Owen Jennings: Now Here’s a Funny Thing.

Airlines have trees to offset their CO2 Greenhouse Gas emissions. That’s recognised and acceptable. More than that it is encouraged and subsidised.

Farmers have grasses to offset their CH4 (methane) Greenhouse Gas emissions. That’s not recognised and it’s not acceptable. More than that, they are heavily criticised and are threatened with severe penalties.

Humans emit CO2 Greenhouse Gas. We are not penalised because we are part of a closed, natural cycle where we eat greens that are grown by photosynthesis that uses CO2. That’s IPCC policy.
Cows emit CH4 Greenhouse Gas. They are to be penalised even though they are also part of the very same, closed, natural cycle where they eat greens that are grown by photosynthesis that uses CO2. That’s IPCC policy. But is it equitable?

I am told size counts. Airlines produce 1.0 billion tonnes of Greenhouse Gas a year. Humans breathing, 2.94 billion tonnes. The world’s sheep and cattle produce 4.03 billion tonnes of Greenhouse Gas a year. Pretty straight forward facts? Well, no, they’re not actually. To get the 4.03 billion tonnes the world’s climate experts multiplied the actual figure by 28. The true amount of methane gas emitted was a much more manageable 144 million tonnes.

Why multiply by 28? Cows and sheep emit methane, and the experts want us all to believe methane is 28 times more of a warming problem than CO2, the gas that aeroplanes and people emit. But is it 28 times stronger, in fact? It’s not, and any school kid doing science could demonstrate why it is not.

Remember the silly question we asked as kids – “what weighs more a tonne of feathers or a tonne of lead?” The explanation included the reality that the feathers took up a huge amount more space. And thereby lies the simple mistake of the ‘28 times’. It’s the reverse to the feathers. The “28 times” proponents use weight instead of volume or mass. Their proposition is that every extra tonne of methane added to the atmosphere does more warming than an extra tonne of CO2.

The fallacy is that warming is done on a molecule by molecule basis, not weight. Methane has an atomic mass of 16 (C=12, H=1), whilst CO2 (O=16) has a mass of 44. So, one kilogram of methane has 2.75 times the number of molecules in an equal weight of CO2. If equal volumes of the two gases are compared, rather than equal weights, the “28 times” is grossly over-stated. Molecule for molecule, the warming ability of methane compared to carbon dioxide is 28 divided by 2.75 times (44/16) – i.e. a much more modest multiplier of 10.2.

The difference between 28 and 10 times is massively significant when the gun is at every farmer’s head to reduce or pay.

But wait, there’s more.

Using weight measures shows that the mass of CO2 currently in the atmosphere is 3000 gigatonnes, as compared to methane at only 5 gigatonnes. By weight, atmospheric methane is a mere one six-hundredth (0.0016%). It is widely accepted, by the IPCC and sceptics alike, that doubling the weight of CO2 in the atmosphere is likely to cause a direct temperature rise (without feedbacks) of about 1.0°C.

Doubling the weight of methane in the atmosphere adds only one six-hundredth as much greenhouse gas as doubling CO2. When multiplied by a multiplier of 10.2, this would produce warming of only (10.2/600 x 1°) or 0.017°C. Now, factor in that all ruminants worldwide, domesticated and wild, are only responsible for 15% of the methane entering the atmosphere so their contribution is now a lowly (0.017C X 15%) or 0.00255 C.

At the present rate of increase methane will need 360 years to double. That means all the cows and sheep on the planet, at the very most, are warming the planet by (0.00255C divided by 360) or 0.000007 C per year.

New Zealand has just 1% of the world’s ruminants so that makes our cocky’s contribution a heroic 0.00000007 degrees C per year. Yes, it’s absurd and beyond all comprehension that many New Zealanders from our “climate-woke” Prime Minister down to the tea person at the University can believe that Kiwi farmers are still a problem.

All these ridiculously miniscule, inconsequential numbers are utterly meaningless because no matter how much we multiply and divide and argue decimal points the simple fact is that farmers are using as much Greenhouse Gas from the atmosphere every day as they put back, if not significantly more. There is literally no scientifically based case to tax ruminant emissions.

As cows consume grass, they stimulate its regrowth, which sequesters additional CO2 through photosynthesis. While cows emit methane as a byproduct of digestion, this methane eventually breaks down into CO₂ and water, completing a natural cycle.

Moreover, livestock contribute to carbon sequestration by storing carbon in their bodies and the soil by enriching it through their waste, promoting further grass growth. This creates a positive feedback loop, enhancing the pasture’s ability to capture more CO2. Methods of increasing soil sequestration are emerging, so several tonnes of carbon per hectare are locked away permanently. Consequently, New Zealand’s pasture-based farming system is acting as a net absorber of greenhouse gases, challenging the notion that livestock farming solely contributes to emissions.

The great tragedy is that New Zealand’s leaders over the last 30 years or so haven’t bothered to learn the facts or even tried to convince the UN and its IPCC sidekick that ruminant methane is not a problem using the available science. Too many of our scientists are unwilling to challenge the prevailing IPCC conclusions – its job threatening and odium producing. Farmers feel sold down the creek.

Owen Jennings, a former Member of Parliament and President of Federated Farmers, maintains a keen interest in ensuring agricultural policies are sensible and fit for purpose.