Why young women going vegetarian for the climate is not necessarily a good thing

Last year one in five of Swedish young women became vegetarian because of climate change. Some might think that this is excellent news. We hear a lot that we should all eat less meat, ideally become vegetarians. The complex problem of food and sustainability has been reduced to the simple statement that vegetables are all good and meat overall bad. Unsurprisingly, such black and white statements are oversimplifications. One of the simplifications is the issue of methane and whether or not it is part of the carbon cycle, as I’ve previously written about here.

Another simplification is how the climate impact of food is calculated. Many calculations are based on how much CO2 is released  per kilogram of the food. This, however, has been criticized by research that shows that calculating CO2 per volume, calorie or even nutrient will give different results. The researchers conclude that “the sustainability of alternative diets, matched for energy and nutrient adequacy, can only be made on the basis of calories and nutrient contents and not per gram of weight”. Surprisingly, if you calculate climate impact per calorie, lettuce appears worse than bacon. Basically, how we calculate the climate impact of food makes a big difference. Like, Gunnar Rundgren I believe that there’s a point in calculating emission per nutrient density.

Taking nutrients into account when calculating climate impact is important because, as Rockström has pointed out, food is both a key factor in the health epidemic as well as the climate. Half of Swedish female adolescents have iron deficiency, one in three women in general. It is well known that iron from meat type of sources is absorbed more easily (25%) than from vegetable sources (5-10%). Research on diets and climate change acknowledges that reduced meat in diets is especially problematic for young women for this reason.

If we encourage women with iron deficiency to become vegetarians, we’d better be sure it is beneficial for the climate.

I am not so sure it is and I’ll use the following example with two high impact foods to illustrate why. Lamb is generally viewed as the meat with the highest climate impact. Rice, because of methane emissions, is among the highest climate impact grains. A Swedish lamb provides a carbon footprint of 16 kg CO2-equivalent per slaughtered kg lamb. A kilo of Thai rice provides between 1.34- 3.57 CO2-e per kg. Let’s say 2.4 kg CO2-e/kg.

Calculating emissions according to weight, yes lamb (16/kg) is much worse for the climate than rice (2.4/kg). You can eat six times as much rice and still release less CO2.

However, we have all heard about empty calories. What’s important is not only how much we eat but the nutrients the food provides us with. And we have to consider a woman’s recommended daily intake of iron, around 15 mg (9 mg for men). So here’s the issue. You would have to eat 3.2 kg rice a day to get the daily iron allowance. And considering the sort of iron and its lower absorption, it is even more. If you instead eat lamb, maybe even liver, 300g/day is enough. Of course, in reality no one would rely on a single food to provide all the necessary iron but the figure shows how efficient liver would be in doing so.

So to get your recommended daily intake of iron, what is the climate impact? For Thai rice the climate impact is at least 7,68 kg CO2-e. For Swedish lamb liver it’s 4,8 kg CO2-e.

Now, you might say, young Swedish women know about empty calories and would go for broccoli rather than rice. Still lamb liver is more efficient than broccoli in delivering iron per kg CO2-e. You would have to eat more than 2,3 kg broccoli to get the recommended daily intake. In climate impact that’s (using the example of UK broccoli) ca 5,3 kg CO2-e.

My message is really this. We have to consider nutrient content and absorption instead of climate impact per weight or calorie. When we consider nutrient content and absorption, we may find that going vegetarian is not a good idea. Instead, eating small amounts of nutrient dense food, like lamb liver, helps young women to maintain their health.

It is more climate friendly to eat small amounts of nutrient dense foods than eating large quantities of empty calories.

The nutrient argument was highlighted by researchers with connections to the Swedish dairy industry in 2010. While we of course have to be wary of industry motives, I still believe the overall idea of considering nutrients in relation to climate impact is a sound idea. And the general lesson here is that how we calculate affects the results we get.

On the picture: grazing sheep on the west coast of Norway, are they really that bad for the climate? It depends on how you calculate.

Can we really compare meat to fossil fuels?

Many sustainability proponents these days encourage us to become vegetarians. At least once a day there is some article along these lines in my Twitter feed. Unfortunately, there are many arguments circulating in this debate that are quite misleading. The worst error people make, in my opinion, is to equate emissions from cattle with emissions from fossil fuels.

This is simply misleading because these emissions have very different relationships to the carbon cycle. By burning fossil fuels we are adding carbon to the carbon cycle whereas emissions from cattle have a role within the carbon cycle, it naturally belongs there.

Let me explain. We all learnt about the carbon cycle in school and thus we should know that carbon circulates between the atmosphere, to plants, to animals and us humans and is yet again released into the air. Microorganisms such as bacteria and fungi etc. also play a role in this. It is how it should work in nature. Animals have a part to play in this cycle by both storing and releasing carbon in different forms.

Now whereas cattle is part of this normal carbon cycle fossil fuels are not. Fossil fuel is stored away carbon that is suddenly released into the atmosphere through human intervention. Because the natural carbon cycle cannot absorb all this added carbon, a larger portion of it remains in the atmosphere. The natural equivalent is a volcanic eruption. But these days we have constant man-made emissions of such stored away carbon. This way, we add carbon to the atmosphere that was not there before and would not have been released without us. This is indisputable and should really be our focus since we know this for certain.

Now some argue that because we hold cattle as part of our food chain we have affected the carbon cycle by raising more cows than what existed before human intervention, i.e. before animal husbandry. That there are more animals on earth today, and particularly ruminants, is a hypothesis that is difficult to prove. We don’t know exactly how many animals existed before our animal husbandry or how many of these were ruminants, so it is only estimates. Even if there are more ruminants living on earth today, it is not necessarily a problem because cattle also absorbs carbon. Just as us humans, their bodies are partly built of carbon that is released through breathing and when we die etc.

The problem with more ruminants on earth, according to the veggie proponents, is that ruminants release more methane than other animals. Thus we have shifted the carbon cycle towards more methane, they argue. However, the more we learn about methane, it is not really an isolated case of cows as such but methane producing bacteria that we find in all kinds of environments. Moreover, most of these emissions do belong to the natural carbon cycle that was there before us. It is possible that human behavior provide more beneficial environments for these methane bacteria, by raising more ruminants (who release methane) and rice agriculture. But then again, there might have been wild animals and natural swamps before and if so there has not been a significant change. We basically don’t know. There are estimates in both directions.

Acting on very incomplete information on how methane acts is in my opinion risky. Before we start to mess with the methane-producing bacteria in the cow’s stomach (which they are now starting to do), let’s learn more on how it actually operates. And when we do address methane, let’s include all man-made sources such as rice, landfills and wetlands too.

Thus we see that equating fossil fuel emissions to emissions from cattle is misleading. In the case of fossil fuels we know that we have added carbon to the carbon cycle and in these amounts it cannot be absorbed in the cycle (although the oceans have compensated a lot). In the case of cows, we don’t really know whether we have shifted the carbon cycle towards more methane because of animal husbandry. Moreover,  the case is not just about cows but methane producing bacteria that could be affected by many of our activities. We still need to learn much more. So until we do, let’s address the things we know for certain and that are urgent: our red meat habit is pretty stable whereas our flying habits have exploded the last decades.

There’s so much more to say on the subject of climate change and food but I find this to be one of the main points.

On the picture: cow at Lovö Prästgård in the Stockholm area.