<p>Let's just talk about cattle here and ignore other factors related to cattle production for now.</p>
<p>The current cattle number (93 million) you found is probably the total number of dairy cow and beef cattle. In your argument, it is possible that bison has much more emission than cattle on pasture. But the emission from cattle in feedlot and dairy farm is much larger than the cattle on pasture because of their diet chosen by us (human).</p>
<p>Typical beef cattle (steers and heifers) in the U.S. spend one year on pasture, and 5-6 month in feedlot before slaughter (unlike Argentina beef cattle which are fully raised on pasture). In feedlot, these young cattle (yearlings) are intensively fed with high protein feed in order to get them fatten up in a very short time. The U.S. dairy cows spent most of their time on dairy farm (unlike the Swiss cows who are raised on pasture). They live for about 5 years and are continuously fed with high protein forage to ensure their milk production. Both beef cattle and dairy cows have a high protein diet that result in high emission of methane (the impact of methane is 25 times worse than CO<sub>2</sub> in terms of warming).</p>
<p>The closest comparable cattle to bison is beef cow which spend most of its life time (about 10 years) on pasture and are only occasionally fed with low quality hay when there is a shortage on pasture. But again, the life span of a beef cow may be different from the buffalo and beef cows may eat more because they are basically pregnant very year(!).</p>
<p>California has this new policy that tries to cope with dairy cow methane emission from their manure. If you are interested, there is a recent study done by University of California Agricultural Issue Center here (<a href="https://aic.ucdavis.edu/wp-content/uploads/2019/01/DairyManure-1.pdf" rel="nofollow noreferrer">https://aic.ucdavis.edu/wp-content/uploads/2019/01/DairyManure-1.pdf</a>).</p>

CC BY-SA 4.0
2019-03-02T22:24:28.137Z
Thank you! I have also come across an article about Canadian beef producers looking into genetically modified stomach flora to reduce emissions. I suppose we could fit each  cow with some kind of catalytic converter (:
R. Rankin
CC BY-SA 4.0
2021-08-11T07:02:19.643Z
I'm not sure about your whole answer, but it contained a piece of info that answered the question for me. I'm not sure carbon emissions themselves matter. Cows are not nuclear reactors. They do not make carbon. To produce 1 Tom of C, they need to consume 1 ton of C. Zero sum. But you've mentioned that methane is 25 times worse. So the real issue is not that they emit carbon. It's that they convert CO2 to CH4. Am I correct?
Ark-kun
CC BY-SA 4.0
2019-02-28T17:31:03.170Z
2021-05-02T05:07:32.540Z
2021-05-02T05:07:32.540Z
Yolanda Pan
<p>There have been a few papers published on that topic. <a href="https://academic.oup.com/jas/article-abstract/73/8/2483/4632901" rel="nofollow noreferrer">Johnsons &amp; Johnson, 1995</a> for example estimate the amount of methane produced in a ruminant livestock to be 250 - 500 L/day. They conclude that cattle will contribute to little less than 2% of the global warming that we might face in 50 - 100 years time.</p>
<p>In contrast in a paper by <a href="https://www.sciencedirect.com/science/article/pii/S0301421510000066" rel="nofollow noreferrer">Oliver et al., 2010</a> the authors looked at the per person CO<sub>2</sub> emission of cruise ships traveling from and to New Zealand. The found that:</p>
<blockquote>
<p>Emissions factors for individual journeys by cruise ships to or from
New Zealand in 2007 ranged between 250 and 2200 g of CO<sub>2</sub> per
passenger-kilometre (g CO<sub>2</sub> per p-km), with a weighted mean of 390 g
CO<sub>2</sub> per p-km. The weighted mean energy use per passenger night for the
“hotel” function of these cruise vessels was estimated as 1600 MJ per
visitor night, 12 times larger than the value for a land-based hotel.</p>
</blockquote>
<p>As you can see cruise ships are probably far more of a „global warming machine“ than cattle - but serve only very few people. I personally think (and I might be wrong with this) that methane production in cattle can and is easily used by political groups to fight against the conditions in which the cattle are held and against the massive consumption of meat.</p>

CC BY-SA 4.0
2019-02-28T13:07:50.447Z
When it comes to answering the question, you're right. Still, the methan contribution to climate change isn't the only factor steming from cattle, you'd have to take into account the production of fodder, transportation, etc. Plus, yeah, the ramifications for human health, which ain't that great.
Erik
CC BY-SA 4.0
2019-03-01T10:30:28.873Z
I don't see how you can compare cattle and cruise ships, based on the figures that you have used.
Semidiurnal Simon
CC BY-SA 4.0
2019-02-28T08:13:53.510Z
2021-05-02T05:09:10.457Z
2021-05-02T05:09:10.457Z
Globoquadrina
<p>Let me be straight up. I'm a physicist, I've no doubt about climate change and the part we play in it.  I had been reading about cattle being one of the alleged main causes of climate change.</p>

<p>I get that they make methane, and we have a LOT of them, So I ran some numbers:</p>

<p>Roughly 93 million cattle in the United states in 2017 (some sources claim lower, but I'm going with the higher one). </p>

<p>Prior to humans killing the Buffalo off, there were approximately 50-100 million of them across the united states.</p>

<p>A quick Wiki search, estimates that buffalo (bison) produce significantly more methane than domestic cattle (though I don't know for sure that this is true).</p>

<p>These numbers seem to match up pretty well insofar as they're greenhouse gas contributions, so now I'm wondering if the argument is viable?  I know there were other herds around the world too, so I just found myself rather curious. Has anyone run the numbers thoroughly?  </p>

<p>On the flip side, I could see the sheer number of humans being an issue, I'll try and run that later.</p>

CC BY-SA 4.0
2019-02-28T05:56:17.390Z
it is mosly the type of food cows get that is to blame for the extra methane they produce,for cows to keep on producing milk they get more than only grass and water.tests where i live have shown it is possible to reduce the release of methane by up to 30% by feeding a salt water algae to the cows to replace the soy and grain they gets now.
trond hansen
CC BY-SA 4.0
2019-02-28T11:39:06.657Z
This [Twitter thread](https://twitter.com/NeolithicSheep/status/1100768673311137794) is very relevant.
Gimelist
CC BY-SA 4.0
2019-02-28T15:08:37.840Z
It is not only the methane. The cattle have to eat something. In Germany, where I live, a lot of soy is imported from other regions of the world -- e.g. South America. There, rain forest is destroyed in order to obtain land for soy production. Additionally, most of the soy is produced by _modern_ farming techniques (e.g. by industrial fertilizer production), which cause higher CO2 emissions than organic farming. Moreover, one needs more than 3 kg of feed to get out 1 kg of meat (there are numbers of 8:1 floating around; not sure if they are correct). Hence, we get a lot of secondary emissions.
daniel.heydebreck
CC BY-SA 4.0
2019-02-28T15:11:19.047Z
Please be aware, that there are a lot _wiki_s available via the internet. Neither in this wiki (https://foswiki.org/System/WebHome) nor in that wiki (https://www.jedipedia.net/wiki) I found any information on bisons ;-) .
daniel.heydebreck
CC BY-SA 4.0
2019-02-28T20:42:32.980Z
But the fact that buffalo did contribute to warming in the past doesn't mean that cattle's contribution today should be dismissed.
Camilo Rada
CC BY-SA 4.0
2021-05-02T02:00:55.313Z
Just fyi there is also a [Sustainability Stack Exchange](https://sustainability.stackexchange.com/) site and searching for "methane" returns [131 posts](https://sustainability.stackexchange.com/search?q=methane).
uhoh
CC BY-SA 4.0
2021-05-04T03:20:32.990Z
first more realistic numbers for bison hover around 30-50 million and there is over a billion cattle on earth today, that's billion with a B
John
CC BY-SA 4.0
2021-05-04T12:51:58.860Z
This question is only for reputation, the Asker already knows cattle contribute to Global Warming. Only asking if it is "Really" happening or "Really occurring, just to farm reputation. I learned this when a moderator pointed it out on another question.
Tardy
CC BY-SA 4.0
2021-05-04T19:14:50.607Z
@MooseSmart    Asking about climate impact of buffalo vs. modern cattle is not to "farm reputation" in fact, I started this account specifically to ask this question with no real intention of being on here in the future. I stick to math and physics SE's.
R. Rankin
CC BY-SA 4.0
2021-05-05T14:27:22.007Z
@R.Rankin Ok I get your point but it doesn't show the "New Contributor" Note.  Also, I did some math myself and for each upvote, you earn 5 points. 5 x 8 = 40 Points. You have 181 Points currently. So you must've asked or answered a question on this site before. So you only joining to ask this question might be false.
Tardy
CC BY-SA 4.0
2021-05-05T14:30:41.553Z
I know I might sound a little harsh, but "Really" Questions on the network is a big problem.
Tardy
CC BY-SA 4.0
2024-03-11T22:01:42.357Z
keep in mind the contribution of beef production is only like a third methane production. and there are 87 million cattle in the US alone. the US devotes more than to cattle production than anything else.
John
<climate-change><greenhouse-gases>
Are cattle really contributing to global warming?
R. Rankin
# Are cattle really contributing to global warming?

(Asked by: username_0 on 2019-02-28)

Let me be straight up. I'm a physicist, I've no doubt about climate change and the part we play in it. I had been reading about cattle being one of the alleged main causes of climate change.

I get that they make methane, and we have a LOT of them, So I ran some numbers:

Roughly 93 million cattle in the United states in 2017 (some sources claim lower, but I'm going with the higher one).

Prior to humans killing the Buffalo off, there were approximately 50-100 million of them across the united states.

A quick Wiki search, estimates that buffalo (bison) produce significantly more methane than domestic cattle (though I don't know for sure that this is true).

These numbers seem to match up pretty well insofar as they're greenhouse gas contributions, so now I'm wondering if the argument is viable? I know there were other herds around the world too, so I just found myself rather curious. Has anyone run the numbers thoroughly?

On the flip side, I could see the sheer number of humans being an issue, I'll try and run that later.

**Tags:** climate-change, greenhouse-gases

> **Comments:**
> **username_1**: it is mosly the type of food cows get that is to blame for the extra methane they produce,for cows to keep on producing milk they get more than only grass and water.tests where i live have shown it is possible to reduce the release of methane by up to 30% by feeding a salt water algae to the cows to replace the soy and grain they gets now.  
> **username_2**: This [Twitter thread](https://twitter.com/NeolithicSheep/status/1100768673311137794) is very relevant.  
> **username_3**: It is not only the methane. The cattle have to eat something. In Germany, where I live, a lot of soy is imported from other regions of the world -- e.g. South America. There, rain forest is destroyed in order to obtain land for soy production. Additionally, most of the soy is produced by _modern_ farming techniques (e.g. by industrial fertilizer production), which cause higher CO2 emissions than organic farming. Moreover, one needs more than 3 kg of feed to get out 1 kg of meat (there are numbers of 8:1 floating around; not sure if they are correct). Hence, we get a lot of secondary emissions.  
> **username_3**: Please be aware, that there are a lot _wiki_s available via the internet. Neither in this wiki (https://foswiki.org/System/WebHome) nor in that wiki (https://www.jedipedia.net/wiki) I found any information on bisons ;-) .  
> **username_4**: But the fact that buffalo did contribute to warming in the past doesn't mean that cattle's contribution today should be dismissed.  
> **username_5**: Just fyi there is also a [Sustainability Stack Exchange](https://sustainability.stackexchange.com/) site and searching for "methane" returns [131 posts](https://sustainability.stackexchange.com/search?q=methane).  
> **username_6**: first more realistic numbers for bison hover around 30-50 million and there is over a billion cattle on earth today, that's billion with a B  
> **username_7**: This question is only for reputation, the Asker already knows cattle contribute to Global Warming. Only asking if it is "Really" happening or "Really occurring, just to farm reputation. I learned this when a moderator pointed it out on another question.  
> **username_0**: @MooseSmart    Asking about climate impact of buffalo vs. modern cattle is not to "farm reputation" in fact, I started this account specifically to ask this question with no real intention of being on here in the future. I stick to math and physics SE's.  
> **username_7**: @R.username_0 Ok I get your point but it doesn't show the "New Contributor" Note.  Also, I did some math myself and for each upvote, you earn 5 points. 5 x 8 = 40 Points. You have 181 Points currently. So you must've asked or answered a question on this site before. So you only joining to ask this question might be false.  
> **username_7**: I know I might sound a little harsh, but "Really" Questions on the network is a big problem.  
> **username_6**: keep in mind the contribution of beef production is only like a third methane production. and there are 87 million cattle in the US alone. the US devotes more than to cattle production than anything else.  

---

## 2 answers

### Answer by username_8 on 2019-02-28. Score: 9

Let's just talk about cattle here and ignore other factors related to cattle production for now.

The current cattle number (93 million) you found is probably the total number of dairy cow and beef cattle. In your argument, it is possible that bison has much more emission than cattle on pasture. But the emission from cattle in feedlot and dairy farm is much larger than the cattle on pasture because of their diet chosen by us (human).

Typical beef cattle (steers and heifers) in the U.S. spend one year on pasture, and 5-6 month in feedlot before slaughter (unlike Argentina beef cattle which are fully raised on pasture). In feedlot, these young cattle (yearlings) are intensively fed with high protein feed in order to get them fatten up in a very short time. The U.S. dairy cows spent most of their time on dairy farm (unlike the Swiss cows who are raised on pasture). They live for about 5 years and are continuously fed with high protein forage to ensure their milk production. Both beef cattle and dairy cows have a high protein diet that result in high emission of methane (the impact of methane is 25 times worse than CO2 in terms of warming).

The closest comparable cattle to bison is beef cow which spend most of its life time (about 10 years) on pasture and are only occasionally fed with low quality hay when there is a shortage on pasture. But again, the life span of a beef cow may be different from the buffalo and beef cows may eat more because they are basically pregnant very year(!).

California has this new policy that tries to cope with dairy cow methane emission from their manure. If you are interested, there is a recent study done by University of California Agricultural Issue Center here (<https://aic.ucdavis.edu/wp-content/uploads/2019/01/DairyManure-1.pdf>).

> **Comments:**
> **username_0**: Thank you! I have also come across an article about Canadian beef producers looking into genetically modified stomach flora to reduce emissions. I suppose we could fit each  cow with some kind of catalytic converter (:  
> **username_9**: I'm not sure about your whole answer, but it contained a piece of info that answered the question for me. I'm not sure carbon emissions themselves matter. Cows are not nuclear reactors. They do not make carbon. To produce 1 Tom of C, they need to consume 1 ton of C. Zero sum. But you've mentioned that methane is 25 times worse. So the real issue is not that they emit carbon. It's that they convert CO2 to CH4. Am I correct?  

---

### Answer by username_10 on 2019-02-28. Score: 3

There have been a few papers published on that topic. [Johnsons & Johnson, 1995](https://academic.oup.com/jas/article-abstract/73/8/2483/4632901) for example estimate the amount of methane produced in a ruminant livestock to be 250 - 500 L/day. They conclude that cattle will contribute to little less than 2% of the global warming that we might face in 50 - 100 years time.

In contrast in a paper by [Oliver et al., 2010](https://www.sciencedirect.com/science/article/pii/S0301421510000066) the authors looked at the per person CO2 emission of cruise ships traveling from and to New Zealand. The found that:

> Emissions factors for individual journeys by cruise ships to or from
> New Zealand in 2007 ranged between 250 and 2200 g of CO2 per
> passenger-kilometre (g CO2 per p-km), with a weighted mean of 390 g
> CO2 per p-km. The weighted mean energy use per passenger night for the
> “hotel” function of these cruise vessels was estimated as 1600 MJ per
> visitor night, 12 times larger than the value for a land-based hotel.

As you can see cruise ships are probably far more of a „global warming machine“ than cattle - but serve only very few people. I personally think (and I might be wrong with this) that methane production in cattle can and is easily used by political groups to fight against the conditions in which the cattle are held and against the massive consumption of meat.

> **Comments:**
> **username_11**: When it comes to answering the question, you're right. Still, the methan contribution to climate change isn't the only factor steming from cattle, you'd have to take into account the production of fodder, transportation, etc. Plus, yeah, the ramifications for human health, which ain't that great.  
> **username_12**: I don't see how you can compare cattle and cruise ships, based on the figures that you have used.  

---

