Review/Oorsig Volume 22, Issue 04 - Page 10

Oorsig/Review Carbon Mooooves Christine Page How carbon moooooves... On average each of us humans breathes out 1kg of carbon dioxide (CO2) every day, the larger you are or the more you exercise, the more CO2. So why don’t we consider human metabolism to be a cause of climate change? After all, there are 7.6 billion of us, that’s a lot of CO2 hitting the atmosphere each day (1). It’s because the carbon dioxide we breathe out originally came from the air, so when we exhale we’re simply putting it back from whence it came: we are part of a continuous carbon cycle, we are not adding new carbon. The same is true for anything that respires, including cows, each of which breathes out a whopping 10kg of carbon dioxide per day! So whether you are a cow, dog, human, ant or elephant, your breathing does not increase CO2 in the atmosphere. The basic carbon cycle goes like this: plants photosynthesise using energy from the sun to take CO2 from the air, split it into carbon and oxygen, release the oxygen back into the air and use the 10 carbon to grow. Humans and animals eat the plant (or animal in the food chain that originally ate the plant), metabolise the carbon, use it for their own growth and repair, and breathe out as CO2 or excrete the rest. Carbon also cycles via the gas methane (CH4), burped by cattle and for which they are much vilified. Yet the carbon in methane from cows, just like that in their breath, is being recycled from the plants they ate, which originally took it from the air. This article aims to clear up the confusion often caused by the conflation of two quite distinct sources of carbon, which has led to the common belief that all cows are bad for the environment. And to explain how cows raised in a particular way not only have a positive impact on the planet by helping reduce atmospheric carbon but are actually essential to rebuilding and restoring the health of the world’s depleted soils. But in order to get to grips with that, we first need to take a look at how carbon mooooves….