[evandijk70]

Do you have a reference for this that tries to quantify the CO2/CH4 emissions per kg beef? For chicken, I've seen estimates of 3.3 kg CO2/kg of industrial chicken meat compared to 5.3 kg CO2/kg of organic chicken meat. Of course, from an animal welfare point of view, organic chicken is a lot better.

[himinlomax]

Carbon emissions from cattle comes from their feed. They're not fed petroleum. There is some incidental fossil fuel consumption involved particularly in producing industrial feed (corn), but that doesn't really apply for pasture-fed cattle. All that carbon was just captured by the grass or otherwise corn used to feed them.

CH4 is another issue, but again, unless I'm missing something, total CH4 from cattle in the atmosphere should be proportional to the average number of heads alive. If we don't increase herd size, it won't go up — unlike CO2 from fossil fuel use.