.5 eggs a week and 1 glass of milk a day. Their proposal also included a cull on starchy veg like potatoes and cassava, but this was more for health reasons than environmental.
Asked why they didn’t simple promote a vegan diet, Prof Willet stated “If we were just minimising greenhouse gases we’d say everyone be vegan, however, it was unclear whether a vegan diet was the healthiest option”
This appears to be corroborated by the new study on influencing factors on low-impact diets that I referred to above. They found that eating meat could make a diet more sustainable than a poor plant-based diet but only in the absence of nutritional supplements. Once supplements were added into the mix the plant-based diet had the lowest-impact again.
If you’re a big fan of cheese and have switched to vegan cheese you may find this article useful, as it talks about the low nutritional value of some vegan cheeses.
Interestingly another study found that reducing all animal based products reduced carbon emissions more than going vegetarian, which typically results in an increase in eggs and dairy. This is particularly interesting if you’re female as a study found that women eating a vegetarian diet are 33% more likely to have a hip fracture.
Is there a risk of Cancer from Soy-based products
There has been some scaremongering in relation to a link between soy and cancer so here are some articles refuting the link from
- Harvard University
- Academic publication The Conversation
- a medical doctor in the US
- a non-commercial, science-based public service provided by Dr. Michael Greger,
And here’s another article that talks about the myth of soy ‘feminising’ men
Can we make Meat and Dairy more sustainable?
There is huge pressure to make the way we farm more sustainable and farmers across the globe are trying new ways to reduce carbon emissions and boost biodiversity. I have no doubt that our farming community has the skill and ambition to make farming in Ireland as sustainable and low-impact as policy allows them to.
At this point I should mention that all of the carbon footprints quoted in the studies I cite don’t take into account the carbon that might be sequestered in the grass being grazed by livestock, or the soil in which fodder was grown in. Some argue that this gives a distorted view of the environmental impact of meat and dairy, but it depends on how you frame your enquiry. The data also doesn’t include the amount of carbon sequestered by the soil used to grow plant-based food for human consumption. It also doesn’t include the carbon we’re forgoing by not converting these fields to forest or bogs.
It’s worth bearing in mind that some of the reduced carbon emissions in the meat and dairy industry is achieved through higher density and younger slaughter ages (Source: Agribusiness Report 2020, pg 16). Considering that currently most cattle are killed for meat between 16 and 24 months, pigs are slaughtered as adolescents (Source: independent.ie) and chicken in a conventional broiler chicken farm lives for 38 days before being sent to slaughter, we may want to pause and consider that before driving for lower carbon emissions achieved this way.
For me, making meat and dairy farming more sustainable, carbon-neutral even, still leaves the question of whether this form of farming is a good use of our carbon allowance, given that we can provide the nutrition in less damaging ways.
Even if meat and dairy production can be made more sustainable we cannot continue to eat it at current rates. Indeed the IDDRI, an environmental think tank, concurred with the Lancet Commission when it stated that it is possible to feed Europe’s population and farm sustainably, but only with a 40% decrease in the consumption.
Conclusion – How to eat more sustainably!
Reduce your meat and diary intake
According to the Food Carbon Footprint Index 2018, which bases their data on the Food and Agriculture Organization (FAO) of the United Nations Balance Sheets, on average someone in Ireland eats the equivalent of 1428 kgCO2eq per annum. This equates to a one-way flight to Turkey or 3,590 miles in a car. To sequester that amount of carbon we’d need 10 years of growth from 23 saplings*.
It’s worth highlighting that we wouldn’t save 1428 kgCO2eq by giving up meat and dairy, after all we’d have to replace them with other food products, but according to an Oxford University study in 2018 we could save between 61-73% of the carbon by switching to an exclusive plant-based diet.
Other types of diets such as vegetarian or pescetarian also offer carbon savings but none as much as a vegan diet. This article gives an overview of the global carbon savings of various diets.
Take supplements if you need them
If you’re concerned about nutrition get your bloods tested and take supplements for the vitamins and minerals you’re short of.
Prioritise locally-grown seasonal fruit and vegetables
This is a no-brainer when it comes to sustainable eating but with only 1% of Irish farms growing vegetables in 2016, there is potential for growth in this sector.
Aim to buy locally grown crops that need as little intervention as possible. Potatoes in Ireland need to be sprayed regularly to keep blight at bay and the same is true of strawberries, which are susceptible to botrytis. Apart from the health benefits of avoiding synthetic chemicals where possible you’ll also be saving on the carbon emissions created by the chemicals and the spraying process.
Interestingly a new study looking at how country, season, sex, dietary supplements, and other details affect low-impact diets found that what might constitute a low-impact diet in one country might be a high-impact diet for another (Source: Antropocene Magazine). The article that I’ve linked to there gives a very good, easy-to-read, explanation of why this might be the case. The academic team behind this study are aiming to create a tool for people to determine which diet is more sustainable for them given their location etc.
Prioritise organic food
I would suggest that eating organic is more sustainable than non-organic but studies have shown that organic farms have a lower yield than non-organic. That said, proponents of organic say that once the soil on an organic farm has had time to rejuvenate itself the yield difference will be negligible.
I think it’s important that we assess the long-term impact of any strategy to make sure we’re not creating more issues for ourselves down the road.
Replace meat junk food with vegan alternatives
Processed meat substitutes can be quite high in salt and fat so do limit your intake of them but if you’re going to eat junk food on occasion it makes sense to make it vegan. And seriously vegan sausage rolls are just as good as meat based ones
Buy Meat Protein that Swims
If you feel you must have non-plant protein in you diet opt for sustainably sourced fish.
Buy Irish Meat & Dairy
If you really want to buy some beef, lamb, pork or chicken make sure it’s Irish. It generates the same or less carbon emissions as meat from other countries but you get to save on transport emissions by buying local.
If you’re interested in reading more about this here’s a link to a good database of research in the area of food.
Thanks for Reading
*I’ve taken the carbon emission figures from Our World in Data, which takes theirs from a 2018 global study looking at carbon emissions for various forms of food production. I’d love to have some specifically Irish figures to put in here instead but despite all my research I haven’t found any.