One stop shopping post on methane part 2
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.
Methane is produced naturally and organically in the environment by microbes, ruminant animals, wild grazing herds and the prodigious activity of insects such as ants and termites.
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
Photosynthesis.
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)
Also, when methane is measured from cows, it's done via "gas chambers" or enclosed systems where only the methane that the bovine burps out is measured. It's often never measured in an ecological context, where methanotrophic bacteria are available at the soil surface to oxidise the methane that the ruminants burp out.
While this is explained pretty well for the layman, another thing that wasn't mentioned was the role of hydroxyl radicals (OH compounds) that also act to oxidise methane. Hydroxyl radical comes from when oxygen reacts to UV light and frees up an oxygen atom; that oxygen atom binds with a hydrogen atom that came from water vapour creating the OH radical, which binds to CH4 to oxidise it, rendering it unstable. These hydroxyls often come from the water vapour put off by transpiration of plants. And of course, the greater the green cover there is (the greater number of green photosynthetic solar panels there are), the more water vapour and oxygen is given off, the greater the efficacy of these natural atmospheric compounds have to oxidise methane.
This is another great article on the topic
Another great article by our friend Caroline Grindrod of Wilderculture
Another:
The methane myth, why cows aren’t responsible for climate change: “The methane budget
But perhaps more significant, however, is the lack of understanding about the methane famously emitted in cows’ burps, and how it acts in the environment.
While methane is 28-times more heat-trapping than carbon dioxide, methane’s lifespan is just a decade, while CO2 — known as a long-life pollutant — remains in the atmosphere for 1000 years.
After ten years, methane is broken down in a process called hydroxyl oxidation into CO2, entering a carbon cycle which sees the gas absorbed by plants, converted into cellulose, and eaten by livestock.
To put that into context, each year 558m tons of methane is produced globally, with 188m tons coming from agriculture. Almost that entire quantity — 548m tons — is broken down through oxidation and absorbed by plants and soils as part of the sink effect.” View here
And finally.. one just for the nerds: “WTF Happens to all the methane?” View here.
