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 though 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.