Starting this year, the university canteens proudly sell vegan food, because it is supposedly the most sustainably-produced nutrition. But how do we know?
Being an animal lover in a world full of cruelty to animals is unrewarding. Most of humanity does not seem particularly concerned about the distress of people who are slightly different, let alone creatures that are not human. So, in recent years, evangelising vegans have decided to focus more on climate: the Earth is where people keep their stuff and their grandchildren – even if they don’t want to protect little piggies, perhaps they’ll help save the planet.
Accordingly, a few weeks ago, the canteens at Leiden University introduced more plant-based food, following a discussion in Mare and an Internet petition demanding this move. Large signs at the entrances report that it’s “the most sustainable type of food”. It seems a bit suspicious to a meat-eater. Most vegans would be vegan anyway, even if it wasn’t better for our climate. Who decides what’s sustainable or not, anyway? And how?
To answer that question, we need a large book rather than a one-page article: a book that would tell you about various agricultural techniques and the extent to which they stimulate, or prevent, micro-organisms storing carbon in the soil, the differences between the CO2 footprints of oysters and mussels, what a healthy diet should contain, the differences between all the ways you can calculate these things, and hundreds of other aspects. Due to the available space, Mare will be brief.
The shortest answer to whether the herbivores are right: yep.
The longer version: Yes, but ...
Before you can make any assertions about the environmental impact of nappies, steaks, diesel-rigging scandals or anything else, you need to do lots of maths. Leiden’s Institute for Environmental Sciences (CML) does them. In fact, they once invented a certain method called the Life Cycle Assessment.
“You examine a product and add up all the environmental effects involved in its entire life cycle, from mining raw materials to when it starts to be recycled, if it is recycled,” explains Paul Behrens, a researcher at CML. Meat has a long, complicated chain: the mine where phosphate is produced for fertiliser, the rubber needed for tractor tyres, electricity for refrigeration, heating sheds, etc.
Actually, Behrens, who calculates the environmental impact of our food and our energy consumption, uses a slightly different system. He works with an “input/output” approach: you consider an industry’s total emission and then estimate that industry’s contribution to a certain product. “The two methods complement each other: one is bottom up while the other is top down.’
So, you can’t get life-cycle figures by testing; you can only calculate them as best you can. There are choices to be made too: if a cow gives milk and then is ground into mince, which part of the environmental impact should be attributed to milk, which to the meat and which to the shoes made from the leather?
The choices affect the figures produced by the calculations, so the results can vary quite a bit. However, if you compare them all, patterns do emerge. A product’s environmental impact is practically always much larger than that of the packaging it comes in, or that of its transportation – especially if it was transported by a large container carrier. Plastic foil around a cucumber is, on balance, better for the environment because fewer cucumbers rot. Butter from New Zealand sold in English supermarkets is better for the climate than butter from England, because the average temperature in New Zealand is slightly higher, so the farmers need less heating in the cowsheds. The transportation of butter produces emissions, but fewer than the heating.
The consequences of a product for our planet do not merely consist of greenhouse-gas emissions. Land use is relevant too: we can’t live anywhere we produce food and that land can’t be a wildlife reserve either. Water consumption is another aspect, because you need to clean polluted water; overdrafting and salinization mean spending money too. That’s why an environmental calculation will produce not one figure, but two or three.
“Animals score badly in all three categories”, Behrens says, summarising the charts. Animals themselves can’t do much about it: they need to eat. Perhaps you’ve heard that the Amazon forest is being cut down for soy plantations. That’s not because vegans chomp away on so much tofu – cows and pigs eat it. So if we were to eat soy instead of beef and pork, it would make a huge difference. Behrens adds: “You lose 90 per cent of the yield for every step further up the food chain. We could improve efficiency by miles if we changed things.”
Those changes would make a difference too. Our animals produce 14.5 per cent of the overall human production of greenhouse gasses, according to the United Nation’s Food and Agriculture Organisation.
The worst culprits are cows – but you know this. About sixty per cent of the total animal emissions can be attributed to beef and cow’s milk. Cows produce methane which is a potent greenhouse gas. An Irish steak involves fewer emissions than a Brazilian one, but red meat does the most damage, by far, to our climate and needs the most land. The emissions involved in a kilo of beef roughly equal five hours of non-stop driving. Lamb causes roughly similar levels of pollution, but we eat less of it. Cheese and pork are slightly better, but still far worse than the plant-based nutrition at the bottom of the list.
“If you really want to do your best for the environment, vegetable products such as soy, cereals and veggie burgers, nuts, tempeh, tofu, Quorn and legumes are the best choice”, says Dutch environment organisation Milieu Centraal. The impact of meat replacements like Valess, made from milk protein, is similar to that of cheese.
If you are serious, you could browse through all the reports. They’d tell you that the emissions of some farmed shellfish are comparable to those of legumes and that about four times as much land is required for one kilo of cashews as for a kilo of chicken.
You could point out that much of the earth’s surface is too rocky or too steep for arable farming and that you could let animals graze and feed animals leftovers instead of soy beans grown specially for them.
You could dig out the famous study by Carnegie Mellon, which allegedly says that lettuce produces three times as many emissions as bacon.
But still, in the Netherlands, we don’t eat many mussels or cashews, and we do eat a lot of beef, cheese and pork. You could let goats graze on a rocky slope or keep a pot-bellied pig in your garden and feed it on leftovers, sure. But you will not be eating the 77 kilos of meat an average Dutch person consumes in a year.
And you can imagine that dividing pollution by the number of calories does not mean very much to consumers: after all, who eats ten lettuces to compensate for an uneaten ounce of bacon?
Nobody knows the ideal diet, the one that has the best impact on our health and the environment. It’s likely that it would still include meat, fish and animal products like milk and eggs, but not in the quantities presently consumed by most Dutch people. The Netherlands Nutrition Centre now stresses the environmental aspects of our diet in its new Guidelines for Good Nutrition and accordingly recommends limiting our meat intake.
Late last year, Behrens and his colleagues calculated that such recommendations, if followed, could make a substantial difference to the environment. But he still believes consumers should make their own choices: “If you try and dictate what people should and shouldn’t eat, you’ll just put them off. Food is very personal. But more knowledge and information about plant-based is available, as are more products. It also helps that a low-meat diet is healthier: most people will do it for their health if not for the environment.”
By Bart Braun
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