Emissions GR Renewables

Nitrogen, climate change and diet

Guest Post by Geoff Russell.

Geoff is a mathematician and computer programmer and is a member of Animal Liberation SA.


Barry has already published a blog on Australia’s biggest climate forcing, livestock. This has prompted some debate about whether to use the warming due to methane (its climate forcing) or its global warming potential (GWP), the forcing averaged over 100 years. Even if you use the smaller factor, then livestock emissions are huge and about the same size as the entire transport sector.

Before getting to this blog post’s topic, its worth clarifying a couple of mistakes that crop up with regular monotony. First is the feeling that grass fed cattle are the answer, this was the response of a Guardian journalist today. If only cattle ate grass like they did when he studied Ag Science in the 60s, and like most Aussie cattle … apart from the ones that ate 5.7 million tonnes of grain in 2005-6, then everything would be alright. The problem is that it isn’t alright because grass fed cattle produce much more methane than grain fed cattle. Every time I see this on the media/internet, I send the author an email, but rarely get a reply and have never seen a correction.

The second usually appears in letters to editors in daily papers. This mistake is to think that because the methane from cattle doesn’t introduce new carbon into the carbon cycle, then it is harmless. This, like the former mistake, is just part of the general argument that meat is natural, so whatever problems it is causing can’t be real. It is true that cattle don’t (directly) introduce new carbon, so methane from cattle is better than methane leaking from a coal seam. But consider a swimming pool … dive in … it offers little resistance. Now freeze the pool … and dive in … ouch, that smarts! You haven’t added any new water, you have just changed some chemical bonds. Ditto methane. Take the carbon from CO2 (carbon dioxide) and turn it into CH4 (methane) and the forcing … the amount of warming it causes goes up dramatically. Even if we weren’t adding new carbon we could easily cook the planet by just changing the ratio of methane to carbon dioxide.

Lets get back to those grass-fed cattle. We can easily reduce the methane by switching to grain feeding. Why don’t we? We are … but there just isn’t enough grain. We now feed about 12 million tonnes of grain to livestock annually in this country. It’s up a little from the ABARE report I linked to earlier … because we imported about 2 million tonnes of mainly soy-meal in 2006/7 (this is data direct from ABARE).

How do we grow grain in Australia? These days we get huge yields (in a good year) with nitrogenous fertiliser … just like the rest of the planet. If people went to Barry’s ccqa3 talk last week, one of Peter Hayman’s slides showed a big kick upward when we started using nitrogen fertiliser in Australia in a big way.

Now we are getting to the tofu of the subject, nitrogen. Nitrogen maketh protein and protein maketh the man. Feed the man meat. One in every 7 households has a diet book (the CSIRO Total Wellbeing Diet) telling them how wonderful protein is. Gyms sell protein powders by the bucket load promising everything from flat stomachs to bulging muscles. This is sales hype, but I may not get time to deal with that in this post.

Nitrogen has a cycle, just like carbon and there are small armies of scientists who study it. To the left is a little image redrawn from a remarkable 2003 paper which traces the impacts of nitrogen through the eco-system. Well worth a read and there was an update on some of the issues in “Science” (320, 889 (2008)) recently.

Take some time to study that image. It is global nitrogen flows in megatonnes.

On the left is the Haber-Bosch process. This sucks nitrogen out of the sky and breaks its tough N2 bond so that we can use it. This is a very energy intensive process. It takes place at high temperature and pressure. It takes about 65 giga joules (18000 kWh) to make a tonne of nitrogenous fertiliser. Getting data on nitrogen fertiliser production in Australia is tough. The AGO these days just publishes ratios of how much is used by which industry.

Without the Haber-Bosch process, about 3 billion people wouldn’t be around today.

We will get to the climate change bit shortly. Be patient, this isn’t the 6 o’clock TV news.

Note in the above figure, how much of the total nitrogen that comes out of crops and goes into animals comes out as human food. Very little. The wasted nitrogen is a problem. Some of it goes into the air as nitrogen oxide(s) … yes, this is one of the big greenhouse gas groups that gets a mention in emission trading schemes. As you can see from the figure, the waste, the greenhouse emissions from crop fertilisation is largely attributable to meat production, because that’s where the crops go.

The stuff that doesn’t go into the air is also a rather serious problem, but lets ignore it and keep going.

Roughly speaking, the figure is saying that animals consume about 2/3 of global crop production. It’s also saying that the devastation of the world’s oceans delivers very little food. Lets just do a quick “sanity check” about how much of the world’s crops are eaten by livestock.

Last year animals ate 700 million tonnes of about 1800 million tonnes of cereals with biofuels consuming just 100 million. In addition they ate most of the world’s legume production (mainly soy) and a vast quantity of fertilised fodder. When the global food crisis hit this year, the biofuels got a lot of bad press, but meat escaped with scarcely a mention, except from animal libbers who seem to be the only people who were listening when ratios were taught in school.

Who uses Australia’s fertiliser?

As you can see from the AGO table below, the big user is pasture in most states.

If you read Garnaut’s draft report he says that sources of nitrogen oxides from human activity include industry, power generation and transport … he forgot about livestock. Even when fertiliser got a mention (p.471) the link with meat was missing. Everybody forgets about livestock. Its the 400 kg bull of climate change that stands quietly in the corner while the gorillas of the coal industry get all the attention. But please don’t misquote me, the coal industry deserves all it gets, and more … we just have to learn to walk and chew gum at the same time. My sister calls it “spotlight brain” Vs “floodlight brain”. We need floodlight brains that can get across more than our pet subject.

And before you ask … how much grain do people eat in Australia? About 2 million tonnes … 1/6 of what our livestock consume.

Of course the drought and our consequent importation of 2 million tonnes of grain to feed pigs and chickens make us a significant cause of the global food shortage. Put simply, the world’s poor used to compete with the livestock of the rich for food, now they compete also with our motor vehicles. Of course, the poor always lose.

The full consequences of our modifications of the nitrogen cycle are huge and go far wider than nitrous oxide. The bulk of those changes are down to meat.

I can’t help adding just a little piece on protein. The data aren’t published yet, but its pretty obvious if you look at the pictures in the earlier work the group with the lowest protein intake in the huge European Prospective Investigation into Cancer and Nutrition is the one with the least obesity, and also has about half the standardised mortality ratio of all major diseases. Indeed, too little protein will kill you, but so will too much.

It also really stuffs up the planet.


By Barry Brook

Barry Brook is an ARC Laureate Fellow and Chair of Environmental Sustainability at the University of Tasmania. He researches global change, ecology and energy.

36 replies on “Nitrogen, climate change and diet”

Hi Geoff

Below is a relevant news item.
Do you have an estimate as to how much of the annual methane emission is produced:
(1) by Other animals
(2) by humans?

Shun meat, says UN climate chief
By Richard Black
Environment correspondent, BBC News website
Livestock production has a bigger climate impact than transport, the UN believes
People should consider eating less meat as a way of combating global warming, says the UN’s top climate scientist.
Rajendra Pachauri, who chairs the Intergovernmental Panel on Climate Change (IPCC), will make the call at a speech in London on Monday evening.
UN figures suggest that meat production puts more greenhouse gases into the atmosphere than transport.
But a spokeswoman for the UK’s National Farmers’ Union (NFU) said methane emissions from farms were declining.
People may not realise that changing what’s on their plate could have an even bigger effect
Joyce D’Silva
Compassion in World Farming

Dr Pachauri has just been re-appointed for a second six-year term as chairman of the Nobel Prize-winning IPCC, the body that collates and evaluates climate data for the world’s governments.
“The UN Food and Agriculture Organization (FAO) has estimated that direct emissions from meat production account for about 18% of the world’s total greenhouse gas emissions,” he told BBC News.
“So I want to highlight the fact that among options for mitigating climate change, changing diets is something one should consider.”
Climate of persuasion

The FAO figure of 18% includes greenhouse gases released in every part of the meat production cycle – clearing forested land, making and transporting fertiliser, burning fossil fuels in farm vehicles, and the front and rear end emissions of cattle and sheep.
Dr Pachauri has chaired the Nobel Prize-winning body since 2002
The contributions of the three main greenhouse gases – carbon dioxide, methane and nitrous oxide – are roughly equivalent, the FAO calculates.
Transport, by contrast, accounts for just 13% of humankind’s greenhouse gas footprint, according to the IPCC.
Dr Pachauri will be speaking at a meeting organised by Compassion in World Farming (CIWF), whose main reason for suggesting people lower their consumption of meat is to reduce the number of animals in factory farms.
CIWF’s ambassador Joyce D’Silva said that thinking about climate change could spur people to change their habits.
“The climate change angle could be quite persuasive,” she said.
“Surveys show people are anxious about their personal carbon footprints and cutting back on car journeys and so on; but they may not realise that changing what’s on their plate could have an even bigger effect.”

Side benefits
There are various possibilities for reducing the greenhouse gas emissions associated with farming animals.
They range from scientific approaches, such as genetically engineering strains of cattle that produce less methane flatus, to reducing the amount of transport involved through eating locally reared animals.
“The NFU is committed to ensuring farming is part of the solution to climate change, rather than being part of the problem,” an NFU spokeswoman told BBC News.
Unnatural roots of the food crisis
Snared in a homemade ‘NitroNet’
“We strongly support research aimed at reducing methane emissions from livestock farming by, for example, changing diets and using anaerobic digestion.”
Methane emissions from UK farms have fallen by 13% since 1990.
But the biggest source globally of carbon dioxide from meat production is land clearance, particularly of tropical forest, which is set to continue as long as demand for meat rises.
Ms D’Silva believes that governments negotiating a successor to the Kyoto Protocol ought to take these factors into account.
“I would like governments to set targets for reduction in meat production and consumption, ” she said.
“That’s something that should probably happen at a global level as part of a negotiated climate change treaty, and it would be done fairly, so that people with little meat at the moment such as in sub-Saharan Africa would be able to eat more, and we in the west would eat less.”
Dr Pachauri, however, sees it more as an issue of personal choice.
“I’m not in favour of mandating things like this, but if there were a (global) price on carbon perhaps the price of meat would go up and people would eat less,” he said.
“But if we’re honest, less meat is also good for the health, and would also at the same time reduce emissions of greenhouse gases.”
Richard.Black- INTERNET@


That is a conundrum… eat meat from grass with more methane as a result, or eat meat from grain and fuel the food shortage and deforest the amazon… I’m not sure the comparison is as straightforward as just comparing the gas in the farts…

I would add however that if there was enough grass to feed all the cattle in the 1st place then they probably would not need to feed them grains…

Any way I look at it there will be less meat per capita to go around in 50 years time regardless of climate change… but don’t say that to a farmer;)


I’m finding 6.H.1 a bit surprising. So much valuable fertiliser going “non-irrigated pasture” – wow ! Do I believe it. I notice it seems to be southern Australian focused with Queensland and the NT having low numbers. Really would like to see much more analysis of those numbers before I’d believe it (especially given it’s AGO fodder). Can believe farmers using fertilser N on irrigated dairy pastures – but extensive systems? Need some more advice pls. Big differences between northern Australian and southern Australian production systems.

Reality for Queensland beef is that much of the production is on extensive native pastures but animals are “finished” in feed lots with grain to change the meat composition to consumer palates.

Northern Australian graziers would be very well to be fearful of methane taxes – they have already shouldered all of Australia’s Kyoto burden with have their land development (see tree clearing rights annexed with zero compensation for billions of dollars in carbon – while the rest of us drive around cities with impunity and increasingly demand energy intensive air-conditioned McMansions as lifestyle demands.

So a carbon tax on power generation will further up the price of nitrogenous fertilser (Haber-Bosch being energy intensive) – all being eventually passed on to the consumer.

Basically, it appears the animal industries are under dire threat from inclusion in the CPRS due to methane emissions, even at a relatively low carbon price. Beef is Queensland’s largest agricultural industry ($3-4B export earner), faces losing between 13-26% of its earnings if some recent ETS projection calculations are correct, and more when the other costs mentioned are factored in. The extra cost to an average wheat/sheep farm in Australia under an ETS is estimated to be $100,000 simply in terms of purchasing the necessary carbon credits, and $130,000 when other indirect costs are included (at $40/tCO2-e). About 60% of the wheat/sheep farm’s carbon production is from methane, so if the farmer gets rid of all his sheep and goes purely to cropping the cost will be reduced to $40,000.

There is considerable research going into methanogenesis but progress is tough.

Bizarrely for graziers – and given they are already shouldering the burden for Australia’s Kyoto sins – their sector may be a net sink if you did wall to wall accounting and included the 100 Mt per annum being sequestered into thickening native woodlands (thickening – not regrowth or woody weed invasion). Much of Australia’s savanna vegetation is thickening up. Add in NSW and the NT – maybe >150Mt p.a.

Of course nobody would want to really know as I think the Kyoto rules only allow counting reductions in land clearing if the sector is a net source. What if proper accounting turns it into a net sink? hmmmm…. Australia’s position suddenly unravels and exposes the rampant growth of our energy and transport sectors. So Aussie doesn’t ride on the sheep’s back anymore – it’s the cockies !

Bloody Queensland – coal, cattle, clearing and coral !


(Andrew#1) Estimates based on national emission inventories are here, but the short answer is livestock enteric fermentation about 80Mt, human methane is probably in “Human Wasterwater disposal” 30Mt, rice 29 Mt. This data is a little old (late 1990s) and new tables are under preparation. In addition it doesn’t have data from dams, which can create huge amounts of methane but there are some rather large fights being waged over how to count/measure this. Rice emissions are going down because (note the irony) nitrogenous fertiliser reduces methane emissions from the archea around the roots of rice plants.

There are substantial methane emissions from land clearing also and these are frequently cattle driven. Eg. total palm oil cultivation in
2006 was about 13.2 million ha. Our grazing area is well over 300 million ha after clearing 60+ million ha and we were clearing about 400,000 ha per annum for cattle
right through the 90s. Brazil’s cattle clearing efforts dwarf the palm oil cowboys. On the other hand, plenty of the palm oil clearing is draining peat and leading to huge emissions which are probably not in any inventory. Inventories + natural emission estimates may be accurate to about 50 Mt. There’s a table in AR4 which I will
track down this afternoon and link to — it is quite revealing about the slop in the estimates.


Thanks Geoff

How consistent are the methane and nitogen emissions levels you cite with the observations/conclusions/recommendations of the AR4 IPCC report?

Do you have a reference to the report in which the table showing the national methane emission inventories appeared?



Further to my note, it will be a major contribution if you plotted your revised estimates of methane and nitrogen emissions from domestic animals, farming, land clearing etc., along with industrial and transport CO2 emissions, to allow direct comparisons, namely in terms of the energy forocing effects of the various components on the atmosphere in Watt/m2.

Of course this may be far too big a task, although if you may be able to achieve this through revisions of already existing estimates by the IPCC, ABRAE and many other sources ???

Although much has been done already, revised/updated direct graphic comparisons may help communicate the relative magnitude of various agricultural/farming effects to politicans and the public.


Homer: “All normal people love meat termites. If I went to a barbeque and there was no meat termites, I would say ‘Yo Goober! Where’s the meat termites!?’. I’m trying to impress people here Lisa. You don’t win friends with salad.”


Excellent article.

Meat eating is an indulgence in a starving world threatened by a worsening Climate Emergency – livestock production involves huge and inefficient diversion of grain foods; beef alone contributes 16% of annual methane production; livestock in general contribute 37% of human-induced methane (see: and ); FAO estimated that livestock contributes about 18% of annual anthropogenic greenhouse gas production [including related deforestation, transport, fertilizer etc etc components] (see “Shun meat says UN climate chief Dr Pachauri”, BBC, 2008: ).
Some salient realities: Indians consume about 1 kg meat per person per year as compared to the average American’s 50 kg meat per person per year; in 2003, 37 percent of the world grain harvest, or nearly 700 million tons, used to produce animal protein; conversion efficiency (kg grain to produce 1 kg gain in live weight): <2 for herbivorous farmed fish (e.g. carp, tilapia, catfish) versus 2 for chicken, 4 for pork and 7 for beef; China has 2/3 of herbivorous fish aquaculture (see “Biofuel famine, biofuel genocide, meat & global food price crisis”: and ) .
16 million people die avoidably each year (2003 data) due to deprivation and deprivation-exacerbated disease (for Web-accessible statistics see “Body Count. Global avoidable mortality since 1950 (2008 lecture)”: ; see also “Body Count. Global avoidable mortality since 1950” , G.M. Polya, Melbourne, 2007: and ).
Biofuel diversion that has been legislatively mandated by the US, UK and the EU has been estimated to contribute about 75% of the global food price rise; UK Government Chief Scientific Adviser Professor John Beddington FRS says that the biofuel diversion threatens “billions” of people; and crop-based biofuel is associated with a huge CO2 pollution debt (for more details and documentation see “Biofuel famine, biofuel genocide and the global food price crisis”: ).


(Luke#3). The fertiliser stats are all locked up these days due to merger of Incitec/Pivot and people with bombs. But I don’t share your distrust of AGO data. When I see what I think is a mistake or inconsistency, I usually contact them and it is invariably me who is wrong :). They know their stuff. On the otherhand the way their data is packaged is pretty questionable. Why separate Land use change from Agriculture? Nobody else knocks down many trees, not even the timber industry.

As for farmers getting credits for sequestration when they plant trees, fair enough, they can already, but what do we do about the millions of acres cleared during the 1990s? And who is doing the work here? I bought some offsets from Carbon Neutral a while back and then Suzanne picked up our seeds from Trees for Life and it turned out that we were growing the trees for Carbon Neutral that I’d paid for — oh well, at least I was sure that somebody was growing them!


Thankyou all for your contributions to this (and other) posts. I have really learned a lot on the subjects. I will continue to publicise this blog to my friends and family. Great to have such a quality resource. We seem to have “lost” some of the more contrarian viewpoints – no doubt they have returned to Mahorasy, Bolt and Bird! Good!


(#7/#8) I don’t do “revised estimates” or methane or nitrogen GHGs. That’s a job for real scientists (who get paid for to do the hard yards!). Even if I could do it, the figure would have as much credibility as something Meat and Livestock Australia produced. So I very deliberately concentrate on just finding the best available data from people who know what they are doing. At most, I do a little accounting and synthesis and try hard to explain stuff clearly to people who haven’t had quantitative training.

That said, the basic problem with estimating the impact of lifestyle choices (like meat eating) is to follow the production chains. For example, the AGO Agriculture emissions don’t include land clearing, or the full refrigerated meat transport chain or the extra hospital beds and the nuclear medicine for treating extra cancers or cooking energy, etc, etc, etc.

The best methodology for measuring this has been devised by the crew at the Institute for Sustainability Analysis at Sydney Uni. They have the data and have worked out the methodology for doing this kind of analysis. I have written to them asking for a quote on doing some work to clarify some of the issues, but don’t hold your breath, and in any event it would be Australian and not global data.


Well eating meat may be a sin, but good luck to you convincing the average Aussie that steaks, snags and chops will be replaced by a tofu burger.

Indeed much of the cattle and sheep in northern Australia are on native pastures and meat production involves converting native grasses into higher grade protein. So the efficiency argument about converting grains to beef isn’t that strong. Plus it’s a big export industry – however if urbanites are willing to pay for graziers to not grow cows but grow trees (well woodlands really) fair enough. (And someone will need to stay behind to rid of the weeds and shoot the ferals (lots of pigs and cats out there)). But I suspect we’re not interested. So we’ll keep driving our cars and running the city lights all night, while sheeting home most of the responsibility on greenhouse to the bush. All care but no responsibility.

Coz that’s we’ve done at the moment. And we’ve only counted half the emissions because of bizarre Australia clause fiddles in Kyoto (IMO of course). The sector may be a net sink? So what does that say about the rest of us? Fair dinkum or full of it?


Professor Ross Garnaut says there’s a real danger a carbon trading scheme could damage the high-emitting livestock industries in Australia, while production increases overseas. He says that, even when agriculture comes into the Government’s carbon trading scheme, livestock industries should get “free permits to create emissions because they’re exposed to trade”.

Surely it should be that schemes attacking climate-change will be in danger from livestock industries’ emissions? Livestock industries, as one of the greatest contributors to climate change, should be the first to be reduced, not protected! Meat and dairy production are not only major sourced of greenhouse gas emissions, but they are also massive users, and polluters, of water. The majority of livestock products go overseas, supporting our economy at the expense of our ecology. Our leaders need to face the 21st century and its unique challenges. Reducing or eliminating meat-dairy in our diets, and our economy, would be the most effective way to address climate change.

We can’t just dismiss the obvious and potent contributor to climate change and be part of the solution.


(Luke#15) “high grade protein”. Meat is compact protein, but high grade? not really, this is just another meat industry myth. The latest NHMRC Recommended Dietary Intakes makes no distinction between plant and animal protein:

(n.b. 315pp download)

Click to access n35.pdf

You can calculate theoretical protein efficiency differences, but in practice they are irrelevant, if you get enough calories and you are eating normal food (ie., stuff that doesn’t come in packages), then you will get enough protein. Most people on 45 g of wheat-only protein stay in nitrogen balance (ie. are getting adequate protein) and this is well under the NHMRC recommended intake which is designed to
cater for the full range of the normal distribution. If you live on coke and chips, you will be deficient in many things, protein included.


But I suspect we’re not interested. So we’ll keep driving our cars and running the city lights all night, while sheeting home most of the responsibility on greenhouse to the bush.

At least with methane generated from beef cattle, the methane in the atmosphere can be reduced much more rapidly than anthropogenic CO2. For example, if the world suddenly got desperate about avoiding global warming and decided to immediately stop both CO2 and CH4 generation, the anthropogenic CH4 level would halve every 8 years while the anthropogenic CO2 level would take centuries to halve. Hence global temperature would continue to rise because the CO2 is still hanging around, while the disappearing methane would quickly reduce its climate forcing.

We could think of the issue in the following way. Suppose the only greenhouse gas was methane and we decided that the world had already reached a temperature high enough to make us decide to suddenly stop generating greenhouse gases. If we did this (when the only GHG was methane) then the climate forcing would halve in 8 years and global temperature would probably be falling within 8 years.

However, if CO2 was the only greenhouse gas, the global temperature would probably not be falling within 8 years of stopping generation and would almost certainly keep increasing for at least 20 years after being cut-off.

So CO2 is more dangerous than CH4 to the extent that its ultimate damage is greater relative to the damage that has already occurred at the time that we decide to seriously reduce GHG emissions.


Vivienne @ #16

Your suggestion that we reduce or eliminate meat-dairy in our diets and economy will be labelled extreme, but there is some compelling logic there. It’s a no-brainer for those who believe that animal protein is not necessary for health, but the meat and livestock industries have convinced the great majority that without a kilo of carrion washed down with a litre of milk every day you’ll look like Mahatma Gandhi after a 40 day fast. And look what happened to him.

On the subject of protein, does anyone remember a great little book from the 70’s called “Diet for a Small Planet” ? The author presented an interesting argument that by combining different plant sourced protein (so-called “incomplete” proteins) one could easily achieve a “sum that was greater than the parts”, by which is meant half a cup of, say, brown rice plus half a cup of chickpeas might combine to have a more useful weight of useable protein than the equivalent weight of animal protein.

I guess it all comes down to education. We badly need a credible counter to the “feed the man meat” mob.

Not only would we reduce the the environmental impacts, but people would be a lot healthier.

Such an education programme could start with Miranda Devine who today in the SMH breathes new life into Lamarckian evolution by suggesting that a switch to meat-eating “by our ancestors” 2 million years triggered the heritable propensity to grow bigger brains.


Well higher grade protein than grass. Reality guys is that all agriculture and pastoralism affects land use. Cotton growing (natural fibre) and rice take large amounts of water.

And think you can maintain yields with no nitrogenous fertilisers and herbicides? NOx 300x CO2 as GHG emissions. Good luck.

And you’re also happy enough to scuttle the entire rural sector? Or perhaps compensate them. You’ve already annexed their carbon in vegetation.

So are you guys prepared personally to under the necessary land management functions that are left? Or leave it to the weeds and ferals?


(Chris#18) Yes, forcings can drop quickly, but heat in the oceans won’t magically vanish. Hansen sees methane reductions as a way of buying time to implement CO2 reductions. The thing about methane reductions is that there are no technical issues. People know how to flare methane from mines, they know how to fix leaky natural gas pipeline and they know how to eat without any or with less meat — most of the world already does this.

(John#19) see #17

(Luke#20) Check page 73 in:

(n.b 10Mb download)

Click to access MDBC_stage2_report.pdf

Dairy water use in Murray Darling Basin almost doubled between 1995 and 2000/1, at the end of this period milk production and water use peaked at more than double that of rice and much more than cotton. Once the drought started to bite, then rice and cotton slowed or stopped planting, but cattle act pretty much like permanent plantings until farmers get desperate enough to destock. Of course, about half of Australia’s dairy produce is exported, so the $11 billion to rescue the MDB can be viewed as a subsidy to the dairy export industry.

Regarding weeds/ferals. You may call them weeds, a grazier would call them improved pastures. We now have 86 million sheep in Australia and we had 170 million in 1990, that’s 84 million less introduced ferals. The market did that, and it took no prisoners, it was brutal. That’s the way markets work, and nobody cares about the consequences except those on the receiving end. My preference is for a planned downsizing of the livestock sector. It could be paid for, eventually, by health care savings. The entire agriculture sector is tiny in GDP terms.

Nature quickly reclaims land that we leave behind, the result may not be to our liking, but I’m not sure that what we like matters all that much.


Gj – there are serious weeds – not thistles – that’s why Australia has had a Weeds CRC – vast swathes of country at ongoing risk from rubbervine, prickly acacia, mesquite, lantana. Then there feral cats, dogs, foxes, pigs, goats, etc etc. It’s a zoo out there mate.

So you’re happy to trust your food supply to Asia eh? mmmmm

Anyway – good luck if you can get a majority of voters to go with you.


Geoff, I have bad news. Those Trees For Life trees (I’ve propagated a few in my time) you’ve planted are making global warming worse.

As I’ve written previously, it has been shown that in temperate latitudes, afforestation of grassland results in net increase of global warming, as the decreased albedo outweighs the CO2 sequestered.

Sorry to jump on this hobby horse again, but evidently this factor needs to be much more widely known than it currently is. Yes, I know there are other ecological benefits to planting trees (and Caldeira, Bala et al. are at pains to point this out), but their work (yet to be refuted AFAIK) that by planting trees in southern Australia, you are warming the planet.


Hansen sees methane reductions as a way of buying time to implement CO2 reductions. The thing about methane reductions is that there are no technical issues. People know how to flare methane from mines, they know how to fix leaky natural gas pipeline and they know how to eat without any or with less meat

The problem is that we are not yet behaving as if we have a shortage of time. When we actually do behave as if there is a shortage of time then I’m sure we will implement every way possible of buying time (including reducing methane emissions). My point is that the methane in the atmosphere is helping to demonstrate the problem (and it’s pretty obvious that a lot of people need the problem demonstrated to them) but once humanity decides to act on the problem then the part caused by methane can be removed much more quickly.

Ask yourself which alternative would cause less damage: (1) x degrees of global warming caused by methane before serious mitigation or (2) x degrees of global warming caused by carbon dioxide before serious mitigation.


Do wild type ruminants produce as much methane as domesticated ones?
Wondering if we’ve accidentally selected out some trait that reduces methane, or lost some commensal beastie that consumes it.


(Mark#23) Here’s what the actual paper by Bala says in the abstract:

Latitude-specific deforestation
experiments indicate that afforestation projects in the
tropics would be clearly beneficial in mitigating global-scale warming,
but would be counterproductive if implemented at high
latitudes and would offer only marginal benefits in temperate

Southern Australia is still temperate as far as I know, so whatever we are doing, it isn’t accurate to assert that the Bala study implies
we are “warming the planet” by our tree growing efforts.

(Hank#25) Yes, its a function of feed intake and feed type. Our AGO collects data on any farmed ruminants, be they deer or cattle. Feed type can make a large difference. This is one reason why some people have advocated a tax on livestock emissions rather than an emission trading mechanism. People seem to accept a motor vehicle tax based
roughly on size, but when people start to trade things, they demand
accurate measurements. I don’t understand why this is so, but that’s
what economists tell me.

(Luke#22) I was out on a little stream off the Bulloo river in
1991 with a friend. We walked down to the edge of the stream and it was obvious that a few pigs liked this place also, they had
trampled an area about 10m wide. My friend looked at the mess in disgust … “[expletive] pigs, bloody destroying the river bank”. Across the stream, 30m away, were about 50 cattle, they and probably many more, had trampled and flattened the bank as far as I could see — bend to bend, about 400m. My friend didn’t notice, just didn’t see it.


Geoff@26, my apologies. While I provided a link to Bala et al 2007, what I actually had in mind was their earlier (2005) work, in which they stated
<blockquote cite=”our simulations indicate that mid-latitude forestation also could lead to warming.”.
Presumably this is superseded by the later work. However, even in the 2007 paper, the effect of temperate deforestation is still net cooling, albeit small (0.04K globally, 0.3 K locally; from Table 2 in Bala et al 2007) – and the reverse is implied.

However, this could all be a moot point, depending on the quality of Bala et al’s modelling. I just came across another paper of theirs, which explores a worst-case scenario. If you can, have a look at Australia 1971-2000 in their Figure 8. It does not inspire confidence. Barry, I’d love to hear your opinion of this.


Grussell – yep and that’s why enlightened operators are moving water points away from streams and fencing riparian areas.
Plenty to be done and being done. See what operators like do

Click to access Pigeon_Hole_Handbook_2007_screen.pdf

QDPI&F apparently are looking at whether kangaroo gut microflora can be adapted to work with cattle. Some wit said – “wouldn’t eating the roos be easier?”.

And yep – not all trees are a good idea. Albedo is an issue as well as carbon sequestration. So is consuming more water from catchments. Double edged sword.


Grass fed meat may produce more methane, but were the co2 emmissions from seeding, fertilizing, harvesting and transporting the grain taken into account?

Much of the soy and maize grown for grain fed beef is irrigated, cropping also requires more pest control and more soil disturbance than permanent pasture, adding to its overall environmental impact.

Huge amounts of fertilizer go to waste every year in both the dairy and piggery industry. The liquid waste is often pumped onto a sacrifice paddock, rather than spread on crops, thus becoming a pollutant rather than an asset.

Tighter nutrient cycling on farm, more use of slow release fertilizers and better use of agricultural waste products and crop residue would make a big difference.

Grass fed beef is a much more humane option too. The animals are able to behave naturally, so whether beef or pigs you get less vice behaviour.
Feed lot conditions are not pleasant. Add to that the fact that grass fed beef is much more healthy than grain fed due to high levels of omega 3 fatty acids and have much lower amounts of E. coli in their gut.

Good article though.


(DbD#29) I’ve been accused of pushing an animal lib agenda, but if I was doing that I’d be telling people to move from chickens and pigs to beef. Regarding grain growing and transport emissions, the only Australian data on transport emissions is by Sophie Gaballa. To produce 200g of lean beef you are looking at about 16 kilograms of CO2eq for the direct emissions + land clearing and, transporting it 267km in Victoria will generate about 13 grams (NB, this is grams
not Kg). Bottom line … transport emissions are swamped by production emissions.

For the US, “Food-Miles and Relative Climate Impacts of Food Choices in the US” Weber and Scott Matthews show that transport emissions are about 11% of total life-cycle emissions of food
in the US — and this is with huge distances involved in US supply chains.

Feedlots are not pleasant, especially when it is hot. People are doing estimates now on heat stress mortality increases in cattle due to increased heat. If you’ve ever smelt a marathon runner in melt down on a hot day (ketosis), you’ll understand what can happen, and the bigger the animal, the worse the problem.


Thanks to Geoff for providing some interesting and very useful commentary. While most of us are focused on fossil fuels, the magnifying effect of turning CO2 into CH4 via grass and livestock is especially significant since we are now thinking of ways to actively cool the planet (if you take any heed of James Hansen’s warnings).

I think there is a mistake some animal liberation activists make in addressing this question: to assume that it is necessary to halt all meat consumption. Obviously this is what vegetarian activists want, but I haven’t yet heard a convincing case that eating meat must stop altogether to have sustainable farming. In fact, most of our grain, vegetable and fruit farming remains far from sustainable.

As I’ve argued on James Woodford’s REAL DIRT blog, it would be counterproductive to environmentalists to adopt pro-vegetarian argumentation holus bolus because we would lose a large part of our potential audience. It’s hard enough to convince people that they need to take any radical environmental action, let alone become vegetarian as well.

Nevertheless, as I started out with, this is very useful information here nonetheless. Overall, Australians ought to eat far less meat to be sustainable and I think it’s just a matter of finding explainable, rational ways to bring that about. “planned downsizing of the livestock sector” is more or less what I think, too.


Ben @ 31
I have to agree with you that it is neither possible to attempt to convince people to become vegetarians. However, as you obviously agree, getting them to cut down to one or two red meat (ruminant) meals a week is a laudable objective. I read that Barry is not a vegetarian and that he occasionally eats red meat, including kangaroo, along with fish, chicken, pork and the very healthy legumes, beans and soy products. I follow the same sort of diet and would encourage anyone to do so as I have lost excess weight and become healthier as a result. A good enough reason, apart from the health of the planet, to persuade most people. I know that Geoff and Peter are committed to the humane treatment of animals and I support and applaud them for their passion.


Permanent pasture where rainfall allows, and sustainably managed rangeland is undoubtedly the most sustainable and humane way to produce meat.

I cannot accept the idea that grain fed, feed lot beef is more environmentally sound, despite the higher methane produced by grass fed animals.

These things do not exist in a vacume, and only looking at the methane produced is not the whole picture.

I feel that the soil disturbance, erosion, land clearing and the double /triple handling involved in grain based meat production create more problems than they solve, and encourages a centalised way of thinking about food production which i just dont feel comfortable with. The recent high fuel costs also make this system unsustainable.

The ideal meat and dairy production system for Australia (in my opinion) is for meat and milk to be produced, processed and consumed in the same area using best practice agriculture for the region. For example in the wheat belt, a lucern and minimum till grain based system, in the semi arid areas a well managed rangeland and fodder tree system, and in the high rainfall and coastal areas a permanent pasture based system.

The meat could then be slaughtered and processed locally, at the nearest regional center, providing more work, minimising transport costs (and minimising animal stress) and keeping money and workers in the local economy.

So from an animal rights perspective, from an economic perspective and a holistic environmental perspective i feel there is no comparison between an intensive, high input, high stress and low quality grain based meat production system and a high quality, low input, low stress, minimum input grass based system, despite this one negative environmental aspect. (methane)

(BTW, Im a ‘nat rat’ (natural resource manager), I live and work in the lower south east of South Australia. My wife manages a dairy farm and has a degree in Ag. production, just in case anyone is wondering what i have based my rather strong opinions on!)


A lot of this stuff seems a bit simplistic to me. On our farm we have a few sheep. When I try to work out the environmental impact of them there are some pluses too. We use the sheep to control weeds and to control growth before our crop comes in and also to crash graze native grasses to keep them in good nick. If we didnt have the sheep to do that we would either have to employ an army of people to hand weed (fat chance)or spend a lot of time on a tractor using up fossil fuels out spraying toxic stuff to kill the weeds or slash the growth in our crop or slashing the native grasses. Plus the sheep provide fertiliser for our crop as well. So we dont buy any fertiliser in.
The weed stuff is important. We cant just leave the mess we have made and think it all might turn out OK. There is a weed wreaking havoc in the same range of hills as us and when it gets going absolutely nothing else will grow at all and its not edible either. If we let that one go there would be no food production at all.


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