The chances are that if you are concerned about the climate crisis, you’ll have heard that a plant-based diet is one of the most effective actions we can take as individuals to reduce our carbon footprint.
But just how much environmental damage is caused by animal agriculture? And are our individual actions significant anyway?
This article is for all people who are worried about global heating. More and more of us can call ourselves climate advocates and activists. Perhaps you try to speak up about the crisis and ask governments and corporations to ensure a safe earth for today’s generations and ones to come. Maybe you are taking action in your own life to reduce your environmental impact.
Changing the way we eat is crucial in responding to the climate crisis.
This is good news.
Discussion of the climate crisis can lead to fear, confusion and even despair. But when we see how massive a role animal agriculture has in the problem, and that it’s possible to live much better without it, we have a chance to feel strengthened and empowered in our work towards healing the relationship between humans and the natural world.
In this long-form article you’ll find information about the impacts of the animal industrial complex on our climate, and how and why a plant-based diet is such a positive choice for nature, society and individuals.
The impact of animal agriculture on climate change
Recent studies have shown that adopting a vegan diet is one of the best things we can do to tackle the climate crisis, because animal agriculture is a leading cause of climate change.
There are four main reasons for its impact:
1. Emissions of extra-potent greenhouse gasses, methane and nitrous oxide, caused by animal agriculture
2. Changes in land use required by animal agriculture, especially deforestation
3. Inefficiency of animal agriculture as a way of supplying people with food
4. The scale of animal agriculture today
The best known figures on the climate impact of eating meat and dairy come from the 2006 report by the Food and Agriculture Organization (FAO) of the UN, which estimates that animal agriculture accounts for 18% of annual CO2e (carbon dioxide equivalent) emissions,¹ and the 2009 report by the World Watch Institute, which put that figure at 51%. The discrepancy between the two can be explained by the different ways they calculate methane’s knock-out global warming impact, and how they account for the cumulative effects of deforestation and land use change.
One thing is clear: climate advocates should take diet choices very seriously.
83.5% of the greenhouse gas (GHG) emissions of the average American diet come from animal foods (meat, fish, eggs and dairy).
Changing the way we eat is a radical action towards healing our planet.
Just how radical can be seen when we cast some light onto these four factors: methane, deforestation, inefficiency, and the scale of animal agriculture.
1. Super GHGs and rapid climate change
Methane and nitrous oxide have a devastating impact on global heating in the short term. Methane heats the atmosphere 34 times more than CO2 over a century, but it is 86 times more powerful over 20 years. The higher short-term effect is because it breaks down in the atmosphere faster than CO2.
Climate advocates understand that short-term impacts are important for our rapidly changing atmosphere, yet the intense short-term heating effect of methane is missed in calculations which use a standard comparison of global warming potential over 100 years.
Methane is powerful, and nitrous oxide even more so. Nitrous oxide traps heat nearly 300 times more than CO2 over a century.
The urgency of our situation is well understood. We must act quickly to prevent runaway climate breakdown. Dramatically cutting emissions of methane and nitrous oxide would have a major immediate effect.
Animal agriculture is a massive source of anthropogenic nitrous oxide and methane emissions: at 65 % and around 35–40% respectively.
In other words, it is easy to cut emissions of these super GHGs dramatically and immediately, and begin the urgent work of repairing our rapidly overheating climate.
We only have to change our diets.
Gretha Thunberg has inspired millions with her words: ‘Our house is on fire… I want you to panic.’ It’s rhetoric, but based on science. The IPCC made clear in 2018 that global warming must not rise above 1.5C, because at 2C, there are severe risks in terms of real human suffering: hunger, drought, homelessness, conflict, disease.
Over the past decade in which I’ve been a climate advocate I’ve heard a lot of discussion but our GHG emissions have continued to rise. Ten years ago CO2 was at 387ppm in the atmosphere. It is now at 407.4 ppm. Our current trajectory takes us quickly into very dangerous territory and there is no sign of slowing. For all our talk of the crisis, GHG emissions are rising.
I’m going to assume that you are already convinced there is a climate crisis. What I’m asking is that you consider the enormous immediate effect of shifting to a plant-based diet and cutting out all those unnecessary methane and nitrous oxide emissions.
This change alone would buy us desperately needed time in finding solutions to wider energy problems.
2. Deforestation, land use and climate solutions
A staggering 83% of the world’s agricultural land is used for animal farming, delivering an unimpressive 18% of our calories. While some of that land is pastureland, in fact 59% of all crop-growing land is used to produce food for livestock.
This is why animal agriculture is the leading cause of deforestation. Over 80% of deforestation of the species-rich, oxygen-pumping Amazon rainforest is for cattle ranching and soy production.
Over 90% of soy is fed to farmed animals around the world (not just cows, also chickens, pigs and even fish). Climate activists are likely to worry that eating soy in a vegan diet contributes to deforestation, especially to the destruction of the rainforest. However, since most soy crops are fed to livestock this worry is misplaced. Choosing a plant-based diet slashes the demand for soy.
In terms of climate change, how bad is deforestation? First of all, it causes immediate, large-scale greenhouse gas emissions: at least 15% of annual global GHG emissions are caused by deforestation. Secondly, there is a long-term, cumulative impact, as year-on-year those lost trees would have been pulling carbon out of the air and returning it to the soil.
While engineers research money-making carbon capture technologies, we already have them: trees and healthy soil.
Restoring forests, wetlands and other natural habitats would greatly mitigate our GHG emissions. It could even make it possible to stabilise the climate at below 2C of warming and meet the targets of the Paris Climate Agreement.
This would be an extraordinary gift to the world, reversing ecological breakdown, and at the same time beginning to heal the damage we have inflicted on the atmosphere and climate.
3. The inefficiency of animal agriculture
Why does animal agriculture require so much land and cause vast amounts of deforestation?
Essentially, because it’s inefficient.
To produce one calorie of meat and dairy food takes ten calories of plant food.²
This is because cows, pigs, sheep and chickens have to use up energy for normal life processes and growth. They ‘waste’ most of the energy from their food. Animal foods are an insanely wasteful way for humans to feed themselves.
Have you ever worried about food waste, and how much food you or your shops are throwing away? Eating one serving of animal food is equivalent to throwing nine plates of nutritious plant food in the trash.
Animals don’t even provide protein efficiently. According to Mike Berners-Lee, ‘The world’s farmed animals destroy nearly three quarters of the protein that they eat, most of which comes in the form of human-edible food.’ (There’s No Planet B, p. 17)
Berners-Lee’s calculations show that ‘Animals contribute 590 kcal to the human food chain (daily). BUT they eat 1740 kcal per person per day of human-edible food as well as 3810 kcal of grass and pasture.’ Lisa Kemmerer tells us that 70% of US grain is fed to livestock.³ That grain took energy to produce, and adds to meat and dairy’s carbon footprint.
A plant-based diet would release 76% of current agricultural land. This land could be rewilded, reforested and restore biodiverse ecosystems. With healthy soil, it would then act as a carbon sink.
As well as land, animal agriculture requires water, and that water costs energy to source, transport and sanitise. One gram of beef protein takes 112 litres of water. One gram of protein from pulses takes just 19 litres. Multiply these numbers up by the number of grams of protein the human body needs (around a gram per day for each kilo of body weight) and the number of people in the world (over 7.5 billion), and we can see that consuming protein in the form of meat is devastating for diminishing fresh water reserves.
4. Animal farm Earth
Another reason why animal agriculture is so destructive to the climate is that the livestock industry today is enormous. To realise quite how big its impact is, we need to acknowledge its scale.
· Over 70 billion land animals are consumed each year. An estimated three trillion fish are consumed each year.
· Calculated by biomass a staggering 96% of mammals on earth today are domesticated mammals (around 60%) and humans (around 36%). Just 4% of mammals are wild.
· Poultry make up 70% of birds on the planet today.
These numbers are just phenomenal. They are the result of exponential growth: the human population grows, and the demand for animal foods from each individual increases, so the number of farmed animals just grows and grows, each increase ballooning from the previous ones.
In his recent book, We Are the Weather, Jonathan Safran-Foer takes a realistic measure of the situation and concludes:
Our planet is an animal farm.
We might think of the climate crisis as an industrial one, a problem of factories and fossil fuel companies. This underestimates how much of our planet is now dedicated to the industrial-scale production of animals for humans to eat, and the massive impacts that follow.
We have seen this food source is inefficient and massively polluting. It also directly causes suffering. When we speak of animal agriculture, it’s important to remember what we’re discussing. It isn’t like aviation or solar panels, which are technologies concerned with objects. Animal agriculture is concerned with sentient beings, animals as we humans are animals, and each one of these billions is an individual, with desires and the potential to experience pleasure and pain. Their lives in our factory farms are full of suffering.⁴
Most of us have better ways to feed ourselves.
Do individual actions count?
By now it’s surely clear: animal agriculture is a problem on an enormous scale. So do our choices as individuals have any meaning, faced with this behemoth?
Climate advocates are familiar with similar arguments about individual responsibility: our personal actions are so small and limited by the system that it makes more sense to campaign for big scale actions by governments and corporations than to waste mental energy worrying about how often to shower.
However, our personal choices are significant. If we want to achieve net zero carbon emissions, we have to imagine and build a world in which that’s possible.
Our combined actions create the momentum towards turning our civilisations away from crisis.
Some actions are very difficult. Transportation, for example, is a tricky problem to solve for many of us. It is nearly impossible to achieve a zero-carbon lifestyle, and campaigners are justified in calling for systematic change. We need green new deals and international agreements to leave fossil fuels in the ground.
But if we want change, we have to act. Our food system has to change if we are to end anthropogenic GHG emissions. We can commit to that change right now by choosing a plant-based diet.
This choice reduces our individual carbon footprint, and sends a direct message that we want change. It’s a choice we make about three times a day. That means every time we buy food, every time we eat and drink, we are taking action and sending a message.
Choosing a plant-based diet is empowering.
Think about some of the other big impact actions an individual can do, like not flying, or having fewer children. These are not daily actions. They may not even be possible for some of us, and may be a very serious sacrifice for others. By contrast, a plant-based diet is accessible to most people.
It is something you act upon many times a day, and the effect of a repeated action is especially powerful. Each time you eat and drink you are performing a certain identity: maybe that is an identity as a climate activist, or as a vegan. You remember who you are and what you value.
When we put food on our plates, we can create carbon impacts like this:
Pounds of CO2e per serving:
Beef: 6.61
Cheese: 2.45
Pork: 1.72
Poultry: 1.26
Eggs: 0.89
Milk: 0.72
Or like this:
Pounds of CO2e per serving:
Rice: 0.16
Legumes: 0.11
Carrots: 0.07
Potatoes: 0.03
Those are big differences.
Many of us assume that local food equals a lower carbon footprint. This isn’t necessarily true. In There is No Planet B, Mike Berners-Lee explains that local hothouse strawberries can require more energy than bananas brought over the ocean by container ships. Air transport has a significant carbon footprint. However, food transported by shipping does not necessarily have a big carbon footprint, and there can be energy savings when it is grown in the most appropriate climate and season.
Many European animals — cows, chickens, pigs and fish — are fed on soya shipped from Brazil. The UK, for example, gets at least a third of its soy for feeding farmed animals from Brazil. In 2018 only 14% of soya imported to the UK was certified deforestation-free.
Because of the feed issues, it is questionable whether a locally slaughtered chicken is local food.
The facts remain: the massive carbon footprint of animal foods dwarves that of a plant-based diet.
The no-steak stakes
While a climate advocate does not have to be vegan to qualify as an environmentalist, switching to a plant-based diet is a powerful way of acting for our world. It has direct environmental benefits, and it sends a strong message about the kind of society we wish to build.
And we do have to change. We cannot protect the climate and life on earth without ending our civilisation’s addiction to animal foods fast.
Within the climate movement some have called for mobilisation on the scale of the allies’ efforts for the Second World War, on the home front and on the battlefield. Slashing consumption of animal products is part of that mobilisation. Why wait another day?
For guidance, try signing up to a vegan challenge that can support you through the first days of switching to a plant-based diet. Challenge 22 does this well, and gives participants access to advice from dieticians and company from others making the same decision. Veganuary is also a useful source of information and guidance.
Vegans are often criticised for pushing their agenda too aggressively. I admit I do have an agenda. I want us to choose a world with less suffering, more compassion, and hope for a safe climate. I want my children’s future to have wild animals in it, and forests, and a living ocean.
We eat several times a day. Each time can be a loving act towards our world and our bodies.
Plant-based eating will bring about a cleaner, kinder, healthier way of living, with more space for wildlife, enough food for humans, and a safer climate. We and our world are worth that.
References
References are provided throughout by hyperlink. Please note, I have tried to provide references for the information given here, but I am not responsible for the content of the linked sites, and citation does not equal endorsement.
1. The FAO later revised the 18% figure down to 14.5%, given in their 2013 report, here.
2. The 1 to 10 statistic is given here: Mike Berners-Lee, There is No Planet B: A Handbook for the Make or Break Years (Cambridge University Press, 2019), p. 17. For more on Feed-to-Food ratios, see here, here and here.
3. Lisa Kemmerer, Eating Earth: Environmental Ethics and Dietary Choice (Oxford University Press, 2015), p. 8
4. If you wish to learn more, the movie Dominion shows footage from farms, and the Compassion in World Farming site explains current farming practices. Please be aware that these links contain disturbing footage.
