by David Mason-Jones
There is an old fake-science idea doing the rounds again at the moment. This is that cows are culprits in the global warming narrative. The problem, however, is that the scary image of cows destroying the planet with their carbon emissions doesn’t fit with how the planet actually works.
No cow alive today, nor any cow that has ever existed, nor any cow that will ever exist, can add single atom of carbon to the atmosphere that wasn’t already there in the first place.
At one point of the carbon cycle, it is true that cows emit carbon dioxide (CO2) and methane (CH4) to the atmosphere, each of which contains one atom of carbon. This is a basic fact of biology – but what about some other basic facts to go with it?
It would seem the fact that ruminants emit carbon gases is regarded as the clincher argument by people like Rosemary Stanton and Kris Barnden, who recently published an article on the ABC News website damning cattle. The problem is they fail to put this isolated fact together with others to give it context and, in this way, create a misleading impression. They fail to describe how a cow exists within the carbon cycle. They fail to ask a fundamental question; ‘Is the carbon a cow emits new carbon to the atmosphere?’
The believer/activists don’t explain that cows eat plants and that all the carbon in a plant comes from the atmosphere, not the ground. The carbon in the leaves comes from the minute traces of carbon dioxide in the air around them via the process of photosynthesis. Even the carbon in the roots of plants comes from the atmosphere and even the carbon in the carbohydrate sugars that the roots exude to soil microbes in a swap for nutrients, comes the air above us. The energy for this is captured by the plant’s own solar panels – its leaves.
The believer/activists don’t explain that when a cow eats a plant it is vicariously ‘eating’ carbon from the atmosphere. They don’t explain that, when that cow exhales carbon dioxide or belches methane, the carbon in those gases goes back to where it ultimately came from – air around them.
The implications of photosynthesis are not divulged to the public by the cows-are-culprits believer/activists. They don’t explain where animals get their energy from and how their food sources become laden with energy. (Hint: it’s ultimately from the Sun and it involves the carbon cycle, the water cycle and photosynthesis.)
Plants combine carbon, hydrogen and oxygen to make carbohydrate chains or ‘sugars’. (C6H12O6)
Cows and other animals consume these carbohydrate sugars and ‘burn’ them as energy to run their bodies. As a result of this ‘combustion’ the by-product of carbon dioxide is produced and exhaled to the atmosphere. We humans do the same thing. Once in the atmosphere, the carbon dioxide again becomes available for photosynthesis in plants, and so the cycle starts over again. This is an example of sustainability in plants and animals.
So, with regard to the carbon dioxide the cow breathes out, it goes straight back to where it came from – the atmosphere.
What about the methane?
The methane issue is a kind of blind spot for those who vilify cows because most bovine critics would see themselves as deeply concerned about preserving a natural and organic environment. Well, methane from cattle is a natural and organic gas but the detractors portray it as something else – something unusual, something particularly sinister. Methane production is also solar powered – another appealing feature to those concerned about natural and organic things. Methane inevitably results from the process of plant growth (photosynthesis) and subsequent fermentation by various agencies such as microbes, insects and ruminant animals. Methane occurs naturally and abundantly in rainforests, wetlands, lakes, swamps, rivers and arid zones.
A cow has a part of its digestive process that we do not have and this enables it to eat tough cellulose food. This fermentation chamber is called a rumen where, with the aid of microbes, the cow processes tough cellulose foods in the absence of oxygen. The by-product of this combustion is methane (CH4) which is then belched.
The methane molecule is unstable in oxygen and, once in the oxygen-rich atmosphere, reverts to carbon dioxide and water vapour – see equation at end. For the period that the methane molecule is in the atmosphere it is a potential global warming gas but its molecular characteristics – its heat absorption capacity – is not well matched to the frequency at which the Earth radiates heat. For this reason the theoretical heat-trapping potential of methane is curtailed when the gas converts to its original form. And, in any case, it is a natural part of the environment that has been happening for hundreds of millions of years by vast herds of ruminant herbivores across the globe.
It seems that the detractors of cattle are reluctant to concede that the emissions of cows are part of a closed and self-completing carbon cycle in the atmosphere. This organic cycle involves all plants and animals, including ourselves.
In conclusion, the carbon gas emissions of cows are just one point in a giant circle that is the atmospheric carbon cycle. If you plot the other points in the cycle, it forms a giant circle which loops back to the start point. There is no new carbon in the atmosphere as a result of a cow’s existence.
Some relevant equations
The general equation for photosynthesis is:
6CO2 + 6H2O + Sunlight absorbed = C6H12O6 + 6O2
Note: The C6H12O6 molecule is a carbohydrate molecule – a food ‘sugar’ which can be eaten by an animal and ‘burnt’ to produce energy. When this molecule is ‘burnt’ it produces carbon dioxide (CO2) as a by-product. This is then exhaled to the atmosphere as the same gas as it was prior to the growth of the plant the cow eventually eats.
The Breakdown of methane.
Conversion of methane to carbon dioxide and water is:
CH4 + 2O2 = CO2+ 2H2O + Energy (Heat given off)
About David Mason-Jones
David Mason-Jones was initially persuaded by the ‘cows-are-the-culprits’ narrative but changed his mind once he studied the subject in more detail.
At the time of publishing his original book on this subject, David was the editor of the monthly rural publication, Small Farms Magazine.
Like many Australians, David was initially influenced by the general public mood that livestock cast a long shadow in terms of their global warming gas emissions. Since researching the matter in more detail however, he has completely reversed his opinion.
His books, ‘Should Meat be on the menu’ and ‘Why didn’t my Grandmother get fat and why did I? deal with the issues of the environmental credentials of cattle as well as the dietary benefits of including animal products in a balanced and healthy diet. These books are available for purchase on his website: