One Cow in One Field

Why cows are innately carbon neutral.

The reason I love this example is because it puts aside all the nuances and plainly corrects the fallacy that ‘cows are bad for the environment’. So let’s do just that; let’s put everything aside including the assumption that we eat meat. For this example, a cow is just a cow.

Imagine putting one singular cow, alone, in a field for a year. For 365 days she walks around, grazing the grass that grows there. She drinks water from the pond over in the corner. She burps an awful lot over this year. For the uninitiated, the problem with cow burps is methane, a greenhouse gas. And what about the farts also, and the emissions from the cow pats, oh and even the c02 she breathes out?! Her emissions of carbon over the year really would add up.

But where has this carbon come from? Has our dear friend the cow just whipped them up out of thin air? Of course not. They have come from the grass that she ate. Yes, that innocent looking grass down there on the ground. Remember it’s the only thing she’s consumed for the year (and water). The cow ate it, digested it and dropped almost all of that carbon out of her back end again, albeit brown and steaming. In the meantime, some of the carbon that was in that grass has become CO2 and some has become methane, CH4. Blame the microbes in her stomach for the methane part.

Now for the real hammer-blow. The grass got the carbon from the air! That’s right, using our old friend photosynthesis from childhood science lessons. Carbon dioxide from the air, and water from rain got turned into grass and oxygen. (Farming is harder than that, I promise).

So, to be clear, our cow made no new carbon or compounds whatsoever. This really is the law of conservation of energy; that states that energy cannot be created or destroyed, it can only change form. Presuming that our field has about the same amount of grass (carbon) on day 1 as day 365, our cow has been carbon neutral.

Optional(?) Nuances

Ok so she’s carbon neutral… but our pretty little cow is not off the hook quite yet. If she wasn’t there, could we not just leave all that carbon in our grass just as… grass, instead of unnecessarily making greenhouse gases? I think that economists call this opportunity cost.

No, no we couldn’t. You see, this carbon stuff is just begging to be cycled. If a cow didn’t eat it, it would decompose anyway, on the soil, and emit damn near the same amount of gas. In some climates, it would dry out, oxidise and would likely burn in a wildfire.

I know I said I wouldn’t do this, but it can’t go unmentioned that the cow does so much more than meets the eye. She cycles nutrients and helps build natural diversity. Importantly, at an opportune moment, we can harvest our friend, the cow, to feed us.