CH4 has a half life of like 10 years or so, so even if you deleted all cows from the world right now, in 20-40 years you'd be back to "only fossil fuel CO2 causing climate change".
Furthermore, has CH4 from cows even increased historically? There are 30m cows in the US, compared to 60m bison 150 years ago.
Furthermore, has CH4 from cows even increased historically? There are 30m cows in the US, compared to 60m bison 150 years ago.