Arguments
How much does animal agriculture and eating meat contribute to global warming?
What the science says...
The burning of fossil fuels for electricity and heat accounts for the majority of greenhouse gas emissions, totaling 31% of annual global greenhouse gas emissions, followed by transportation at 15%, manufacturing at 12.4% and animal agriculture at 11% (World Resources Institute).
Climate Myth...
Animal agriculture and eating meat are the biggest causes of global warming
"Livestock and their byproducts actually account for at least 32,564 million tons of CO2e per year, or 51 percent of annual worldwide GHG emissions." (source: Robert Goodland and Jeff Anhang)
The three largest contributors to global greenhouse gas emissions are as follows:
- Burning fossil fuels for electricity and heat (31% of annual global human greenhouse gas emissions);
- Transportation (15%); and
- Manufacturing (12.4%).
The fourth largest contributor is animal agriculture accounting for 11% of greenhouse gas (GHG) emissions according to estimates from the World Resources Institute, as shown in Figure 1.
One myth argues that animal agriculture is the greatest contributor to global greenhouse gas emissions, claiming it accounts for 51% of annual global GHG emissions.
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Figure 1: Global manmade GHG emissions by sector reported by the World Resources Institute. Electricity and heat make the largest contribution at 31% with animal agriculture making up 11%. |
While animal agriculture is a significant contributor to GHG emissions, it is not actually the biggest contributor, as the myth claims. The calculations used to get the 51% of global GHG emissions are, at times, inaccurate or inappropriate, leading ultimately to a misrepresentation of the impact of animal agriculture. This rebuttal will be split into two main parts, the first discussing the actual causes of GHG emissions and the second discussing how the non-peer reviewed report by Goodland and Anhang arrives at the 51% number.
Burning Fossil Fuels Really Accounts For The Majority Of Emissions
All estimates of carbon emissions have uncertainty, but different credible sources agree that burning fossil fuels for heat and energy is the largest contributor to global GHG emissions. Independent reports, some of which will be discussed in the following paragraphs, use different methodologies to arrive at the contribution of global GHG emissions. These differences are largely due to things like how the variables are grouped, such as grouping land use with animal agriculture or combining manufacturing and production with industrial processes. It is important to note, however, that while there are differences in these figures and numbers, the reports consistently conclude that burning fossil fuels for energy and heat is the largest contributor.
The World Resources Institute is a global research nonprofit that studies environmental sustainability, economic opportunity, and human well-being. The World Resources Institutes Climate Analysis Indicators Tool, a tool designed to analyze GHG emissions by sector and country, concludes that the energy sector accounts for the majority of emissions, around 72%. Within that 72%, are electricity and heat, transportation, and manufacturing which account for 31%, 15%, and 12.4% of annual global greenhouse gas emissions, respectively. Animal agriculture accounts for 11% of the GHG emissions (World Resources Institute). Figure 1 shows a 2013 compilation of these estimates put together using data from the World Resources Institute, showing that the energy sector accounts for the majority of these emissions.
This is not the only estimate of various sectors impact on global emissions. The Intergovernmental Panel on Climate Change (IPCC) is a body of the United Nations focused on studying and understanding human induced climate change. The United States Environmental Protection Agency reports global emissions in the same way that is reported by the IPCC, shown in Figure 2. By these estimates, electricity and heat production account for 25% of global emissions, agriculture, forestry, and land use make up 24%, industry 21%, and transportation 14%. These estimates are different from those noted before, but the reason for the difference is important.
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Figure 2: Global manmade GHG emissions by sector reported by the IPCC, electricity and heat production make the largest contribution at 25% followed by animal agriculture, forestry, and other land use making up 24% (IPCC). |
For the World Resources Institute and IPCC, the sources for their information and how the numbers are derived are publicly available, compiling reported data from across the globe. As mentioned before, the reason for the differences are largely in grouping. The following section will discuss how the 51% myth bases its numbers on exaggerations and uses completely different methodologies from both of these groups in deriving its numbers.
The 51% Figure Is Based On Poor Assumptions and Exaggeration
As mentioned above, the 51% claim comes from a non peer reviewed paper, containing a series of flaws and fallacies used in arriving at their number. A peer reviewed critique of the paper highlights many of the flaws that consistently exaggerate the effects of animal agriculture. One example is how the paper handles livestock respiration. When animals and humans breathe, CO2 is emitted into the atmosphere and taken in by plants, then converted to oxygen. We breathe and eat the plants and the cycle continues, so when we breathe out, we are returning CO2 that was already there. This is why human and animal respiration are excluded from carbon dioxide emission assessments, as the carbon cycle is accepted to be net zero over the span of years to decades.
Figure 3 helps illustrate the carbon cycle. If this paper chose to take a stance that animal respiration is not net zero, it is possible to account for animal respiration in the emission budget. However, it is also important to calculate the absorption and consumption of CO2 as well to quantify the imbalance due to respiration, which is not done. On top of that, and more pertinent to the matter, if the authors of the paper think that the carbon cycle is not net zero, it would also be necessary to include human respiration in the calculations to adequately assess the appropriate contribution of human CO2 emissions. They assume that the emissions of over 7.5 billion humans alive today are net zero, and livestock emissions are not, which is cherry picking. As is, the paper oversimplifies the issues, leading to a misrepresentation of animal agriculture's contribution to global GHG emissions. Accounting for these issues would cause a major change to the 51% value in the report, as over 26% of the reported emissions by animal agriculture come from animal respiration.
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Figure 3: A simple diagram of the carbon cycle showing how humans and animals emit CO2 that is then used by plants to make oxygen, which are then eaten (modified from a chart made by Patrick Brown). |
Oversights of this sort occur throughout the paper. Another example is CO2 emissions from land and land use, which contributes to 8.2% of animal agriculture emissions. In the paper the myth partially arises from, an extra source of CO2 emissions is added to animal agriculture's contribution using a hypothetical ‘what-if scenario’. The paper postulates that if land for animal agriculture were converted to activities such as growing crops for humans or biofuel, there could be emissions savings. These potential savings were then added to the other sources of animal agriculture emissions and treated as a way that animal agriculture contributes to total GHG emissions.
This hypothetical approach is inconsistent with the way that the World Resources Institute and IPCC report global GHG emissions. It is a problematic approach because it then uses the total worldwide emissions that both of these sources report to derive its 51% as opposed to driving and reporting a different, larger, total worldwide GHG emissions total, as would be necessary. Other sources, like fossil fuel burning, are not scrutinized to the point of considering what emissions would be if they were also changed to meet these ‘what-if scenarios’, which would ultimately lead to a vastly different worldwide emission totals (Herrero et al 2011). That is not to discredit ‘what-if’ thought experiments - they can be helpful in outlining potential future changes. But in a study on actual current emissions, it is inconsistent and inappropriate to include them as emissions. Altogether, these errors consistently overestimate the impact of animal agriculture.
Everyone Can Help The Environment In Their Own Way
There is a lot of discussion on how animal agriculture impacts various countries differently. It is possible to cherry pick examples from countries and argue that animal agricultural emissions are far more (or less) impactful on emissions than global numbers show. However, just because there are some countries that show different contributions from animal agriculture than are shown in a look at the globe as a whole, it does not mean that animal agriculture is misrepresented globally.
Similarly, one oversimplifying argument is that even if animal agriculture is not the main cause of global emissions, going vegan is the easiest thing one as an individual can do to lower their impact on global emissions. This is a difficult argument to support or disprove, as the benefit and ease of going vegan comes down to personal choices as well as the region one lives in. Everyone lives a different life and a person’s health, their living situation, and personal choices all play a role in the impact that they can make in reducing GHG emissions. There is no cookie-cutter, one-size-fits-all solution as to what can be done. The best way that you can lower your impact on global emissions is to be cognizant of your actions and actively work to minimize activities that create emissions whenever possible. For anyone interested, a list of some ways you can modify your lifestyle is included here. While animal agriculture does not contribute most of the CO2 emissions, it is still a significant contributor. Nevertheless, creating misleading or erroneous statistics to push a false narrative is counterproductive and only serves to hurt the causes that one is seeking to advocate for.
Last updated on 13 November 2020 by ZackChester. View Archives
Very interesting. Thanks for putting things in perspective.
However, it seems like this confirms part of the "Myth" you wished to debunk:
"Becoming Vegan or cutting down on your own personal meat consumption could be the single most effective action that you can do to help reduce green house gas emissions."
Short of going off the grid, that is. You have compared emissions from agriculture to emissions from the fossil fuel industry. Since your case seems to be built for the US where much power/electricty comes from fossil fuel, a person can hardly act so as to stop using fossil fuels. Even by selling their cars. However, they can stop eating meat.
So it seems, although the impact of animal agriculture is sometimes overblown, eating a plant-based diet would still be the single most effective action an individual could undertake, short of going off the grid. No?
"eating a plant-based diet would still be the single most effective action an individual could undertake, short of going off the grid."
If you look at where the individual contributions of energy use are (eg the MacKay analysis for UK is here - I have done similar for NZ), you would see that food and even going off grid arent that big a deal (particularly if you use non-FF heating). Getting off the plane is probably the biggest saving you can make. Finding ways to get out of the car would be next followed by sharply reducing your consumption of stuff.
Thanks for this great discussion.
Check out this Eshel paper-Climate impact of beef: an analysis considering multiple time scales and production methods without use of global warming potentials- R T Pierrehumbert1 and G Eshel2
Published 4 August 2015 • © 2015 IOP Publishing Ltd • Environmental Research Letters, Volume 10, Number 8
http://m.iopscience.iop.org/article/10.1088/1748-9326/10/8/085002/meta
The study conclusions include that certain forms of pastured beef have substantially lower climate impact than feedlot systems.
To full address climate change impacts, we need to consider different types of livestock management — for their threats and potential benefits — ghg emissions reductions/sequestration as well as natural water storage, flood mitigation, and biodiversity enhancement...
It seems we should eat much less beef and when we do eat it, we need to it the right kind...
Also, my understanding is that all agriculture (not just livestock) GHG emissions are estimated at 15% of global total by FAO 2013; and 13% by UNEP 2015.
[PS] fixed link.
I'm concerned with the presentation of this page http://www.skepticalscience.com/how-much-meat-contribute-to-gw.html.
The Zero Carbon Australia Land Use Report found that a proper and full accounting of GHG emissions pegs Land Use at 55% of emissions using 20 year GWP. As you'd be aware 20 yr GWP is significant, given the perilous state of many climatic system and stocks of ice etc. Even using 100 year GWP which tends to obscure the effects in near term on climate systems of methane and black carbon it will soon be at 100 years,
The major contributing factors were found to be land clearing (often cyclical), savannah burning (repeated) and centric fermentation. This would make it likely that GHG emissions in North and South America might be in that vicinity given the large amount of Amazonian and other old growth forest clearing going on to grow cattle and soy crops to feed north american cattle.
90% of that 55% of national emissions using 20yr GWP is associated with livestock ruminants, mostly the large extended zone pastural operations in northern Australia, mostly for cattle.
By presenting this argument using standard UNFCCC accounting which majorly obscures, re-assigns and ignores emissions and removal of sequestration sources associate with Land Use Sector you are in fact perpetuating a myth not debunking one.
To my best knowledge the ZCA Land Use Report was peer reviewed and supervised within MSSI (University of Melbourne) and has not be refuted in the literature. Nor has it's conclusion that 55% of Australia's national GHG emissions using 20 yr PWG are from the Land Use Sector. I'd ask the you rename these pages to be less pejorative and more in line with the science and debate if you want to call it that.
Given that much of the old growth forest clearing going on in the world to produce more ruminnent grazing pasture and crops to feed ruminents and animals in general, and that this OGF is the greatest CO2 sequester known to man, and that it's impossible to regain the sequestration levels once OGFs are logged, even after a century, it's doubly important that land use sector emissions be seen as the major problem, perhaps the greatest problem in the short term for GHGs reduction (ignoring the politics of livestock lobby vs ff lobby), then renaming this Page and the old version is required.
Alastair Leith
Climate Activist and Campaigner
Zero Carbon Australia Land Use Report
The Zero Carbon Australia Land Use Report (link fixed) mentioned above:
"A number of agricultural industries are among the most emissions intensive activities in Australia. Beef production, for example, is more emissions intensive than aluminium and steel production. Emissions from agriculture are even more significant when the impact of activities is calculated over 20 years instead of the more common 100-year accounting approach. When considered from this perspective, agricultural emissions could account for as much as 54% of Australia’s total emissions."
Yes, the 100 horizon for methane is whistling in the dark, presuming there are no non-linearities and tipping points in the near future.
OK, I have a question... So, supposedly not eating meat will reduce carbon emissions and help reduce global warming correct ? But so far it seems the main way animal agriculture contributes to global warming is through deforestation for feedcrops and pasture land. If more humans start eating plants instead of animals however, while the need for pastures and feed crop land will reduce, won't the need for farmland to grow all these in demand plants just increase ? For example the U.S is already unable to produce enough fruits and veggies to feed its citizens and relies on other countries as a supplement..if the decrease in land needed for animals doesn't match up to the increase in land needed for plant farming , won't this result in even more land cleared in other places to keep up with supply and demand (aka money to be made ? )
Theresab @8, this SKS page discusses the issue directly. Essentially, deforrestation contributes more to global warming than does agriculture (18.2% vs 13.5%), but most deforrestation is driven by the lumber industry, not land clearing for agriculture. From agriculture, the major contributors are agricultural soils (6%) and livestock and manure (5.1%). All percentages are of global totals in CO2eq, from 2000 data.
Crops require far less land area than does pasturing cattle. Indeed, in general, you will require 10 times as much land area for animals as you will for plants for the same total food production. That said, some area on which livestock is grazed is not suitable for cropping due to inadequate rainfall or other factors.
This is a ridiculous assertion. The single greatest reason USA imports fruit and vegetables is cost. Paying workers in Sth American nations $1 a day rather than US workers $12 an hour or whatever minimum wage is in USA today (although many workers in southern states are migrant workers from Mexico who are paid less than minimum wage). In Australia orchardists are regualrly removing fruit orchards when canneries are closing, if demand for their fruit and vege went up, production would go up. Meanwhile livestock production is subsidised by way of no price on the extensive emissions, over access to waterways and so on.
The amount of agricutural land devoted to fruit and vegetables globally is trivially small compared with the vast domains of rangelands for grazing and to a much lesser extent, cropping areas.
@Tom Curtis, almost all land clearing (and cyclical clearing) in Australia is for grazing ruminent livestock, themselves a huge emissions source. In nations where logging occurs (I'm thinking Indonesia, Malaysia, Brazil,…) the logging is just a more profitable way to clear the land than burning it off. If it was most cost effective to burn it off then they'd do that, they often do both in Indonesia and the fires are so vast the smoke travels to other countries and creates air quality health impacts. They are clearing the land for livestock principlaly in Sth American amazon region and crops to feed their livestock (like soy beans). In SE Asia they're often clearing for vast palm oil plantations. It's all about agricuture, if it ewas about logging timber they'd be harvesting it sustaniably and returning logged areas to forest production. They aren't.
The more we eat, the more we eat, the more we need to increase the amount of animals. And from the document, it is said that the cow has a large amount of gaseous emissions. The more the glass is, the more likely it will be the greenhouse effect. But the industry is another factor in greenhouse gases, but methane emissions have led to clean gas (http://faculty.college-prep.org/~bernie/). sciproject / project / Kingdoms / Bacteria3 / methanogens.htm)
The responsible animal industry has the second highest potential for methane to make clean energy.
The issue is clearly what type of animal husbandry we are talking about. Managed properly Beef production can be the most effect sink, or improperly managed a very significant emissions source.
All depends if the CAFO feedlot model is used or not.
Red Baron, this is a difficult thing. On one side of this issue, prairie style beef grazing creates a good long term carbon sink. Meat is an excellent source of protein.
On the other side of the issue, meat is an inefficient form of calories compared to crops and has a significant carbon footprint ( but as you say it depends how its farmed). Whats more, a growing population will put pressure on available land, and this will particularly include converting areas of beef grazing to crops.
The way out of the dilemma is this: If you want your cows, you better be promoting smaller human population size!
No nigelj, you are wrong there. The current factory farming style of animal husbandry is labor efficient but not land efficient or energy efficient or even cost efficient. Overall it is mostly inefficient.
Converting to regenerative ag in this case increases food output on less land at a lower cost and higher profit and improves that land rather than degrades it.
We could easily support far more population, not less.
Red Baron @16, I'm pretty sure you would get more calories per acre (or hectare) from crop land farming, or chicken farming, as against grasslands cattle farming or indeed any conceivable form of cattle farming, no matter how efficient. The following article and research sums it up. Cattle have to eat a lot of food stocks or grasses, and burn much of it off in energy. I can't see how that would possibly change no matter how the farming is done.
However grasslands and beef cattle farming are important as a carbon sink, thats the other side of the equation. If we want to preserve them, higher population pressure cannot help.
Answer me a question. Why does the world need more people? Doesn't the environmental, economic, and social evidence suggest we have more than enough people ?
Nigelij,
Here is what you are missing: Earth has lost a third of arable land in past 40 years, scientists say
Now what do you suppose can regenerate those highly degraded croplands? You guessed it, properly managed livestock. Completely unfit for crops yet it certainly not only can be used to provide high quality food, the production of food by grazing can if done right heal the land enough that once again it can become arable! in this case it is clear. Animals always produce more because you can't produce crops there anymore at all. The land became "farmed out".
You remove all animal husbandry and this very important tool is lost. Then we are locked into the slow slide into desertification and ultimately a crash of all human civilization as farming ends. That's not as far away as you think actually. Only 60 Years of Farming Left If Soil Degradation Continues
But what about land still capable of producing crops?
Read that carefully. It says "IF soil degradation continues" emphasis on the "if". And how do we reverse this trend of soil degradation? By properly integrating animal husbandry back on the farm. When you do that correctly you produce far more calories per acre than without.
Cant see it? Look here from Australia:
Why pasture cropping is such a Big Deal
Read that carefully. See what is going on? The crop is still there, but you get a bonus of forages when the land isn't producing a crop! Whether sheep or cows is irrelevant. The point is that you gain extra food production you would otherwise not had, and restore fertility to the land simultaneously.
So you get X yields PLUS the extra yields from animals.
Same goes for many other types of animal husbandry done properly. Culls and scraps being fed to chickens and pigs, goats eating brush and weeds instead of herbicides use, Ducks weeding between rice, the list is very long. In all cases though the integrated farm produces more calories per acre sustainably than crop production alone. Always!
Either it produces more because you can't even grow crops at all, or... it produces more because you use the animals to cycle waste material and turn it into fertility making crops grow better and gain a bonus of additional animal foods AT THE SAME TIME.
Reb Baron @18, ok those are good points, particularly the use of low quality arable land for cattle, and going back more to mixed farming, that combines crops, chickens and pigs, and this is a good sustainable multi purpose model.
I stress test ideas, to see if they stand up to being poked at, it doesn't mean I'm promoting vegetariansim or anything. Increasingly I'm becoming suspicious of any extreme solutions to most forms of problems. Eliminating all meat consumption completely seems as dubious as this very high meat Atkins diet. But I digress.
However I think you are still left with the same population problems.
@ wideEyedPupil #4: Your points remain unchallenged. I read thru the ZCA report (linked HERE), and I was unable to find any statement that substantiates your text from #4: "The Zero Carbon Australia Land Use Report found that a proper and full accounting of GHG emissions pegs Land Use at 55% of emissions using 20 year GWP". In fact, when I read the summary to this report in the 1st paragraph of the site linked above, I read the following text: "The UNFCCC National Inventory Report suggests that sources of land use emissions, such as land clearing for agriculture and enteric (intestinal) fermentation from digestive processes in livestock, contribute 15% of national emissions." If I am reading this correctly, this seems to disagree with your statement. In addition, I glossed over the body of the whole ZCA report, and was not able to find any text indicating that land-use & agriculture accounts for "55% of emissions". The ZCA report link you provided in #5 no longer works. Could you provide an updated link with location of page to back up your "55% of emissions" text. Thank you very much!
Below are two passages quoted in Nourishing Traditions by Sally Fallon. The first is by Charles Hallmark from Health Freedom News:
If it were not for beef, the United States could produce perhaps 25% of the small grain it does. . .. The factors that would limit our production is winter kill and tillering.
First, winter kill happens when small grains, such as wheat or oats, get into what is called the joint stage. Grain planted in the fall sprouts and grows fairly rapidly. Once it sends up the stem that the grain head grows on, and it makes the first joint in that stem, if it gets about 10 degrees Fahrenheit it will kill the plant.
To prevent this from happening, cattlemen and wheat farmers graze small grains with cattle. Without cattle grazing, the wheat, all wheat planted as well as oats, would have to be planted in the spring. Usually, moisture conditions remain too wet for this to work well.
Without beef you can kiss goodbye probably to 50% of the earth's population.
Another misconception is water supposedly taken up by cattle. Water weighs approximately eight pounds per gallon. A one thousand-pound steer, if 100% water, would be 125 gallons of water. Where is the rest of the thousands of gallons of water? If handled properly, the waste water from cattle is a very valuable resource. It removes nitrate nitrogens and ammoniacal nitrogens and returns them to the soil. Nitrate nitrogens make forage, and ammoniacal nitrogens make seeds and flowers. Farmers pay big money for these in bag form to apply to the land.
And the second is by Mark Purdey from The Nutcracker Suite:
One of the most nutty, stereotype fallacies. . .is the vegetarian claim that crop husbandry is less chemically and energy intensive than livestock farming. Whilst this is true in consideration of the intensive grain-fed livestock units, the traditional mixed farming unit raises livestock for meat and milk off extensively managed, low-input grassland systems; and each acre of well-managed grassland can produce four harvests a season of high-protein forage utilizing its all-inclusive clover plants as a green manure for fixing free atmospheric nitrogen into the soil. Whereas, an arable cropping system will only yield one or two crops per season and will largely remain reliant on the inputs of artificial fertilizer for its nitrogen source; one ton of which requires ten tons of crude oil in the manufacturing process. . .. Well-managed grassland is rarely sprayed with pesticide/fungicide/herbicide, not even on the most chemically orientated of farms. Yet virtually all vegetable and arable systems receive an average of ten chemical sprayings annually through from the initial seed stage to the final storage of the produce. Vegetables are so heavily sprayed that the more perceptive elements of the medical establishment have actually linked the victims of a mystery, novel neurological syndrome to the fact that they are all vegetarians in common. One team led by Dr. David Ratner from the Central Emek Hospital, Afula, in Israel, bloodtested several isolated cases of those suffering from this syndrome and found that various organophosphate pesticide residues intensively present in their vegetarian diet were responsible. Once the victims were convinced that they should return to a diet including meat and milk products, their symptoms and abnormal blood enzyme levels normalized rapidly.
[db] Off-topic snipped.
Ben, interesting but this would be a lot more convincing if backed with some peer-reviewed science. Some of the sweeping statement "Without beef you can kiss goodbye probably to 50% of the earth's population" is pretty hard to support. This appears to be an extrapolation of NA farming practice (7.5% of world wheat production by FAO 2014) to rest of world. This isnt a farming practise here, and I suspect it also isnt the practice in major producers like EU,China,India, Russia.
The question over water usage looks like a straw man. The water issues around cattle here focus on irrigation of pasture mostly. eg 1000 litres of water needed to produce 1 litre of milk. 15400 litres for 1kg of beef (eg see here). That is very high compared to plant-based protein sources.
I do not contest the value of well-managed, low-input rangeland but at first glance your sources are unconvincing and smack of rhetoric.
I'm wondering if anyone who has access to it has reviewed this report, which suggests that eliminating beef could get most of the way toward meeting President Obama's 2020 emissions goals that he announced in 2009.
Sorry, but this is not true. Read this:
LINK1
Global meat industy has a very important role on greenhouse gas.
And if you have this in mind:
one kilo meat cost approximately 15000 litre water. - LINK2
How many meat we eat globally world wide?
read this article:
LINK3
So please don't say that the meat industry is not responsible for the greenhouse gas that is produced every year.
That fact is that the meat industry is responsible for more then the car industry and the airplane industry together!
[DB] Your first link does not materially disagree with the OP of this post, and where it does your link cites older sources than does the OP of this post.
Shortened and hyperlinked URLs breaking page formatting. Sloganeering snipped.
And read this article:
LINK
[DB] Shortened and hyperlinked URL.