Taking normal things and then mass producing them isn’t a part of the normal carbon cycle

All carbon coming from cow farts must be created using carbon from the air. If you look at carbon levels in the atmosphere you'll see the cycle and human activity in this space will just make the cycle more spikey instead of tending up like it does now.

This isn't a question of "natural good". Natural sucks. This is good because it poses few long term existential risks.

Fossil fuel emissions are an existential risk. Cow farts and land use can be important if you want to protect biodiversity and such, but not for global warming.