Cow farts: worse than all coal-fired power stations combined

It’s almost a year since Barry Brook, Professor of Climate Change at Adelaide University, posted a piece on his blog about Australia’s most powerful global warming agent. That piece, co-authored with Peter Singer and I, showed that Australia’s livestock cause more warming than all our coal-fired power stations.

It wasn’t a defence of coal, it was a plea for people to understand the role of methane as a potent climate forcing and to understand that cattle methane is no laughing matter.

At that time, news media regularly and wrongly claimed that methane as a greenhouse gas has a warming impact “only” 21 (or 23, or 25) times that of CO2. Even the well read Professor Ross Garnaut showed a stunning ignorance of methane’s true warming impact in his report.

Unfortunately, not much has changed. The world’s media continues to misrepresent the potency of methane and cattle methane continues to prompt cartoons rather than action.

But in an opinion piece in last week’s New Scientist, Kirk Smith, Professor of Global Environmental Health at the University of California in Berkeley, makes a forceful call for methane’s real warming impact to be accurately counted in international agreements. He points out that a tonne of methane contributes 100 times more warming during the first five years of its lifetime as a tonne of CO2, yet under current Kyoto rules, its comparative potency is set at 21. This is because the relative impacts of ALL greenhouse gases are averaged over the same period 100 years, regardless of their atmospheric lifetimes.

This is like applying a blow torch to your leg for 10 seconds but calculating its average temperature as just 48 degrees because that’s what it is when averaged over 20 minutes, with 20 minutes being used because that happens to be some agreed international standard when measuring heat sources applied to legs. The implication being, of course, that a blow torch for 10 seconds and a 48 degree hot water bottle for 20 minutes have the same effect. Some standards have little rational basis, and this particular standard isn’t just dumb but globally and dangerously counter productive. If methane’s warming were properly accounted for, there would be more incentive for reductions.

Any budding Miss Marple investigating the issue would soon realise that climate scientists don’t use this Kyoto factor for methane in their global climate models. They use its true forcing, integrated, if required, over the time span under study. It’s really just economists, bankers, politicians and international climate horse traders, the kind of people who gave us the global financial meltdown, who prefer a wrong but simple number to the truth.

Climate scientists have known about the Kyoto methane bungle for well over a decade with NASA’s chief climate scientist James Hansen remarking on the inappropriateness of the Kyoto factor in a number of papers over the past decade. But changing a poor standardisation decision is like trying to stop a tidal flow with a teaspoon, especially when the constant underestimation of the full impact of livestock methane favours a rich and powerful industry like the global beef industry.

Smith’s article refers to recent modelling showing that methane and black carbon reductions are the quickest way to reduce warming and give the planet a fighting chance of avoiding dangerous climate tipping points. James Hansen worked this out somewhat differently a few years back, but went even further in his 2007 paper on trace gases estimating that while control of CO2 is absolutely necessary to avoid dangerous climate change, it IS NOT sufficient. Even if we quickly and efficiently reduce all CO2 emissions, we are still toast unless we control methane and other trace gases — - plus black carbon.

The activities which generate methane and black carbon are many, including livestock production, emissions escaping from coal mining operations (called colorfully “fugitive emissions”), leaky natural gas pipes, rice growing and, for black carbon, inefficient wood stoves and deforestation (we call this “land clearing” or, even more creatively, fodder harvesting when it happens in Australia).

Somewhat synchronously, an editorial in last week’s Nature science journal calls for increased attention on both black carbon and methane. But the world’s most prestigious science journal follows what a study last year in Public Health Nutrition found to be standard practice for news stories when discussing methane … it ignored the single biggest anthropogenic source, livestock. The study looked at 4582 climate change articles between 2005 and 2008 and found that 0.5% mentioned food animal methane emissions. The Nature editorial follows the Fawlty Tower’s climate change rule … Don’t mention the meat .

But while many articles, like Smith’s, list rice production and livestock as sources of methane, their relative contributions are rarely quantified. The Edgar greenhouse gas inventory database has recently been updated with 2005 data and the key anthropogenic methane players are listed in the table below:

Global Methane production
( Megatonnes )
Livestock 97
Manure management 11
Fugitive Oil/Gas 73
Fugitive Coal 38
Wastewater 35
Rice 34
Landfill 29

As you can see, methane from livestock and its manure is roughly the same as the combined fugitive emissions of all fossil fuels. Rice methane is about 30% of these. Most of the livestock methane is from ruminants and, believe it or not, ruminant meat provides just 1.7% of global calories for that 108 mega tonnes of methane. More than a few of those calories are saturated fat and even the CSIRO’s professional red meat groupies recommend they be thrown out because they cause heart disease and erectile dysfunction … just for starters. But throwing the fat out makes an environmentally destructive industry even worse. A study in New York state in 2007 showed that it takes 75% more land to produce a thousand calories of lean beef than normal beef. Australians and others in the developed world have an exagerated view of the importance of beef and sheep meat in the global food supply, and even in Australia, beef and sheep meat are just 7.6% of apparent consumption. Apparent consumption is a carcase figure which includes waste, the actual amount consumed is even less. We export about two thirds of all beef, so the massive deforestation of Queenland in the 1990s was just a beef subsidy by the environment.

The logical course of action is to quickly phase out global beef production. This would not only make a significant dent in global climate forcings, it would free up a mountain of grain and allow reafforestation on a massive scale. The planet’s 900 million malnourished people who cannot currently outbid cattle for grain would at last have a fighting chance. Rice on the other hand provides 19% of global calories for its 34 megatonnes. Rice yields are typically 10 tonnes per hectare, about 5 times that of cereals like wheat, so cutbacks to rice production would be difficult or impossible.

A study covered in New Scientist earlier in the year estimated that the cost of climate mitigation could be reduced by $20 trillion dollars by sharply reducing red meat (including pork) consumption. Reductions in total meat production have been recommended by the head of the IPCC, Rajendra Pachauri, but with the emphasis on trading as the tool of choice for reducing emissions, and with the Kyoto rules crippled by the methane factor blunder, any emissions trading strategy will be tackling methane with both hands tied behind its back.

It’s high time Kyoto’s methane factor mistake was fixed. Methane is far more potent than the figure of 21 or 25 that is consistently cited. A factor of 72 would be a reasonable compromise between accuracy and simplicity and would help in driving the changes required to reduce fugitive emissions and cattle populations.

12 Comments

  1. Terry Barnes
    Posted Tuesday, 7 July 2009 at 1:48 pm | Permalink

    I’ll happily help to reduce cow methane - waiter, another rib eye steak please…

    Seriously, though, this is a shocking piece of naive intellectual smugness. Come off it Geoff, man is not a herbivore and your brand of vegan activism won’t solve the climate problems of our planet. And incidentally, if you have your way large swathes of the less arable parts of the Third World with high meat, low vegetable diets (Mongolia comes to mind for starters) will starve. Is that what you mind - I somehow doubt it.

  2. Hugh (Charlie) McColl
    Posted Tuesday, 7 July 2009 at 3:42 pm | Permalink

    Terry Barnes, I would like to see just one checkable statistic which properly demonstrates that “…large swathes of the less arable parts of the Third World with high meat, low vegetable diets…” actually exist. Smugness won’t come into it.

  3. Paul Ferraro
    Posted Tuesday, 7 July 2009 at 4:16 pm | Permalink

    Terry Barnes - fair shake of the sauce bottle, mate.

    Unless I completely missed the nonsense statement you attribute to the author, the article argues primarily for an increased recognition for the critical role of methane in climate change and suggests a significant reduction in global red meat consumption may achieve this.

    Although this may arguably be an unrealistic short-term goal (consider the economic and cultural ‘importance’ of the agriculture industry within our society) it is a more constructive component of a necessary conversation than the flippant motherhood statements which are predictably rolled out in response.

  4. meski
    Posted Tuesday, 7 July 2009 at 4:23 pm | Permalink

    Paul, I think Terry alludes to the biased POV that the author has. A similar POV would be the coal industry asserting that burning coal doesn’t increase carbon in the atmosphere, and they wouldn’t be that hypocritical, surely?

  5. Damon Schultz
    Posted Tuesday, 7 July 2009 at 4:27 pm | Permalink

    Terry - that’s a shabby, illogical response that misses the point of the article entirely.

    You either acknowledge that methane from beef production is a significant and growing factor in global warming, or you don’t. If you don’t, then it’s up to you to demonstrate why not in the face of the science which seems (to this non-scientist) to be movingm to an acceptance of the role of methane in global warming.

    If on the other hand you do accept this nexus, then metaphorically holding your hands against your ears and pretending you can’t hear the message, i.e. “man is not a herbivore”, “your brand of vegan activism won’t solve the climate problems of our planet”, etc. isn’t really a viable strategy for how we deal with the problem.

    To be fair, some solutions not involving reduction in animal meat production have been proposed. But then, of course, there is the solution of reducing our consumption of (cow) meat. Fairly obvious parallels to reducing our consumption of energy surely exist, and I really don’t see why reducing our consumption of (fossil fuel-derived) energy can be seen as a viable and responsible strategy by those involved in public policy, yet reducing our consumption of animal products is seen as “vegan activism”.

    There was a time when those who advocated changing energy consumption for the sake of avoiding catastrophic climate change were seen as “climate extremists”. Those times - thankfully - are increasingly behind us. Why should reducing the emission of methane by reducing our animal meat consumption be seen in such a different light? That is the question that critics of so-called “vegan activists” need to answer, and with more considered responses than setting up straw-men arguments about herbivores and carnivores.

    (By the way, “man” [sic] has survived - and indeed, thrived - on much, much smaller servings of animal meat until very, very recently. That’s worth bearing in mind before you dismiss the capacity of human beings to change their diet to achieve other goals.)

  6. Paul Ferraro
    Posted Tuesday, 7 July 2009 at 4:46 pm | Permalink

    Meski, in what manner is the article biased? Is it because the author’s affiliations?

    I would suggest that the article draws upon the findings of numerous scientific studies - each of which had to have passed through the rigours of the peer review process prior to publication.

    Two sentences seem adequate justification for this piece:

    1. …It [the previous article] wasn’t a defence of coal, it was a plea for people to understand the role of methane as a potent climate forcing and to understand that cattle methane is no laughing matter…

    2. …Unfortunately, not much has changed. The world’s media continues to misrepresent the potency of methane and cattle methane continues to prompt cartoons rather than action…

  7. Tim Errington
    Posted Tuesday, 7 July 2009 at 5:23 pm | Permalink

    If we replace cow and sheep consumption with kangaroo consumtion, this should solve the problem and create a huge export market for Australia.

  8. Roger Clifton
    Posted Tuesday, 7 July 2009 at 5:49 pm | Permalink

    Methane does at least have the redeeming feature that it punishes the generation which emitted it. In contrast, the consequences of our carbon dioxide emissions will be visited upon many generations of our descendants, long past any conversion from carbon fuels.

  9. Kirk Broadhurst
    Posted Wednesday, 8 July 2009 at 3:24 pm | Permalink

    I agree completely that methane is overlooked, and most likely because of the attachment that most people have to meat.

    However I think that your analogy of blowtorch v hotwater bottle is quite a stretch. As you note yourself,

    the relative impacts of ALL greenhouse gases are averaged over the same period 100 years”.

    This means that after 100 years the impact of the tonne of methane will be equivalent to that of 23 tonnes of CO2.

    You could not state that after apply a blowtorch for 10 seconds and a hot water bottle for 20 minutes would have the same impact after 20 minutes. Skin is not like an atmosphere. The analogy is quite poor.

    If you compared impact over 5 years, then the focus on methane would rightly be relatively higher. I believe that the long term view is more important than the 5 year view. CO2 is also an important part of the equation, and if we only looked at a 5 year view then we would be giving far too much weighting to methane and other gases which break down relatively quickly.

  10. Douglas Purser
    Posted Thursday, 9 July 2009 at 10:59 am | Permalink

    1. Cattle eructate (belch) methane it is not derived from farting.

    2. Cattle do not burn fossil C. They consume forage that has captured atmospheric C during the growth of the forage. Of the C consumed in the forage only 4.5% is belched as methane. Using the factor of 21 (the factor of 100 is a different issue) belched methane as CO2-e is about equal to the CO2 trapped by the growing plant. The net contribution of cattle to CO2-e will only be the CO2 derived from cattle in addition to methane. Consequently decreasing the cattle population, while having a significant impact upon emissions, will have at best a small impact upon climate change.
    The net change in CO2-e is the measure that has an impact upon climate change. Emissions (outputs) are only half of the overall biological system, inputs must also be considered to allow an estimate of net change.
    The eurocentric rules of the Kyoto agreement focus only on emissions, and Australia for that reason has to control emissions but the Australian community should be aware that control of emissions will not necessarily relate to a proportionate impact upon climate change, particularly in the case of cattle.

    I am surprised that someone who appears to be a self professed knowledgeable person is unaware that methane from cattle is belched, not farted, and suggests that decreasing cattle numbers will have a significant impact on climate change and does this by using only half of the relevant information to support the argument. I can only assume that the passion is associated with issues other than climate change alone.

    I am not a climate skeptic and discussion is needed but such discussion needs to consider all of the components not just a selection.

  11. meski
    Posted Thursday, 9 July 2009 at 11:21 am | Permalink

    Paul, yes, that’s what I’m suggesting. And giving an analogy. It’s unfortunate perhaps that these perceptions exist, but they do, encouraged by sponsored pseudo-research that goes on. Chocolate is good for you? Research sponsored by Cadbury. Cigarettes don’t cause harm? Sponsored by BAT. In the same way, an article written by PETA/Animal liberation/ etc about the non-desirability of red meat consumption because of methane production rather than the ethics that are usually used to support their arguments is going to attract scepticism.

  12. Roger Clifton
    Posted Thursday, 9 July 2009 at 11:39 am | Permalink

    Any destination for vegetation growth involves at least some methane emission. For example, termites and fire also emit methane. It seems that there is a rough balance in biospheric carbon. So far most methane emissions are biological, with Congo and Amazon basins among the main emitting areas. Far from accelerating, the graph of atmospheric methane rise has tapered off in the last decade, as land use changed.

    What we do need to watch is the growth of fugitive emissions from “natural” gas which must accelerate as pipelines and LNG facilities age. Arctic clathrates also stand to count far more than biospheric methane emissions.