Mrs O’Leary’s Cow

homer.jpg Did you know that all cows are carbon neutral? That all the fuss about forcing farmers into an emissions trading scheme is stuff and nonsense? You do now, thanks to the sterling efforts of the Carbon Sense Coalition, an Australian organisation. They issued a press release yesterday, news of which reached me via the Royal Society‘s daily news alert:

News release: Farm lobbies abandon farmers. The Carbon Sense Coalition today accused the big farming lobby groups, government departments, politicians and Ministers representing agriculture of ignoring science and abandoning farmers to unjustified carbon taxation.

Ignoring science, eh? I went in search of what they might be on about…

[Warning: do not read while drinking – extreme beverage/screen interface risk]

The text of the Coalition’s release, written by chairman Viv Forbes is here (PDF). This seems to be the basis of his argument:

“In the farm sector carbon balance, apart from any fossil fuel used, it is a zero sum game, and all farm animals have ZERO NET CARBON EMISSIONS. Grazing animals have not yet learned to live on coal or diesel fuel, and they cannot create carbon out of rocks, soil or water. Therefore they must extract it, via grasses and grains, from that marvellous gas of life in our atmosphere, carbon dioxide. All foods and organic matter represent carbon that has been sequestered by life processes into living matter. The carbon is simply recycled at ZERO COST.” [ Mr Forbes’ capitals].

This revelation is based on an earlier pronouncement, titled “All cows are green” which includes the following passage:

In fact all farm animals should get a carbon credit, because they sequester part of the carbon extracted from the air in bones, meat, milk and wool. Much of this carbon then gets transferred to the bones and flesh of the growing human population, and eventually gets sequestered in sewerage (often, unfortunately, on the sea floor), bones in the coffins, and soil in the cemeteries. This is a proven process which provides more secure and far cheaper carbon sequestration than some of the billion dollar schemes being investigated.

I don’t know what I can add. I prostrate myself before this remarkable wisdom. However, since that missive sallied forth in April, Mr Forbes has clearly learned a thing or two because he correctly intuits that one or two people may point out that a chunk of the carbon emerges from cows as methane. The latest statement therefore includes a footnote for doubters:

“But,” they will claim, “ruminants emit methane, which is responsible for 16% of greenhouse emissions.” Putting aside for a moment the likelihood that this figure is correct (who measures the methane seeping from swamps, escaping from the Black Sea, and being released from the huge methane hydrate deposits on the continental shelves?), the fact is that methane is a natural product, it gets quickly oxidised in the atmosphere to its cousin CO2 and water, and the methane content of the atmosphere is falling, not rising. Besides, are we going to tax the wild herds of wildebeests, moose and caribou?

Classic crank stuff. Wrong in principle, wrong in detail, and almost as funny as some of Ken Ring‘s writings on the subject of climate change.

But wait! There’s more. I dig further into the background of what I will henceforth refer to as the Carbon Nonsense Coalition, and who should I find in the list of members? Why, it’s Ken Ring himself! Is he perhaps providing scientific advice for the Nonsense Coalition? But it gets better…

Muriel Newman’s a supporter. This week her NZ Centre for Political Research provides room for David Bellamy to buy into Forbes’ foolishness. The whiskery one joins the bovine chorus:

The molecules of carbon that make up their flesh, wool, hide, burps and farts is not fossil carbon. It was sequestered from their pasture rarely longer than a year and most within a few days before their release back into the atmosphere.Although somewhat modified by human influence they are part of the 97% of the main cycle of carbon dioxide that makes the living world go round. Not the 3% that the global warmers say are tipping the World, towards an omnivore driven armageddon.

You’ve got to hand it to the old bugger. He’s got a neat turn of phrase. “Omnivore driven armageddon.” Try saying that after two pints of milk. Meanwhile, Muriel’s own thoughts lead me to another luminary, “agricultural tutor and consultant” Robin Grieve, in an opinion column in Straight Furrow (a farming paper). He provides some numbers:

A milking cow each day eats 7kgs of carbon in the grass. 25kgs of CO2 were removed from the atmosphere to produce that carbon – CO2 is 28% carbon.

Each day, she emits, as a byproduct, 300 to 500gms of methane. Methane breaks down to CO2 and water after eight to 10 years, so the methane a cow emits does not add to the methane in the atmosphere, it simply replaces it. The methane becomes CO2, which becomes grass which the cow eats. It all goes around and around, so there should be no tax to pay.

Even if we follow the Kyoto Rules and assign a value to methane emissions of 20 times CO2 then the 300 to 500gms of methane equate to 6 to 10kgs CO2. The cow has removed 25kgs of CO2 from the atmosphere and emits 6 to 10kgs CO2 equivalents in methane. She is in credit between 15 – 19kgs.

And then, to bring the whole thing round to a sort of cranky full circle, underneath are two comments from the great and the good of the NZ Climate “Science” Coalition. Owen McShane, that experienced judge of quality science, offers his congratulations to Mr Grieve, as does Chris de Freitas, who goes so far as to say:

“Robin, You are quite correct.”

Oh dear. Here’s one major flaw in the argument. The global warming potential (GWP) of methane is 25 (AR4) not 20. Doesn’t affect Robin’s numbers too badly. But that’s over a long timescale – 100 years. Unfortunately, if you look at the GWP of methane over shorter timescales, say 20 years, it’s actually 72. It’s a fearsomely efficient greenhouse gas. So Daisy’s half a kilo of daily methane is equivalent over her lifetime to the impact of 36kg of CO2. On policy relevant timescales, Daisy is in deficit to the tune of 11kgs a day. And that’s before you take into account the effect of her urine and manure. It doesn’t all magically go into the soil…

Meanwhile, I suspect that this argument is going to find a fertile furrow in certain sectors of the agricultural establishment. Anybody care to help me nip it in the bud? All arguments gratefully received…

14 thoughts on “Mrs O’Leary’s Cow”

  1. Carbon “Sense” Coalition? Climate “Science” Coalition? Argh, they’re starting to look the same to me…

    Another colourful characters in the, um, C”S”C:

    “Mr Ray Evans, Melbourne, Vic, Australia
    “President of the H R Nicholls Society and Secretary of the Lavoisier Group”

    It’s… the Lavoisier Group

    I was half expecting Chris Schoneveld to be there too. After all, last I knew he’s also in Queensland…

    — bi, International Journal of Inactivism

  2. The general problem is:
    including efforts to lessen belched methane.

    Cow manure is a resource if used well, which we try to do in CA:

    From 2004 in Marin County:

    And larger expansion in 2008:

    And, back to Oz + NZ:

    BOTTOM LINE, speaking as an old farmboy:
    a farmer can deny the problem, or they can make money from:

    a) Methods to lessen the belched methane, which not only increase AGW but cost money in production.

    b) Use of manure to generate power [of course, burning CH4 yields CO2, but the the greenhouse impact is lower, as you point out, and I’d much rather burn CH4 from manure than from the ground…]

  3. I should perhaps point out that NZ sees researching the reduction of methane from ruminants as one the “big” things it can do to address emissions. We have as much if not more expertise in this field (ha!) as any country in the world.

    For an overview, try this glossy brochure from Agresearch (3.4MB PDF)

  4. It can only be a matter of time before the CSC recruit Dr Floor Anthoni into their ranks .. he is an utterly, er, unorthodox maverick marine ‘scientist’ who has spent a great deal of his life campaigning AGAINST marine reserves. He’d fit right in.

  5. This seems to be a very late takeup of Keith Woodford’s paper (2006)”Agriculture’s greenhouse emissions. How should they be calculated?” It seems a valid discussion to me, but if you want to just “nip it in the bud” you might miss a valid point. Take a look at Keith’s paper (Keith is also behind the A1/A2 milk debate) here: but keep an open mind please, no point letting bias get in the way.

  6. Thanks for the link, Nigel. Yes, it’s an interesting little paper, but isn’t really addressing the “carbon neutral cow” – what it’s looking at is the underlying assumptions about gas effectiveness. There’s a link to a discussion of “global warming potential” in the post (above), and that’s what Prof Woodward is really talking about. He suggests that instead of using a 100 year span for GWP we should use 500 years. Magically, most of our emissions go away.

    Methane is oxidised in the atmosphere by hydroxyl radicals (OH) to CO2 and water. This takes, for the average molecule somewhere between 8 and 12 years. During that time, the methane is acting as a GHG, and a very good one – much more effective than CO2. By looking at longer timespans than the lifetime of the methane, we’re attempting to allow for the warming effect of the extra CO2 from the methane oxidation. CO2 atmospheric residence time is measured in 100s of years.

    But the crucial point is that the vast majority of the warming effect happens in the first ten years – while the methane’s still around. It’s of no relevance to the atmosphere now, or over policy-relevant timescales that Daisy’s still having a tiny residual warming effect a century hence. Over the ten year timescale, methane’s GWP is 72 times that of CO2. That’s the number that’s really relevant to the warming we experience.

    Of course, how you treat methane in an emissions trading scheme or in an international treaty is quite another thing. Politicians can decide what they want. But the basics of what’s going on are clear. Cows take carbon and make methane. That methane is a powerful GHG. Cows are most certainly not carbon neutral.

  7. Another query though, RE: “By looking at longer timespans than the lifetime of the methane, we’re attempting to allow for the warming effect of the extra CO2 from the methane oxidation”

    Should “extra” CO2 be included? since this CO2 has not directly come from a fossilised source, rather is has completed a cycle from atmosphere to pasture to cow and back. For a short time it was methane, which I accept is relevant as a potent GHG needing to be tallied.

  8. What I am wondering is why the C”S”C care about this at all. If AGW doesn’t exist then it doesn’t exist…doesn’t matter what the cows do.

    Unless they are attempting to further distance themselves from their middle name…. and see how many people they can take along for the ride.

    Another thought is that landfill gas must be subject to the same logic. Let’s whip away those Carbon Credits the Christchurch Council got for heating QE2 pool with Burwood landfill gas. Keep on heating the pool with our inexhaustible gas supplies (sorry make that coal) – give the gas explorers a nice fat tax break to go and find more of the stuff….and just let the methane slip away into the atmosphere – if it wasn’t so short lived it might help us ward off the next ice age.

  9. Nigel, for methane that doesn’t come from biological sources you have to take into account the extra CO2 (gas from coalfields, oil, pipeline leakage etc). With methane from permafrost & hydrates you’re also dealing with carbon that’s been removed form the overall carbon cycle, so again the idea’s valid. It doesn’t change the short term impact, though. Neater acounting, perhaps, but mostly irrelevant to our concerns. Check out the “It’s a gas, gas, gas” post for why…

  10. So it looks like there is a point though, i.e. calculating emissions from agriculture should be based on any land use change, and methane emissions over a ten year period.

    However the carbon dioxide component is derived from and returned to the atmosphere on a very short timescale. Perhaps similar to the distinction between production of carbon dioxide from aerobic composting vs methane from anaerobic decomposition in a landfill, only from the same source.

  11. Hi Gareth (or anyone else suitable qualified to answer),

    The Robin Grieve stuff which you mention above has been repeated pretty much word for word in the Rural Advocate in Northland where I live. I’m trying to put together a response but I’m unsure about the correct way to deal with agricultural methane as a Greenhouse Gas.

    It’s clear that you need to quote a time period when talking about a gas’s Global Warming Potential, but what is the correct time period to choose for agricultural methane? Can you point me to any sources which show the calculations behind the oft-quoted ‘agriculture is responsible for roughly half of NZ’s GHG emissions’? How did they do it, what did they use as methane’s GWP?

    Any help much appreciated.

  12. Hi mick,

    The numbers Grieve uses for grass/carbon/methane conversion are all about right, according to an AgResearch scientist I checked with, but the key issue is the conversion of carbon to methane. Grieve uses the standard multiplier of 23 to arrive at his impact, but ignores the actual lifetime of the gas when he considers whether the cow is carbon neutral. The grass is using CO2 not CH4, so the CH4 accumulates.

    My point about using the shorter term calculation (70ish) was to emphasise that on policy relevant timescales, CH4 is much worse than CO2.

    The background to the official NZ emissions data is all at the government’s climate change website.

    Hope that helps.

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