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.