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Comment by lucio | Hacker News Reader

How relevant are cow farts in global warming? is there a percent figure? as in cows contribute x% of gas emissions

16.5% of methane emissions, give or take. If you could further apply this to all livestock, it's around 30%.

I thought it was mainly burps (eructation), read that somewhere recently, eg http://news.nationalgeographic.com/2015/08/150803-cows-burp-....

Combining this with electric cars, we are looking at 50% reduction I think.

Cars produce CO2, not methane.

wow thats an insane number

Here are couple of articles about it. http://www.npr.org/sections/thesalt/2014/04/11/301794415/gas...

http://timeforchange.org/are-cows-cause-of-global-warming-me...

How does it compare with the great buffalo herds that roamed the plains 200 years ago?

>How does it compare with the great buffalo herds that roamed the plains 200 years ago?

There are about 92 million cows and calves in the U.S. today.[1] Estimates for the number of bison at their peak range from 30 million to 60 million.

[1]https://www.nass.usda.gov/Newsroom/2016/01_29_2016.php

I wonder too if the methane production from a modern cow fed for human consumption is very different from that of a wild buffalo.

Grass fed cows are supposed to produce greater than 40% more methane than the industry standard grain fed cows. This guy[1] seems to have thought a little about this too.

[1] http://jaysonlusk.com/blog/2014/8/22/buffalo-extermination-e...

With deforestation to make cow farms and methane released, its estimated at 18-30%.

The really relevant thing is not the farts but 1. the CO_2 emissions for feedstuff production and transport, plus 2. the deforestation for said feedstuff production, plus 3. the insane ratio of agricultural surface requirements of plants-needed-to-feed-humans vs plants-needed-to-feed-cattle-to-feed-humans (which is approx. 1:10)

For these very reasons organic meat is much better for CO_2 reduction. It doesn't use fossil fuels just to feed cattle, it limits the area foodprint of cattle production and by making meat scarcer, it last not least shifts meat based nutrition towards five-a-day nutrition.

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