littlebabyjesus
one of Maxwell's demons
The fundamental difference between cattle farts (it's burps mostly that are the problem) and emissions from petroleum-derived products is that the former are part of an existing carbon cycle while the latter add new carbon to the cycle.The good thing about carbon emissions from cattle farts is they can be offset elsewhere. Nitrates from chemical fertilisers, on the other hand, can't be offset. They're polluting the rivers and killing everything, and the more people turn vege, the worse it's going to get.
We need to stop digging up fossil fuels and using them for energy, ferts, etc. That's the change in behaviour that is needed to address climate change. And it will require an enormous collective effort that we've not even begun to take. Even the easy stuff like plugging gas leaks hasn't been done yet (the fossil fuel industry puts a lot more methane in the atmosphere than cows - this being new carbon previously locked up underground).