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It is often said that meat is among the most damaging foods from a climate change perspective. However, I don't quite understand why that is true, in the long run.

Disclaimer: I am a vegan for animal rights reasons, however I still want to understand those who make the environmental case against beef.

If I understand correctly, the primary contribution of beef production to climate change is the burping and farting the cows do when they digest their food.

Now, all carbon dioxide emitted by human and animal bodies should be carbon neutral. This is because we get our carbon from the food we eat and that food was just recently grown, the plants having built themselves out of carbon from the atmosphere. Thus, so long as we don't eat coal, we are all solar powered with a delay of a few months (or slightly longer, for non-vegans). The same must be true for farts, except that because methane is far more potent (maybe 20-30 times) as a greenhouse gas, it does more damage, once emitted, than the CO2 (captured a few months prior) that it is replacing. However, methane in the atmosphere is short lived: It breaks down to carbon dioxide after only about 12 years. So shouldn't this mean any environmental damage from cow burps and farts is temporary, lasting only 12 years? And shouldn't this mean that if meat consumption remains constant the planet would only warm a little for that amount of meat consumption and not continue warming?

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If I understand correctly, the primary contribution of beef production to climate change is the burping and farting the cows do when they digest their food.

There are other important factors, such as deforestation for growing animal fodder. However, burping is a real issue as well.

As you've already pointed out, cows burp methane, not carbon dioxide. Methane is a much stronger greenhouse gas than carbon dioxide. Therefore, any process that turns carbon dioxide into methane and then releases it into the atmosphere contributes to climate change in the short-to-medium term.

However, methane in the atmosphere is short lived: It breaks down to carbon dioxide after only about 12 years. So shouldn't this mean any environmental damage from cow burps and farts is temporary, lasting only 12 years? And shouldn't this mean that if meat consumption remains constant the planet would only warm a little for that amount of meat consumption and not continue warming?

I think 12 years is the half-life, not the total lifetime. But even with constant meat consumption, that means there's constantly a higher level of methane in the atmosphere. If we're unlucky, this triggers a climate threshold.

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  • $\begingroup$ So, this means eating meat doesn't really contribute to climate change in the same way that flying, driving, or burning gas for power does. Am I right? $\endgroup$ Jul 17, 2023 at 19:54
  • $\begingroup$ @IsaacD.Cohen - if we dealt with the energy emissions successfully the livestock emissions (about 6% of total) would seem less urgent, but still too high for stabilisation at a new global average temperature. There are other possible options than cutting back or cessation of meat eating. $\endgroup$
    – Ken Fabian
    Jul 17, 2023 at 21:53
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In addition to all the valid points given in gerrit's answer, a critical part of the methane emissions from livestock is emmitted from their manure. Once solid and liquid manure (their poop and their pee-pee) are stored together like in a typical stable in industrial agriculture anaerobic microbes process the nitrogen present in both mainly into methane. This is in contrast to letting livestock graze on pasture, where they naturally do not poop in the same place they pee and carefully till the soil with their hoof - both of which lead to nitrogen fixation into the soil such that far less nitrogen (in the form of methane) is emitted to the air.

In fact, pasture feeding (especially in locations where crop-based agriculture is not possible) has a considerably better ecological and climate impact than industrial, stable-based holding of livestock.

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  • $\begingroup$ Nitrogen is a chemical element. How can this be processed into methane? $\endgroup$ Sep 15, 2023 at 16:26
  • $\begingroup$ Methane from manure is generated during anaerobic decomposition of organic matter in faecal matter and bedding material (...). These organic compounds are degraded into other compounds such as volatile acids by acid producing bacteria. Methane producing bacteria then use the volatile acids to produce CH4. The absence of oxygen is a precondition for production of CH4 via microbial metabolism of organic material in livestock manure. Methane production from manure is affected by environmental factors such as temperature (...), biomass composition and management of the manure. $\endgroup$
    – hschoell
    Sep 21, 2023 at 9:10
  • $\begingroup$ source: doi.org/10.1016/j.anifeedsci.2011.04.036 $\endgroup$
    – hschoell
    Sep 21, 2023 at 9:10

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