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Are Livestock Responsible for 51% of Greenhouse Gas Emissions?
Adam Stein, 16 Nov 09

New report makes questionable claim

cow-burp.jpg Conventional wisdom has it that meat production is responsible for about 18% of global greenhouse gas emissions - a shocking enough figure as it is. But lately a much higher number has been circulating, with some claiming that meat is responsible for an astonishing 51% of worldwide emissions.

Some skepticism is in order here, so I went looking for the source of the figure. It appears to be this recent report from the Worldwatch Institute. Long story short: I read about 2 pages into the report and then gave up, because its conclusions appear to be hopelessly addled.

Among several "overlooked" sources of emissions, the report attributes a whopping 13.7% of worldwide CO2 to breathing by livestock. This is odd, because breathing is normally considered part of the natural carbon cycle. That is, the CO2 we breathe out is constantly being recycled by plants, which we then ingest, and so on in a cycle that doesn't add any net CO2 to the atmosphere.

Does the Worldwatch report expose some previously unseen flaw in this reasoning? No:

Livestock (like automobiles) are a human invention and convenience, not part of pre-human times, and a molecule of CO2 exhaled by livestock is no more natural than one from an auto tailpipe.

Natural doesn't enter into the picture here. The question is whether the CO2 comes from some previously sequestered source, such as a coal bed, or whether it was in the air to begin with. Cars run on oil. Cows run on plants. Enough said. (Before people rush to point out that industrial agriculture requires the use of lots of fossil fuels, keep in mind that these emissions are already accounted for in previous estimates of emissions from livestock. Adding breathing into the mix just double-counts them.)

Today, tens of billions more livestock are exhaling CO2 than in pre-industrial days, while Earth’s photosynthetic capacity (its capacity to keep carbon out of the atmosphere by absorbing it in plant mass) has declined sharply as forest has been cleared.

This is a non sequitur. Again, deforestation from livestock production was already accounted for in previous estimates. I took a quick skim through the rest of the report and saw nothing that inspired any greater confidence (in fact, just the opposite). For now, I'll stick with the 18% figure.

Meanwhile, Nicolette Hahn Niman, of Niman Ranch fame, takes to the pages of the New York Times to launch an equally confused defense of beef - or at least grass-fed beef. The crux of her argument is that the problem isn't beef so much as how the beef is produced.

Now, this is already a somewhat dubious claim. The greenhouse gas implications of grass-fed beef seem to be fairly difficult to tally, and Niman doesn't grapple with the numbers in any way that clarifies. But her argument really goes off the rails when she looks askance at vegetarians who eat soy beans of unknown provenance:

Unfortunately for vegetarians who rely on it for protein, avoiding soy from deforested croplands may be more difficult: as the Organic Consumers Association notes, Brazilian soy is common (and unlabeled) in tofu and soymilk sold in American supermarkets.

Although I happen to think the Niman Ranch does good work, this statement strikes me as almost sleazy in its implication that American grass-fed beef is somehow better for the environment than Brazilian-grown soy. Soy is a commodity traded on a global market. It doesn't matter where you personally get your tofu from. What matters is the aggregate demand. In this regard, soy is like oil, which is also why it doesn't really matter whether you buy gasoline that comes from U.S. well fields or from some nasty regime.

So what's putting pressure on aggregate demand? Livestock, of course. The reason those Brazilian rainforests are getting mowed down is not because of unethical vegetarians, but because so much land is needed in order to feed cattle and pigs and fish.

So, yeah, if you're in the mood for a burger, the environment is probably better off if it comes from a grass-fed cow. But given the reality of the global meat supply, the planet would probably prefer that you have a salad.

This piece originally appeared on The TerraPass Footprint.

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I appreciate the sarcasm. Great read.

I am here to serve.
The Window Man

Posted by: The Window Man on 27 Nov 09


Para poder repartir y diseminar la información contenida en el último informe del World Watch Institute, "la campaña" del 51%; ha sido lanzado por una organización protectora de animales y del medio ambiente. Los organizadores desean informar a ésos que atienden a Copenhague que el 51% de todas las emisiones de gases de efecto invernadero son del sector del ganado, es por esto que han creado la página .

Si usted visita la página de "soluciones" hay varias medidas que usted puede tomar, por ejemplo la 2da solución permite que usted envíe una carta a un número de los funcionarios de los ministros de ambiente por todo el mundo. Usted puede también agregar una bandera del 51% a su blog o Web site. Tan a la víspera de Copenhague, visite por favor ¡y envíe una carta a los que van a atender a COP15 y compatre este Web site a con todos!

Posted by: SAAW on 27 Nov 09

Thanks for the analysis - I completely concur that the World Watch report wildly overstates livestock's contribution to global warming.

1. The World Watch report includes GHG emissions from all pre-existing land set aside for animal agriculture (not just land which is currently being deforested) because the land could otherwise be used to do climate-friendly things like grow biofuels. But it is disingenuous to count any land as a source of GHGs simply because it isn’t currently being used to offset GHGs. If we did so, we’d have to count my bathroom floor as a source of GHGs.

2. The World Watch report includes including livestock emissions from breathing, digestion, etc. while not including the same emissions from other sources (humans and other animals). Mathematically, this astronomically and incorrectly inflates the percent of emissions coming from livestock.

There are other problems too; for my whole analysis see my blog post at

Posted by: AngeliqueC on 4 Dec 09

A well balanced article. Well said. Even if the ghg percentage coming from livestock is 18 and not 51, it's still clearly good for the environment for people to reduce their meat consumption.

Posted by: John G. on 5 Dec 09

Very few sentences in this review of the WorldWatch report are based on anything actually in the report itself, as you yourself admit in that you didn't even read it carefully.


"I read about 2 pages into the report and then gave up, because its conclusions appear to be hopelessly addled."

Perhaps you should finish reading the report before you call something addled. I read the report and very little about it struck me as addled.


"Cars run on oil. Cows run on plants. Enough said."

This is an argument? "Enough said"? Did you not get the memo that cows do NOT just run on "plants" anymore. Are you not aware they are fed not just everything-but-grass, but also fish and all manner of other sentient life.

Has been overtaken by Fox News ? Did you actually read the report?


"'Today, tens of billions more livestock are exhaling CO2 than in pre-industrial days, while Earth’s photosynthetic capacity (its capacity to keep carbon out of the atmosphere by absorbing it in plant mass) has declined sharply as forest has been cleared.'

This is a non sequitur."

ER, NO, IT IS NOT A NON-SEQUITUR. It is a statement of two important facts, which are obviously related when talking about greenhouse gases.

I don't see a single iota of information in your review that offers a solid refutation of the 51% figure. Even if that figure is wrong, "skimming" a report isn't the way to come to such a conclusion.

Since when did we all stop reading?

As an ethical vegan--I didn't stop eating cows because I was worried about the environment; I stopped eating them because I was worried about the cows--I'm happy to see you end this blindfolded critique of the report with a defense of soy-eating vegetarians over grass-fed cow-eaters, but the kneejerk dismissal of the WorldWatch report -- without even reading it! -- is a bit disturbing.

Posted by: Christopher Barden on 16 Dec 09

I took a deliberately glib -- or perhaps excessively honest -- tone in the article, so I'm not surprised to get dinged for it. Tone aside, though, everything I wrote in my analysis stands. The conceptual confusions in the Worldwatch Institute report are glaring, and a deeper read doesn't clarify them.

Again, cow respiration is part of the natural carbon cycle. Cows don't eat fossil fuels. I'm not sure why you dismiss this fact. The carbon atoms in cattle feed -- whether made of fish meal, grass, genetically modified corn, or whatever -- do not come from underground stores. Tallying the carbon from cows' respiration makes no sense.

Contrary to your assertion, I do point out in the article that the food supply chain in industrial agriculture carries a heavy carbon footprint. This footprint is important; it's also already accounted for in the earlier 18% figure.

Deforestation is an incredibly urgent problem, but its urgency has nothing to do with livestock exhalation. Actually, the entire point about "photosynthetic capacity" makes little sense. Forests provide long-term sequestration, not some sort of short-term carbon sponge effect.

In fighting climate change, it's important to correctly diagnose the problem. The Worldwatch Institute report doesn't help.

Posted by: Adam Stein on 16 Dec 09

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