How much anthropogenic greenhouse gas emissions are due to livestock?

Question

According to the World Resources Institute, livestock and manure only account for 5.1% of worldwide anthropogenic greenhouse gas emissions.

http://cait.wri.org/figures.php?page=World-FlowChart&view=100

But according to the United Nations Food and Agriculture Organization, when land use is taken into account, livestock accounts for 9% of our CO2 emissions, 65% of nitrous oxide, 37% of methane, and thus 18% of our overall CO2 equivalent greenhouse gas emissions.

http://www.fao.org/newsroom/en/news/2006/1000448/index.html

I'm wondering why these figures are so different. Anyone know the source of the discrepancy, and which is more accurate?

Answer 1

The difference is that the FAO number includes CO2 emissions from land use changes, not just the direct agricultural production. Other than that there doesn't appear to be large differences between the two sources. For example, the 5.1% of the methane comes from agriculture out of a total of 14%, so that agriculture produces a little over 1/3 of the methane, which is consistent from both the FAO and WRI numbers.

You already figured this out though right? I wasted 10 minutes. Again.

Edit: Ok, maybe that wasn't as clear as it could have been. WRI says 5.1% of the total of 14% CO2 equivalent methane comes from manure, so 36% of the worlds methane comes from manure (i.e., the FAO number). WRI says 6% of the 8% CO2 equivalent N2O comes from agricultural land use, so 75% of the worlds N2O comes from agriculture (i.e., close to the FAO number). If you add together all the agricultural contributions and then take about half of the CO2 from land use from the WRI figure you get a number around 20% of the total, which again is close to the FAO number. In short, the two data sets are consistent, they're just two different ways of expressing the numbers.

Answer 2

This is, still, an argument from ignorance: 'what else can it be?' Invalidation of a hypothesis does not require an alternate hypothesis; all that is required is for a single experiment to contradict the proposed hypothesis. As Einstein said: “No amount of experimentation can ever prove me right; a single experiment can prove me wrong.” As an aside, I (respectfully) do not agree that the 'current' warming is current, rapid, or unusual, when compared to natural variability over the last 200k years. For example, temperatures were higher than present during the last interglacial, and again during several of the climate optimums during the current interglacial (i.e. MWP). The rate of warming in the 20th century (abt 0.6°C/century) is not unusual or unprecedented;i.e. it is an insignificant rate as compared to the entry and exit to and from the Younger Dryas, circa 8k-12k ybp. We do not yet know what caused those changes (though there are some hypotheses); and without knowing that I do not see how we can be sure that the warming since the end of the LIA is not from some cause other than CO2. I am curious about this statement: ...where is this in your references? I would like to read that, but there is too much volume there to wade through, and the JGR paper is behind a paywall (that seems like it should be the one to have that info) The abstract gives the number of an increase in forcing of 2.2W/m^2 per decade. Assuming this is correct, what has happened to all that energy since 1996? The RSS data show no significant warming since then... 16 years of no change... I haven't crunched the numbers, but that is going to be a *huge* amount of energy... where, in the AGW hypothesis, is this energy stored?

Answer 3

I think the second is more accurate, because the total impact of livestock isn't just the animals themselves. You also have to take into account the land use, the inefficient use of plants (far more plants consumed when they are filtered through an animal then if we just ate them directly), use of water and use of other resources. There is also an environmental impact (though not toward global warming) in the form of antibiotics used on factory farms. Antibiotics are used on healthy animals in massive amounts just so that they can be crammed into small spaces without fear of spreading disease, thus creating strains of superbacteria. You will probably call my opinion biased, but I think the overall environmental impact of factory farmed livestock is even greater than the UN accounts for.

Here is an article on the subject: http://goveg.com/environment.asp

Mr. Jello, livestock is a product of humans because they would not exist if we didn't farm them. Cows don't multiply like that on an open prairie; they don't even breed naturally in a factory farm setting, they are artificially inseminated.

Edit: What I am seeing from the other answers on here is that people really do not understand what factory farming is and how harmful it is. There is a HUGE difference between animals roaming the plains as nature intended and massive amounts of cows, chickens and pigs being confined in small areas and shot full of horomones and antibiotics. There is so much waste in this process, even a good portion of the animals themselves grow so fast that they die, then they are just plowed into the ground or piled up in a heap as waste. If you want to eat meat you should get off your lazy butt and farm it yourself, seek out a local small farm or kill it yourself. These factory animals are not a product of nature.

Answer 4

Numbers and causes are not important as long as they are no political will to change anything!! Those animals never asked to be breed, but animal factories are just there to respond to a market demand... No demand, no waste, no anthropogenic effects! So if peoples would stop asking to have what they wish, then those things could be avoided! Humans keep complaining about everything, without ever wondering if their own actions are toxic to this world!

Well then I call this ignorance, and this world is full of it!
When peoples will understand, it will be too late!

Answer 5

I'm afraid it's the higher figure that is more accurate. At least when it comes to "beef factories". We do need to reconsider how much meat we are consuming and how we can support a more sustainable way of raising cattles.

Answer 6

I love how so many people still think that their meat comes from some idealistic family farm, or open prairie cow grazing. The disconnect between Americans and their food production is stunning.

I've heard higher numbers than both of yours to be honest. i think the point is that we need to rethink our current high intensity industrial livestock system, for moral and ecological reasons that go FAR beyond greenhouse gas emissions.

Answer 7

The UN report no doubt counts more indirect effects. Whether or not that expalins the difference - I don't know.

I find myself in rare agreement with =^_^= on an animal food issue. The way we do factory farming is an environmental disaster.

"There is no antropogenic global warming. I can't believe anyone believes that crap."

You mean anyone like every major scientific organization?

http://en.wikipedia.org/wiki/Scientific_opinion_on_climate_change

Answer 8

If cows weren't roaming the plains, it would be buffalo (bison). Does anyone really believe there is a significant difference in the methane and other emmissions? I don't. So why do some want to exaggerate that number? Could it be a political agenda?

Answer 9

Don't believe those numbers! McDonald's is funding a disinformation campaign to make us believe that meat farming is not the main source of global warming!

Answer 10

Hi,

I agree that cows fart and crap a lot but that is of no real consequence.

The 'Global Warming' that everyone seems to be so concerned about is just the last ice age coming to its final end.

Before the ice age dinosaurs and other big mammals roamed the 'whole' earth, living in tropical conditions and that is what we are heading for again.

That will be the dawning of the next ice age.

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