Welcome to the first week of Carbon Neutral Lent! The pancakes are gone, which means the time has come for spreadsheets. This week we will be looking at the messy and complicated topic of the carbon footprint of food. Don’t forget to head over to the CNL landing page to download the tracker spreadsheet which will allow you to estimate your carbon ‘foodprint’ at the end of each week by asking you one simple question! Also, come on down to our event in the Landmark pub in Dublin on the 3rd of March, where CNL founder Darragh Wynne will be joined by a variety of guests to talk about the carbon footprint of food. Come for the information, stay for the music!

Ireland’s carbon footprint is an unusual one. At 34% of the total national emissions, agriculture has a greater impact on our emissions profile than any other European country. For comparison, waste (which includes the footprint of all our plastic) is responsible for just 1.5% of our emissions. Even so, it seems like businesses and well-meaning citizens are far more concerned with ditching plastic straws than they are with reducing the footprint of the foods that we eat.

Our unusually high agricultural footprint is not, however, necessarily a result of our eating habits. It is because we make our money producing extremely high-carbon foods and then exporting them to other countries. To be precise, it is because we produce a whole lot of beef and dairy. Dairy cow numbers increased in Ireland by 27% between 2013 and 2018, in large part due to the removal of the milk quota in 2015.

This goes to show that the types of food we grow and eat can have a massive effect on our emissions. A kilogram of locally grown, in season carrots comes in at 0.25 kgs of CO2e (carbon dioxide equivalent). The same weight of beef is a whopping 17kg CO2e. In other words, pound for pound, beef produces 68 times more carbon than locally grown carrots.

Of course, the comparison is not so simple as this. A kilogram of beef contains about 5 times more calories and about 25 times more protein than a kilogram of carrots. Still, 5 times the calories for 68 times the carbon is a monster trade-off. Getting 1 calorie from beef produces around 14 times more carbon than one calorie from a carrot. Plus, carrots contain far more fiber and carbohydrates and far less fat than beef.

As for protein, how much you need depends on how much you weigh and how active you are. The rule for a sedentary person is that you need 0.8 grams of protein per kilogram of body weight per day. As a 70 kilo man, I would need 56 grams of protein per day. Conveniently, that is exactly the average recommended intake for a sedentary man. That’s about 3.2 Tesco beef burgers of 84 grams each.

Alternatively, you could get that protein from non-animal sources for a fraction of the carbon price. Quorn burgers, for example, contain 18g of protein per hundred grams. In other words, I’d need 3.7 Quorn burgers of 84 grams each to get my daily dose of protein. What’s more, the carbon footprint would be reduced by 90%!

Quorn is far from being the only low-carbon source of protein. We get protein from almost everything we eat. 100 grams of chickpeas, for example will give you 20 grams of protein. Soybeans are also a great source, with 100 grams containing 16.6 grams of protein.  It is easy to see how, over the course of a day, we can take in as much protein as we need without the help of meat.

It is important to note, however, that the recommended protein intake for someone who partakes in a strenuous physical activity like weight lifting or endurance running is considerably higher. Nearly twice as high, in fact, with strength and endurance athletes recommended to take in 1.2 to 1.7 grams of protein per kilogram of body weight per day. If I were to spend all day in the gym, then, I would need 119 grams of protein per day. For active people such as this, protein shakes can provide the rest of the daily protein that you are not getting from food. Plus, there are vegan options available!

That brings us nicely to the question of how much better veganism is for the environment than vegetarianism. One study found that you can cut 1.82 kilograms of CO2e per day by switching from a medium-meat diet to a vegetarian one. The same study found that switching from a vegetarian to a vegan diet would save nearly a kilogram more carbon per day. In other words, going vegan is a fair bit better for emissions.

Cheese is the third highest-emissions food after beef and lamb. That’s right, a kilo of cheese produces more emissions than a kilo of pork or chicken, although it must be said that cheese is usually eaten in much smaller quantities. Vegan food also uses less land and water to produce than eggs and dairy, further reducing a vegan’s impact on the environment. Whether or not food comes from animals is perhaps the best indicator of how high-carbon it will be. If you hadn’t guessed, animal products are almost always worse. But why is meat so bad for the environment?

The simple answer is that growing crops and eating them is a far more efficient process than raising animals for food. That is because you have to grow a lot of crops to feed to the animals while they grow big enough for slaughter. It uses much less land and water and produces far fewer emissions to cut out the middleman and go straight to the source of the nutrition; the plants.

Plants build their bodies using carbon they take from the air, water they take from the ground and energy they take from the sun. They don’t need to move, digest food, pump blood around their bodies or keep themselves warm and that saves them a lot of energy.

Animals, on the other hand, burn up most of the energy they take in from plants by walking around, breathing and keeping warm. If you feed a cow 100 calories in the form of grain, only 3% of those calories will be returned in the meat. That means that you have to feed them a whole lot more over their lifetime than you will get back in the end.

In the case of ‘ruminant’ animals like cattle and sheep, there is the added problem of methane. Ruminants are hoofed mammals that have a 4-chambered stomach, one of which is called the rumen. Microbes break down the ruminant’s food in a process known as ‘enteric fermentation’, which produces a lot of methane. To be precise, it produces 30% of all anthropogenic methane emissions.

Water use is another major consideration, with a 2003 study finding that “Producing 1 kg of animal protein requires about 100 times more water than producing 1 kg of grain protein”. I worked out for a previous article that eating a pound of beef wastes about as much water as leaving your shower on for about 15 hours.

Eating plants is not just low-carbon. It is also gives a much higher yield per hectare than producing meat. In a much-cited study from 2013, Emily Cassidy et al. found that “given the current mix of crop uses, growing food exclusively for direct human consumption could, in principle, increase available food calories by as much as 70%, which could feed an additional 4 billion people”.

In other words, if it were not for the fact that we waste plant nutrition by feeding it to livestock, the population could grow to 10 billion by 2050 (as projected) and we could still feed every person on earth with ease. According to the same study, “36% of the calories produced by the world’s crops are being used for animal feed, and only 12% of those feed calories ultimately contribute to the human diet”. That is a huge amount of waste considering how many people do not have enough to eat.

That brings us very neatly to the incredibly important topic of food waste. In Ireland, over a million tonnes of food are wasted each year. The excellent Climate Queens podcast figured out that that’s enough to fill Croke Park with food waste twice each year. Globally, one third of all food produced goes to waste. That is more than enough to feed the roughly 11% of people in the world who are chronically malnourished.

If food waste were a country, it would have the third highest emissions of any country on earth after the US and China. That is because approximately 10% of all carbon emissions globally come from food waste, costing the world about €550 billion per year.

Food waste is a win-win area in which we can both seriously cut emissions and increase the total food available for consumption. Try keeping a journal of which foods you are throwing out. If you find that you are regularly throwing out half a tub of coleslaw, for example, you can start buying a smaller tub. It really is that simple!

There is so much more we could say about the carbon footprint of food. I haven’t even touched on the emissions from fertilizers, how different types of feed affect the emissions profile of livestock or the very important topic of animal cruelty in agriculture.

If you take two things away from this piece, however, let them be that
a) you should cut down on meat and dairy as much as possible and
b) you should eat the food that you buy.

If we all made these two simple rules a priority when it comes to which food we choose to buy, we could massively cut emissions of CO2, methane and nitrous oxide. In the process, we would also increase the land available for crop production, forests, wetlands and renewable energy projects. Plus, we would save a whole lot of money and water.

What are you waiting for?